XINTRA8
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An XIntra8 frame (also known as a J-type frame or J-frame) is a type of frame similar to an I-frame. They are used in Microsoft's MPEG-4 variation codec WMV2/WMV8 and the same coding method (with a different header) is used in WMV3 Complex Profile under the name "X8". XIntra8 frames are a type of intra frame (spatial prediction). This is why they are said to be similar to I-frames, because both B-frames and P-frames use inter-frame prediction (temporal prediction). XIntra8 frames operate on 8x8 pixel blocks. XIntra8 frame types are missing in WMV9. XIntra8 frames reportedly operate in 10 different modes (need more info on this).
MPlayer on x86 can play files containing these frames using a binary codec. ffmpeg can also play files containing Xintra8 frames, but, those frames will be skipped. Xintra8 have not been reverse engineered, so there is no documentation available. If a stream contains Xintra8 frames the Xintra8 bit will be set in the stream's extradata.
Note: J-frame is the notation used by FFmpeg developers. XMV SDK calls it XIntra8 frame and in WMV3 it's called Intra_X8.
The main differences between XIntra8-frames and I-frames:
- They are not derived from MPEG-4 standard.
- Picture is coded as blocks, not as macroblocks.
- Each frame may use its own Huffman codes.
Reference [1] (in german).
Decoding
Overall decoding process:
for(y = 0; y < blocks_height; y++){
for(x = 0; x < blocks_width; x++){
decode_block(luma, x, y);
if ((x & 1) && (y & 1)){
decode_block(chroma_u, x/2, y/2);
decode_block(chroma_v, x/2, y/2);
}
}
}
Huffman Decoding
When each type code is read first time, reader checks if VLC table is set. If not then it reads codes lengths as nibbles and constructs balanced tree from them.
Block Decoding
- Read "joint" code
- Divide this code into two parts - DC value and block_coded bit
- If block is coded then decode coefficients
- Read code
- Split read code into vector (value, skip, last)
- Skip skip coefficients and set coefficient value to value
- If last is true then end decoding
Decoding AC coefficient:
vlc = read_vlc();
base = some_table[vlc];
if(!base) base = read_vlc();
vlc = 0..15: skip = 0; value = vlc; last = 0;
vlc = 16..19: skip = 1; value = vlc-16; last = 0;
vlc = 20..21: skip = 2; value = vlc-20; last = 0;
vlc = 22: skip = 3; value = 0; last = 0;
vlc = 23..38: skip = 0; value = vlc-23; last = 1;
vlc = 39..42: skip = 1; value = vlc-39; last = 1;
vlc = 43..44: skip = 2; value = vlc-43; last = 1;
vlc = 45: skip = 3; value = 0; last = 1;
vlc = 46..47: skip = 0; value = Off0[vlc-46]+base; last = 0;
vlc = 48..49: skip = 1; value = Off0[vlc-46]+base; last = 0;
vlc = 50: skip = 0; value = Off0[vlc-46]+base; last = 0;
vlc = 51: skip = 1; value = Off0[vlc-46]+base; last = 0;
vlc = 52..56: skip = 0; value = Off0[vlc-46]+base; last = 0;
vlc = 57..58: skip = 0; value = Off0[vlc-46]+base; last = 0;
vlc = 59..64: skip = 0; value = Off1[vlc-59]+base; last = 1;
vlc = 65..67: skip = 1; value = Off1[vlc-59]+base; last = 1;
vlc = 68..70: skip = 0; value = Off1[vlc-59]+base; last = 1;
vlc = 71..72: skip = 1; value = Off1[vlc-59]+base; last = 1;
vlc = 73..74:
code = base & 3;
base >>= 2;
switch(code){
case 0: skip = 2; value = base + 2;
case 1: skip = 2; value = base + 3;
case 2: skip = (base & 1)+3; value = (base>>1) + 3;
case 3: skip = (base & 3)+5; value = (base>>2) + 3;
}
last = vlc - 73;
else: skip = base>>7; value = (base>>1) & 0x3F; last = base & 1;
Tables
Arrays with the huffman code lengths that wmv2 J-Frames use (not sure all are really used) in a sanitized form (decoder stores 2 per byte and with -1 offset). There are codes for values 0..11, 0..76 (these one are used for AC decoding) and 0..33.
