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IBM UltiMotion

2006-10-12T20:35:27Z

Ultimotion: /* Decoding Algorithm */

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP Ultimotion Digital Video Data Stream Specification]
* Additional Documentation: [http://multimedia.cx/ultimotion-format.txt 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov ].''
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]
* Codec: [http://hobbes.nmsu.edu/cgi-bin/h-viewer?sh=1&fname=/pub/windows/ultimo.zip Win32 Ultimotion decoder]

IBM Ultimotion is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats. Full codecs were available for Windows 3.1 (VfW), OS/2 and AIX. It is primarily a vector quantizing algorithm with simple inter-frame coding (unchanged block). Ultimotion encoding is significantly more computationally intensive than decoding.

== Decoding Algorithm ==

The Ultimotion algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels (quadrant), each of the 16 pixels has a luminance (Y) sample and the entire block shares one chrominance sample expressed as two color difference components : Cb (or U) and Cr (or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for each chrominance component) are transmitted in the final bitstream.

The Ultimotion algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 quadrants. The 4 quadrants, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be encoded using a single chrominance sample or unique chrominance sample for each quadrant. Each quadrant has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of Ultimotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle uniq flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 quadrant in the block, arranged in the quadrant pattern:

extract quadrant coding mode from b0:
bits 7-6: quadrant 0 coding mode
bits 5-4: quadrant 1 coding mode
bits 3-2: quadrant 2 coding mode
bits 1-0: quadrant 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip quadrant (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
0 = gradient fill pattern A
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern B
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0, Y2 = Y0 + 1, Y3 = Y0 + 1
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on either
four samples retrieved from a 4,096-entry codebook using an index
coded in the stream or four samples coded in the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see section Luminance
Codebook Enumeration)
if bit 3 of the gradient fill pattern is set
swap Y0 with Y3 and Y1 with Y2
clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern C (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with an
arbitrary pattern using two samples and a set of flags coded in the
stream, or with a gradient fill pattern and four samples coded in the
stream, or with 16 samples coded in the stream
if mode is 0
if bit 7 of b1 is 0
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the quadrant, else Y0
else
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b2)
Y0 = ((b1 & 0x0F) << 2) | (b2 >> 6)
Y1 = bits 5-0 of b2
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 12 bytes from the stream as 16 6-bit numbers as the 16
luminance samples (Y0..Y15) for the quadrant
fill luminance samples according to Y0..Y15 and gradient fill
pattern D (see section Gradient Fill Patterns)

finally, output quadrant:
bits 7-4 of the chrominance byte represent the Cr (or V) component
while bits 3-0 represent the Cb (U) component
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A

if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 12 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 (or 16) luminance samples.

* Gradient Pattern 0: (0 degrees)
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3

* Gradient Pattern 1: (22.5 degrees)
Y1 Y2 Y3 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y0 Y1 Y2

* Gradient Pattern 2: (45 degrees)
Y1 Y2 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y1 Y2

* Gradient Pattern 3: (67.5 degrees)
Y2 Y3 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y0 Y1

* Gradient Pattern 4: (90 degrees)
Y3 Y3 Y3 Y3
Y2 Y2 Y2 Y2
Y1 Y1 Y1 Y1
Y0 Y0 Y0 Y0

* Gradient Pattern 5: (112.5 degrees)
Y3 Y3 Y3 Y2
Y3 Y2 Y2 Y1
Y2 Y1 Y1 Y0
Y1 Y0 Y0 Y0

* Gradient Pattern 6: (135 degrees)
Y3 Y3 Y2 Y2
Y3 Y2 Y1 Y1
Y2 Y2 Y1 Y0
Y1 Y1 Y0 Y0

* Gradient Pattern 7: (157.5 degrees)
Y3 Y3 Y2 Y1
Y3 Y2 Y1 Y0
Y3 Y2 Y1 Y0
Y2 Y1 Y0 Y0

* Gradient Pattern A: (homogeneous)
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0

* Gradient Pattern B: (270 degrees)
Y0 Y0 Y0 Y0
Y1 Y1 Y1 Y1
Y2 Y2 Y2 Y2
Y3 Y3 Y3 Y3

* Gradient Pattern C: (subsampled)
Y0 Y0 Y1 Y1
Y0 Y0 Y1 Y1
Y2 Y2 Y3 Y3
Y2 Y2 Y3 Y3

* Gradient Pattern D: (16 samples)
Y0 Y1 Y2 Y3
Y4 Y5 Y6 Y7
Y8 Y9 Y10 Y11
Y12 Y13 Y14 Y15

== Luminance Codebook Enumeration ==

The following pseudo-code creates the Ultimotion Luminance Transition Coding codebook

i = 0
for Y0 = 0 to 61
for Y3 = Y0 + 2 to 63
Yd = Y3 - Y0
if Yd in (2,3,5,6,7,8,11,14,17,20)
LTC[i++] = (Y0, Y0 + Yd/3, Y3 - Yd/3, Y3)
endif
if Yd in (4,5,6,7,8,11,14,17,20,23,26,29,32,36)
LTC[i++] = (Y0, Y0 + Yd/2, Y3 - Yd/4, Y3)
LTC[i++] = (Y0, Y0 + Yd/4, Y3 - Yd/4, Y3)
LTC[i++] = (Y0, Y0 + Yd/4, Y3 - Yd/2, Y3)
endif
if Yd in (6,8,11,14,17,20,23,26,29,32,35,40,46)
LTC[i++] = (Y0, Y3, Y3, Y3)
LTC[i++] = (Y0, Y0, Y3, Y3)
LTC[i++] = (Y0, Y0, Y0, Y3)
endif
next Y3
next Y0

It should be noted there is an error in the "Ultimotion Digital Video Data Stream Specification" - the pre-determined linear transitions are for Y deltas of 2, 3, 5, 6, 7, 8, 11, 14, 17, 20 (not 4). (If 4 is included then there are 4156 transitions. The various transitions are handled by the low contrast edge transitions.)

== Converting Ultimotion Scaled YUV To Correct YUV ==

To convert Ultimotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert Ultimotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg Ultimotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-12T20:34:57Z

Ultimotion: /* Decoding Algorithm */

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP Ultimotion Digital Video Data Stream Specification]
* Additional Documentation: [http://multimedia.cx/ultimotion-format.txt 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov ].''
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]
* Codec: [http://hobbes.nmsu.edu/cgi-bin/h-viewer?sh=1&fname=/pub/windows/ultimo.zip Win32 Ultimotion decoder]

IBM Ultimotion is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats. Full codecs were available for Windows 3.1 (VfW), OS/2 and AIX. It is primarily a vector quantizing algorithm with simple inter-frame coding (unchanged block). Ultimotion encoding is significantly more computationally intensive than decoding.

== Decoding Algorithm ==

The Ultimotion algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels (quadrant), each of the 16 pixels has a luminance (Y) sample and the entire block shares one chrominance sample (expressed as two color difference components : Cb (or U) and Cr (or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for each chrominance component) are transmitted in the final bitstream.

The Ultimotion algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 quadrants. The 4 quadrants, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be encoded using a single chrominance sample or unique chrominance sample for each quadrant. Each quadrant has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of Ultimotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle uniq flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 quadrant in the block, arranged in the quadrant pattern:

extract quadrant coding mode from b0:
bits 7-6: quadrant 0 coding mode
bits 5-4: quadrant 1 coding mode
bits 3-2: quadrant 2 coding mode
bits 1-0: quadrant 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip quadrant (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
0 = gradient fill pattern A
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern B
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0, Y2 = Y0 + 1, Y3 = Y0 + 1
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on either
four samples retrieved from a 4,096-entry codebook using an index
coded in the stream or four samples coded in the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see section Luminance
Codebook Enumeration)
if bit 3 of the gradient fill pattern is set
swap Y0 with Y3 and Y1 with Y2
clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern C (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with an
arbitrary pattern using two samples and a set of flags coded in the
stream, or with a gradient fill pattern and four samples coded in the
stream, or with 16 samples coded in the stream
if mode is 0
if bit 7 of b1 is 0
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the quadrant, else Y0
else
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b2)
Y0 = ((b1 & 0x0F) << 2) | (b2 >> 6)
Y1 = bits 5-0 of b2
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 12 bytes from the stream as 16 6-bit numbers as the 16
luminance samples (Y0..Y15) for the quadrant
fill luminance samples according to Y0..Y15 and gradient fill
pattern D (see section Gradient Fill Patterns)

finally, output quadrant:
bits 7-4 of the chrominance byte represent the Cr (or V) component
while bits 3-0 represent the Cb (U) component
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A

if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 12 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 (or 16) luminance samples.

