On Fri, Jun 17, 2016 at 01:26:10AM +0200, Michael Niedermayer wrote:
> On Thu, Jun 16, 2016 at 05:26:14PM +0200, Matthieu Bouron wrote:
> > From: Matthieu Bouron <matthieu.bou...@stupeflix.com>
> >
> > Fixes packet pts of samples which contain ctts entries with count=0.
> > ---
> >
> > Hello,
> >
> > The following patch fixes packet pts of samples which contain ctts values
> > with
> > count=0 (so the ctts entry does not apply to any sample if I understand
> > correctly). Such samples are produced by a LG G4 phone. I don't have any
> > sample I can share at the moment (and thus no fate test following this patch
> > yet).
> >
> > An alternative to this patch is to remove directly the entry when the ctts
> > atom
> > is parsed. Would you prefer this alternative ?
>
> i dont know what is preferred but i agree about either solution
>
> removing them on load would avoid any issues with ctts_count > 0
> and no real entries, i dont know though if that ever matters
I've attached the alternative patch that removes the CTTS entries with
count <= 0 at parsing time. I think it's better in the end (I first liked
the idea to keep the ctts table as is in memory but after some thoughts I
think it's really useful). Anyway I'll go with whatever patch you prefer.
Matthieu
[...]
>From 3bf2a6a81b8cca09bee4c0b6ef6f6ce78e276f0d Mon Sep 17 00:00:00 2001
From: Matthieu Bouron <matthieu.bou...@stupeflix.com>
Date: Thu, 16 Jun 2016 13:16:52 +0200
Subject: [PATCH] lavf/mov: ignore ctts that do not apply to a least one sample
Fixes packet pts of samples which contain ctts values with count <= 0.
---
libavformat/mov.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 57a0354..8eab34c 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -2574,7 +2574,7 @@ static int mov_read_ctts(MOVContext *c, AVIOContext *pb, MOVAtom atom)
{
AVStream *st;
MOVStreamContext *sc;
- unsigned int i, entries;
+ unsigned int i, entries, ctts_count = 0;
if (c->fc->nb_streams < 1)
return 0;
@@ -2600,8 +2600,16 @@ static int mov_read_ctts(MOVContext *c, AVIOContext *pb, MOVAtom atom)
int count =avio_rb32(pb);
int duration =avio_rb32(pb);
- sc->ctts_data[i].count = count;
- sc->ctts_data[i].duration= duration;
+ if (count <= 0) {
+ av_log(c->fc, AV_LOG_TRACE,
+ "ignoring CTTS entry with count=%d duration=%d\n",
+ count, duration);
+ continue;
+ }
+
+ sc->ctts_data[ctts_count].count = count;
+ sc->ctts_data[ctts_count].duration = duration;
+ ctts_count++;
av_log(c->fc, AV_LOG_TRACE, "count=%d, duration=%d\n",
count, duration);
@@ -2617,7 +2625,7 @@ static int mov_read_ctts(MOVContext *c, AVIOContext *pb, MOVAtom atom)
mov_update_dts_shift(sc, duration);
}
- sc->ctts_count = i;
+ sc->ctts_count = ctts_count;
if (pb->eof_reached)
return AVERROR_EOF;
--
2.8.3
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