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• Stacking 3 gmp4-files using Avisynth and VirtualDub, results in wrong colors and distorted files

  22 juin 2015, par Frederik Amann

  I need to conduct the seemingly simple task of stacking 3 files next to each other. They are all the same : .avi Container, 320x240, 4:3, 25 fps, GeoVision Advanced MPEG-4 GEO codec.
  I installed the GeoVision codec (http://www.geovision.com.tw/english/5_8.asp# - select "other utilities"), so my system (windows media player, media player classic) can play back the files. Also, I can open and work with them in Virtual Dub. I installed AviSynth and wrote the simple script for stacking them next to each other

  h1 = AVISource("Event20150423075842001.avi")
  
  
  
  h2 = AVISource("Event20150423075842002.avi")
  
  
  
  h3 = AVISource("Event20150423075848003.avi")
  
  
  
  StackHorizontal(h1, h2, h3)

  now, when I save it as .avs and then open it using VirtualDub, I see three videos nicely put next to each other, but the colors are weird and parts of the video are upside down and everything is just ..wrong - see Screenshot http://www.linkfile.de/download-46f71057ed130f9be29510f68ce4ee71.php. First I thought it has something to do with avisynth taking the wrong codec, so i forced it on gmp4 (as you can also see in the screenshot), but the result is the same. I have now also Avisynth+ installed, as well as VirtualDubMod.
  When I open the .avs in VDMod, I get "couldn’t locate decompressor for format YV24", but it still opens the video which looks a little better though (but when I make a direct stream copy and save it, then play it back in MPC it looks exactly the same as it looked on the first screenshot). So this error points me toward something related to the colorspace.
  Now my questions :

  • How can I find out in which format my files are ? YUV24, YUV12, ..?
  • And then, how can I tell Avisynth to use a format that VirtualDubMod can deal with ?
  • Or how can I make VirtualDub deal with YUV24 ? Am I just missing a codec ? Is my train of thought even slightly on the right track, or is my problem something totally different ?

  I also found this related thread : Editing/Decoding AVI files using system-installed proprietary codecs, but using avisynth and ffmpeg, I get similar results as with VirtualDub.

  I can’t use the solution of converting all my files first and then do the stacking in a second step - because the actual files I have to work with are about 180 videos, each like 8hours long and the time it would consume would stand in no relation to my possibilities..

  I really have looked for solutions during the past week, and I think I’m close, but I sadly just don’t know enough about programming to be able to solve it on my own.. so I also want to excuse for any apparent stupidities in my explanation ;)
  I’m very thankfull for any help

  Have a good time everybody

  EDIT :
  So I have some more Info, and an example file, which I can’t link in this post -.- because I -again- have not enough reputation, very nice. I will try to comment and post the links :)

  Here is what the info() command brought me :
  Colorspace : YV24,
  FieldBased (Separated) Video : NO,
  Parity : Bottom Field First,
  Video Pitch : 320 bytes,
  Audio : NO,
  CPU detected : x87 MMX ISSE SSE4.1 SSSE3

• FFMPEG [mp3float @ 0x7fd42f813200] Header missing

  10 février 2021, par rahi82

  I have a problem with some mp3 files. When transcoding the file with FFMPEG I get the following error :

  


  [mp3float @ 0x7fd42f813200] Header missing
Error while decoding stream #0:0: Invalid data found when processing input


  


  Is this a problem of the file itself, and how it is produced ?
Or is it a problem of FFMPEG ?

  


  Here full decoding message :

  


  ffmpeg version git-2020-07-28-dfd12ee Copyright (c) 2000-2020 the FFmpeg developers
  built with Apple clang version 11.0.0 (clang-1100.0.33.16)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/HEAD-dfd12ee_2 --enable-shared --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-libaom --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-libsnappy --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-demuxer=dash --disable-libjack --disable-indev=jack --enable-opencl --enable-videotoolbox --disable-htmlpages --enable-libfdk-aac --enable-nonfree
  libavutil      56. 57.100 / 56. 57.100
  libavcodec     58. 97.102 / 58. 97.102
  libavformat    58. 49.100 / 58. 49.100
  libavdevice    58. 11.101 / 58. 11.101
  libavfilter     7. 87.100 /  7. 87.100
  libswscale      5.  8.100 /  5.  8.100
  libswresample   3.  8.100 /  3.  8.100
  libpostproc    55.  8.100 / 55.  8.100
[mp3 @ 0x7fd42f808200] Estimating duration from bitrate, this may be inaccurate
Input #0, mp3, from 'Ice Mc - Think About The Way.mp3':
  Metadata:
    title           : Think About The Way
    TBPM            : 133
    artist          : Ice MC
    date            : 1994
    track           : 4/15
    disc            : 0
    album_artist    : ICE MC
  Duration: 00:04:16.39, start: 0.000000, bitrate: 323 kb/s
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, fltp, 320 kb/s
    Stream #0:1: Video: mjpeg (Baseline), yuvj420p(pc, bt470bg/unknown/unknown), 600x592 [SAR 72:72 DAR 75:74], 90k tbr, 90k tbn, 90k tbc (attached pic)
    Metadata:
      comment         : Other
Stream mapping:
  Stream #0:1 -> #0:0 (mjpeg (native) -> wrapped_avframe (native))
  Stream #0:0 -> #0:1 (mp3 (mp3float) -> pcm_s16le (native))
Press [q] to stop, [?] for help
Output #0, null, to 'pipe:':
  Metadata:
    title           : Think About The Way
    TBPM            : 133
    artist          : Ice MC
    date            : 1994
    track           : 4/15
    disc            : 0
    album_artist    : ICE MC
    encoder         : Lavf58.49.100
    Stream #0:0: Video: wrapped_avframe, yuvj420p(progressive), 600x592 [SAR 72:72 DAR 75:74], q=2-31, 200 kb/s, 90k fps, 90k tbn, 90k tbc (attached pic)
    Metadata:
      comment         : Other
      encoder         : Lavc58.97.102 wrapped_avframe
    Stream #0:1: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
    Metadata:
      encoder         : Lavc58.97.102 pcm_s16le
[mp3float @ 0x7fd42f813200] Header missing
Error while decoding stream #0:0: Invalid data found when processing input
frame=    1 fps=0.0 q=-0.0 Lsize=N/A time=00:04:16.60 bitrate=N/A speed= 725x    
video:1kB audio:44204kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown


  


  What is also noticed is that this mp3 has the cover embedded as a video stream. And there is also this weird cross mapping. Not sure if that is normal ?

  


• how can I set GOP size to be a multiple of the input framerate ?

  3 septembre 2020, par agconti

  Question :

  


  How can I set GOP size to be a multiple of the input framerate ?

  


  Context :

  


  My ideal GOP size formula is source_fps * 2. My source's framerate can be either 30 or 60 fps so I'm unable to set a static value that works for both. Is there a variable that ffmpeg exposes that I can use ? I know you can get metadata about the source input when using the -vf option with variables like iw or ih. Is there a similar method for FPS ?

  


  Example command where GOP size and keyint_min is hardcoded :

  


  ffmpeg -i <input /> -keyint_min 120 -g 120 -f dash /path/to/out.mpd&#xA;

  


  Desired command where e GOP size and keyint_min are based on the source framerate :

  


  ffmpeg -i <input /> -keyint_min source_framerate * 2 -g source_framerate * 2 -f dash /path/to/out.mpd&#xA;