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• ffmpeg : Concatenating videos with different formats with as little quality loss as possible

  12 juin 2020, par linesd

  I have sets of video segments with different formats that need to be concatenated and uploaded to a database as a single video. I need to do this with as little quality loss as possible. For example, one set is :

  



  video_1.mov - 796 frames, 432Mb,
video_2.mp4 - 913 frames, 58Mb,
video_3.mov - 625 frames, 345Mb


  



  This should be concatenated into one file :
output.mov - 2334 frames, ?Mb

  



  So far I am doing this :

  



  

  1. Convert the .mp4 to .mov with lossless encoding :

  


  



  ffmpeg -i video_2.mp4 -c:v libx264 -preset veryslow -crf 0 -c:a copy video_2.mov

  



  an error is produced during this step :

  



  [h264 @ 0x558298795760] error while decoding MB 110 37, bytestream -69483.1kbits/s speed=0.227x     
[h264 @ 0x558298795760] concealing 3659 DC, 3659 AC, 3659 MV errors in P frame


  



  This still outputs video_2.mov -  frames 913, 112Mb

  



  

  2. Use concat demuxer to combine the videos :

  


  



  ffmpeg -f concat -safe 0 -i mylist.txt -c copy output.mov

  



  where mylist.txt is :

  



  file 'video_1.mov'
file 'video_2.mov'
file 'video_3.mov'


  



  However, the concat demuxer command gives the error :

  



  [concat @ 0x561cbae96900] Could not find codec parameters for stream 2 (Unknown: none): unknown codec.Consider increasing the value for the 'analyzeduration' and 'probesize' options


  



  Followed by many lines of :

  



  [mov @ 0x555b5dca4f00] Non-monotonous DTS in output stream 0:1; previous: 1527575, current: 1168413; changing to 1527576. This may result in incorrect timestamps in the output file.


  



  The result of these steps is a output.mov which is the correct size of 432+345+112=889Mb but only has 1421 frames equal to the frames from video_1.mov - 796 frames and video_3.mov - 625 frames. When I play the concatenated version, output.mov, it freezes for the duration of the video_2.mov segment and then continues as normal for video_3.mov.

  



  Any help with this would be hugely appreciated.

  



  EDIT :

  



  ---

  



  Running ffmpeg -n -i video_1.mov -i video_2.mp4 -i video_3.mov per the comments produced :

  