* Gradient Pattern 0: (0 degrees)
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3

* Gradient Pattern 1: (22.5 degrees)
Y1 Y2 Y3 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y0 Y1 Y2

* Gradient Pattern 2: (45 degrees)
Y1 Y2 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y1 Y2

* Gradient Pattern 3: (67.5 degrees)
Y2 Y3 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y0 Y1

* Gradient Pattern 4: (90 degrees)
Y3 Y3 Y3 Y3
Y2 Y2 Y2 Y2
Y1 Y1 Y1 Y1
Y0 Y0 Y0 Y0

* Gradient Pattern 5: (112.5 degrees)
Y3 Y3 Y3 Y2
Y3 Y2 Y2 Y1
Y2 Y1 Y1 Y0
Y1 Y0 Y0 Y0

* Gradient Pattern 6: (135 degrees)
Y3 Y3 Y2 Y2
Y3 Y2 Y1 Y1
Y2 Y2 Y1 Y0
Y1 Y1 Y0 Y0

* Gradient Pattern 7: (157.5 degrees)
Y3 Y3 Y2 Y1
Y3 Y2 Y1 Y0
Y3 Y2 Y1 Y0
Y2 Y1 Y0 Y0

* Gradient Pattern A: (homogeneous)
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0

* Gradient Pattern B: (270 degrees)
Y0 Y0 Y0 Y0
Y1 Y1 Y1 Y1
Y2 Y2 Y2 Y2
Y3 Y3 Y3 Y3

* Gradient Pattern C: (subsampled)
Y0 Y0 Y1 Y1
Y0 Y0 Y1 Y1
Y2 Y2 Y3 Y3
Y2 Y2 Y3 Y3

* Gradient Pattern D: (16 samples)
Y0 Y1 Y2 Y3
Y4 Y5 Y6 Y7
Y8 Y9 Y10 Y11
Y12 Y13 Y14 Y15

== Luminance Codebook Enumeration ==

The following pseudo-code creates the Ultimotion Luminance Transition Coding codebook

i = 0
for Y0 = 0 to 61
for Y3 = Y0 + 2 to 63
Yd = Y3 - Y0
if Yd in (2,3,5,6,7,8,11,14,17,20)
LTC[i++] = (Y0, Y0 + Yd/3, Y3 - Yd/3, Y3)
endif
if Yd in (4,5,6,7,8,11,14,17,20,23,26,29,32,36)
LTC[i++] = (Y0, Y0 + Yd/2, Y3 - Yd/4, Y3)
LTC[i++] = (Y0, Y0 + Yd/4, Y3 - Yd/4, Y3)
LTC[i++] = (Y0, Y0 + Yd/4, Y3 - Yd/2, Y3)
endif
if Yd in (6,8,11,14,17,20,23,26,29,32,35,40,46)
LTC[i++] = (Y0, Y3, Y3, Y3)
LTC[i++] = (Y0, Y0, Y3, Y3)
LTC[i++] = (Y0, Y0, Y0, Y3)
endif
next Y3
next Y0

It should be noted there is an error in the "Ultimotion Digital Video Data Stream Specification" - the pre-determined linear transitions are for Y deltas of 2, 3, 5, 6, 7, 8, 11, 14, 17, 20 (not 4). (If 4 is included then there are 4156 transitions. The various transitions are handled by the low contrast edge transitions.)

== Converting Ultimotion Scaled YUV To Correct YUV ==

To convert Ultimotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert Ultimotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg Ultimotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-12T20:33:36Z

Ultimotion: /* Luminance Codebook Enumeration */

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP Ultimotion Digital Video Data Stream Specification]
* Additional Documentation: [http://multimedia.cx/ultimotion-format.txt 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov ].''
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]
* Codec: [http://hobbes.nmsu.edu/cgi-bin/h-viewer?sh=1&fname=/pub/windows/ultimo.zip Win32 Ultimotion decoder]

IBM Ultimotion is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats. Full codecs were available for Windows 3.1 (VfW), OS/2 and AIX. It is primarily a vector quantizing algorithm with simple inter-frame coding (unchanged block). Ultimotion encoding is significantly more computationally intensive than decoding.

== Decoding Algorithm ==

The Ultimotion algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels (quadrant), each of the 16 pixels has a luminance (Y) sample and the entire block shares one chrominance sample (expressed as two color difference components : Cb (or U) and Cr (or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for each chrominance component) are transmitted in the final bitstream.

The Ultimotion algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 quadrants. The 4 quadrants, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be encoded using a single chrominance sample or unique chrominance sample for each quadrant. Each quadrant has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of Ultimotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle uniq flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 quadrant in the block, arranged in the quadrant pattern:

extract quadrant coding mode from b0:
bits 7-6: quadrant 0 coding mode
bits 5-4: quadrant 1 coding mode
bits 3-2: quadrant 2 coding mode
bits 1-0: quadrant 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip quadrant (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
0 = gradient fill pattern A
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern B
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0, Y2 = Y0 + 1, Y3 = Y0 + 1
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on either
four samples retrieved from a 4,096-entry codebook using an index
coded in the stream or four samples coded in the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for Ultimotion luminance codebook)
if bit 3 of the gradient fill pattern is set
swap Y0 with Y3 and Y1 with Y2
clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern C (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with an
arbitrary pattern using two samples and a set of flags coded in the
stream, or with a gradient fill pattern and four samples coded in the
stream, or with 16 samples coded in the stream
if mode is 0
if bit 7 of b1 is 0
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the quadrant, else Y0
else
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b2)
Y0 = ((b1 & 0x0F) << 2) | (b2 >> 6)
Y1 = bits 5-0 of b2
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 12 bytes from the stream as 16 6-bit numbers as the 16
luminance samples (Y0..Y15) for the quadrant
fill luminance samples according to Y0..Y15 and gradient fill
pattern D (see section Gradient Fill Patterns)

finally, output quadrant:
bits 7-4 of the chrominance byte represent the Cr (or V) component
while bits 3-0 represent the Cb (U) component
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A

if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 12 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 (or 16) luminance samples.

* Gradient Pattern 0: (0 degrees)
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3

* Gradient Pattern 1: (22.5 degrees)
Y1 Y2 Y3 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y0 Y1 Y2

* Gradient Pattern 2: (45 degrees)
Y1 Y2 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y1 Y2

* Gradient Pattern 3: (67.5 degrees)
Y2 Y3 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y0 Y1

* Gradient Pattern 4: (90 degrees)
Y3 Y3 Y3 Y3
Y2 Y2 Y2 Y2
Y1 Y1 Y1 Y1
Y0 Y0 Y0 Y0

* Gradient Pattern 5: (112.5 degrees)
Y3 Y3 Y3 Y2
Y3 Y2 Y2 Y1
Y2 Y1 Y1 Y0
Y1 Y0 Y0 Y0

* Gradient Pattern 6: (135 degrees)
Y3 Y3 Y2 Y2
Y3 Y2 Y1 Y1
Y2 Y2 Y1 Y0
Y1 Y1 Y0 Y0

* Gradient Pattern 7: (157.5 degrees)
Y3 Y3 Y2 Y1
Y3 Y2 Y1 Y0
Y3 Y2 Y1 Y0
Y2 Y1 Y0 Y0

* Gradient Pattern A: (homogeneous)
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0

* Gradient Pattern B: (270 degrees)
Y0 Y0 Y0 Y0
Y1 Y1 Y1 Y1
Y2 Y2 Y2 Y2
Y3 Y3 Y3 Y3

* Gradient Pattern C: (subsampled)
Y0 Y0 Y1 Y1
Y0 Y0 Y1 Y1
Y2 Y2 Y3 Y3
Y2 Y2 Y3 Y3

* Gradient Pattern D: (16 samples)
Y0 Y1 Y2 Y3
Y4 Y5 Y6 Y7
Y8 Y9 Y10 Y11
Y12 Y13 Y14 Y15

== Luminance Codebook Enumeration ==

The following pseudo-code creates the Ultimotion Luminance Transition Coding codebook

i = 0
for Y0 = 0 to 61
for Y3 = Y0 + 2 to 63
Yd = Y3 - Y0
if Yd in (2,3,5,6,7,8,11,14,17,20)
LTC[i++] = (Y0, Y0 + Yd/3, Y3 - Yd/3, Y3)
endif
if Yd in (4,5,6,7,8,11,14,17,20,23,26,29,32,36)
LTC[i++] = (Y0, Y0 + Yd/2, Y3 - Yd/4, Y3)
LTC[i++] = (Y0, Y0 + Yd/4, Y3 - Yd/4, Y3)
LTC[i++] = (Y0, Y0 + Yd/4, Y3 - Yd/2, Y3)
endif
if Yd in (6,8,11,14,17,20,23,26,29,32,35,40,46)
LTC[i++] = (Y0, Y3, Y3, Y3)
LTC[i++] = (Y0, Y0, Y3, Y3)
LTC[i++] = (Y0, Y0, Y0, Y3)
endif
next Y3
next Y0

It should be noted there is an error in the "Ultimotion Digital Video Data Stream Specification" - the pre-determined linear transitions are for Y deltas of 2, 3, 5, 6, 7, 8, 11, 14, 17, 20 (not 4). (If 4 is included then there are 4156 transitions. The various transitions are handled by the low contrast edge transitions.)

== Converting Ultimotion Scaled YUV To Correct YUV ==

To convert Ultimotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert Ultimotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg Ultimotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-12T20:17:29Z

Ultimotion: /* Decoding Algorithm */

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP Ultimotion Digital Video Data Stream Specification]
* Additional Documentation: [http://multimedia.cx/ultimotion-format.txt 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov ].''
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]
* Codec: [http://hobbes.nmsu.edu/cgi-bin/h-viewer?sh=1&fname=/pub/windows/ultimo.zip Win32 Ultimotion decoder]

IBM Ultimotion is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats. Full codecs were available for Windows 3.1 (VfW), OS/2 and AIX. It is primarily a vector quantizing algorithm with simple inter-frame coding (unchanged block). Ultimotion encoding is significantly more computationally intensive than decoding.

== Decoding Algorithm ==

The Ultimotion algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels (quadrant), each of the 16 pixels has a luminance (Y) sample and the entire block shares one chrominance sample (expressed as two color difference components : Cb (or U) and Cr (or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for each chrominance component) are transmitted in the final bitstream.

The Ultimotion algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 quadrants. The 4 quadrants, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be encoded using a single chrominance sample or unique chrominance sample for each quadrant. Each quadrant has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of Ultimotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle uniq flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 quadrant in the block, arranged in the quadrant pattern:

extract quadrant coding mode from b0:
bits 7-6: quadrant 0 coding mode
bits 5-4: quadrant 1 coding mode
bits 3-2: quadrant 2 coding mode
bits 1-0: quadrant 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip quadrant (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
0 = gradient fill pattern A
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern B
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0, Y2 = Y0 + 1, Y3 = Y0 + 1
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on either
four samples retrieved from a 4,096-entry codebook using an index
coded in the stream or four samples coded in the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for Ultimotion luminance codebook)
if bit 3 of the gradient fill pattern is set
swap Y0 with Y3 and Y1 with Y2
clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern C (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with an
arbitrary pattern using two samples and a set of flags coded in the
stream, or with a gradient fill pattern and four samples coded in the
stream, or with 16 samples coded in the stream
if mode is 0
if bit 7 of b1 is 0
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the quadrant, else Y0
else
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b2)
Y0 = ((b1 & 0x0F) << 2) | (b2 >> 6)
Y1 = bits 5-0 of b2
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 12 bytes from the stream as 16 6-bit numbers as the 16
luminance samples (Y0..Y15) for the quadrant
fill luminance samples according to Y0..Y15 and gradient fill
pattern D (see section Gradient Fill Patterns)

finally, output quadrant:
bits 7-4 of the chrominance byte represent the Cr (or V) component
while bits 3-0 represent the Cb (U) component
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A

if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 12 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 (or 16) luminance samples.