huffman header:
index for code table: depends on number of code tables for mode (1, 2 or 3 bits)
gacCodeLengthsOrientLowRate[][] = {
{2, 2, 3, 3, 3, 6, 5, 6, 6, 6, 6, 6},
{1, 2, 3, 5, 5, 7, 6, 7, 7, 7, 7, 7}
};
gacCodeLengthsOrientHighRate[][] = {
{1, 3, 3, 4, 4, 6, 5, 6, 6, 6, 6, 6},
{5, 5, 5, 2, 2, 4, 5, 3, 4, 4, 5, 5},
{2, 2, 3, 3, 3, 6, 6, 5, 6, 6, 6, 6},
{3, 4, 4, 2, 2, 5, 5, 4, 5, 5, 5, 5}
};
gacCodeLengthsInterLowRate[][] = {
{
3, 4, 6, 6, 7, 6, 15, 8, 15, 9, 15, 9, 15, 15, 15, 14,
5, 6, 9, 9, 7, 7, 9, 2, 3, 4, 4, 5, 6, 8, 7, 6,
7, 8, 14, 7, 7, 7, 9, 5, 6, 9, 8, 9, 9, 14, 14, 14,
8, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 9, 14, 14, 14, 14,
14, 14, 9, 14, 9, 14, 14, 14, 14, 9, 14, 14, 14
},{
3, 4, 4, 5, 6, 6, 6, 6, 7, 8, 8, 8, 8, 14, 10, 10,
4, 5, 6, 7, 5, 6, 5, 4, 5, 5, 6, 6, 6, 6, 6, 7,
8, 8, 7, 7, 7, 7, 8, 7, 7, 8, 8, 8, 14, 10, 9, 14,
5, 9, 14, 14, 5, 8, 14, 14, 14, 6, 8, 7, 8, 9, 8, 14,
14, 8, 9, 14, 14, 14, 14, 9, 14, 5, 8, 9, 14
},{
4, 5, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 11, 11, 11, 11,
11, 11, 11, 11, 11, 11, 11, 1, 2, 5, 5, 5, 11, 11, 11, 11,
11, 11, 11, 11, 11, 11, 11, 5, 11, 11, 11, 11, 11, 11, 11, 11,
11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11
},{
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 1, 8, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
},{
9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
9, 9, 9, 9, 9, 9, 8, 2, 1, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8
},{
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
10, 10, 10, 10, 9, 9, 9, 1, 3, 9, 9, 2, 9, 9, 9, 9,
9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9
},{
2, 4, 5, 5, 6, 6, 7, 8, 8, 8, 9, 9, 10, 9, 10, 15,
3, 5, 6, 6, 4, 7, 5, 5, 7, 7, 7, 8, 7, 7, 8, 8,
8, 8, 8, 8, 8, 9, 8, 8, 8, 9, 15, 10, 10, 10, 15, 10,
6, 9, 15, 15, 4, 6, 10, 15, 14, 6, 8, 14, 10, 14, 14, 14,
14, 8, 10, 10, 14, 14, 14, 14, 14, 5, 10, 14, 14
},{
3, 4, 5, 5, 6, 8, 7, 6, 7, 13, 8, 8, 13, 13, 13, 8,
4, 5, 7, 6, 6, 7, 6, 3, 5, 5, 4, 6, 6, 6, 5, 8,
6, 6, 6, 6, 8, 8, 7, 5, 7, 7, 13, 7, 8, 13, 13, 13,
7, 7, 13, 13, 8, 13, 13, 13, 13, 8, 13, 7, 8, 13, 13, 13,
