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avcodec/mpeg4videodec: Don't set chroma matrices unnecessarily

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Only the studio profile uses chroma_inter/intra matrices;
the ordinary profile has only inter/intra matrices.
And our code (namely the MPEG-2 unquantize functions)
only use these two matrices (the MPEG-2 decoder unquantizes
on its own while parsing).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This commit is contained in:
Andreas Rheinhardt 2025-04-30 15:54:50 +02:00
parent bd6e6495ae
commit dfb4477191
1 changed files with 0 additions and 4 deletions
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4
libavcodec/mpeg4videodec.c
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@ -2787,14 +2787,12 @@ static int decode_vol_header(Mpeg4DecContext *ctx, GetBitContext *gb)
last = v;
j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
s->intra_matrix[j] = last;
s->chroma_intra_matrix[j] = last;
}
/* replicate last value */
for (; i < 64; i++) {
int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
s->intra_matrix[j] = last;
s->chroma_intra_matrix[j] = last;
}
}
@ -2814,14 +2812,12 @@ static int decode_vol_header(Mpeg4DecContext *ctx, GetBitContext *gb)
last = v;
j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
s->inter_matrix[j] = v;
s->chroma_inter_matrix[j] = v;
}
/* replicate last value */
for (; i < 64; i++) {
int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
s->inter_matrix[j] = last;
s->chroma_inter_matrix[j] = last;
}
}