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• Is there a way to calculate a average bitrate of video stream for each second ? Using ffmpeg or gsteamer toolkits [closed]

  15 mai 2012, par IOException

  I've encoded some video sample by different x264 presets. I already gathered some metric for each preset's file sample (PSNR,SSIM http://en.wikipedia.org/wiki/Structural_similarity)
  Now I am curious in instant (every seconds) file sample's bitrate, to compare them.

  I found out simple solution by googling around :

  http://akuvian.org/src/mplayer/avi_bitrate.pl
  This works on AVI files (regardless of codec), so you'd have to remux it first.
  Requires perl, mplayer, and gnuplot.

  I works for me

• WMA Lossless and ProRes Encoder

  4 mars 2012, par Multimedia Mike — General

  The projects (FFmpeg / Libav) just got a WMA lossless decoder. For those keeping score, this means that there are open source methods for decoding every single one of Microsoft’s proprietary audio codecs (Windows Media Audio, or WMA) : WMA v1, WMA v2, WMA9/Pro, WMA Voice, and now WMA lossless. Currently, it’s only advertised to decode 16-bit audio (no 24-bit). Also, when I first tried it a few days ago, it didn’t decode the very end of the single sample file I concocted many years ago (luckynight.wma). But that might be cleared up by now.

  Some other recent developments in the projects that I wanted to call out : An encoder for the Apple ProRes encoder from Kostya ; XWD (X window dump) image decoding and encoding from Paul B. Mahol ; a Sun rasterfile encoder from Aneesh Dogra.

  And then there’s the new playback system for CDXL files, also courtesy of Paul B. Mahol. I wasn’t familiar with this format until I wrote this post, which is surprising, given the format’s vintage. This was a CD-ROM FMV format favored for Amiga computers. Here it is in all its 160x120x10fps glory :

  
  
  

  That’s the amigaball.cdxl sample available in the repository. The sample is 3835910 bytes large and plays for about 24 seconds. This yields a data rate of about 159 kbytes/second. So, yeah, single-speed CD-ROM FMV.

• How to increase video encoding speed in ffmpeg ?

  16 octobre 2017, par Ashutosh Tiwari

  I am recording video clips and then joining all the clips in a final video.
  Everything goes fine but the joining process takes too long.

  Tried to using some ffmpeg filters from here :
  https://trac.ffmpeg.org/wiki/Encode/H.264

  And here is my ffmpeg command that I am using to increase the speed (which seems to be wrong) :

  command = new String[]{"-y",
  
                  "-f",
  
                  "concat",
  
                  "-safe",
  
                  "0",
  
                  "-i",
  
                  "/storage/emulated/0/DCIM/my_file.txt",
  
                  "-c:v",
  
                  "-preset",
  
                  "fast",
  
                  "-crf",
  
                  "22",
  
                  "copy",
  
                  "-flags",
  
                  "+global_header",
  
                  "/storage/emulated/0/DCIM/SampleApp/" + videoOutputPath
  
          };

  Please help ! Thanks much.