* Gradient Pattern 0: (0 degrees)
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3

* Gradient Pattern 1: (22.5 degrees)
Y1 Y2 Y3 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y0 Y1 Y2

* Gradient Pattern 2: (45 degrees)
Y1 Y2 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y1 Y2

* Gradient Pattern 3: (67.5 degrees)
Y2 Y3 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y0 Y1

* Gradient Pattern 4: (90 degrees)
Y3 Y3 Y3 Y3
Y2 Y2 Y2 Y2
Y1 Y1 Y1 Y1
Y0 Y0 Y0 Y0

* Gradient Pattern 5: (112.5 degrees)
Y3 Y3 Y3 Y2
Y3 Y2 Y2 Y1
Y2 Y1 Y1 Y0
Y1 Y0 Y0 Y0

* Gradient Pattern 6: (135 degrees)
Y3 Y3 Y2 Y2
Y3 Y2 Y1 Y1
Y2 Y2 Y1 Y0
Y1 Y1 Y0 Y0

* Gradient Pattern 7: (157.5 degrees)
Y3 Y3 Y2 Y1
Y3 Y2 Y1 Y0
Y3 Y2 Y1 Y0
Y2 Y1 Y0 Y0

* Gradient Pattern A: (homogeneous)
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0

* Gradient Pattern B: (270 degrees)
Y0 Y0 Y0 Y0
Y1 Y1 Y1 Y1
Y2 Y2 Y2 Y2
Y3 Y3 Y3 Y3

* Gradient Pattern C: (subsampled)
Y0 Y0 Y1 Y1
Y0 Y0 Y1 Y1
Y2 Y2 Y3 Y3
Y2 Y2 Y3 Y3

* Gradient Pattern D: (16 samples)
Y0 Y1 Y2 Y3
Y4 Y5 Y6 Y7
Y8 Y9 Y10 Y11
Y12 Y13 Y14 Y15

== Converting Ultimotion Scaled YUV To Correct YUV ==

To convert Ultimotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert Ultimotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg Ultimotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-12T20:16:54Z

Ultimotion: /* Gradient Fill Patterns */

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP Ultimotion Digital Video Data Stream Specification]
* Additional Documentation: [http://multimedia.cx/ultimotion-format.txt 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov ].''
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]
* Codec: [http://hobbes.nmsu.edu/cgi-bin/h-viewer?sh=1&fname=/pub/windows/ultimo.zip Win32 Ultimotion decoder]

IBM Ultimotion is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats. Full codecs were available for Windows 3.1 (VfW), OS/2 and AIX. It is primarily a vector quantizing algorithm with simple inter-frame coding (unchanged block). Ultimotion encoding is significantly more computationally intensive than decoding.

== Decoding Algorithm ==

The Ultimotion algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels (quadrant), each of the 16 pixels has a luminance (Y) sample and the entire block shares one chrominance sample (expressed as two color difference components : Cb (or U) and Cr (or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for each chrominance component) are transmitted in the final bitstream.

The Ultimotion algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 quadrants. The 4 quadrants, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be encoded using a single chrominance sample or unique chrominance sample for each quadrant. Each quadrant has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of Ultimotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle uniq flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 quadrant in the block, arranged in the quadrant pattern:

extract quadrant coding mode from b0:
bits 7-6: quadrant 0 coding mode
bits 5-4: quadrant 1 coding mode
bits 3-2: quadrant 2 coding mode
bits 1-0: quadrant 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip quadrant (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
0 = gradient fill pattern A
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern B
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0, Y2 = Y0 + 1, Y3 = Y0 + 1
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on either
four samples retrieved from a 4,096-entry codebook using an index
coded in the stream or four samples coded in the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for Ultimotion luminance codebook)
if bit 3 of the gradient fill pattern is set
swap Y0 with Y3 and Y1 with Y2
clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern C (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with an
arbitrary pattern using two samples and a set of flags coded in the
stream, or with a gradient fill pattern and four samples coded in the
stream, or with 16 samples coded in the stream
if mode is 0
if bit 7 of b1 is 0
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the quadrant, else Y0
else
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b2)
Y0 = ((b1 & 0x0F) << 2) | (b2 >> 6)
Y1 = bits 5-0 of b2
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 12 bytes from the stream as 16 6-bit numbers as the 16
luminance samples (Y0..Y16) for the quadrant
fill luminance samples according to Y0..Y16 and gradient fill
pattern D (see section Gradient Fill Patterns)

finally, output quadrant:
bits 7-4 of the chrominance byte represent the Cr (or V) component
while bits 3-0 represent the Cb (U) component
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A

if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 12 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 (or 16) luminance samples.

* Gradient Pattern 0: (0 degrees)
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3

* Gradient Pattern 1: (22.5 degrees)
Y1 Y2 Y3 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y0 Y1 Y2

* Gradient Pattern 2: (45 degrees)
Y1 Y2 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y1 Y2

* Gradient Pattern 3: (67.5 degrees)
Y2 Y3 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y0 Y1

* Gradient Pattern 4: (90 degrees)
Y3 Y3 Y3 Y3
Y2 Y2 Y2 Y2
Y1 Y1 Y1 Y1
Y0 Y0 Y0 Y0

* Gradient Pattern 5: (112.5 degrees)
Y3 Y3 Y3 Y2
Y3 Y2 Y2 Y1
Y2 Y1 Y1 Y0
Y1 Y0 Y0 Y0

* Gradient Pattern 6: (135 degrees)
Y3 Y3 Y2 Y2
Y3 Y2 Y1 Y1
Y2 Y2 Y1 Y0
Y1 Y1 Y0 Y0

* Gradient Pattern 7: (157.5 degrees)
Y3 Y3 Y2 Y1
Y3 Y2 Y1 Y0
Y3 Y2 Y1 Y0
Y2 Y1 Y0 Y0

* Gradient Pattern A: (homogeneous)
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0

* Gradient Pattern B: (270 degrees)
Y0 Y0 Y0 Y0
Y1 Y1 Y1 Y1
Y2 Y2 Y2 Y2
Y3 Y3 Y3 Y3

* Gradient Pattern C: (subsampled)
Y0 Y0 Y1 Y1
Y0 Y0 Y1 Y1
Y2 Y2 Y3 Y3
Y2 Y2 Y3 Y3

* Gradient Pattern D: (16 samples)
Y0 Y1 Y2 Y3
Y4 Y5 Y6 Y7
Y8 Y9 Y10 Y11
Y12 Y13 Y14 Y15

== Converting Ultimotion Scaled YUV To Correct YUV ==

To convert Ultimotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert Ultimotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg Ultimotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-12T20:15:21Z

Ultimotion: /* Decoding Algorithm */

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP Ultimotion Digital Video Data Stream Specification]
* Additional Documentation: [http://multimedia.cx/ultimotion-format.txt 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov ].''
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]
* Codec: [http://hobbes.nmsu.edu/cgi-bin/h-viewer?sh=1&fname=/pub/windows/ultimo.zip Win32 Ultimotion decoder]

IBM Ultimotion is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats. Full codecs were available for Windows 3.1 (VfW), OS/2 and AIX. It is primarily a vector quantizing algorithm with simple inter-frame coding (unchanged block). Ultimotion encoding is significantly more computationally intensive than decoding.

== Decoding Algorithm ==

The Ultimotion algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels (quadrant), each of the 16 pixels has a luminance (Y) sample and the entire block shares one chrominance sample (expressed as two color difference components : Cb (or U) and Cr (or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for each chrominance component) are transmitted in the final bitstream.

The Ultimotion algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 quadrants. The 4 quadrants, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be encoded using a single chrominance sample or unique chrominance sample for each quadrant. Each quadrant has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of Ultimotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle uniq flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 quadrant in the block, arranged in the quadrant pattern:

extract quadrant coding mode from b0:
bits 7-6: quadrant 0 coding mode
bits 5-4: quadrant 1 coding mode
bits 3-2: quadrant 2 coding mode
bits 1-0: quadrant 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip quadrant (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
0 = gradient fill pattern A
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern B
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0, Y2 = Y0 + 1, Y3 = Y0 + 1
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on either
four samples retrieved from a 4,096-entry codebook using an index
coded in the stream or four samples coded in the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for Ultimotion luminance codebook)
if bit 3 of the gradient fill pattern is set
swap Y0 with Y3 and Y1 with Y2
clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern C (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with an
arbitrary pattern using two samples and a set of flags coded in the
stream, or with a gradient fill pattern and four samples coded in the
stream, or with 16 samples coded in the stream
if mode is 0
if bit 7 of b1 is 0
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the quadrant, else Y0
else
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b2)
Y0 = ((b1 & 0x0F) << 2) | (b2 >> 6)
Y1 = bits 5-0 of b2
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 12 bytes from the stream as 16 6-bit numbers as the 16
luminance samples (Y0..Y16) for the quadrant
fill luminance samples according to Y0..Y16 and gradient fill
pattern D (see section Gradient Fill Patterns)

finally, output quadrant:
bits 7-4 of the chrominance byte represent the Cr (or V) component
while bits 3-0 represent the Cb (U) component
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A

if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 11 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 luminance samples.

