On Fri, Jun 21, 2019 at 06:51:54PM +0200, Andreas Rheinhardt wrote:
> Commit 31f9032b added the audio_preload feature; its goal is to
> interleave audio earlier than the rest. Unfortunately, it has never ever
> worked, because the check for whether a packet should be interleaved
> before or after another packet was completely wrong: When audio_preload
> vanishes, interleave_compare_dts returns 1 if the new packet should be
> interleaved earlier than the packet it is compared with and that is what
> the rest of the code expects. But the codepath used when audio_preload is
> set does the opposite.
>
> Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com>
> ---
> libavformat/mux.c | 7 +++----
> libavformat/version.h | 2 +-
> 2 files changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/libavformat/mux.c b/libavformat/mux.c
> index 83fe1de78f..e954c0326b 100644
> --- a/libavformat/mux.c
> +++ b/libavformat/mux.c
> @@ -1005,11 +1005,10 @@ static int interleave_compare_dts(AVFormatContext *s,
> AVPacket *next,
> int64_t ts = av_rescale_q(pkt ->dts, st ->time_base, AV_TIME_BASE_Q)
> - s->audio_preload*(st ->codecpar->codec_type == AVMEDIA_TYPE_AUDIO);
> int64_t ts2= av_rescale_q(next->dts, st2->time_base, AV_TIME_BASE_Q)
> - s->audio_preload*(st2->codecpar->codec_type == AVMEDIA_TYPE_AUDIO);
> if (ts == ts2) {
> - ts= ( pkt ->dts* st->time_base.num*AV_TIME_BASE -
> s->audio_preload*(int64_t)(st ->codecpar->codec_type == AVMEDIA_TYPE_AUDIO)*
> st->time_base.den)*st2->time_base.den
> - -( next->dts*st2->time_base.num*AV_TIME_BASE -
> s->audio_preload*(int64_t)(st2->codecpar->codec_type ==
> AVMEDIA_TYPE_AUDIO)*st2->time_base.den)* st->time_base.den;
> - ts2=0;
> + ts = (pkt ->dts* st->time_base.num*AV_TIME_BASE -
> s->audio_preload*(int64_t)(st ->codecpar->codec_type == AVMEDIA_TYPE_AUDIO)*
> st->time_base.den)*st2->time_base.den;
> + ts2 = (next->dts*st2->time_base.num*AV_TIME_BASE -
> s->audio_preload*(int64_t)(st2->codecpar->codec_type ==
> AVMEDIA_TYPE_AUDIO)*st2->time_base.den)* st->time_base.den;this is incorrect, the computation has to stay within one of the 2 variables so that overflows cancel out. It needs to use uint64_t though > } > - comp= (ts>ts2) - (ts<ts2); > + comp = (ts2 > ts) - (ts2 < ts); this change looks correct [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB I know you won't believe me, but the highest form of Human Excellence is to question oneself and others. -- Socrates
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