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• ffmpeg not finding audio streams ?

  24 septembre 2013, par Jim Miller

  I'm doing some video conversion with ffmpeg v. N-54271-g7f866c1 (a fresh pull from the git sources in late June 2013) on Fedora 19. One of the things I want to do is to concatenate two videos and then convert the result to an mp4. The following code is working well for me :

  ffmpeg -i video_a.mov -i video_b.mov -acodec libfaac -vcodec libx264 
  
       -preset fast -crf 22  -s 940x528 -pix_fmt yuv420p 
  
       -filter_complex '[0:1] [0:0] [1:1] [1:0]  concat=n=2:v=1:a=1 [v] [a]' 
  
       -map '[v]' -map '[a]' output.mp4

  except for a couple of older hunks of test video I've been using. On those, ffmpeg isn't finding the audio stream, and so the above call dies with ffmpeg complaining that Stream specifier ':1' in filtergraph description [0:1][0:0][1:1][1:0] concat=n=2:v=1:a=1 [v] [a] matches no streams. The catch, of course, is that there is an audio stream in the video ; it's just not getting found.

  When ffmpeg starts, I get a description of the input like so :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/var/www/priv/videorising7/raw_take_video/v2261-MTQxMzgwMDM4NzAx.mov':
  
    Metadata:
  
      major_brand     : qt  
  
      minor_version   : 537199360
  
      compatible_brands: qt  
  
      creation_time   : 2011-10-13 16:08:18
  
    Duration: 00:00:25.52, start: 0.000000, bitrate: 49 kb/s
  
      Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 608x342, 47 kb/s, 10.03 fps, 10 tbr, 1k tbn, 2k tbc
  
      Metadata:
  
        creation_time   : 2011-10-13 16:08:18
  
        handler_name    : Apple Alias Data Handler

  I suppose the video might just be so old (2006 ?) that I should be lucky that it plays at all. However, I'm able to run these videos through some other ffmpeg jobs (converting from .mov to .mp4, for instance), but those don't require explicitly referencing the audio and video tracks. Any insights out there ?

• Improve the quality of webm video using ffmpeg

  3 octobre 2013, par Leke

  I'm trying out two codecs and was wondering if I could improve the results of the webm output ...

  ffmpeg -i test.ts -t 10 -f webm -vcodec libvpx output.webm

  to match the quality of the mp4 output...

  ffmpeg -i test.ts -t 10 -b 1500k -vcodec libx264 output.mp4

  What settings would give me the best webm rip ?

  Thanks.

  Edit :
  Here is an error output when trying some rip improvements...

  ffmpeg -i test.ts -c:v libvpx -crf 4 -b:v 1M -c:a libvorbis output.webm
  
  
  
  ffmpeg version 0.8.6-4:0.8.6-0ubuntu0.12.04.1, Copyright (c) 2000-2013 the Libav developers
  
    built on Apr  2 2013 17:00:59 with gcc 4.6.3
  
  *** THIS PROGRAM IS DEPRECATED ***
  
  This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.
  
  [mpeg2video @ 0x9cde5c0] mpeg_decode_postinit() failure
  
      Last message repeated 4 times
  
  [mpegts @ 0x9cda240] max_analyze_duration reached
  
  [mpegts @ 0x9cda240] PES packet size mismatch
  
  Input #0, mpegts, from 'test.ts':
  
    Duration: 00:03:59.53, start: 4630.845422, bitrate: 1977 kb/s
  
      Stream #0.0[0x20b]: Video: mpeg2video (Main), yuv420p, 720x576 [PAR 64:45 DAR 16:9], 15000 kb/s, 25.60 fps, 25 tbr, 90k tbn, 50 tbc
  
      Stream #0.1[0x28f]: Audio: mp2, 48000 Hz, stereo, s16, 224 kb/s
  
  
  
  Unrecognized option 'c:v'
  
  Failed to set value 'libvpx' for option 'c:v'

• ffmpeg need some quality advices

  2 octobre 2013, par xakepp35

  help ! current dir : contains files in .bmp formt ! I need to get *.avi at 4fps from frames i have alredy got in current forlder

  D:\WORK\MyFrames>"C:\Users\Den\Downloads\ffmpeg-latest-win32-static\ffmpeg-201 30928-git-c461265-win32-static\bin\ffmpeg.exe" -i d:\WORK\MyFrames\IMG_%4d.bmp
  
   -r 4 -vcodec h264 -y out.avi
  
  ffmpeg version N-56715-gc461265 Copyright (c) 2000-2013 the FFmpeg developers built on Sep 28 2013 18:02:00 with gcc 4.8.1 (GCC)
  
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-av
  
  isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
  
  le-iconv --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetyp
  
  e --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --ena
  
  ble-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-l
  
  ibopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libsp
  
  eex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aa
  
  cenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavp
  
  ack --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
  
  libavutil      52. 46.100 / 52. 46.100
  
  libavcodec     55. 33.101 / 55. 33.101
  
  libavformat    55. 18.104 / 55. 18.104
  
  libavdevice    55.  3.100 / 55.  3.100
  
  libavfilter     3. 88.100 /  3. 88.100
  
  libswscale      2.  5.100 /  2.  5.100
  
  libswresample   0. 17.103 /  0. 17.103
  
  libpostproc    52.  3.100 / 52.  3.100
  
  [image2 @ 022cfa60] Could find no file with path 'd:\WORK\MyFrames\IMG_%4d.bmp
  
  ' and index in the range 0-4
  
  d:\WORK\Serega28-3\IMG_%4d.bmp: No such file or directory