13, 8, 13, 13, 13, 13, 13, 8, 12, 6, 12, 12, 12
}
};
gacCodeLengthsInterHighRate[][] = {
{
2, 3, 4, 5, 6, 7, 7, 7, 9, 8, 8, 8, 10, 10, 10, 10,
4, 7, 9, 10, 6, 7, 7, 4, 4, 5, 5, 5, 6, 6, 6, 6,
7, 7, 7, 7, 7, 7, 7, 8, 9, 10, 14, 14, 14, 14, 10, 14,
9, 14, 14, 14, 8, 14, 14, 14, 14, 10, 14, 7, 8, 8, 9, 14,
14, 14, 14, 14, 14, 14, 14, 14, 13, 13, 13, 13, 13
},{
3, 5, 7, 6, 6, 8, 8, 8, 14, 14, 7, 14, 14, 14, 14, 14,
6, 8, 14, 8, 14, 14, 14, 2, 3, 5, 4, 4, 4, 6, 7, 7,
7, 7, 8, 7, 6, 6, 6, 6, 8, 14, 8, 8, 8, 14, 14, 14,
8, 14, 14, 14, 13, 13, 13, 13, 13, 13, 13, 6, 13, 13, 13, 13,
13, 7, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13
},{
2, 3, 3, 4, 5, 5, 6, 6, 7, 7, 7, 8, 8, 8, 9, 10,
4, 6, 8, 9, 6, 9, 8, 5, 6, 6, 6, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 8, 16, 16, 15, 12, 15, 15, 15, 8, 10,
9, 12, 15, 15, 8, 15, 15, 15, 15, 9, 15, 7, 8, 8, 11, 12,
15, 15, 15, 15, 15, 15, 15, 15, 15, 9, 15, 15, 15
},{
2, 3, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 9, 10, 10,
3, 5, 7, 7, 4, 7, 5, 6, 7, 7, 7, 8, 8, 8, 8, 8,
8, 9, 8, 8, 8, 9, 11, 10, 11, 15, 10, 15, 15, 15, 9, 11,
7, 12, 15, 15, 5, 7, 8, 10, 11, 7, 10, 8, 8, 10, 10, 12,
15, 11, 15, 15, 15, 15, 15, 15, 15, 7, 14, 12, 12
},{
3, 4, 4, 5, 6, 6, 6, 7, 6, 7, 8, 8, 8, 9, 9, 8,
4, 5, 6, 6, 4, 6, 5, 5, 6, 6, 6, 6, 6, 6, 6, 7,
7, 7, 7, 7, 7, 8, 11, 7, 7, 8, 9, 9, 9, 10, 9, 10,
6, 8, 15, 15, 4, 7, 9, 15, 15, 6, 10, 7, 8, 8, 10, 9,
15, 9, 10, 10, 10, 15, 14, 14, 14, 5, 9, 14, 14
},{
2, 4, 5, 5, 6, 6, 7, 8, 8, 8, 9, 11, 8, 10, 11, 15,
3, 5, 6, 7, 4, 6, 5, 6, 7, 8, 7, 8, 7, 8, 7, 8,
8, 9, 9, 9, 9, 9, 11, 9, 10, 11, 15, 10, 11, 11, 10, 11,
6, 8, 15, 15, 4, 5, 7, 7, 9, 6, 8, 8, 10, 11, 15, 10,
15, 10, 10, 15, 15, 14, 14, 14, 14, 5, 10, 11, 9
},{
2, 4, 5, 6, 6, 8, 9, 10, 10, 9, 15, 15, 10, 15, 10, 15,
4, 5, 8, 8, 5, 9, 8, 3, 3, 4, 5, 6, 6, 7, 7, 7,
8, 8, 9, 8, 10, 15, 9, 6, 6, 9, 10, 8, 8, 10, 15, 15,
9, 15, 15, 15, 8, 15, 15, 15, 15, 9, 15, 9, 15, 15, 15, 15,
15, 10, 10, 15, 15, 15, 15, 15, 15, 8, 14, 14, 14
},{
4, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
11, 10, 10, 10, 10, 10, 10, 1, 2, 10, 4, 4, 10, 10, 10, 10,
