[FFmpeg-trac] #7640(undetermined:new): first part of cut out video only contains audio

FFmpeg trac at avcodec.org
Thu Dec 27 17:08:21 EET 2018


#7640: first part of cut out video only contains audio
-------------------------------------+-------------------------------------
             Reporter:  hanshenrik   |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:  git-
  undetermined                       |  master
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug: when cutting out 10.8 seconds starting at 00:11:32
 from the video at https://www.youtube.com/watch?v=PojTP32lE_o , the first
 2 seconds of the cut only contains the audio (video resumes 2 seconds in)
 - notably, this doesn't happen if omitting "-c:v copy -c:a copy"


 How to reproduce:
 {{{
 youtube-dl 'https://www.youtube.com/watch?v=PojTP32lE_o' -o in.mkv -q
 2>/dev/null

 ffmpeg -i "in.mkv" -c:v copy -c:a copy  -ss 00:11:32 -t 10.8 -y test.mkv


 ffmpeg version N-92820-gd702600350 Copyright (c) 2000-2018 the FFmpeg
 developers
   built with gcc 8.2.1 (GCC) 20181201
   configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-
 fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-
 libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-
 amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus
 --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora
 --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp
 --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg
 --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-
 libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex
 --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-
 ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec
 --enable-dxva2 --enable-avisynth --enable-libopenmpt
   libavutil      56. 25.100 / 56. 25.100
   libavcodec     58. 42.104 / 58. 42.104
   libavformat    58. 25.100 / 58. 25.100
   libavdevice    58.  6.101 / 58.  6.101
   libavfilter     7. 46.101 /  7. 46.101
   libswscale      5.  4.100 /  5.  4.100
   libswresample   3.  4.100 /  3.  4.100
   libpostproc    55.  4.100 / 55.  4.100
 Input #0, matroska,webm, from 'in.mkv':
   Metadata:
     COMPATIBLE_BRANDS: iso6avc1mp41
     MAJOR_BRAND     : dash
     MINOR_VERSION   : 0
     ENCODER         : Lavf58.3.100
   Duration: 00:20:31.64, start: -0.007000, bitrate: 430 kb/s
     Stream #0:0: Video: h264 (Main), yuv420p(progressive), 640x480 [SAR
 1:1 DAR 4:3], 29.97 fps, 29.97 tbr, 1k tbn, 59.94 tbc (default)
     Metadata:
       HANDLER_NAME    : ISO Media file produced by Google Inc. Created on:
 11/13/2018.
       DURATION        : 00:20:31.630000000
     Stream #0:1(eng): Audio: opus, 48000 Hz, stereo, fltp (default)
     Metadata:
       DURATION        : 00:20:31.641000000
 Output #0, matroska, to 'test.mkv':
   Metadata:
     COMPATIBLE_BRANDS: iso6avc1mp41
     MAJOR_BRAND     : dash
     MINOR_VERSION   : 0
     encoder         : Lavf58.25.100
     Stream #0:0: Video: h264 (Main) (H264 / 0x34363248),
 yuv420p(progressive), 640x480 [SAR 1:1 DAR 4:3], q=2-31, 29.97 fps, 29.97
 tbr, 1k tbn, 1k tbc (default)
     Metadata:
       HANDLER_NAME    : ISO Media file produced by Google Inc. Created on:
 11/13/2018.
       DURATION        : 00:20:31.630000000
     Stream #0:1(eng): Audio: opus ([255][255][255][255] / 0xFFFFFFFF),
 48000 Hz, stereo, fltp (default)
     Metadata:
       DURATION        : 00:20:31.641000000
 Stream mapping:
   Stream #0:0 -> #0:0 (copy)
   Stream #0:1 -> #0:1 (copy)
 Press [q] to stop, [?] for help
 frame=  264 fps=0.0 q=-1.0 Lsize=     257kB time=00:00:10.78 bitrate=
 195.3kbits/s speed=57.7x
 video:92kB audio:159kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: 2.594684%
 }}}

 the resulting "test.mkv" is missing the first 2 seconds of video. (but not
 the first 2 seconds of audio)


 and per the instructions at https://ffmpeg.org/bugreports.html :

