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• Converting series of images with ffmpeg results in black video [migrated]

  27 avril 2013, par Marco Gagliardi

  I've just downloaded ffmpeg since it seems to perfectly match my needs (make a video from a set of pictures). I'm currently playing around with some examples just to get started and there's something weird happening that I can't explain.
  I'm trying this command (provided in the official documentation) :

  ffmpeg -f image2 -pattern_type glob -i 'foo-*.jpeg' -r 12 -s WxH foo.avi

  on a data set of 10 jpg pictures (of course I changed the pattern with '*.jpg'). The video seems to be encoded correctly but it's simply too fast to be sure about that (anyway it stops on the last frame that corresponds to the last picture). In order to get a longer video i thought to low the frame rate from 12 to 1 (one sec each picture) or 0.5 (2 sec each one) and so on.. no way ! with low rate values even if the video is played the pictures are simply not displayed. The player (VLC in my case) just shows a blank/empty video for a few seconds.

  Am I making something wrong or have I misunderstood the -r parameter ? Is it something related to codecs involved ? Finally.. How can i get each picture displayed for 1 or 2 seconds ?

  Here's the output :

  MacBook-Pro$ ffmpeg -f image2 -pattern_type glob -i '*.jpg' -r 1 -s 200x300 foo.avi
  
  ffmpeg version N-52517-g1e4f75d Copyright (c) 2000-2013 the FFmpeg developers
  
    built on Apr 27 2013 19:41:11 with llvm-gcc 4.2.1 (LLVM build 2336.11.00)
  
    configuration: --disable-yasm
  
    libavutil      52. 27.101 / 52. 27.101
  
    libavcodec     55.  6.100 / 55.  6.100
  
    libavformat    55.  3.100 / 55.  3.100
  
    libavdevice    55.  0.100 / 55.  0.100
  
    libavfilter     3. 61.100 /  3. 61.100
  
    libswscale      2.  2.100 /  2.  2.100
  
    libswresample   0. 17.102 /  0. 17.102
  
  Input #0, image2, from '*.jpg':
  
    Duration: 00:00:00.40, start: 0.000000, bitrate: N/A
  
      Stream #0:0: Video: mjpeg, yuvj422p, 2560x1920 [SAR 1:1 DAR 4:3], 25 fps, 25 tbr, 25 tbn, 25 tbc
  
  File 'foo.avi' already exists. Overwrite ? [y/N] y
  
  Output #0, avi, to 'foo.avi':
  
    Metadata:
  
      ISFT            : Lavf55.3.100
  
      Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 200x300 [SAR 2:1 DAR 4:3], q=2-31, 200 kb/s, 1 tbn, 1 tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (mjpeg -> mpeg4)
  
  Press [q] to stop, [?] for help
  
  frame=    2 fps=0.0 q=2.0 Lsize=      43kB time=00:00:02.00 bitrate= 177.1kbits/s dup=0 drop=8    
  
  video:38kB audio:0kB subtitle:0 global headers:0kB muxing overhead 15.099197%
  
  MacBook-Pro$ 

• ffmpeg/PHP - Problems converting any video format to ogg - Choppy Video / No Audio - win64

  9 août 2013, par IIIOXIII

  Let me first appologize if this is a re-post/similar-post as I did my best to search for a specific solution to my issue within the already created posts on here, and on google, but could not.

  I am using ffmpeg on localhost on win64 system to create/test video conversion scripts prior to uploading them to the server.

  I am able to successfully convert to/from mp4/flv/wmv/mov without issue, however, whenever I try to convert to .ogg from any other format, I run into issues.

  First I tried this :

  exec($ffmpegPath." -i ".$srcFile." ".$destFile);

  but ended up with a corrupt file without video/sound. Then I did some reading that and found some posts that said that you must explicitly enable libvorbis/libtheora when converting to .ogg, so I tried this :

  $aCodec = ' -acodec libvorbis';
  
  $vCodec = ' -vcodec libtheora';
  
  exec($ffmpegPath." -i ".$srcFile.$aCodec.$vCodec." ".$destFile);

  This time I got a valid .ogg file, with sound, however, the video output is VERY choppy. In hopes to try and find the issue, I started making edits to the exec line and ended up with this :

  $ffmpegObj = new ffmpeg_movie($srcFile);
  
  $srcVB = intval($ffmpegObj->getVideoBitRate());
  
  $vCodec = ' -vcodec libtheora';
  
  exec($ffmpegPath." -i ".$srcFile.$vCodec." -vb ".$srcVB." ".$destFile);

  which outputs the .ogg video in good quality but without sound.

  Any ideas as to what else may be this issue prior to needing to install further software (ffmpeg2theora), etc.?

  Also, if it helps, I echoed out the output from ffmpeg and when approach #2 above is used and many errors are displayed.

  100 buffers queued in output stream 0:1, something may be wrong.
  
  [ogg @ 00000000024bf780] st:0 PTS: 6743 DTS: 6743 < 7745 invalid, clipping
  
  [ogg @ 00000000024bf780] st:0 PTS: 6871 DTS: 6871 < 7746 invalid, clipping
  
  [ogg @ 00000000024bf780] st:0 PTS: 6999 DTS: 6999 < 7747 invalid, clipping
  
  [ogg @ 00000000024bf780] st:0 PTS: 7127 DTS: 7127 < 7748 invalid, clipping
  
  [ogg @ 00000000024bf780] st:0 PTS: 7255 DTS: 7255 < 7749 invalid, clipping
  
  [ogg @ 00000000024bf780] st:0 PTS: 7383 DTS: 7383 < 7750 invalid, clipping

  It seems that libvorbis and libtheora are not playing nice together ?

  Finally, I have changed ffmpeg.exe builds several times and still receive the same issue.

  Thanks in advance.

  EDIT : As a possible workaround, is there a way I can simply encode the video / audio separately and then slap them back together ? Would this cause possible audio/video sync issues ?

• matroskadec : Verify realaudio codec parameters

  16 septembre 2013, par Martin Storsjö

  matroskadec : Verify realaudio codec parameters
  Reported-by : Mateusz "j00ru" Jurczyk and Gynvael Coldwind
  
  CC : libav-stable@libav.org
  
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DH] libavformat/matroskadec.c