Recherche avancée

Sur d’autres sites (10325)

• dnxhddec : better support for 4:4:4

  4 octobre 2015, par Christophe Gisquet

  dnxhddec : better support for 4:4:4
  Profiles 1256 & 1270 (currently) signal at the frame header and MB
  
  levels the colorspace used, either RGB or YUV. While a MB-level
  
  varying colorspace is not supported, whether it is constant can be
  
  tracked so as to determine the exact colorspace.
  This requires having bitdepth and the ACT and 4:4:4 flags, in turn
  
  needing the CID. Because setting those before having validated
  
  enough things may result in invalid/unset DSP fucntions, setting
  
  the bitdepth in the context is delayed.
  It is not tested against a true RGB sequence, though.
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavcodec/dnxhddec.c

• Fix some broken clamping in rate control.

  11 octobre 2015, par Tim Terriberry

  Fix some broken clamping in rate control.
  If we have some dupe frames right near the end of the buffer, our
  
   metric window can be slightly larger than the buffer.
  
  However, the clamping we use to determine how many frames' worth of
  
   metrics to add to the buffer had a mix of signed and unsigned
  
   types, so if that number when negative, instead of clamping
  
   against zero, it would ask for all remaining frames in the file.
  
  That would cause an infinite loop when we tried to find the last
  
   keyframe in the circular buffer in oc_enc_select_qi() (which was
  
   not big enough to actually hold that many frames).
  This patch changes the clamp to a form that works with all unsigned
  
   values.
  Thanks to Brion Vibber for the report.
  Fixes #2229
  git-svn-id : http://svn.xiph.org/trunk/theora@19507 0101bb08-14d6-0310-b084-bc0e0c8e3800
  

  • [DH] lib/rate.c

• ffmpeg selects shortest movie but leaves full length audio

  26 octobre 2015, par Stan James

  I’ve created a tool to create a grid of movies, like in the Brady Bunch opening. It’s a cool, funny effect.

  Here’s a sample movie showing the grid.

  

  The problem is that ffmpeg is choosing the shortest movie to determine the maximum length of overlaid videos, but still using the full length of the first audio track to determine the overall output movie length.

  So all my videos stop moving when the shortest one ends, but the audio plays on for full length of the first movie.

  How can I either (1) set the length of the output movie to the longest input movie or (2) match the audio length to the shortest movie length as well ?

  Gist of my script.

  Based on this ffmpeg example usage which exhibits the same audio problem :

  ffmpeg
  
      -i 1.avi -i 2.avi -i 3.avi -i 4.avi
  
      -filter_complex "
  
          nullsrc=size=640x480 [base];
  
          [0:v] setpts=PTS-STARTPTS, scale=320x240 [upperleft];
  
          [1:v] setpts=PTS-STARTPTS, scale=320x240 [upperright];
  
          [2:v] setpts=PTS-STARTPTS, scale=320x240 [lowerleft];
  
          [3:v] setpts=PTS-STARTPTS, scale=320x240 [lowerright];
  
          [base][upperleft] overlay=shortest=1 [tmp1];
  
          [tmp1][upperright] overlay=shortest=1:x=320 [tmp2];
  
          [tmp2][lowerleft] overlay=shortest=1:y=240 [tmp3];
  
          [tmp3][lowerright] overlay=shortest=1:x=320:y=240
  
      "
  
      -c:v libx264 output.mkv