[FFmpeg-trac] #7800(avformat:new): ffmpeg fails to get the duration of some webm files

[FFmpeg]

#7800: ffmpeg fails to get the duration of some webm files
----------------------------------+--------------------------------------
             Reporter:  KTSamy    |                     Type:  defect
               Status:  new       |                 Priority:  normal
            Component:  avformat  |                  Version:  git-master
             Keywords:            |               Blocked By:
             Blocking:            |  Reproduced by developer:  0
Analyzed by developer:  0         |
----------------------------------+--------------------------------------
 FFmpeg fails to get the duration of some WebM files. Works fine with VLC
 and MediaInfo.



 {{{
 $ ffprobe.git -v trace /Users/Shared/Lydian\'s\ Two-Piano\ Medley\ for\
 \$1M\ Prize\ -\ The\ World\'s\ Best\ Finale.webm
 ffprobe version N-93384-g0dda0f3bdb-tessus  https://evermeet.cx/ffmpeg/
 Copyright (c) 2007-2019 the FFmpeg developers
   built with Apple LLVM version 10.0.0 (clang-1000.11.45.5)
   configuration: --cc=/usr/bin/clang --prefix=/opt/ffmpeg --extra-
 version=tessus --enable-avisynth --enable-fontconfig --enable-gpl
 --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d
 --enable-libfreetype --enable-libgsm --enable-libmodplug --enable-
 libmp3lame --enable-libmysofa --enable-libopencore-amrnb --enable-
 libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-
 libopus --enable-librubberband --enable-libshine --enable-libsnappy
 --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame
 --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-
 libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-
 libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-libzmq
 --enable-libzvbi --enable-version3 --pkg-config-flags=--static --disable-
 ffplay
   libavutil      56. 26.100 / 56. 26.100
   libavcodec     58. 47.103 / 58. 47.103
   libavformat    58. 26.101 / 58. 26.101
   libavdevice    58.  6.101 / 58.  6.101
   libavfilter     7. 48.100 /  7. 48.100
   libswscale      5.  4.100 /  5.  4.100
   libswresample   3.  4.100 /  3.  4.100
   libpostproc    55.  4.100 / 55.  4.100
 [NULL @ 0x7fbdb1000000] Opening '/Users/Shared/Lydian's Two-Piano Medley
 for $1M Prize - The World's Best Finale.webm' for reading
 [file @ 0x7fbdb0500240] Setting default whitelist 'file,crypto'
 Probing matroska,webm score:100 size:2048
 Probing mp3 score:1 size:2048
 [matroska,webm @ 0x7fbdb1000000] Format matroska,webm probed with
 size=2048 and score=100
 st:0 removing common factor 1000000 from timebase
 st:1 removing common factor 1000000 from timebase
 [matroska,webm @ 0x7fbdb1000000] Before avformat_find_stream_info() pos:
 4722 bytes read:32768 seeks:0 nb_streams:2
 [vp9 @ 0x7fbdb0808000] Format yuv420p chosen by get_format().
 [matroska,webm @ 0x7fbdb1000000] All info found
 [matroska,webm @ 0x7fbdb1000000] stream 0: start_time: 0.000 duration:
 -9223372036854776.000
 [matroska,webm @ 0x7fbdb1000000] stream 1: start_time: 0.000 duration:
 -9223372036854776.000
 [matroska,webm @ 0x7fbdb1000000] format: start_time: 0.000 duration:
 -9223372036854.775 bitrate=0 kb/s
 [matroska,webm @ 0x7fbdb1000000] After avformat_find_stream_info() pos:
 5084 bytes read:32768 seeks:0 frames:2
 Input #0, matroska,webm, from '/Users/Shared/Lydian's Two-Piano Medley for
 $1M Prize - The World's Best Finale.webm':
   Metadata:
     encoder         : Lavf56.40.101
   Duration: N/A, start: 0.000000, bitrate: N/A
     Stream #0:0(eng), 1, 1/1000: Video: vp9 (Profile 0), 1 reference
 frame, yuv420p(tv, bt709/unknown/unknown), 1280x720, 0/1, SAR 1:1 DAR
 16:9, 29.97 fps, 29.97 tbr, 1k tbn, 1k tbc (default)
     Stream #0:1(eng), 1, 1/1000: Audio: vorbis, 44100 Hz, stereo, fltp
 (default)
 [AVIOContext @ 0x7fbdb07000c0] Statistics: 32768 bytes read, 0 seeks
 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/7800>
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