On Sat, Jan 18, 2025 at 11:12 PM Nuo Mi <nuomi2...@gmail.com> wrote:
> > > On Sat, Jan 18, 2025 at 4:18 AM Frank Plowman <p...@frankplowman.com> > wrote: > >> When the chroma format changes mid-sequence, c->pix_fmt and s->pix_fmt >> can get out-of-sync. More specifically, >> 1. export_frame_params is called. >> c->pix_fmt and s->pix_fmt are both set to their new values. >> 2. set_output_format is called. >> c->pix_fmt is set back to its old value. >> >> The two getting out of sync results in a memory error. The check in >> export_frame_params passes as it only tests the s->pix_fmt, therefore >> c->pix_fmt keeps the old value and the buffers are not allocated for the >> new pixel format. >> >> Patch fixes this by not setting c->pix_fmt in set_output_format. >> >> Signed-off-by: Frank Plowman <p...@frankplowman.com> >> --- >> @Nuo Mi, Fei Wang: >> Does this look okay? I am not really sure why c->pix_fmt was set again >> in set_output_format, was this accounting for some specific scenario? >> In terms of bitstreams where the pix_fmt changes, I only have fuzzed >> bitstreams unfortunately, so while this prevents crashing it is >> difficult to know whether the output is correct. >> > Hi Frank, > I agree with you; it's better to remove the duplicate pix_fmt in the VVC > context. > If we need it for hardware, it should be renamed to hw_fmt or something > more descriptive. > Could you share the clip? > Hi Frank, Thank you for the clip. If c->pix_fmt is not needed, we might also remove ff_set_dimensions, as setting dimensions without a format is meaningless. Hi @Frank Plowman <p...@frankplowman.com> and @Wang, Fei W <fei.w.w...@intel.com>, please help review https://patchwork.ffmpeg.org/project/ffmpeg/list/?series=13775 --- >> libavcodec/vvc/dec.c | 1 - >> 1 file changed, 1 deletion(-) >> >> diff --git a/libavcodec/vvc/dec.c b/libavcodec/vvc/dec.c >> index 1cb168de7e..53e3eeec6d 100644 >> --- a/libavcodec/vvc/dec.c >> +++ b/libavcodec/vvc/dec.c >> @@ -970,7 +970,6 @@ static int set_output_format(const VVCContext *s, >> const AVFrame *output) >> if ((ret = ff_set_dimensions(c, output->width, output->height)) >> < 0) >> return ret; >> } >> - c->pix_fmt = output->format; >> return 0; >> } >> >> -- >> 2.47.0 >> >> _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
