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• FFmpeg not copying all audio streams

  15 juin 2016, par user2513268

  I’m having trouble getting ffmpeg to copy all audio streams from a .mp4 file. After hours of searching online, it appears this should copy all streams (as shown in example 4 here) :

  ffmpeg -i in.mp4 -map 0 -c copy out.mp4

  in.mp4 contains 3 streams :

  • Video
  • Audio track 1
  • Audio track 2

  out.mp4 (which should be identical to in.mp4) contains only 2 streams :

  • Video
  • Audio track 1

  FFmpeg does appear to correctly identify all 3 streams, but doesn’t copy all of them over. Output from FFmpeg :

  Stream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
    Stream #0:1 -> #0:1 (copy)
  
    Stream #0:2 -> #0:2 (copy)

  Edit : Output from ffmpeg -v 9 -loglevel 99 -i in.mp4 :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from in.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf57.36.100
  
    Duration: 00:00:06.03, start: 0.000000, bitrate: 5582 kb/s
  
      Stream #0:0(und), 1, 1/15360: Video: h264 (Main), 1 reference frame (avc1 /
  
  0x31637661), yuv420p(tv, bt470bg/unknown/unknown, left), 1920x1080 (0x0) [SAR 1:
  
  1 DAR 16:9], 0/1, 5317 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und), 1, 1/48000: Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz,
  
   stereo, fltp, 128 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
      Stream #0:2(und), 1, 1/48000: Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz,
  
   stereo, fltp, 128 kb/s
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Successfully opened the file.
  
  At least one output file must be specified
  
  [AVIOContext @ 0000000001c2b9e0] Statistics: 153350 bytes read, 2 seeks

  Edit 2 (solved) : I managed to find the correct syntax from this ticket. For any others that are interested, the correct syntax is :

  ffmpeg -i in.mp4 -vcodec copy -c:a copy -map 0 out.mp4

  This will copy all streams.

• Calculate frames to remove to get timelapse of desired length

  12 juin 2016, par Espen Birk

  I’ve got lots of images stored on a server, and a reference in a MySQL database so that i can easily query it for image from specific dates/time.

  Images is taken with an interval of 7 images/hour.

  Lets say i want to create a timelapse from the last 4 days, and make a 5 sec movie. How can i calculate how to evenly drop frames to get to that desired length of 5 seconds ?

  This is what i got so far.

  Total images : 4 Days * 24 hours * 7 images/hour = 672 images
  Required images at 24 fps : 24 * 5 = 120 images

  Divide the total images with the required images to find out which/every frame i need to keep

  672 / 120 = 5.6

  Then i loop trough all 672 images, and every 5th or 6th time i store a reference to the image in an array.

  Here is my problem. If i round up i get a video thats longer than i want, and if i round down i get a video thats shorter.

  If i keep every 5th image when looping : 134 images / 24 fps = 5.6 sec video
  If i keep every 6th image when looping : 112 images / 24 fps = 4.6 sec video

  Is it possible to get it better, and still skip images evenly ?

  Solved this using xxfelixxx’s answer in PHP
  Heres the code in PHP :

  $start  = 1;
  
  $stop   = 672; // Total Images
  
  
  
  $dur    = 5;   // Video Duration
  
  $n      = 24 * $dur; // Required frames - 24 FPS * Duration
  
  $next   = $start;
  
  $step = ( $stop - $start ) / $n;
  
  
  
  $frames = array();
  
  
  
  for ($i = 1; $i <= $n; $i++) {
  
      $frames[] = round($next);
  
      $next += $step;
  
  };
  
  
  
  var_dump($frames);

• FFMPEG on Windows [on hold]

  22 mai 2016, par Sagar Shirke

  I am using ffmpeg-20160522-git-566be4f-win64-static for streaming HLS. I have successfully published my HLS stream on to a CDN. My requirement is to use FFMPEG for 24*7 streaming workflow.

  Below is the command that I use.

  ffmpeg -i "LIVE TS UDP?fifo_size=5000000" -vcodec libx264 -s 720x576 -profile:v baseline -level 3.1 -vb 1500k -minrate 1500k -maxrate 1500k -bufsize 3000k -pix_fmt yuv420p -r 25 -force_key_frames "expr:gte(t,n_forced*2)" -flags -global_header -acodec aac -ab 64k -ac 2 -ar 48000 -f segment -segment_time 10 -segment_start_number 1 -segment_wrap 0 -segment_list PlaybackURL/Layer3_master.m3u8 -segment_format mpeg_ts -segment_list_type m3u8 -segment_list_flags +live -segment_list_size 0 EntryPoint/Layer3_master_%05d.ts

  The issue is that the stream fails after few hours with an error in red
  

  "av_interleaved_write_frame(): Unknown error
Erros writing trailer of EntryPoint/Layer3_master_%05d.ts: Invalid argument"

  Is there some parameter missing in my command ? Also this failure does not add EXT-ENDLIST tag in my HLS manifest. Please help.

  Regards,
  Sagar Shirke