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10
}
};
gacCodeLengthsIntraLowRate[][] = {
3, 4, 5, 5, 5, 5, 6, 7, 6, 7, 8, 7, 7, 8, 8, 9,
4, 6, 6, 7, 5, 8, 6, 4, 4, 5, 6, 6, 6, 6, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 9, 9, 9, 11, 9, 6, 8,
5, 7, 9, 9, 7, 10, 14, 14, 14, 7, 10, 7, 8, 9, 8, 7,
14, 7, 7, 10, 10, 14, 14, 10, 14, 6, 9, 8, 14
},{
2, 4, 5, 5, 6, 7, 7, 7, 8, 9, 9, 9, 9, 15, 10, 11,
3, 5, 6, 7, 4, 5, 4, 6, 7, 7, 8, 8, 7, 8, 9, 8,
9, 9, 9, 9, 10, 11, 11, 9, 9, 11, 15, 10, 15, 15, 15, 15,
6, 8, 15, 15, 4, 7, 8, 11, 15, 5, 8, 11, 10, 15, 15, 15,
15, 9, 15, 14, 14, 14, 14, 14, 14, 5, 14, 14, 14
},{
3, 4, 4, 5, 6, 7, 6, 7, 9, 9, 8, 15, 9, 15, 15, 15,
3, 5, 7, 7, 4, 6, 5, 4, 4, 5, 6, 6, 6, 6, 7, 8,
7, 8, 10, 8, 9, 10, 10, 6, 7, 9, 9, 8, 10, 9, 15, 15,
7, 9, 15, 15, 5, 8, 14, 14, 14, 6, 9, 9, 10, 10, 14, 14,
14, 8, 14, 14, 10, 14, 14, 9, 14, 6, 8, 9, 14
},{
3, 4, 5, 5, 6, 6, 7, 7, 6, 6, 7, 7, 9, 9, 7, 8,
5, 6, 9, 7, 6, 7, 7, 3, 3, 5, 5, 6, 6, 6, 7, 7,
8, 8, 8, 8, 7, 6, 7, 7, 6, 8, 9, 14, 14, 14, 7, 9,
7, 8, 14, 14, 8, 14, 13, 13, 13, 8, 13, 6, 7, 9, 6, 7,
13, 7, 7, 13, 13, 13, 13, 13, 13, 8, 13, 9, 13
},{
2, 4, 5, 5, 6, 6, 7, 7, 7, 8, 9, 9, 10, 10, 10, 15,
3, 5, 6, 7, 4, 6, 6, 4, 5, 6, 6, 6, 7, 7, 7, 7,
8, 8, 8, 8, 8, 8, 10, 7, 8, 9, 9, 10, 10, 12, 10, 12,
6, 8, 15, 15, 6, 9, 15, 15, 15, 7, 12, 10, 10, 15, 12, 11,
15, 8, 9, 15, 12, 15, 15, 15, 14, 6, 12, 11, 14
},{
3, 4, 4, 5, 5, 6, 7, 8, 11, 9, 11, 10, 11, 15, 15, 15,
4, 5, 6, 7, 5, 7, 6, 3, 4, 5, 5, 5, 5, 6, 6, 7,
8, 8, 8, 7, 8, 9, 11, 5, 7, 8, 8, 7, 10, 9, 9, 15,
7, 15, 15, 15, 7, 11, 15, 14, 14, 7, 14, 9, 10, 10, 9, 14,
14, 8, 11, 14, 14, 14, 14, 9, 14, 7, 9, 14, 14
},{
3, 4, 4, 5, 5, 5, 5, 6, 7, 5, 7, 13, 7, 13, 7, 13,
4, 6, 7, 7, 5, 7, 5, 6, 6, 7, 6, 7, 7, 13, 7, 7,
13, 13, 12, 7, 7, 12, 12, 7, 12, 12, 12, 12, 12, 12, 5, 6,
4, 5, 12, 7, 5, 12, 12, 12, 12, 6, 12, 6, 12, 12, 12, 12,
12, 6, 12, 12, 12, 12, 12, 12, 12, 5, 12, 7, 12
},{
3, 4, 5, 6, 6, 8, 8, 8, 11, 15, 15, 15, 15, 15, 15, 15,
4, 6, 7, 9, 5, 8, 8, 2, 3, 5, 5, 5, 6, 6, 8, 8,
9, 8, 7, 8, 9, 11, 15, 5, 7, 8, 9, 8, 9, 9, 15, 15,
8, 10, 15, 15, 8, 15, 15, 15, 15, 9, 15, 8, 9, 15, 15, 15,