* Gradient Pattern 0: (0 degrees)
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3

* Gradient Pattern 1: (22.5 degrees)
Y1 Y2 Y3 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y0 Y1 Y2

* Gradient Pattern 2: (45 degrees)
Y1 Y2 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y1 Y2

* Gradient Pattern 3: (67.5 degrees)
Y2 Y3 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y0 Y1

* Gradient Pattern 4: (90 degrees)
Y3 Y3 Y3 Y3
Y2 Y2 Y2 Y2
Y1 Y1 Y1 Y1
Y0 Y0 Y0 Y0

* Gradient Pattern 5: (112.5 degrees)
Y3 Y3 Y3 Y2
Y3 Y2 Y2 Y1
Y2 Y1 Y1 Y0
Y1 Y0 Y0 Y0

* Gradient Pattern 6: (135 degrees)
Y3 Y3 Y2 Y2
Y3 Y2 Y1 Y1
Y2 Y2 Y1 Y0
Y1 Y1 Y0 Y0

* Gradient Pattern 7: (157.5 degrees)
Y3 Y3 Y2 Y1
Y3 Y2 Y1 Y0
Y3 Y2 Y1 Y0
Y2 Y1 Y0 Y0

* Gradient Pattern A: (homogeneous)
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0

* Gradient Pattern B: (270 degrees)
Y0 Y0 Y0 Y0
Y1 Y1 Y1 Y1
Y2 Y2 Y2 Y2
Y3 Y3 Y3 Y3

* Gradient Pattern C: (subsampled)
Y0 Y0 Y1 Y1
Y0 Y0 Y1 Y1
Y2 Y2 Y3 Y3
Y2 Y2 Y3 Y3

== Converting Ultimotion Scaled YUV To Correct YUV ==

To convert Ultimotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert Ultimotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg Ultimotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-12T19:54:45Z

Ultimotion: /* Decoding Algorithm */

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP Ultimotion Digital Video Data Stream Specification]
* Additional Documentation: [http://multimedia.cx/ultimotion-format.txt 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov ].''
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]
* Codec: [http://hobbes.nmsu.edu/cgi-bin/h-viewer?sh=1&fname=/pub/windows/ultimo.zip Win32 Ultimotion decoder]

IBM Ultimotion is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats. Full codecs were available for Windows 3.1 (VfW), OS/2 and AIX. It is primarily a vector quantizing algorithm with simple inter-frame coding (unchanged block). Ultimotion encoding is significantly more computationally intensive than decoding.

== Decoding Algorithm ==

The Ultimotion algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels (quadrant), each of the 16 pixels has a luminance (Y) sample and the entire block shares one chrominance sample (expressed as two color difference components : Cb (or U) and Cr (or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for each chrominance component) are transmitted in the final bitstream.

The Ultimotion algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 quadrants. The 4 quadrants, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be encoded using a single chrominance sample or unique chrominance sample for each quadrant. Each quadrant has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of Ultimotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle uniq flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 quadrant in the block, arranged in the quadrant pattern:

extract quadrant coding mode from b0:
bits 7-6: quadrant 0 coding mode
bits 5-4: quadrant 1 coding mode
bits 3-2: quadrant 2 coding mode
bits 1-0: quadrant 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip quadrant (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
6-bit sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
0 = gradient fill pattern A
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern B
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0, Y2 = Y0 + 1, Y3 = Y0 + 1
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on
either 4 6-bit samples coded in the stream or 4 6-bit samples
retrieved from a 16,384-entry codebook using an index coded in
the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for Ultimotion luminance codebook)
if bit 3 of the gradient fill pattern is set, swap Y0 with Y3
and Y1 with Y2; clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit
number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern 8 (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with 16
6-bit samples coded in the stream, or with a gradient fill
pattern and 4 6-bit luminance samples coded in the stream, or
with an arbitrary pattern using 2 luminance samples and a set of
flags coded in the stream
if mode is 0
get the next byte in the stream (b1)
if bit 7 of b1 is set
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b1)
Y0 = ((b1 & 0x0F) << 2) | (b1 >> 6)
Y1 = bits 5-0 of b1
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the quadrant, else Y0
else (mode is non-zero)
get the next 16 6-bit numbers from the stream as the 16
luminance samples for the quadrant, thus consuming 96 bits,
or 12 bytes from the stream

finally, output quadrant:
bits 7-4 of the chrominance byte represent the Cr (or V) component
while bits 3-0 represent the Cb (U) component
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A

if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 11 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 luminance samples.

* Gradient Pattern 0: (0 degrees)
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3

* Gradient Pattern 1: (22.5 degrees)
Y1 Y2 Y3 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y0 Y1 Y2

* Gradient Pattern 2: (45 degrees)
Y1 Y2 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y1 Y2

* Gradient Pattern 3: (67.5 degrees)
Y2 Y3 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y0 Y1

* Gradient Pattern 4: (90 degrees)
Y3 Y3 Y3 Y3
Y2 Y2 Y2 Y2
Y1 Y1 Y1 Y1
Y0 Y0 Y0 Y0

* Gradient Pattern 5: (112.5 degrees)
Y3 Y3 Y3 Y2
Y3 Y2 Y2 Y1
Y2 Y1 Y1 Y0
Y1 Y0 Y0 Y0

* Gradient Pattern 6: (135 degrees)
Y3 Y3 Y2 Y2
Y3 Y2 Y1 Y1
Y2 Y2 Y1 Y0
Y1 Y1 Y0 Y0

* Gradient Pattern 7: (157.5 degrees)
Y3 Y3 Y2 Y1
Y3 Y2 Y1 Y0
Y3 Y2 Y1 Y0
Y2 Y1 Y0 Y0

* Gradient Pattern A: (homogeneous)
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0

* Gradient Pattern B: (270 degrees)
Y0 Y0 Y0 Y0
Y1 Y1 Y1 Y1
Y2 Y2 Y2 Y2
Y3 Y3 Y3 Y3

* Gradient Pattern C: (subsampled)
Y0 Y0 Y1 Y1
Y0 Y0 Y1 Y1
Y2 Y2 Y3 Y3
Y2 Y2 Y3 Y3

== Converting Ultimotion Scaled YUV To Correct YUV ==

To convert Ultimotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert Ultimotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg Ultimotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-12T19:48:46Z

Ultimotion: /* Gradient Fill Patterns */

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP Ultimotion Digital Video Data Stream Specification]
* Additional Documentation: [http://multimedia.cx/ultimotion-format.txt 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov ].''
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]
* Codec: [http://hobbes.nmsu.edu/cgi-bin/h-viewer?sh=1&fname=/pub/windows/ultimo.zip Win32 Ultimotion decoder]

IBM Ultimotion is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats. Full codecs were available for Windows 3.1 (VfW), OS/2 and AIX. It is primarily a vector quantizing algorithm with simple inter-frame coding (unchanged block). Ultimotion encoding is significantly more computationally intensive than decoding.

== Decoding Algorithm ==

The Ultimotion algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels (quadrant), each of the 16 pixels has a luminance (Y) sample and the entire block shares one chrominance sample (expressed as two color difference components : Cb (or U) and Cr (or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for each chrominance component) are transmitted in the final bitstream.

The Ultimotion algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 quadrants. The 4 quadrants, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be encoded using a single chrominance sample or unique chrominance sample for each quadrant. Each quadrant has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of Ultimotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle uniq flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 quadrant in the block, arranged in the quadrant pattern:

extract quadrant coding mode from b0:
bits 7-6: quadrant 0 coding mode
bits 5-4: quadrant 1 coding mode
bits 3-2: quadrant 2 coding mode
bits 1-0: quadrant 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip quadrant (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
6-bit sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
bits 5-0 of b1 indicate luminance sample Y0
0 = fill quadrant with Y0
1 = gradient fill pattern 3
Y1 = Y0, Y2 = Y0 + 1, Y3 = Y0 + 1
2 = gradient fill pattern 5
Y1 = Y0, Y2 = Y0 + 1, Y3 = Y0 + 1
3 = gradient fill pattern 5
Y3 = Y0, Y2 = Y0, Y1 = Y0 + 1, Y0 = Y0 + 1
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on
either 4 6-bit samples coded in the stream or 4 6-bit samples
retrieved from a 16,384-entry codebook using an index coded in
the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for Ultimotion luminance codebook)
if bit 3 of the gradient fill pattern is set, swap Y0 with Y3
and Y1 with Y2; clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit
number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern 8 (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with 16
6-bit samples coded in the stream, or with a gradient fill
pattern and 4 6-bit luminance samples coded in the stream, or
with an arbitrary pattern using 2 luminance samples and a set of
flags coded in the stream
if mode is 0
get the next byte in the stream (b1)
if bit 7 of b1 is set
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b1)
Y0 = ((b1 & 0x0F) << 2) | (b1 >> 6)
Y1 = bits 5-0 of b1
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the quadrant, else Y0
else (mode is non-zero)
get the next 16 6-bit numbers from the stream as the 16
luminance samples for the quadrant, thus consuming 96 bits,
or 12 bytes from the stream

finally, output quadrant:
bits 7-4 of the chrominance byte represent the Cr (or V) component
while bits 3-0 represent the Cb (U) component
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A

if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 11 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 luminance samples.

* Gradient Pattern 0: (0 degrees)
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3

* Gradient Pattern 1: (22.5 degrees)
Y1 Y2 Y3 Y3
Y0 Y1 Y2 Y3
Y0 Y1 Y2 Y3
Y0 Y0 Y1 Y2

* Gradient Pattern 2: (45 degrees)
Y1 Y2 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y1 Y2

* Gradient Pattern 3: (67.5 degrees)
Y2 Y3 Y3 Y3
Y1 Y2 Y2 Y3
Y0 Y1 Y1 Y2
Y0 Y0 Y0 Y1

* Gradient Pattern 4: (90 degrees)
Y3 Y3 Y3 Y3
Y2 Y2 Y2 Y2
Y1 Y1 Y1 Y1
Y0 Y0 Y0 Y0

* Gradient Pattern 5: (112.5 degrees)
Y3 Y3 Y3 Y2
Y3 Y2 Y2 Y1
Y2 Y1 Y1 Y0
Y1 Y0 Y0 Y0

* Gradient Pattern 6: (135 degrees)
Y3 Y3 Y2 Y2
Y3 Y2 Y1 Y1
Y2 Y2 Y1 Y0
Y1 Y1 Y0 Y0

* Gradient Pattern 7: (157.5 degrees)
Y3 Y3 Y2 Y1
Y3 Y2 Y1 Y0
Y3 Y2 Y1 Y0
Y2 Y1 Y0 Y0

* Gradient Pattern A: (homogeneous)
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0
Y0 Y0 Y0 Y0

* Gradient Pattern B: (270 degrees)
Y0 Y0 Y0 Y0
Y1 Y1 Y1 Y1
Y2 Y2 Y2 Y2
Y3 Y3 Y3 Y3

* Gradient Pattern C: (subsampled)
Y0 Y0 Y1 Y1
Y0 Y0 Y1 Y1
Y2 Y2 Y3 Y3
Y2 Y2 Y3 Y3

== Converting Ultimotion Scaled YUV To Correct YUV ==

To convert Ultimotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert Ultimotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg Ultimotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-12T19:41:54Z

Ultimotion: /* Decoding Algorithm */

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP Ultimotion Digital Video Data Stream Specification]
* Additional Documentation: [http://multimedia.cx/ultimotion-format.txt 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov ].''
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]
* Codec: [http://hobbes.nmsu.edu/cgi-bin/h-viewer?sh=1&fname=/pub/windows/ultimo.zip Win32 Ultimotion decoder]

IBM Ultimotion is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats. Full codecs were available for Windows 3.1 (VfW), OS/2 and AIX. It is primarily a vector quantizing algorithm with simple inter-frame coding (unchanged block). Ultimotion encoding is significantly more computationally intensive than decoding.

