Carl Eugen Hoyos: > Am Fr., 20. Sept. 2019 um 00:30 Uhr schrieb Andreas Rheinhardt > <andreas.rheinha...@gmail.com>: >> >> Fixes lots of FATE tests, e.g. lavf-nut, as well as the nut part of >> ticket #7980. >> >> Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com> >> --- >> This patch is made to match the previous behaviour; whether the previous >> behaviour is correct at all if the header length is zero is unknown to >> me. >> >> libavformat/nutenc.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/libavformat/nutenc.c b/libavformat/nutenc.c >> index e9a3bb49db..dc714eb809 100644 >> --- a/libavformat/nutenc.c >> +++ b/libavformat/nutenc.c >> @@ -791,8 +791,9 @@ static int get_needed_flags(NUTContext *nut, >> StreamContext *nus, FrameCode *fc, >> flags |= FLAG_CHECKSUM; >> if (pkt->size < nut->header_len[fc->header_idx] || >> (pkt->size > 4096 && fc->header_idx) || >> - memcmp(pkt->data, nut->header[fc->header_idx], >> - nut->header_len[fc->header_idx])) >> + (nut->header_len[fc->header_idx] > 0 && >> + memcmp(pkt->data, nut->header[fc->header_idx], >> + nut->header_len[fc->header_idx]))) >> flags |= FLAG_HEADER_IDX; > > Is this different from the patch I sent? > (Why does it look different) > https://patchwork.ffmpeg.org/patch/13782/ > > Carl Eugen
Yes. a) Your patch checks whether nut->header[fc->header_idx] is NULL. b) Michael's proposal is to check for fc->header_idx instead. This would work, because it is the index of the only used pointer in nut->header that is NULL, and this proposal has the advantage of one dereferencing less than a). c) My* patch checks whether nut->header_len[fc->header_idx] is zero. Given that nut->header_len[fc->header_idx] is already used in the very first check, my solution should not entail a dereference at all. Furthermore, b) is very specific to the nutenc situation here and a) might hide a situation where nut->header_len[fc->header_idx] is > 0, but nut->header[fc->header_idx] == NULL, which should of course not happen. And it singles out one of the two pointer arguments. - Andreas *: It is also what Reimar proposed (I was completely unaware of the earlier patch when I submitted mine). _______________________________________________ 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".
