[FFmpeg-user] mjpeg stream

[Gabriel Zachmann]

I would love to get some insights.

I have a video that contains 3 streams (see below for the full output of ffprobe).
This is causing me a bit of a headache.

My questions are:
-  what is Stream #0.2 ? is it the same video footage as Stream #0.0, except in a different codec ? why is it there?
-  can I just delete it, or is it necessary to view the video as a whole?
-  when converting the video (as a whole) , should I convert it , too, or just copy it? or can I safely omit it?
-  Can I assume that if there is a second video stream in a file, then it is usually not really needed?
-  If yes, can I assume that the second video stream is usually the one that could be omitted?
-  in Quicktime Player 7, I can see only one video track - why don't I see two tracks?

I would greatly appreciated all kinds of insights - I am not an expert in video formats.

IF you would like to look at the video for yourself, here it is:
   https://www.dropbox.com/s/f2ili147h1pn80v/Immersive%20Virtual%20Reality%20Anatomy%20Atlas%20V01.mp4?dl=0

Thanks a lot in advance.
Best regards, Gabriel


% ffprobe Immersive\ Virtual\ Reality\ Anatomy\ Atlas\ V01.mp4 
ffprobe version 4.1 Copyright (c) 2007-2018 the FFmpeg developers
  built with Apple LLVM version 10.0.0 (clang-1000.11.45.5)
  configuration: --prefix=/opt/local --enable-swscale --enable-avfilter --enable-avresample --enable-libmp3lame --enable-libvorbis --enable-libopus --enable-librsvg --enable-libtheora --enable-libopenjpeg --enable-libmodplug --enable-libvpx --enable-libsoxr --enable-libspeex --enable-libass --enable-libbluray --enable-lzma --enable-gnutls --enable-fontconfig --enable-libfreetype --enable-libfribidi --disable-libjack --disable-libopencore-amrnb --disable-libopencore-amrwb --disable-libxcb --disable-libxcb-shm --disable-libxcb-xfixes --disable-indev=jack --enable-opencl --disable-outdev=xv --enable-audiotoolbox --enable-videotoolbox --enable-sdl2 --disable-securetransport --mandir=/opt/local/share/man --enable-shared --enable-pthreads --cc=/usr/bin/clang --arch=x86_64 --enable-x86asm --enable-libx265 --enable-gpl --enable-postproc --enable-libx264 --enable-libxvid --enable-version3 --enable-libsmbclient --enable-nonfree --enable-libfdk-aac
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fa5ef80cc00] stream 0, timescale not set
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Immersive Virtual Reality Anatomy Atlas V01.mp4':
  Metadata:
    major_brand     : M4V 
    minor_version   : 512
    compatible_brands: isomiso2avc1
    encoder         : Lavf56.36.100
  Duration: 00:01:10.47, start: 0.000000, bitrate: 3649 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 3502 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 127 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
    Stream #0:2: Video: mjpeg, yuvj420p(pc, bt470bg/unknown/unknown), 960x536 [SAR 144:144 DAR 120:67], 90k tbr, 90k tbn, 90k tbc