[FFmpeg-devel] [PATCH] Fix segment muxer

[Vasily]

Can I have _any_ response please? It was more than a week of silence... :(

Thanks,
Vasily

чт, 10 окт. 2019 г., 13:05 Vasily <just.one.man at yandex.ru>:

> Anything else I have to do to make this patch eventually taken in?
>
> Thanks,
> Vasily
>
> пн, 7 окт. 2019 г. в 15:54, <just.one.man at yandex.ru>:
>
>> When incoming media has non-zero start PTS,
>> segment muxer would fail to correctly calculate
>> the point where to chunk segments, as it always
>> assumed that media starts with PTS==0.
>>
>> This change removes this assumption by remembering
>> the PTS of the very first frame passed through the muxer.
>>
>> Also fix starting points of first segment
>> ---
>>  libavformat/segment.c |   12 +++++++++++-
>>  1 file changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/libavformat/segment.c b/libavformat/segment.c
>> index e308206..8b985df 100644
>> --- a/libavformat/segment.c
>> +++ b/libavformat/segment.c
>> @@ -87,6 +87,7 @@ typedef struct SegmentContext {
>>      int64_t last_val;      ///< remember last time for wrap around
>> detection
>>      int cut_pending;
>>      int header_written;    ///< whether we've already called
>> avformat_write_header
>> +    int64_t start_pts;     ///< pts of the very first packet processed,
>> used to compute correct segment length
>>
>>      char *entry_prefix;    ///< prefix to add to list entry filenames
>>      int list_type;         ///< set the list type
>> @@ -702,6 +703,7 @@ static int seg_init(AVFormatContext *s)
>>          if ((ret = parse_frames(s, &seg->frames, &seg->nb_frames,
>> seg->frames_str)) < 0)
>>              return ret;
>>      } else {
>> +        seg->start_pts = AV_NOPTS_VALUE;
>>          /* set default value if not specified */
>>          if (!seg->time_str)
>>              seg->time_str = av_strdup("2");
>> @@ -914,7 +916,15 @@ calc_times:
>>                  seg->cut_pending = 1;
>>              seg->last_val = wrapped_val;
>>          } else {
>> -            end_pts = seg->time * (seg->segment_count + 1);
>> +            if (seg->start_pts != AV_NOPTS_VALUE) {
>> +                end_pts = seg->start_pts + seg->time *
>> (seg->segment_count + 1);
>> +            } else if (pkt->stream_index == seg->reference_stream_index
>> && pkt->pts != AV_NOPTS_VALUE) {
>> +                // this is the first packet of the reference stream we
>> see, initialize start point
>> +                seg->start_pts = av_rescale_q(pkt->pts, st->time_base,
>> AV_TIME_BASE_Q);
>> +                seg->cur_entry.start_time = (double)pkt->pts *
>> av_q2d(st->time_base);
>> +                seg->cur_entry.start_pts = seg->start_pts;
>> +                end_pts = seg->start_pts + seg->time *
>> (seg->segment_count + 1);
>> +            }
>>          }
>>      }
>>
>> --
>> 1.7.9.5
>>
>> Now I tried to re-format as Nicolas George said, hopefully this is okay
>> and won't make a third entry in patchwork (if it does - how do I stop it
>> from doing so?)
>>
>> 07.10.2019, 15:15, "Nicolas George" <george at nsup.org>:
>> > just.one.man at yandex.ru (12019-10-07):
>> >>  Updated patch
>> >
>> > This should be after the triple dash, because it does not belong in the
>> > commit message.
>> >
>> >>  ---
>> >>
>> >>  When incoming media has non-zero start PTS,
>> >>  segment muxer would fail to correctly calculate
>> >>  the point where to chunk segments, as it always
>> >>  assumed that media starts with PTS==0.
>> >>
>> >>  This change removes this assumption by remembering
>> >>  the PTS of the very first frame passed through the muxer.
>> >>
>> >>  Also fix starting points of first segment
>> >>  ---
>> >
>> > This should be before the triple dash, because it does belong in the
>> > commit message.
>> >
>> > I did not look at the code.
>> >
>> > Regards,
>> >
>> > --
>> >   Nicolas George
>> > ,
>> >
>> > _______________________________________________
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>> >
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>
>