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• Creating MOV from PNGs with ffmpeg : playback issue in older quicktime (7.6.6)

  15 avril 2013, par Jim Lindstrom

  I'm using ffmpeg to create a MOV file from a series of images. When I view the movie in Quicktime 7.7.x, it looks great (left image). When I view in Quicktime 7.6.6 I get this weird issue (on the right) :

  
  

  Any idea even what this is, much less how to fix it ?

  Details

  My source images are a mix of PNGs and JPGs that I pre-process with ImageMagick (to draw text, captions, etc). I store intermediate results as MPCs, and final frames as PNMs.

  To draw the above frame, I'm doing this :

  convert -background none -fill white -font my_font.ttf -pointsize 132 -gravity \
  
          center -size 945x550 caption:"Stills Demo" background-template.png     \
  
          +swap -composite -resize 1920x1080! /tmp/title_screen4338355.png
  
  convert -auto-orient /tmp/title_screen4338355.png -resize 100% -type TrueColor \
  
          /tmp/1b2764754ce6e420986ed74b942bcf67.mpc
  
  convert /tmp/1b2764754ce6e420986ed74b942bcf67.mpc -set option:distort:viewport \
  
          1920x1080+0+0  +distort SRT '960.0,540.0 1.0 0 960.0,540.0'            \
  
          /tmp/stills-project-6224/video_frames/img_0000.pnm

  I render frames with ffmpeg like so :

  ffmpeg -y -f image2 -i /tmp/stills-project-6224/video_frames/img_%04d.pnm      \
  
         -i /tmp/soundtrack_8702693.wav -vcodec libx264 -pix_fmt yuvj444p        \
  
         -b:v 2200k  -r 25 -strict experimental                                  \
  
         /tmp/stills-project-6224/video_rendered/output.mov

  The rest of the video is fine. The other images are photos (jpgs or pngs) that I process in the same way. I have also noticed that if I don't apply text to this background-template, the image shows up fine, so I think the issue has something to do with either how I'm processing or saving that image.

• Incorrect frame rate in video (Xuggler + MPEG 4 + H.264)

  12 novembre 2014, par Vladislav Bauer

  I have a problem with incorrect value of frame rate in output file, after converting. I made a really simple example to describe a problem :

  public static void main(String[] args) {
  
      // reader
  
      IMediaReader reader = ToolFactory.makeReader("/tmp/1/i3.avi");
  
      IMediaWriter writer = ToolFactory.makeWriter("/tmp/1/o3.mp4", reader);
  
      reader.addListener(writer);
  
  
  
      while (true) {
  
          try {
  
              final IError error = reader.readPacket();
  
              if(error != null) {
  
                  System.err.println("Error decoding packet " + error.getDescription());
  
  
  
                  if (!reader.isOpen()) {
  
                      break;
  
                  }
  
              }
  
          } catch (final Exception ex) {
  
              System.err.println("Error decoding packet " + ex.getMessage());
  
              if (!reader.isOpen()) {
  
                  break;
  
              }
  
          }
  
      }
  
  }

  Any additional parameters for video or audio streams/codecs aren’t configured .

  The input video file ("/tmp/1/i3.avi") has the following features :

  • General
    • Container : Audio Video Interleave (AVI)
  • Video
    • Dimensions : 624x352
    • Codec : XVID MPEG-4
    • Framerate : 24 frames per second
    • Bitrate : N/A
  • Audio :
    • Codec : MPEG-1 Layer 3 (MP3)
    • Channels : Stereo
    • Sample rate : 48000 Hz
    • Bitrate : 112 kbps

  The output video file ("/tmp/1/o3.avi") has the following features :

  • General
    • Container : Quicktime
  • Video
    • Dimensions : 624x352
    • Codec : H.264
    • Framerate : 8 frames per second
    • Bitrate : 378 kbps
  • Audio :
    • Codec : MPEG-4 AAC
    • Channels : Stereo
    • Sample rate : 48000 Hz
    • Bitrate : 127 kbps

  So, the frame rate in output file is 8 instead of 24. How can I fix it ? Please, help me..

  PS : I’ve already tried Xuggler H264 FPS encoding issue and few another solutions, it doesn’t help..

  ---

  UPD : After a long war with Xugler I wrote my own pure-java interface to the avconv and it works fine for me : https://github.com/vbauer/avconv4java

• using pocketsphinx_continuous with a .wav file

  3 avril 2013, par user2242131

  I am attempting to write an application that will allow a user to speak a small set of commands from a remote system and have them executed on my server. Using pocketsphinx to parse the spoken text. When run locally with the microphone, pocketsphinx_continuous works perfectly no matter how I slur the words. But when importing the audio file and using ffmpeg to downsample the audio to a single channel, 16 bit PCM file, it will parse the first word without difficulty. Then it will skip everything else and treat it as . I am confident that the problem is in the file format and not in the pocketsphinx configuration.

  Using command line
  ffmpeg -y -i Sound\AddSheet.wav -ac 1 -f s16le -acodec pcm_s16le -ar 16k AddTmp.wav
  in a batch file.

  The bottom of the output I get is :

  INFO: fsg_search.c(1407): Start node ADD.0:5:47
  
  INFO: fsg_search.c(1407): Start node <sil>.0:2:49
  
  INFO: fsg_search.c(1446): End node <sil>.126:128:305 (-486)
  
  INFO: fsg_search.c(1662): lattice start node <s>.0 end node <sil>.126
  
  INFO: ps_lattice.c(1352): Normalizer P(O) = alpha(<sil>:126:305) = -175371
  
  INFO: ps_lattice.c(1390): Joint P(O,S) = -176076 P(S|O) = -705
  
  000000000: ADD USER
  
  </sil></sil></s></sil></sil>

  Which is not the audio in the file. The words spoken in the file are "ADD SPREADSHEET", which works perfectly from the same microphone without the intervening .wav file.

  I have tried increasing the audio volume and decreasing the background noise using sox :

  sox -v 3.0 Sound\%1 Sound\%1-loud.wav ffmpeg -i Sound\%1-loud.wav -vn -ss 00:00:00 -t 00:00:01 -y Sound\%1-noiseaud.wav 
  
  sox Sound\%1-noiseaud.wav -n noiseprof Sound\%1-noise.prof 
  
  sox Sound\%1 Sound\%1-clean.wav noisered sound\noise.prof 0.21 
  
  ffmpeg -y -i Sound\%1-clean.wav -ac 1 -f s16le -acodec pcm_s16le -ar 16k AddTmp.wav

  with no noticeable effect on the final results.

  If you look at the output you will notice that fsg_search.c has found ADD as the start node, then silence for the remainder. Please help on this.