[FFmpeg-devel] [PATCH v3] avformat/movenc: split empty text sample when duration overflow

[Jun Li]

On Wed, Oct 2, 2019 at 3:22 PM Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:

> Am Mi., 2. Okt. 2019 um 02:21 Uhr schrieb Jun Li <junli1026 at gmail.com>:
> >
> > On Tue, Oct 1, 2019 at 4:19 AM Carl Eugen Hoyos <ceffmpeg at gmail.com>
> wrote:
> >
> > > Am Di., 10. Sept. 2019 um 21:12 Uhr schrieb Jun Li <
> junli1026 at gmail.com>:
> > > >
> > > > Fix #7637
> > > > One empty/end sample is created and inserted between two caption
> lines
> > > when there is a gap.
> > > > This patch is to split the sample into multiple ones when its
> duration
> > > is too long (>= INT_MAX).
> > > > ---
> > > >  libavformat/movenc.c                          | 24
> ++++++++++++++-----
> > > >  tests/fate/subtitles.mak                      |  6 +++++
> > > >  tests/ref/fate/binsub-movtextenc-long-dur     |  1 +
> > > >  .../fate/binsub-movtextenc-long-dur-timebase  |  1 +
> > > >  4 files changed, 26 insertions(+), 6 deletions(-)
> > > >  create mode 100644 tests/ref/fate/binsub-movtextenc-long-dur
> > > >  create mode 100644
> tests/ref/fate/binsub-movtextenc-long-dur-timebase
> > > >
> > > > diff --git a/libavformat/movenc.c b/libavformat/movenc.c
> > > > index edddfeeb00..aeb7de351f 100644
> > > > --- a/libavformat/movenc.c
> > > > +++ b/libavformat/movenc.c
> > > > @@ -5746,7 +5746,8 @@ static int mov_write_packet(AVFormatContext *s,
> > > AVPacket *pkt)
> > > >           *
> > > >           * 2) For each subtitle track, check if the current packet's
> > > >           * dts is past the duration of the last subtitle sample. If
> > > > -         * so, we now need to write an end sample for that subtitle.
> > > > +         * so, we now need to write one or multiple end samples for
> > > > +         * that subtitle.
> > > >           *
> > > >           * This must be done conditionally to allow for subtitles
> that
> > > >           * immediately replace each other, in which case an end
> sample
> > > > @@ -5760,11 +5761,22 @@ static int mov_write_packet(AVFormatContext
> *s,
> > > AVPacket *pkt)
> > > >              int ret;
> > > >
> > > >              if (trk->par->codec_id == AV_CODEC_ID_MOV_TEXT &&
> > > > -                trk->track_duration < pkt->dts &&
> > > > -                (trk->entry == 0 ||
> !trk->last_sample_is_subtitle_end))
> > > {
> > > > -                ret = mov_write_subtitle_end_packet(s, i,
> > > trk->track_duration);
> > > > -                if (ret < 0) return ret;
> > > > -                trk->last_sample_is_subtitle_end = 1;
> > > > +                trk->track_duration < pkt->dts) {
> > > > +                int max_duration = INT_MAX - 1;
> > > > +                if (trk->entry == 0 ||
> > > !trk->last_sample_is_subtitle_end) {
> > > > +                    ret = mov_write_subtitle_end_packet(s, i,
> > > trk->track_duration);
> > >
> > > > +                    if (ret < 0) return ret;
> > >
> > > > +                    trk->last_sample_is_subtitle_end = 1;
> > > > +                }
> > > > +                if (trk->last_sample_is_subtitle_end &&
> > > > +                    pkt->dts - trk->track_duration > max_duration) {
> > > > +                    int64_t dts = trk->track_duration;
> > > > +                    while(pkt->dts - dts > max_duration) {
> > > > +                        dts += max_duration;
> > > > +                        ret = mov_write_subtitle_end_packet(s, i,
> dts);
> > >
> > > > +                        if (ret < 0) return ret;
> > >
> > > Please add two CRLFs and I am threatening to push this.
> > >
> > > Carl Eugen
> > > _______________________________________________
> > > ffmpeg-devel mailing list
> > > ffmpeg-devel at ffmpeg.org
> > > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> > >
> > > To unsubscribe, visit link above, or email
> > > ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
> >
> >
> > Thanks Carl for review. Code is updated as follows.
>
> git returns an error message ("corrupt line") when I try to
> commit this patch.
>
> Thanks for your time, I rebased the code and re-generated a patch,
together with the fate test file, in the attachments.
Could you please help do a re-try ? Thanks.

-Jun


> Carl Eugen
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
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