15, 9, 15, 15, 15, 15, 15, 10, 14, 7, 9, 14, 14
}
};
gacCodeLengthsIntraHighRate[][] = {
{
3, 4, 4, 5, 6, 7, 6, 8, 8, 9, 10, 9, 9, 9, 15, 11,
4, 5, 6, 7, 5, 7, 5, 3, 4, 5, 5, 5, 5, 6, 6, 7,
8, 8, 8, 8, 8, 9, 10, 6, 7, 8, 8, 8, 11, 10, 11, 15,
7, 14, 14, 14, 6, 10, 14, 14, 14, 7, 14, 8, 9, 11, 10, 11,
14, 8, 10, 14, 14, 14, 14, 14, 14, 6, 9, 11, 14
},{
2, 3, 4, 5, 6, 6, 7, 8, 8, 8, 9, 9, 11, 11, 11, 11,
3, 5, 6, 7, 4, 6, 4, 8, 9, 10, 9, 10, 10, 12, 10, 10,
10, 10, 11, 12, 10, 12, 12, 15, 15, 15, 15, 14, 14, 14, 11, 11,
8, 10, 12, 14, 4, 6, 7, 8, 10, 6, 8, 11, 10, 14, 11, 12,
14, 14, 14, 14, 14, 14, 14, 14, 14, 6, 11, 11, 10
},{
3, 4, 5, 6, 7, 8, 8, 8, 10, 9, 10, 10, 16, 10, 10, 16,
3, 5, 6, 8, 3, 5, 4, 7, 9, 9, 9, 9, 9, 10, 10, 10,
10, 10, 10, 9, 10, 11, 16, 10, 11, 10, 11, 10, 16, 11, 15, 15,
7, 9, 15, 15, 3, 4, 6, 6, 8, 5, 7, 15, 15, 15, 15, 11,
15, 11, 11, 11, 15, 15, 15, 15, 15, 5, 11, 8, 8
},{
2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 8, 8, 8, 9,
4, 6, 7, 9, 6, 8, 7, 6, 6, 6, 6, 6, 7, 7, 7, 7,
7, 7, 7, 7, 8, 8, 9, 11, 10, 15, 15, 15, 15, 15, 7, 8,
8, 12, 9, 15, 7, 9, 15, 15, 15, 8, 11, 6, 7, 8, 8, 7,
9, 11, 11, 15, 15, 15, 14, 14, 14, 8, 14, 14, 14
},{
2, 4, 5, 6, 6, 7, 7, 8, 8, 8, 9, 9, 10, 10, 14, 12,
3, 5, 6, 7, 4, 6, 5, 5, 6, 6, 6, 7, 7, 8, 7, 8,
8, 8, 8, 8, 9, 10, 10, 7, 8, 9, 9, 10, 11, 9, 9, 10,
7, 8, 12, 12, 4, 6, 8, 8, 9, 6, 8, 9, 10, 10, 11, 10,
11, 9, 9, 11, 11, 14, 14, 11, 14, 6, 9, 9, 10
},{
2, 3, 4, 5, 5, 6, 6, 7, 7, 7, 8, 8, 8, 9, 10, 9,
3, 5, 7, 8, 5, 7, 6, 5, 6, 7, 7, 7, 8, 8, 7, 8,
8, 8, 8, 8, 8, 9, 9, 11, 12, 12, 15, 13, 15, 15, 8, 9,
8, 10, 9, 13, 5, 7, 9, 9, 15, 7, 11, 8, 8, 8, 9, 8,
11, 12, 13, 15, 15, 15, 15, 15, 15, 7, 14, 11, 11
},{
3, 4, 4, 5, 5, 6, 6, 7, 8, 8, 8, 9, 9, 9, 11, 12,
3, 5, 6, 7, 4, 6, 5, 4, 5, 6, 6, 7, 7, 7, 7, 7,
7, 8, 8, 8, 9, 8, 10, 7, 8, 9, 11, 9, 10, 12, 9, 15,
6, 7, 15, 15, 5, 7, 9, 11, 15, 6, 9, 8, 9, 10, 10, 11,
15, 8, 9, 15, 15, 15, 14, 14, 14, 5, 10, 9, 14
},{
2, 4, 5, 6, 7, 7, 8, 8, 9, 9, 9, 10, 15, 15, 15, 15,
3, 5, 6, 7, 4, 6, 4, 8, 8, 9, 10, 9, 10, 9, 10, 10,
15, 10, 11, 11, 15, 10, 15, 9, 11, 15, 15, 11, 11, 15, 11, 15,
