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

[Jun Li]

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.
>

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