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• Revision 80a4f55989 : Enable background detection for adaptive quantizer control This commit enables

  17 avril 2014, par Jingning Han

  Changed Paths :
   Modify /vp9/encoder/vp9_aq_cyclicrefresh.c

  
   Modify /vp9/encoder/vp9_block.h

  
   Modify /vp9/encoder/vp9_encodeframe.c

  
  
  Enable background detection for adaptive quantizer control

  This commit enables a background detection approach for adaptive
  quantizer control. It combines the cyclic refresh pattern and the
  background information to determine the segment id for adaptive
  quantizer selection, prior to the non-RD mode decision process.
  It hence allows proper quantization information update for a more
  precise rate-distortion modeling in the non-RD mode decision.

  The compression performance of speed -5 for rtc set is improved
  by 2.5%, at no speed change.

  Change-Id : Ic3713e8ed9185b403b5b1679d19dabd57506d452

• Bash : displaying selected output, do not print unnecessary output

  2 juillet 2014, par Guillaume

  I don’t know if it’s possible :
  I’m using ffmpeg and I would like to reduce the output of a command. I have this result :

  ffmpeg version 2.2.git Copyright (c) 2000-2014 the FFmpeg developers
  
    built on Jun 17 2014 11:08:12 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
  
    configuration: --prefix=/usr/local --enable-gpl --enable-nonfree --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-libvidstab --enable-libx265
  
    libavutil      52. 89.100 / 52. 89.100
  
    libavcodec     55. 67.100 / 55. 67.100
  
    libavformat    55. 43.100 / 55. 43.100
  
    libavdevice    55. 13.101 / 55. 13.101
  
    libavfilter     4.  8.100 /  4.  8.100
  
    libswscale      2.  6.100 /  2.  6.100
  
    libswresample   0. 19.100 /  0. 19.100
  
    libpostproc    52.  3.100 / 52.  3.100
  
  Input #0, hls,applehttp, from 'http://ftvodhdsecz-f.akamaihd.net/i/streaming-adaptatif_france-dom-tom/2014/S26/J7/104904507-20140629-,398,632,934,k.mp4.csmil/index_2_av.m3u8?null=':
  
    Duration: 00:51:05.07, start: 0.100667, bitrate: 0 kb/s
  
    Program 0 
  
      Metadata:
  
        variant_bitrate : 0
  
      Stream #0:0: Video: h264 (Main) ([27][0][0][0] / 0x001B), yuv420p, 704x396 [SAR 1:1 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc
  
      Stream #0:1: Audio: aac ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 67 kb/s
  
      Stream #0:2: Data: timed_id3 (ID3  / 0x20334449)
  
  File '/media/path/video.mkv' already exists. Overwrite ? [y/N] y
  
  [matroska @ 0x2958840] Error parsing AAC extradata, unable to determine samplerate.
  
  Output #0, matroska, to '/media/path/video.mkv':
  
    Metadata:
  
      encoder         : Lavf55.43.100
  
      Stream #0:0: Video: h264 (H264 / 0x34363248), yuv420p, 704x396 [SAR 1:1 DAR 16:9], q=2-31, 25 fps, 1k tbn, 90k tbc
  
      Stream #0:1: Audio: aac ([255][0][0][0] / 0x00FF), 48000 Hz, stereo, 67 kb/s
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
    Stream #0:1 -> #0:1 (copy)
  
  Press [q] to stop, [?] for help
  
  [hls,applehttp @ 0x2864c20] Failed to open segment of playlist 0ate= 844.6kbits/s    
  
  frame= 3000 fps=174 q=-1.0 Lsize=   12325kB time=00:02:00.00 bitrate= 841.4kbits/s 

  I just would like to have this 4 informations :

  1) Duration: 00:51:05.07, start: 0.100667, bitrate: 0 kb/s
  
  2)  File '/media/path/video.mkv' already exists. Overwrite ? [y/N] y
  
  3)  Output #0, matroska, to '/media/path/video.mkv':
  
  4)  frame= 3000 fps=174 q=-1.0 Lsize=   12325kB time=00:02:00.00 bitrate= 841.4kbits/s 

  I’ve tried the -v option, but the output is either -v info (this long output), or -v warning, or -v error. There’s not what I would like to have.
  I’ve seen this question but the output is totally clear. Can I put an exception for specially string ?
  Thanks all

  Edit : my line in my script is like that :

  ffmpeg -i "${M3U2}" -vcodec copy -acodec copy "${Directory}/${PROG}_${ID}.mkv"

• Split a movie so that each GIF is under a certain file size

  9 novembre 2014, par Terence Eden

  Problem

  I want to convert a long movie into a series on animated GIFs.

  Each GIF needs to be <5MB.

  Is there any way to determine how large a GIF will be while it is being encoded ?

  Progress So Far

  I can split the movie into individual frames :

  ffmpeg -i movie.ogv -r 25 frameTemp.%05d.gif

  I can then use convert from ImageMagick to create GIFs. However, I can’t find a way to determine the likely file size before running the command.

  Alternatively, I can split the movie into chunks :

  ffmpeg -i movie.ogv -vcodec copy -ss 00:00:00 -t 00:20:00 output1.ogv

  But I’ve no way of knowing if, when I convert the file to a GIF it will be under 5MB.

  A 10 second scene with a lot of action may be over 5MB (bad !) and a static scene could be under 5MB (not a problem, but not very efficient).

  Ideas

  I think that what I want to do is convert the entire movie into a GIF, then find a way to split it by file size.

  Looking at ImageMagick, I can split a GIF into frames, but I don’t see a way to split it into animated GIFs of a certain size / length.

  So, is this possible ?