Vivo H.263: Difference between revisions
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* Samples: http://samples.mplayerhq.hu/vivo/ | * Samples: http://samples.mplayerhq.hu/vivo/ | ||
This is a variant of [[H.263]] with such features as AIC and PB-frames but with quantisation approach closer to [[MPEG-4|MPEG-4 ASP]]. | |||
== Picture header == | |||
Vivo 1/2 picture header is almost the same as H.263 but with some subtle changes. | |||
22 bits - syncword (0x000020) | |||
8 bits - TR | |||
1 bit - marker | |||
1 bit - should be zero | |||
1 bit - split screen indicator? | |||
1 bit - document camera indicator? | |||
1 bit - freeze picture release? | |||
3 bits - source format (0 - illegal, 6 - extended) | |||
1 bit - inter frame | |||
1 bit - UMV | |||
1 bit - SAC? | |||
1 bit - APM | |||
1 bit - is PB-frame | |||
if source format == 6 { | |||
3 bits - actual source format (0 and 6 are illegal ones) | |||
1 bit - AIC | |||
1 bit - deblocking | |||
1 bit - unknown | |||
1 bit - unknown | |||
1 bit - unknown | |||
1 bit - unknown | |||
1 bit - PB plus mode | |||
1 bit - unknown | |||
1 bit - interlaced mode | |||
1 bit - unknown | |||
1 bit - unknown | |||
} | |||
5 bits - quantiser | |||
1 bit - should be zero | |||
if PB-frame { | |||
3 bits - TRB | |||
2 bits - DBQUANT | |||
} | |||
1-n bits - PEI | |||
Notable differences: | |||
* in AIC mode coefficient prediction is done before quantisation | |||
* deblocking is performed on all edges using <code>(3 * (p1 - q1) + 8 * (q0 - p0)) >> 4</code> as delta. | |||
Interlacing does not affect bitstream decoding, just reconstruction of the image. | |||
[[Category:Video Codecs]] | [[Category:Video Codecs]] |
Latest revision as of 03:53, 1 January 2021
- FOURCCs: viv2
- Company: Vivo Software
- Samples: http://samples.mplayerhq.hu/vivo/
This is a variant of H.263 with such features as AIC and PB-frames but with quantisation approach closer to MPEG-4 ASP.
Picture header
Vivo 1/2 picture header is almost the same as H.263 but with some subtle changes.
22 bits - syncword (0x000020) 8 bits - TR 1 bit - marker 1 bit - should be zero 1 bit - split screen indicator? 1 bit - document camera indicator? 1 bit - freeze picture release? 3 bits - source format (0 - illegal, 6 - extended) 1 bit - inter frame 1 bit - UMV 1 bit - SAC? 1 bit - APM 1 bit - is PB-frame if source format == 6 { 3 bits - actual source format (0 and 6 are illegal ones) 1 bit - AIC 1 bit - deblocking 1 bit - unknown 1 bit - unknown 1 bit - unknown 1 bit - unknown 1 bit - PB plus mode 1 bit - unknown 1 bit - interlaced mode 1 bit - unknown 1 bit - unknown } 5 bits - quantiser 1 bit - should be zero if PB-frame { 3 bits - TRB 2 bits - DBQUANT } 1-n bits - PEI
Notable differences:
- in AIC mode coefficient prediction is done before quantisation
- deblocking is performed on all edges using
(3 * (p1 - q1) + 8 * (q0 - p0)) >> 4
as delta.
Interlacing does not affect bitstream decoding, just reconstruction of the image.