[FFmpeg-trac] #9241(undetermined:new): probing incomplete with flvs containing subtitles and data

[FFmpeg]

#9241: probing incomplete with flvs containing subtitles and data
-------------------------------------+-------------------------------------
             Reporter:  j0sh         |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:
  undetermined                       |  unspecified
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:

 If a FLV is detected as having a subtitle stream AND data stream, probing
 prematurely stops on the 3rd stream without waiting for additional
 streams. This usually means detecting audio, but missing video.

 This can often happen when encoders introduce leading audio before video,
 or if pulling from a RTMP server that sends audio immediately but
 withholds video until the next keyframe (we don't necessarily want to
 trust metadata here).

 For example, the attached representative file `flv-probe-missing-
 streams.flv` has some extraneous metadata along with an audio and video
 track. But only the audio is detected.

 How to reproduce:
 {{{
 % ffprobe flv-probe-missing-streams.flv
 ...
 Input #0, flv, from 'flv-probe-missing-streams.flv':
   Duration: 00:00:09.98, start: 0.000000, bitrate: 273 kb/s
     Stream #0:0: Data: none
     Stream #0:1: Subtitle: text
     Stream #0:2: Audio: aac (LC), 44100 Hz, mono, fltp
 }}}

 Here is a patch fixing this:
 https://patchwork.ffmpeg.org/project/ffmpeg/patch/1620949077-2936-1-git-
 send-email-joshua.allmann at gmail.com/

 ffprobe output after the patch:
 {{{
 % ffprobe flv-probe-missing-streams.flv
 ...
 Input #0, flv, from 'flv-probe-missing-streams.flv':
   Duration: 00:00:09.98, start: 0.000000, bitrate: 273 kb/s
     Stream #0:0: Data: none
     Stream #0:1: Subtitle: text
     Stream #0:2: Audio: aac (LC), 44100 Hz, mono, fltp
     Stream #0:3: Video: h264 (High), yuv420p(tv, progressive), 320x240
 [SAR 1:1 DAR 4:3], 25 fps, 25 tbr, 1k tbn
 }}}
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/9241>
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