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

[Jun Li]

On Thu, Sep 26, 2019 at 6:07 PM Jun Li <junli1026 at gmail.com> wrote:

>
>
> On Fri, Sep 20, 2019 at 9:46 PM Jun Li <junli1026 at gmail.com> wrote:
>
>>
>> On Sat, Sep 14, 2019 at 2:06 PM Jun Li <junli1026 at gmail.com> wrote:
>>
>>>
>>>
>>> On Tue, Sep 10, 2019 at 12:16 PM Jun Li <junli1026 at gmail.com> wrote:
>>>
>>>>
>>>>
>>>> On Tue, Sep 10, 2019 at 12:12 PM Jun Li <junli1026 at gmail.com> wrote:
>>>>
>>>>> 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;
>>>>> +                    }
>>>>> +                }
>>>>>              }
>>>>>          }
>>>>>
>>>>> diff --git a/tests/fate/subtitles.mak b/tests/fate/subtitles.mak
>>>>> index 0042902161..4c2b34c431 100644
>>>>> --- a/tests/fate/subtitles.mak
>>>>> +++ b/tests/fate/subtitles.mak
>>>>> @@ -34,6 +34,12 @@ fate-sub-movtext: CMD = fmtstdout ass -i
>>>>> $(TARGET_SAMPLES)/sub/MovText_capabilit
>>>>>  FATE_SUBTITLES-$(call ENCDEC, MOVTEXT, MOV) += fate-binsub-movtextenc
>>>>>  fate-binsub-movtextenc: CMD = md5 -i
>>>>> $(TARGET_SAMPLES)/sub/MovText_capability_tester.mp4 -map 0 -scodec mov_text
>>>>> -f mp4 -flags +bitexact -fflags +bitexact -movflags frag_keyframe+empty_moov
>>>>>
>>>>> +FATE_SUBTITLES-$(call ENCDEC, MOVTEXT, MOV) +=
>>>>> fate-binsub-movtextenc-long-dur
>>>>> +fate-binsub-movtextenc-long-dur: CMD = md5 -i
>>>>> $(TARGET_SAMPLES)/sub/WebVTT_movtext_long_dur.vtt -map 0 -scodec mov_text
>>>>> -f mp4 -flags +bitexact -fflags +bitexact -movflags frag_keyframe+empty_moov
>>>>> +
>>>>> +FATE_SUBTITLES-$(call ENCDEC, MOVTEXT, MOV) +=
>>>>> fate-binsub-movtextenc-long-dur-timebase
>>>>> +fate-binsub-movtextenc-long-dur-timebase: CMD = md5 -i
>>>>> $(TARGET_SAMPLES)/sub/WebVTT_movtext_long_dur.vtt -map 0 -scodec mov_text
>>>>> -time_base 1000 -f mp4 -flags +bitexact -fflags +bitexact -movflags
>>>>> frag_keyframe+empty_moov
>>>>> +
>>>>>  FATE_SUBTITLES_ASS-$(call DEMDEC, MPL2, MPL2) += fate-sub-mpl2
>>>>>  fate-sub-mpl2: CMD = fmtstdout ass -i
>>>>> $(TARGET_SAMPLES)/sub/MPL2_capability_tester.txt
>>>>>
>>>>> diff --git a/tests/ref/fate/binsub-movtextenc-long-dur
>>>>> b/tests/ref/fate/binsub-movtextenc-long-dur
>>>>> new file mode 100644
>>>>> index 0000000000..eb8a3f8fc7
>>>>> --- /dev/null
>>>>> +++ b/tests/ref/fate/binsub-movtextenc-long-dur
>>>>> @@ -0,0 +1 @@
>>>>> +7f78c11bb4a6b16335540ef31ba10219
>>>>> diff --git a/tests/ref/fate/binsub-movtextenc-long-dur-timebase
>>>>> b/tests/ref/fate/binsub-movtextenc-long-dur-timebase
>>>>> new file mode 100644
>>>>> index 0000000000..185dcc0aab
>>>>> --- /dev/null
>>>>> +++ b/tests/ref/fate/binsub-movtextenc-long-dur-timebase
>>>>> @@ -0,0 +1 @@
>>>>> +349d78698cc1226d33d4e6699dbf46d9
>>>>> --
>>>>> 2.17.1
>>>>>
>>>>>
>>>> Fate test passed, the attachment is the new added sample file.
>>>> Will send email to samples-request@ if the patch is approved.
>>>>
>>>
>>> Ping.
>>>
>>
>> Ping x2.
>>
>
> Ping x3
>

Ping x4, could someone please help to review ?