7, 10, 15, 15, 3, 5, 7, 7, 9, 5, 7, 9, 11, 15, 14, 14,
14, 9, 9, 14, 14, 14, 14, 14, 14, 5, 11, 8, 10
}
};
gacCodeLengthsDCLowRate[][] = {
{ 5, 4, 4, 5, 5, 4, 5, 5, 7, 7, 12, 12, 12, 12, 12, 12, 12,
3, 2, 3, 4, 5, 5, 7, 8, 12, 12, 12, 12, 12, 12, 12, 12, 12 },
{ 3, 3, 3, 4, 4, 3, 4, 4, 6, 7, 7, 11, 11, 11, 11, 11, 11,
6, 4, 5, 5, 6, 5, 7, 7, 11, 7, 11, 11, 11, 11, 11, 10, 10 },
{ 7, 7, 6, 7, 6, 7, 8, 8, 13, 13, 13, 13, 13, 13, 13, 13, 12,
1, 2, 3, 5, 6, 8, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12 },
{ 4, 3, 3, 4, 4, 3, 3, 3, 5, 5, 7, 11, 11, 11, 11, 11, 11,
5, 7, 6, 6, 7, 7, 7, 7, 11, 11, 11, 7, 11, 11, 11, 10, 10 },
{ 8, 7, 7, 7, 9, 8, 9, 14, 14, 14, 14, 14, 14, 14, 14, 13, 13,
2, 1, 3, 4, 6, 7, 9, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13 },
{ 7, 7, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 1, 6, 6, 6, 6, 6, 6 },
{ 5, 4, 5, 5, 6, 5, 6, 6, 8, 8, 13, 13, 13, 13, 13, 13, 13,
2, 2, 3, 4, 5, 5, 8, 9, 13, 13, 13, 13, 13, 13, 13, 13, 13 },
{ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
1, 2, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7 }
};
gacCodeLengthsDCHighRate[][] = {
{ 5, 4, 5, 5, 5, 5, 6, 6, 8, 8, 13, 13, 13, 13, 13, 13, 13,
2, 2, 3, 4, 5, 6, 8, 9, 13, 13, 13, 13, 13, 13, 13, 13, 13 },
{ 4, 3, 3, 4, 4, 3, 4, 3, 4, 4, 5, 6, 9, 9, 13, 13, 13,
6, 6, 6, 7, 9, 7, 8, 9, 13, 13, 13, 12, 12, 9, 12, 12, 12 },
{ 4, 3, 3, 4, 4, 4, 4, 4, 6, 6, 7, 7, 12, 12, 12, 12, 12,
4, 3, 4, 5, 6, 6, 7, 8, 12, 12, 12, 12, 12, 12, 12, 11, 11 },
{ 4, 2, 3, 3, 3, 3, 4, 4, 6, 6, 7, 8, 14, 14, 14, 14, 13,
9, 7, 8, 8, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13 },
{ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
1, 2, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7 },
{ 5, 4, 5, 6, 6, 6, 7, 6, 7, 6, 8, 7, 8, 13, 13, 13, 13,
3, 1, 3, 7, 8, 9, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 12 },
{ 4, 2, 3, 3, 4, 4, 5, 6, 7, 7, 8, 14, 14, 10, 9, 14, 14,
4, 3, 5, 6, 8, 8, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 13 },
{ 6, 6, 6, 7, 7, 6, 6, 6, 7, 8, 8, 9, 10, 14, 14, 14, 14,
1, 2, 4, 5, 6, 7, 8, 14, 14, 14, 14, 14, 14, 14, 14, 13, 13 }
};