  `ffmpeg version 3.4.6-0ubuntu0.18.04.1 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 7 (Ubuntu 7.3.0-16ubuntu3)
  configuration: --prefix=/usr --extra-version=0ubuntu0.18.04.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
  libavutil      55. 78.100 / 55. 78.100
  libavcodec     57.107.100 / 57.107.100
  libavformat    57. 83.100 / 57. 83.100
  libavdevice    57. 10.100 / 57. 10.100
  libavfilter     6.107.100 /  6.107.100
  libavresample   3.  7.  0 /  3.  7.  0
  libswscale      4.  8.100 /  4.  8.100
  libswresample   2.  9.100 /  2.  9.100
  libpostproc    54.  7.100 / 54.  7.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video_1.mov':
  Metadata:
    major_brand     : qt  
    minor_version   : 0
    compatible_brands: qt  
    creation_time   : 2019-11-16T09:57:04.000000Z
    keywords        : iMovie
    description     : 
    title           : 
    com.apple.quicktime.description: 
    com.apple.quicktime.displayname: 
    com.apple.quicktime.keywords: iMovie
    com.apple.quicktime.title:
  Duration: 00:00:31.84, start: 0.000000, bitrate: 108530 kb/s
    Stream #0:0(eng): Audio: pcm_s16be (lpcm / 0x6D63706C), 48000 Hz, stereo, s16, 1536 kb/s (default)
    Metadata:
      creation_time   : 2019-11-16T09:57:04.000000Z
      handler_name    : Core Media Data Handler
    Stream #0:1(und): Video: prores (apcn / 0x6E637061), yuv422p10le(bt709, progressive), 1920x1080, 106992 kb/s, SAR 1:1 DAR 16:9, 25 fps, 25 tbr, 25 tbn, 25 tbc (default)
    Metadata:
      creation_time   : 2019-11-16T09:57:04.000000Z
      handler_name    : Core Media Data Handler
      encoder         : Apple ProRes 422
      timecode        : 00:00:00:00
    Stream #0:2(und): Data: none (tmcd / 0x64636D74), 0 kb/s (default)
    Metadata:
      creation_time   : 2019-11-16T09:57:04.000000Z
      handler_name    : Core Media Data Handler
      timecode        : 00:00:00:00
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'video_2.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 1
    compatible_brands: mp41mp42isom
    creation_time   : 2019-11-16T09:55:40.000000Z
  Duration: 00:00:30.71, start: 0.000000, bitrate: 15320 kb/s
    Stream #1:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 165 kb/s (default)
    Metadata:
      creation_time   : 2019-11-16T09:55:40.000000Z
      handler_name    : Core Media Audio
    Stream #1:1(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080, 15277 kb/s, 29.98 fps, 29.97 tbr, 90k tbn, 60 tbc (default)
    Metadata:
      creation_time   : 2019-11-16T09:55:40.000000Z
      handler_name    : Core Media Video
Input #2, mov,mp4,m4a,3gp,3g2,mj2, from 'video_3.mov':
  Metadata:
    major_brand     : qt  
    minor_version   : 0
    compatible_brands: qt  
    creation_time   : 2019-11-16T09:57:19.000000Z
    keywords        : iMovie
    description     : 
    title           : 
    com.apple.quicktime.description: 
    com.apple.quicktime.displayname: 
    com.apple.quicktime.keywords: iMovie
    com.apple.quicktime.title:
  Duration: 00:00:25.00, start: 0.000000, bitrate: 110329 kb/s
    Stream #2:0(eng): Audio: pcm_s16be (lpcm / 0x6D63706C), 48000 Hz, stereo, s16, 1536 kb/s (default)
    Metadata:
      creation_time   : 2019-11-16T09:57:19.000000Z
      handler_name    : Core Media Data Handler
    Stream #2:1(und): Video: prores (apcn / 0x6E637061), yuv422p10le(bt709, progressive), 1920x1080, 108790 kb/s, SAR 1:1 DAR 16:9, 25 fps, 25 tbr, 25 tbn, 25 tbc (default)
    Metadata:
      creation_time   : 2019-11-16T09:57:19.000000Z
      handler_name    : Core Media Data Handler
      encoder         : Apple ProRes 422
      timecode        : 00:00:00:00
    Stream #2:2(und): Data: none (tmcd / 0x64636D74), 0 kb/s (default)
    Metadata:
      creation_time   : 2019-11-16T09:57:19.000000Z
      handler_name    : Core Media Data Handler
      timecode        : 00:00:00:00


  


• ffmpeg command to merge file with good quality

  21 janvier 2016, par Hemant Kumar

  I am looking for a better command that can merge both audio & video files into one with a better quality.

  I found this command from Muaz Khan’s WebRTC APIs.

  ffmpeg -i {$audioFile} -i {$videoFile} -map 0:0 -map 1:0 {$mergedFileName}

  Later on server i had to add "-strict -2" with this command as on server it says that above command is experimental if I still want to use it you should add "-strict -2" with it.

  It is working well but my video file (.webm) with size 2.2MB and audio file (.wav) with size 1.5MB was merged into a new file (.webm) with size 422.5KB. This new video file is having lag.

  Also I want the meta information for duration of video is already written on the resulting video file.

  Is there any command which can give the merged file without lagging and both video and audio of the new file are of good quality ?

• compat/cuda/ptx2c : remove shell loop ; fix BSD sed compat

  22 août 2019, par rcombs

  compat/cuda/ptx2c : remove shell loop ; fix BSD sed compat
  This fixes building on macOS, and improves build times dramatically there
  

  • [DH] compat/cuda/ptx2c.sh