== Decoding Algorithm ==

The Ultimotion algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels (quadrant), each of the 16 pixels has a luminance (Y) sample and the entire block shares one chrominance sample (expressed as two color difference components : Cb (or U) and Cr (or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for each chrominance component) are transmitted in the final bitstream.

The Ultimotion algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 quadrants. The 4 quadrants, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be encoded using a single chrominance sample or unique chrominance sample for each quadrant. Each quadrant has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of Ultimotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle uniq flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 quadrant in the block, arranged in the quadrant pattern:

extract quadrant coding mode from b0:
bits 7-6: quadrant 0 coding mode
bits 5-4: quadrant 1 coding mode
bits 3-2: quadrant 2 coding mode
bits 1-0: quadrant 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip quadrant (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
6-bit sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
bits 5-0 of b1 indicate luminance sample Y0
0 = fill quadrant with Y0
1 = gradient fill pattern 3
Y1 = Y0, Y2 = Y0 + 1, Y3 = Y0 + 1
2 = gradient fill pattern 5
Y1 = Y0, Y2 = Y0 + 1, Y3 = Y0 + 1
3 = gradient fill pattern 5
Y3 = Y0, Y2 = Y0, Y1 = Y0 + 1, Y0 = Y0 + 1
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on
either 4 6-bit samples coded in the stream or 4 6-bit samples
retrieved from a 16,384-entry codebook using an index coded in
the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for Ultimotion luminance codebook)
if bit 3 of the gradient fill pattern is set, swap Y0 with Y3
and Y1 with Y2; clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit
number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern 8 (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with 16
6-bit samples coded in the stream, or with a gradient fill
pattern and 4 6-bit luminance samples coded in the stream, or
with an arbitrary pattern using 2 luminance samples and a set of
flags coded in the stream
if mode is 0
get the next byte in the stream (b1)
if bit 7 of b1 is set
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b1)
Y0 = ((b1 & 0x0F) << 2) | (b1 >> 6)
Y1 = bits 5-0 of b1
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the quadrant, else Y0
else (mode is non-zero)
get the next 16 6-bit numbers from the stream as the 16
luminance samples for the quadrant, thus consuming 96 bits,
or 12 bytes from the stream

finally, output quadrant:
bits 7-4 of the chrominance byte represent the Cr (or V) component
while bits 3-0 represent the Cb (U) component
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A

if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 9 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 luminance samples.

* Gradient Pattern 0:
0 1 2 3
0 1 2 3
0 1 2 3
0 1 2 3

* Gradient Pattern 1:
1 2 3 3
0 1 2 3
0 1 2 3
0 0 1 2

* Gradient Pattern 2:
1 2 3 3
1 2 2 3
0 1 1 2
0 0 1 2

* Gradient Pattern 3:
2 3 3 3
1 2 2 3
0 1 1 2
0 0 0 1

* Gradient Pattern 4:
3 3 3 3
2 2 2 2
1 1 1 1
0 0 0 0

* Gradient Pattern 5:
3 3 3 2
3 2 2 1
2 1 1 0
1 0 0 0

* Gradient Pattern 6:
3 3 2 2
3 2 1 1
2 2 1 0
1 1 0 0

* Gradient Pattern 7:
3 3 2 1
3 2 1 0
3 2 1 0
2 1 0 0

* Gradient Pattern 8:
0 0 1 1
0 0 1 1
2 2 3 3
2 2 3 3

== Converting Ultimotion Scaled YUV To Correct YUV ==

To convert Ultimotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert Ultimotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg Ultimotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-12T19:29:44Z

Ultimotion:

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP Ultimotion Digital Video Data Stream Specification]
* Additional Documentation: [http://multimedia.cx/ultimotion-format.txt 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov ].''
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]
* Codec: [http://hobbes.nmsu.edu/cgi-bin/h-viewer?sh=1&fname=/pub/windows/ultimo.zip Win32 Ultimotion decoder]

IBM Ultimotion is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats. Full codecs were available for Windows 3.1 (VfW), OS/2 and AIX. It is primarily a vector quantizing algorithm with simple inter-frame coding (unchanged block). Ultimotion encoding is significantly more computationally intensive than decoding.

== Decoding Algorithm ==

The Ultimotion algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels (quadrant), each of the 16 pixels has a luminance (Y) sample and the entire block shares one chrominance sample (expressed as two color difference components : Cb (or U) and Cr (or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for each chrominance component) are transmitted in the final bitstream.

The Ultimotion algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 quadrants. The 4 quadrants, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be encoded using a single chrominance sample or unique chrominance sample for each quadrant. Each quadrant has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of Ultimotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle uniq flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 quadrant in the block, arranged in the quadrant pattern:

extract quadrant coding mode from b0:
bits 7-6: quadrant 0 coding mode
bits 5-4: quadrant 1 coding mode
bits 3-2: quadrant 2 coding mode
bits 1-0: quadrant 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip quadrant (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
6-bit sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
0 = gradient fill pattern 0
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern 4, swap Y0 with Y3 and Y1 with Y2
after unpacking Y samples
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0
if gradient fill pattern is pattern 0
Y2 = Y0 + 1 (saturated to an upper limit of 0x3F)
Y3 = Y2
else
Y2 = Y3 = Y0
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on
either 4 6-bit samples coded in the stream or 4 6-bit samples
retrieved from a 16,384-entry codebook using an index coded in
the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for Ultimotion luminance codebook)
if bit 3 of the gradient fill pattern is set, swap Y0 with Y3
and Y1 with Y2; clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit
number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern 8 (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with 16
6-bit samples coded in the stream, or with a gradient fill
pattern and 4 6-bit luminance samples coded in the stream, or
with an arbitrary pattern using 2 luminance samples and a set of
flags coded in the stream
if mode is 0
get the next byte in the stream (b1)
if bit 7 of b1 is set
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b1)
Y0 = ((b1 & 0x0F) << 2) | (b1 >> 6)
Y1 = bits 5-0 of b1
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the quadrant, else Y0
else (mode is non-zero)
get the next 16 6-bit numbers from the stream as the 16
luminance samples for the quadrant, thus consuming 96 bits,
or 12 bytes from the stream

finally, output quadrant:
bits 7-4 of the chrominance byte represent the Cr (or V) component
while bits 3-0 represent the Cb (U) component
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A

if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 9 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 luminance samples.

* Gradient Pattern 0:
0 1 2 3
0 1 2 3
0 1 2 3
0 1 2 3

* Gradient Pattern 1:
1 2 3 3
0 1 2 3
0 1 2 3
0 0 1 2

* Gradient Pattern 2:
1 2 3 3
1 2 2 3
0 1 1 2
0 0 1 2

* Gradient Pattern 3:
2 3 3 3
1 2 2 3
0 1 1 2
0 0 0 1

* Gradient Pattern 4:
3 3 3 3
2 2 2 2
1 1 1 1
0 0 0 0

* Gradient Pattern 5:
3 3 3 2
3 2 2 1
2 1 1 0
1 0 0 0

* Gradient Pattern 6:
3 3 2 2
3 2 1 1
2 2 1 0
1 1 0 0

* Gradient Pattern 7:
3 3 2 1
3 2 1 0
3 2 1 0
2 1 0 0

* Gradient Pattern 8:
0 0 1 1
0 0 1 1
2 2 3 3
2 2 3 3

== Converting Ultimotion Scaled YUV To Correct YUV ==

To convert Ultimotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert Ultimotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg Ultimotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-11T20:06:57Z

Ultimotion:

''This page is based on the document 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov found at [http://multimedia.cx/ultimotion-format.txt http://multimedia.cx/ultimotion-format.txt].''

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP http://multimedia.cx/UMSPEC.ZIP]
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]
* Codec: [http://hobbes.nmsu.edu/cgi-bin/h-viewer?sh=1&fname=/pub/windows/ultimo.zip Win32 Ultimotion decoder]

IBM UltiMotion (henceforth ULTI) is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats.

== Decoding Algorithm ==

The ULTI algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels (quadrant), each of the 16 pixels has a luminance (Y) sample and the entire block shares one chrominance sample (expressed as two color difference components : Cb (or U) and Cr (or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for each chrominance component) are transmitted in the final bitstream.

