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avcodec/vc1dec: Set pointers for hwaccel even without hwaccel 

VC-1 uses a 0x03 escaping scheme like H.26x and our decoder
unescapes data for this purpose, but hardware accelerations
just want the data as-is and therefore get fed the original
data. The pointers to the actual data are only setcorrectly
if avctx->hwaccel is set (after all, they are only used in
this case).

There are two problems with this: The first is that the branch
is pointless; the second is that it is harmful, because
a hardware acceleration may be added after the packet has been
parsed (in case there is a reconfiguration e.g. due to frame
size changes) in which case decoding the first few frames
won't work.

So delete these branches.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This commit is contained in:
Andreas Rheinhardt 2024-02-05 22:15:31 +01:00
parent 687a287e14
commit 38f234c06e
1 changed files with 3 additions and 6 deletions
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9
libavcodec/vc1dec.c
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@ -846,14 +846,12 @@ static int vc1_decode_frame(AVCodecContext *avctx, AVFrame *pict,
if (size <= 0) continue;
switch (AV_RB32(start)) {
case VC1_CODE_FRAME:
if (avctx->hwaccel)
buf_start = start;
buf_start = start;
buf_size2 = v->vc1dsp.vc1_unescape_buffer(start + 4, size, buf2);
break;
case VC1_CODE_FIELD: {
int buf_size3;
if (avctx->hwaccel)
buf_start_second_field = start;
buf_start_second_field = start;
av_size_mult(sizeof(*slices), n_slices+1, &next_allocated);
tmp = next_allocated ? av_fast_realloc(slices, &slices_allocated, next_allocated) : NULL;
if (!tmp) {
@ -918,8 +916,7 @@ static int vc1_decode_frame(AVCodecContext *avctx, AVFrame *pict,
ret = AVERROR_INVALIDDATA;
goto err;
} else { // found field marker, unescape second field
if (avctx->hwaccel)
buf_start_second_field = divider;
buf_start_second_field = divider;
av_size_mult(sizeof(*slices), n_slices+1, &next_allocated);
tmp = next_allocated ? av_fast_realloc(slices, &slices_allocated, next_allocated) : NULL;
if (!tmp) {