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avcodec/mpegvideo: Reduce stack usage when copying MpegEncContext

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(GCC did not perform this on its own; Clang did.)

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This commit is contained in:
Andreas Rheinhardt
2025-06-14 01:48:55 +02:00
parent f8c0ac9984
commit 5cdce56a79
1 changed files with 13 additions and 16 deletions
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29
libavcodec/mpegvideo.c
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@ -171,27 +171,24 @@ static av_cold void free_duplicate_contexts(MpegEncContext *s)
free_duplicate_context(s); free_duplicate_context(s);
} }
static void backup_duplicate_context(MpegEncContext *bak, MpegEncContext *src)
{
#define COPY(a) bak->a = src->a
COPY(sc);
COPY(blocks);
COPY(block);
COPY(start_mb_y);
COPY(end_mb_y);
COPY(dc_val);
COPY(ac_val);
#undef COPY
}
int ff_update_duplicate_context(MpegEncContext *dst, const MpegEncContext *src) int ff_update_duplicate_context(MpegEncContext *dst, const MpegEncContext *src)
{ {
MpegEncContext bak; #define COPY(M) \
M(ScratchpadContext, sc) \
M(void*, blocks) \
M(void*, block) \
M(int, start_mb_y) \
M(int, end_mb_y) \
M(int16_t*, dc_val) \
M(void*, ac_val)
int ret; int ret;
// FIXME copy only needed parts // FIXME copy only needed parts
backup_duplicate_context(&bak, dst); #define BACKUP(T, member) T member = dst->member;
COPY(BACKUP)
memcpy(dst, src, sizeof(MpegEncContext)); memcpy(dst, src, sizeof(MpegEncContext));
backup_duplicate_context(dst, &bak); #define RESTORE(T, member) dst->member = member;
COPY(RESTORE)
ret = ff_mpv_framesize_alloc(dst->avctx, &dst->sc, dst->linesize); ret = ff_mpv_framesize_alloc(dst->avctx, &dst->sc, dst->linesize);
if (ret < 0) { if (ret < 0) {