 {{{
 $ ffmpeg -v 9 -loglevel 99 -i in.mkv
 ffmpeg version N-92820-gd702600350 Copyright (c) 2000-2018 the FFmpeg
 developers
   built with gcc 8.2.1 (GCC) 20181201
   configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-
 fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-
 libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-
 amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus
 --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora
 --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp
 --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg
 --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-
 libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex
 --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-
 ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec
 --enable-dxva2 --enable-avisynth --enable-libopenmpt
   libavutil      56. 25.100 / 56. 25.100
   libavcodec     58. 42.104 / 58. 42.104
   libavformat    58. 25.100 / 58. 25.100
   libavdevice    58.  6.101 / 58.  6.101
   libavfilter     7. 46.101 /  7. 46.101
   libswscale      5.  4.100 /  5.  4.100
   libswresample   3.  4.100 /  3.  4.100
   libpostproc    55.  4.100 / 55.  4.100
 Splitting the commandline.
 Reading option '-v' ... matched as option 'v' (set logging level) with
 argument '9'.
 Reading option '-loglevel' ... matched as option 'loglevel' (set logging
 level) with argument '99'.
 Reading option '-i' ... matched as input url with argument 'in.mkv'.
 Finished splitting the commandline.
 Parsing a group of options: global .
 Applying option v (set logging level) with argument 9.
 Successfully parsed a group of options.
 Parsing a group of options: input url in.mkv.
 Successfully parsed a group of options.
 Opening an input file: in.mkv.
 [NULL @ 00000000004d0e40] Opening 'in.mkv' for reading
 [file @ 00000000004d1740] Setting default whitelist 'file,crypto'
 Probing matroska,webm score:100 size:2048
 [matroska,webm @ 00000000004d0e40] 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 @ 00000000004d0e40] Before avformat_find_stream_info() pos:
 1047 bytes read:32768 seeks:0 nb_streams:2
 [h264 @ 00000000004d6e00] nal_unit_type: 7(SPS), nal_ref_idc: 3
 [h264 @ 00000000004d6e00] nal_unit_type: 8(PPS), nal_ref_idc: 3
 [h264 @ 00000000004d6e00] nal_unit_type: 7(SPS), nal_ref_idc: 3
 [h264 @ 00000000004d6e00] nal_unit_type: 8(PPS), nal_ref_idc: 3
 [h264 @ 00000000004d6e00] nal_unit_type: 5(IDR), nal_ref_idc: 3
 [h264 @ 00000000004d6e00] Format yuv420p chosen by get_format().
 [h264 @ 00000000004d6e00] Reinit context to 640x480, pix_fmt: yuv420p
 [h264 @ 00000000004d6e00] no picture
 [matroska,webm @ 00000000004d0e40] All info found
 [matroska,webm @ 00000000004d0e40] stream 0: start_time: 0.000 duration:
 -9223372036854776.000
 [matroska,webm @ 00000000004d0e40] stream 1: start_time: -0.007 duration:
 -9223372036854776.000
 [matroska,webm @ 00000000004d0e40] format: start_time: -0.007 duration:
 1231.641 bitrate=430 kb/s
 [matroska,webm @ 00000000004d0e40] After avformat_find_stream_info() pos:
 15422 bytes read:32768 seeks:0 frames:5
 Input #0, matroska,webm, from 'in.mkv':
   Metadata:
     COMPATIBLE_BRANDS: iso6avc1mp41
     MAJOR_BRAND     : dash
     MINOR_VERSION   : 0
     ENCODER         : Lavf58.3.100
   Duration: 00:20:31.64, start: -0.007000, bitrate: 430 kb/s
     Stream #0:0, 3, 1/1000: Video: h264 (Main), 1 reference frame,
 yuv420p(progressive, left), 640x480 [SAR 1:1 DAR 4:3], 0/1, 29.97 fps,
 29.97 tbr, 1k tbn, 59.94 tbc (default)
     Metadata:
       HANDLER_NAME    : ISO Media file produced by Google Inc. Created on:
 11/13/2018.
       DURATION        : 00:20:31.630000000
     Stream #0:1(eng), 2, 1/1000: Audio: opus, 48000 Hz, stereo, fltp,
 delay 312 (default)
     Metadata:
       DURATION        : 00:20:31.641000000
 Successfully opened the file.
 At least one output file must be specified
 [AVIOContext @ 00000000004daa00] Statistics: 32768 bytes read, 0 seeks
 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/7640>
FFmpeg <https://ffmpeg.org>
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