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avcodec/mpegvideo_dec: Document which codecs take which codepath

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Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This commit is contained in:
Andreas Rheinhardt
2025-05-20 23:40:48 +02:00
parent 2e8a3e6645
commit f2c04fd587
1 changed files with 6 additions and 0 deletions
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6
libavcodec/mpegvideo_dec.c
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@ -962,6 +962,9 @@ void mpv_reconstruct_mb_internal(MpegEncContext *s, int16_t block[12][64],
/* add dct residue */
if (!(IS_MPEG12_H261(s) || s->msmpeg4_version != MSMP4_UNUSED ||
(s->codec_id == AV_CODEC_ID_MPEG4 && !s->mpeg_quant))) {
// H.263, H.263+, H.263I, FLV, RV10, RV20 and MPEG-4 with MPEG-2 quantization
// Also RV30, RV40 when performing error resilience, but
// all blocks are skipped in this case.
add_dequant_dct(s, block[0], 0, dest_y , dct_linesize, s->qscale);
add_dequant_dct(s, block[1], 1, dest_y + block_size, dct_linesize, s->qscale);
add_dequant_dct(s, block[2], 2, dest_y + dct_offset , dct_linesize, s->qscale);
@ -973,6 +976,9 @@ void mpv_reconstruct_mb_internal(MpegEncContext *s, int16_t block[12][64],
add_dequant_dct(s, block[5], 5, dest_cr, uvlinesize, s->chroma_qscale);
}
} else if (is_mpeg12 == DEFINITELY_MPEG12_H261 || lowres_flag || (s->codec_id != AV_CODEC_ID_WMV2)) {
// H.261, MPEG-1, MPEG-2, MPEG-4 with H.263 quantization,
// MSMP4V1-3 and WMV1.
// Also the VC-1 family when performing error resilience
add_dct(s, block[0], 0, dest_y , dct_linesize);
add_dct(s, block[1], 1, dest_y + block_size, dct_linesize);
add_dct(s, block[2], 2, dest_y + dct_offset , dct_linesize);