The ULTI algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 quadrants. The 4 quadrants, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be encoded using a single chrominance sample or unique chrominance sample for each quadrant. Each quadrant has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of UltiMotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle uniq flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 quadrant in the block, arranged in the quadrant pattern:

extract quadrant coding mode from b0:
bits 7-6: quadrant 0 coding mode
bits 5-4: quadrant 1 coding mode
bits 3-2: quadrant 2 coding mode
bits 1-0: quadrant 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip quadrant (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
6-bit sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
0 = gradient fill pattern 0
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern 4, swap Y0 with Y3 and Y1 with Y2
after unpacking Y samples
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0
if gradient fill pattern is pattern 0
Y2 = Y0 + 1 (saturated to an upper limit of 0x3F)
Y3 = Y2
else
Y2 = Y3 = Y0
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on
either 4 6-bit samples coded in the stream or 4 6-bit samples
retrieved from a 16,384-entry codebook using an index coded in
the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for UltiMotion luminance codebook)
if bit 3 of the gradient fill pattern is set, swap Y0 with Y3
and Y1 with Y2; clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit
number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern 8 (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with 16
6-bit samples coded in the stream, or with a gradient fill
pattern and 4 6-bit luminance samples coded in the stream, or
with an arbitrary pattern using 2 luminance samples and a set of
flags coded in the stream
if mode is 0
get the next byte in the stream (b1)
if bit 7 of b1 is set
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b1)
Y0 = ((b1 & 0x0F) << 2) | (b1 >> 6)
Y1 = bits 5-0 of b1
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the quadrant, else Y0
else (mode is non-zero)
get the next 16 6-bit numbers from the stream as the 16
luminance samples for the quadrant, thus consuming 96 bits,
or 12 bytes from the stream

finally, output quadrant:
bits 7-4 of the chrominance byte represent the Cr (or V) component
while bits 3-0 represent the Cb (U) component
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A

if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 9 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 luminance samples.

* Gradient Pattern 0:
0 1 2 3
0 1 2 3
0 1 2 3
0 1 2 3

* Gradient Pattern 1:
1 2 3 3
0 1 2 3
0 1 2 3
0 0 1 2

* Gradient Pattern 2:
1 2 3 3
1 2 2 3
0 1 1 2
0 0 1 2

* Gradient Pattern 3:
2 3 3 3
1 2 2 3
0 1 1 2
0 0 0 1

* Gradient Pattern 4:
3 3 3 3
2 2 2 2
1 1 1 1
0 0 0 0

* Gradient Pattern 5:
3 3 3 2
3 2 2 1
2 1 1 0
1 0 0 0

* Gradient Pattern 6:
3 3 2 2
3 2 1 1
2 2 1 0
1 1 0 0

* Gradient Pattern 7:
3 3 2 1
3 2 1 0
3 2 1 0
2 1 0 0

* Gradient Pattern 8:
0 0 1 1
0 0 1 1
2 2 3 3
2 2 3 3

== Converting UltiMotion Scaled YUV To Correct YUV ==

To convert UltiMotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert UltiMotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg UltiMotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-11T19:59:33Z

Ultimotion: /* Decoding Algorithm */

''This page is based on the document 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov found at [http://multimedia.cx/ultimotion-format.txt http://multimedia.cx/ultimotion-format.txt].''

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP http://multimedia.cx/UMSPEC.ZIP]
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]

IBM UltiMotion (henceforth ULTI) is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats.

== Decoding Algorithm ==

The ULTI algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels (quadrant), each of the 16 pixels has a luminance (Y) sample and the entire block shares one chrominance sample (expressed as two color difference components : Cb (or U) and Cr (or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for each chrominance component) are transmitted in the final bitstream.

The ULTI algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 quadrants. The 4 quadrants, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be encoded using a single chrominance sample or unique chrominance sample for each quadrant. Each quadrant has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of UltiMotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle uniq flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 quadrant in the block, arranged in the quadrant pattern:

extract quadrant coding mode from b0:
bits 7-6: quadrant 0 coding mode
bits 5-4: quadrant 1 coding mode
bits 3-2: quadrant 2 coding mode
bits 1-0: quadrant 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip quadrant (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
6-bit sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
0 = gradient fill pattern 0
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern 4, swap Y0 with Y3 and Y1 with Y2
after unpacking Y samples
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0
if gradient fill pattern is pattern 0
Y2 = Y0 + 1 (saturated to an upper limit of 0x3F)
Y3 = Y2
else
Y2 = Y3 = Y0
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on
either 4 6-bit samples coded in the stream or 4 6-bit samples
retrieved from a 16,384-entry codebook using an index coded in
the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for UltiMotion luminance codebook)
if bit 3 of the gradient fill pattern is set, swap Y0 with Y3
and Y1 with Y2; clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit
number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern 8 (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with 16
6-bit samples coded in the stream, or with a gradient fill
pattern and 4 6-bit luminance samples coded in the stream, or
with an arbitrary pattern using 2 luminance samples and a set of
flags coded in the stream
if mode is 0
get the next byte in the stream (b1)
if bit 7 of b1 is set
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b1)
Y0 = ((b1 & 0x0F) << 2) | (b1 >> 6)
Y1 = bits 5-0 of b1
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the quadrant, else Y0
else (mode is non-zero)
get the next 16 6-bit numbers from the stream as the 16
luminance samples for the quadrant, thus consuming 96 bits,
or 12 bytes from the stream

finally, output quadrant:
bits 7-4 of the chrominance byte represent the Cr (or V) component
while bits 3-0 represent the Cb (U) component
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A

if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 9 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 luminance samples.

* Gradient Pattern 0:
0 1 2 3
0 1 2 3
0 1 2 3
0 1 2 3

* Gradient Pattern 1:
1 2 3 3
0 1 2 3
0 1 2 3
0 0 1 2

* Gradient Pattern 2:
1 2 3 3
1 2 2 3
0 1 1 2
0 0 1 2

* Gradient Pattern 3:
2 3 3 3
1 2 2 3
0 1 1 2
0 0 0 1

* Gradient Pattern 4:
3 3 3 3
2 2 2 2
1 1 1 1
0 0 0 0

* Gradient Pattern 5:
3 3 3 2
3 2 2 1
2 1 1 0
1 0 0 0

* Gradient Pattern 6:
3 3 2 2
3 2 1 1
2 2 1 0
1 1 0 0

* Gradient Pattern 7:
3 3 2 1
3 2 1 0
3 2 1 0
2 1 0 0

* Gradient Pattern 8:
0 0 1 1
0 0 1 1
2 2 3 3
2 2 3 3

== Converting UltiMotion Scaled YUV To Correct YUV ==

To convert UltiMotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert UltiMotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg UltiMotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-11T19:57:22Z

Ultimotion: /* Decoding Algorithm */

''This page is based on the document 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov found at [http://multimedia.cx/ultimotion-format.txt http://multimedia.cx/ultimotion-format.txt].''

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP http://multimedia.cx/UMSPEC.ZIP]
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]

IBM UltiMotion (henceforth ULTI) is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats.

== Decoding Algorithm ==

The ULTI algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels (quadrant), each of the 16 pixels has a luminance (Y) sample and the entire block shares one chrominance sample (expressed as two color difference components : Cb (or U) and Cr (or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for each chrominance component) are transmitted in the final bitstream.

The ULTI algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 quadrants. The 4 quadrants, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be encoded using a single chrominance sample or unique chrominance sample for each quadrant. Each quadrant has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of UltiMotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle uniq flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 quadrant in the block, arranged in the quadrant pattern:

extract quadrant coding mode from b0:
bits 7-6: quadrant 0 coding mode
bits 5-4: quadrant 1 coding mode
bits 3-2: quadrant 2 coding mode
bits 1-0: quadrant 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip quadrant (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
6-bit sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
0 = gradient fill pattern 0
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern 4, swap Y0 with Y3 and Y1 with Y2
after unpacking Y samples
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0
if gradient fill pattern is pattern 0
Y2 = Y0 + 1 (saturated to an upper limit of 0x3F)
Y3 = Y2
else
Y2 = Y3 = Y0
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on
either 4 6-bit samples coded in the stream or 4 6-bit samples
retrieved from a 16,384-entry codebook using an index coded in
the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for UltiMotion luminance codebook)
if bit 3 of the gradient fill pattern is set, swap Y0 with Y3
and Y1 with Y2; clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit
number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern 8 (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with 16
6-bit samples coded in the stream, or with a gradient fill
pattern and 4 6-bit luminance samples coded in the stream, or
with an arbitrary pattern using 2 luminance samples and a set of
flags coded in the stream
if mode is 0
get the next byte in the stream (b1)
if bit 7 of b1 is set
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b1)
Y0 = ((b1 & 0x0F) << 2) | (b1 >> 6)
Y1 = bits 5-0 of b1
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the quadrant, else Y0
else (mode is non-zero)
get the next 16 6-bit numbers from the stream as the 16
luminance samples for the quadrant, thus consuming 96 bits,
or 12 bytes from the stream

finally, output quadrant:
bits 7-4 of the chrominance byte represent the Cr (or V) component
while bits 3-0 represent the Cb (U) component
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A

if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 9 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 luminance samples.

* Gradient Pattern 0:
0 1 2 3
0 1 2 3
0 1 2 3
0 1 2 3

* Gradient Pattern 1:
1 2 3 3
0 1 2 3
0 1 2 3
0 0 1 2

* Gradient Pattern 2:
1 2 3 3
1 2 2 3
0 1 1 2
0 0 1 2

* Gradient Pattern 3:
2 3 3 3
1 2 2 3
0 1 1 2
0 0 0 1

* Gradient Pattern 4:
3 3 3 3
2 2 2 2
1 1 1 1
0 0 0 0

* Gradient Pattern 5:
3 3 3 2
3 2 2 1
2 1 1 0
1 0 0 0

* Gradient Pattern 6:
3 3 2 2
3 2 1 1
2 2 1 0
1 1 0 0

* Gradient Pattern 7:
3 3 2 1
3 2 1 0
3 2 1 0
2 1 0 0

* Gradient Pattern 8:
0 0 1 1
0 0 1 1
2 2 3 3
2 2 3 3

== Converting UltiMotion Scaled YUV To Correct YUV ==

To convert UltiMotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert UltiMotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg UltiMotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-11T19:41:12Z

Ultimotion: /* Decoding Algorithm */

''This page is based on the document 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov found at [http://multimedia.cx/ultimotion-format.txt http://multimedia.cx/ultimotion-format.txt].''

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP http://multimedia.cx/UMSPEC.ZIP]
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]

IBM UltiMotion (henceforth ULTI) is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats.

== Decoding Algorithm ==

The ULTI algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels (quadrant), each of the 16 pixels has a luminance (Y) sample and the entire block shares one chrominance sample (expressed as two color difference components : Cb (or U) and Cr (or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for each chrominance component) are transmitted in the final bitstream.

The ULTI algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 quadrants. The 4 quadrants, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be encoded using a single chrominance sample or each quadrant can be coded with its own pair of chrominance samples. Each sub block has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of UltiMotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle mode flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous
frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 sub block in the block, arranged in the sub block pattern:

extract sub block coding mode from b0:
bits 7-6: sub block 0 coding mode
bits 5-4: sub block 1 coding mode
bits 3-2: sub block 2 coding mode
bits 1-0: sub block 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip sub block (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
6-bit sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
0 = gradient fill pattern 0
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern 4, swap Y0 with Y3 and Y1 with Y2
after unpacking Y samples
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0
if gradient fill pattern is pattern 0
Y2 = Y0 + 1 (saturated to an upper limit of 0x3F)
Y3 = Y2
else
Y2 = Y3 = Y0
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on
either 4 6-bit samples coded in the stream or 4 6-bit samples
retrieved from a 16,384-entry codebook using an index coded in
the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for UltiMotion luminance codebook)
if bit 3 of the gradient fill pattern is set, swap Y0 with Y3
and Y1 with Y2; clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit
number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern 8 (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with 16
6-bit samples coded in the stream, or with a gradient fill
pattern and 4 6-bit luminance samples coded in the stream, or
with an arbitrary pattern using 2 luminance samples and a set of
flags coded in the stream
if mode is 0
get the next byte in the stream (b1)
if bit 7 of b1 is set
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b1)
Y0 = ((b1 & 0x0F) << 2) | (b1 >> 6)
Y1 = bits 5-0 of b1
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the sub block, else Y0
else (mode is non-zero)
get the next 16 6-bit numbers from the stream as the 16
luminance samples for the sub block, thus consuming 96 bits,
or 12 bytes from the stream

finally, output sub block:
bits 7-4 of the chrominance byte represent the red chrominance
value for the sub block while bits 3-0 represent the blue value
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A
if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 9 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 luminance samples.

* Gradient Pattern 0:
0 1 2 3
0 1 2 3
0 1 2 3
0 1 2 3

* Gradient Pattern 1:
1 2 3 3
0 1 2 3
0 1 2 3
0 0 1 2

* Gradient Pattern 2:
1 2 3 3
1 2 2 3
0 1 1 2
0 0 1 2

* Gradient Pattern 3:
2 3 3 3
1 2 2 3
0 1 1 2
0 0 0 1

* Gradient Pattern 4:
3 3 3 3
2 2 2 2
1 1 1 1
0 0 0 0

* Gradient Pattern 5:
3 3 3 2
3 2 2 1
2 1 1 0
1 0 0 0

* Gradient Pattern 6:
3 3 2 2
3 2 1 1
2 2 1 0
1 1 0 0

* Gradient Pattern 7:
3 3 2 1
3 2 1 0
3 2 1 0
2 1 0 0

* Gradient Pattern 8:
0 0 1 1
0 0 1 1
2 2 3 3
2 2 3 3

== Converting UltiMotion Scaled YUV To Correct YUV ==

To convert UltiMotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert UltiMotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg UltiMotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-11T17:46:47Z

Ultimotion: /* Decoding Algorithm */

''This page is based on the document 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov found at [http://multimedia.cx/ultimotion-format.txt http://multimedia.cx/ultimotion-format.txt].''

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP http://multimedia.cx/UMSPEC.ZIP]
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]

IBM UltiMotion (henceforth ULTI) is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats.

== Decoding Algorithm ==

The ULTI algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels, each of the 16 pixels has a luminance (Y) sample and the entire block shares one blue
chrominance sample (Cb or U) and one red chrominance sample (Cr or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for chrominance) are transmitted in the final bitstream.

The ULTI algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 blocks. The 4 sub blocks, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be coded using the same chrominance samples, or each sub block can be coded with its own pair of chrominance samples. Each sub block has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of UltiMotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle mode flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous
frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 sub block in the block, arranged in the sub block pattern:

extract sub block coding mode from b0:
bits 7-6: sub block 0 coding mode
bits 5-4: sub block 1 coding mode
bits 3-2: sub block 2 coding mode
bits 1-0: sub block 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip sub block (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
6-bit sample coded in the stream

get next byte from stream (b1)
bits 7-6 of b1 indicate gradient fill pattern:
0 = gradient fill pattern 0
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern 4, swap Y0 with Y3 and Y1 with Y2
after unpacking Y samples
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0
if gradient fill pattern is pattern 0
Y2 = Y0 + 1 (saturated to an upper limit of 0x3F)
Y3 = Y2
else
Y2 = Y3 = Y0
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on
either 4 6-bit samples coded in the stream or 4 6-bit samples
retrieved from a 16,384-entry codebook using an index coded in
the stream
if mode is 0
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for UltiMotion luminance codebook)
if bit 3 of the gradient fill pattern is set, swap Y0 with Y3
and Y1 with Y2; clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)
else (mode is non-zero)
get the next 3 bytes from the stream as a big endian 24-bit
number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern 8 (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with 16
6-bit samples coded in the stream, or with a gradient fill
pattern and 4 6-bit luminance samples coded in the stream, or
with an arbitrary pattern using 2 luminance samples and a set of
flags coded in the stream
if mode is 0
get the next byte in the stream (b1)
if bit 7 of b1 is set
gradient fill pattern = bits 6-4 of b1
get the next byte in the stream (b1)
Y0 = ((b1 & 0x0F) << 2) | (b1 >> 6)
Y1 = bits 5-0 of b1
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else
flagsA = b1
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the sub block, else Y0
else (mode is non-zero)
get the next 16 6-bit numbers from the stream as the 16
luminance samples for the sub block, thus consuming 96 bits,
or 12 bytes from the stream

finally, output sub block:
bits 7-4 of the chrominance byte represent the red chrominance
value for the sub block while bits 3-0 represent the blue value
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A
if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 9 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 luminance samples.

* Gradient Pattern 0:
0 1 2 3
0 1 2 3
0 1 2 3
0 1 2 3

* Gradient Pattern 1:
1 2 3 3
0 1 2 3
0 1 2 3
0 0 1 2

* Gradient Pattern 2:
1 2 3 3
1 2 2 3
0 1 1 2
0 0 1 2

* Gradient Pattern 3:
2 3 3 3
1 2 2 3
0 1 1 2
0 0 0 1

* Gradient Pattern 4:
3 3 3 3
2 2 2 2
1 1 1 1
0 0 0 0

* Gradient Pattern 5:
3 3 3 2
3 2 2 1
2 1 1 0
1 0 0 0

* Gradient Pattern 6:
3 3 2 2
3 2 1 1
2 2 1 0
1 1 0 0

* Gradient Pattern 7:
3 3 2 1
3 2 1 0
3 2 1 0
2 1 0 0

* Gradient Pattern 8:
0 0 1 1
0 0 1 1
2 2 3 3
2 2 3 3

== Converting UltiMotion Scaled YUV To Correct YUV ==

To convert UltiMotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert UltiMotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg UltiMotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-11T17:40:15Z

Ultimotion: /* Decoding Algorithm */

''This page is based on the document 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov found at [http://multimedia.cx/ultimotion-format.txt http://multimedia.cx/ultimotion-format.txt].''

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP http://multimedia.cx/UMSPEC.ZIP]
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]

IBM UltiMotion (henceforth ULTI) is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats.

== Decoding Algorithm ==

The ULTI algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels, each of the 16 pixels has a luminance (Y) sample and the entire block shares one blue
chrominance sample (Cb or U) and one red chrominance sample (Cr or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for chrominance) are transmitted in the final bitstream.

The ULTI algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 blocks. The 4 sub blocks, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be coded using the same chrominance samples, or each sub block can be coded with its own pair of chrominance samples. Each sub block has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of UltiMotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle mode flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous
frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 sub block in the block, arranged in the sub block pattern:

extract sub block coding mode from b0:
bits 7-6: sub block 0 coding mode
bits 5-4: sub block 1 coding mode
bits 3-2: sub block 2 coding mode
bits 1-0: sub block 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip sub block (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
6-bit sample coded in the stream

get next byte from stream (b0)
bits 7-6 of b0 indicate gradient fill pattern:
0 = gradient fill pattern 0
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern 4, swap Y0 with Y3 and Y1 with Y2
after unpacking Y samples
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0
if gradient fill pattern is pattern 0
Y2 = Y0 + 1 (saturated to an upper limit of 0x3F)
Y3 = Y2
else
Y2 = Y3 = Y0
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on
either 4 6-bit samples coded in the stream or 4 6-bit samples
retrieved from a 16,384-entry codebook using an index coded in
the stream
if mode is non-zero
get the next 3 bytes from the stream as a big endian 24-bit
number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern 8 (see section Gradient Fill Patterns)

else (mode is 0)
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for UltiMotion luminance codebook)
if bit 3 of the gradient fill pattern is set, swap Y0 with Y3
and Y1 with Y2; clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with 16
6-bit samples coded in the stream, or with a gradient fill
pattern and 4 6-bit luminance samples coded in the stream, or
with an arbitrary pattern using 2 luminance samples and a set of
flags coded in the stream
if mode is non-zero
get the next 16 6-bit numbers from the stream as the 16
luminance samples for the sub block, thus consuming 96 bits,
or 12 bytes from the stream
if mode is 0
get the next byte in the stream (b0)
if bit 7 of b0 is set
gradient fill pattern = bits 6-4 of b0
get the next byte in the stream (b1)
Y0 = ((b0 & 0x0F) << 2) | (b1 >> 6)
Y1 = bits 5-0 of b1
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else
flagsA = b0
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the sub block, else Y0

finally, output sub block:
bits 7-4 of the chrominance byte represent the red chrominance
value for the sub block while bits 3-0 represent the blue value
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A
if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 9 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 luminance samples.

* Gradient Pattern 0:
0 1 2 3
0 1 2 3
0 1 2 3
0 1 2 3

* Gradient Pattern 1:
1 2 3 3
0 1 2 3
0 1 2 3
0 0 1 2

* Gradient Pattern 2:
1 2 3 3
1 2 2 3
0 1 1 2
0 0 1 2

* Gradient Pattern 3:
2 3 3 3
1 2 2 3
0 1 1 2
0 0 0 1

* Gradient Pattern 4:
3 3 3 3
2 2 2 2
1 1 1 1
0 0 0 0

* Gradient Pattern 5:
3 3 3 2
3 2 2 1
2 1 1 0
1 0 0 0

* Gradient Pattern 6:
3 3 2 2
3 2 1 1
2 2 1 0
1 1 0 0

* Gradient Pattern 7:
3 3 2 1
3 2 1 0
3 2 1 0
2 1 0 0

* Gradient Pattern 8:
0 0 1 1
0 0 1 1
2 2 3 3
2 2 3 3

== Converting UltiMotion Scaled YUV To Correct YUV ==

To convert UltiMotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert UltiMotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg UltiMotion Luminance Codebook]

[[Category:Video Codecs]]

IBM UltiMotion

2006-10-11T16:57:45Z

Ultimotion:

''This page is based on the document 'Description of the IBM UltiMotion (ULTI) Video Codec' by Mike Melanson and Konstantin Shishkov found at [http://multimedia.cx/ultimotion-format.txt http://multimedia.cx/ultimotion-format.txt].''

* FourCC: ULTI
* Company: [[IBM]]
* Official Description: [http://multimedia.cx/UMSPEC.ZIP http://multimedia.cx/UMSPEC.ZIP]
* Samples: [http://samples.mplayerhq.hu/V-codecs/ULTI/ http://samples.mplayerhq.hu/V-codecs/ULTI/]

IBM UltiMotion (henceforth ULTI) is a video codec typically seen in [[AVI]] files, though there is no reason it could not be used in other container formats.

== Decoding Algorithm ==

The ULTI algorithm operates natively on a scaled-down [[Raw YUV|YUV]] 4:1:0 planar colorspace. This means that for each 4x4 block of pixels, each of the 16 pixels has a luminance (Y) sample and the entire block shares one blue
chrominance sample (Cb or U) and one red chrominance sample (Cr or V). The colorspace is actually non-linear quantized to fixed values from 2 tables. Indices into these tables (64 possible values for luminance and 16 for chrominance) are transmitted in the final bitstream.

The ULTI algorithm codes a frame by dividing it into a series of 8x8 blocks. Each 8x8 block is subdivided and coded as 4 4x4 blocks. The 4 sub blocks, 0-3, are coded in the following arrangement:

0 3
1 2

Each block can be coded using the same chrominance samples, or each sub block can be coded with its own pair of chrominance samples. Each sub block has 16 luminance samples that can be coded using a variety of methods.

To decode a frame of UltiMotion data, follow this process:

initialize uniq and mode flags to 0

for each 8x8 block in the frame, iterating from left -> right, top -> bottom:

get the next byte in the stream (b0)
if (b0 & 0xF8) == 0x70, handle escape code:
if b0 is 0x70
mode = next byte in stream
note: only mode values of 0 or 1 are valid
if b0 is 0x71
uniq flag = -1
if b0 is 0x72
toggle mode flag (0/1)
if b0 is 0x73
end of frame, stop decoding
if b0 is 0x74
get the next byte in stream (b1)
skip next (b1) blocks in the output frame (unchanged from previous
frame)

else
if b0 is non-zero and uniq flag is 0
chrominance byte = next byte from stream

for each 4x4 sub block in the block, arranged in the sub block pattern:

extract sub block coding mode from b0:
bits 7-6: sub block 0 coding mode
bits 5-4: sub block 1 coding mode
bits 3-2: sub block 2 coding mode
bits 1-0: sub block 3 coding mode

if coding mode is non-zero and uniq flag is non-zero
chrominance byte = next byte from stream

coding mode 0:
skip sub block (unchanged from the previous frame)

coding mode 1:
paint the luminance samples using a gradient pattern based on one
6-bit sample coded in the stream

get next byte from stream (b0)
bits 7-6 of b0 indicate gradient fill pattern:
0 = gradient fill pattern 0
1 = gradient fill pattern 2
2 = gradient fill pattern 6
3 = gradient fill pattern 4, swap Y0 with Y3 and Y1 with Y2
after unpacking Y samples
bits 5-0 of b1 indicate luminance sample Y0
Y1 = Y0
if gradient fill pattern is pattern 0
Y2 = Y0 + 1 (saturated to an upper limit of 0x3F)
Y3 = Y2
else
Y2 = Y3 = Y0
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 2:
paint the luminance samples using a gradient pattern based on
either 4 6-bit samples coded in the stream or 4 6-bit samples
retrieved from a 16,384-entry codebook using an index coded in
the stream
if mode is non-zero
get the next 3 bytes from the stream as a big endian 24-bit
number:
Y0 = bits 23-18
Y1 = bits 17-12
Y2 = bits 11-6
Y3 = bits 5-0
fill luminance samples according to Y0..Y3 and gradient fill
pattern 8 (see section Gradient Fill Patterns)

else (mode is 0)
get the next 2 bytes from the stream as a big endian 16-bit
number:
gradient fill pattern = bits 15-12
luminance codebook index = bits 11-0
Y0..Y3 are set according to the codebook entry (see References
for UltiMotion luminance codebook)
if bit 3 of the gradient fill pattern is set, swap Y0 with Y3
and Y1 with Y2; clear bit 3 of the gradient fill pattern
fill luminance samples according to Y0..Y3 and the gradient fill
pattern (see section Gradient Fill Patterns)

coding mode 3:
flexible coding mode that can paint the luminance samples with 16
6-bit samples coded in the stream, or with a gradient fill
pattern and 4 6-bit luminance samples coded in the stream, or
with an arbitrary pattern using 2 luminance samples and a set of
flags coded in the stream
if mode is non-zero
get the next 16 6-bit numbers from the stream as the 16
luminance samples for the sub block, thus consuming 96 bits,
or 12 bytes from the stream
if mode is 0
get the next byte in the stream (b0)
if bit 7 of b0 is set
gradient fill pattern = bits 6-4 of b0
get the next byte in the stream (b1)
Y0 = ((b0 & 0x0F) << 2) | (b1 >> 6)
Y1 = bits 5-0 of b1
Y2 = next byte in stream & 0x3F
Y3 = next byte in stream & 0x3F
fill luminance samples according to Y0..Y3 and the gradient
fill pattern (see section Gradient Fill Patterns)
else
flagsA = b0
flagsB = next byte in the stream
Y0 = next byte in stream & 0x3F
Y1 = next byte in stream & 0x3F
the 16 bits between flagsA and flagsB represent the pattern
used to place either Y0 or Y1 into the luminance grid

A7 A6 A5 A4
A3 A2 A1 A0
B7 B6 B5 B4
B3 B2 B1 B0

for example, if bit 3 of flagsB is 1, Y1 would be used in
the lower left corner of the sub block, else Y0

finally, output sub block:
bits 7-4 of the chrominance byte represent the red chrominance
value for the sub block while bits 3-0 represent the blue value
convert the 16 luminance values and the 2 chrominance values to a
proper YUV colorspace using the conversion tables in Appendix A
if uniq flag is -1
uniq flag = 0

== Gradient Fill Patterns ==

The ULTI codec has 9 gradient fill patterns for painting 4x4 sub blocks of luminance data using 4 luminance samples.

* Gradient Pattern 0:
0 1 2 3
0 1 2 3
0 1 2 3
0 1 2 3

* Gradient Pattern 1:
1 2 3 3
0 1 2 3
0 1 2 3
0 0 1 2

* Gradient Pattern 2:
1 2 3 3
1 2 2 3
0 1 1 2
0 0 1 2

* Gradient Pattern 3:
2 3 3 3
1 2 2 3
0 1 1 2
0 0 0 1

* Gradient Pattern 4:
3 3 3 3
2 2 2 2
1 1 1 1
0 0 0 0

* Gradient Pattern 5:
3 3 3 2
3 2 2 1
2 1 1 0
1 0 0 0

* Gradient Pattern 6:
3 3 2 2
3 2 1 1
2 2 1 0
1 1 0 0

* Gradient Pattern 7:
3 3 2 1
3 2 1 0
3 2 1 0
2 1 0 0

* Gradient Pattern 8:
0 0 1 1
0 0 1 1
2 2 3 3
2 2 3 3

== Converting UltiMotion Scaled YUV To Correct YUV ==

To convert UltiMotion 6-bit luminance values to proper luminance samples, use the following conversion table:

unsigned char ulti_lumas[64] =
{ 0x10, 0x13, 0x17, 0x1A, 0x1E, 0x21, 0x25, 0x28,
0x2C, 0x2F, 0x33, 0x36, 0x3A, 0x3D, 0x41, 0x44,
0x48, 0x4B, 0x4F, 0x52, 0x56, 0x59, 0x5C, 0x60,
0x63, 0x67, 0x6A, 0x6E, 0x71, 0x75, 0x78, 0x7C,
0x7F, 0x83, 0x86, 0x8A, 0x8D, 0x91, 0x94, 0x98,
0x9B, 0x9F, 0xA2, 0xA5, 0xA9, 0xAC, 0xB0, 0xB3,
0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, 0xCC, 0xCF,
0xD3, 0xD6, 0xDA, 0xDD, 0xE1, 0xE4, 0xE8, 0xEB};

To convert UltiMotion 4-bit chrominance values to proper chrominance samples, use the following conversion table:

unsigned char ulti_chromas[16] =
{ 0x60, 0x67, 0x6D, 0x73, 0x7A, 0x80, 0x86, 0x8D,
0x93, 0x99, 0xA0, 0xA6, 0xAC, 0xB3, 0xB9, 0xC0};

== References ==

* [http://xanim.polter.net/ XAnim]

* [http://mplayerhq.hu/cgi-bin/cvsweb.cgi/~checkout~/ffmpeg/libavcodec/ulti_cb.h?content-type=text/x-cvsweb-markup&cvsroot=FFMpeg UltiMotion Luminance Codebook]

[[Category:Video Codecs]]