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• Revision 1e30547984 : Skip mode search based on reference frame consistency This commit enables the e

  12 août 2014, par Jingning Han

  Changed Paths :
   Modify /vp9/encoder/vp9_rdopt.c

  
  
  Skip mode search based on reference frame consistency

  This commit enables the encoder to skip NEARMV and ZEROMV if the
  above and left blocks have identical reference frame, and the
  current reference is different from that. It reduces the runtime
  of speed 3 for test sequences :
  bus cif at 1000 kbps 10064 ms -> 9823 ms
  pedestrian 1080p at 2000 kbps 193078 ms -> 189559 ms

  The compression performance is changed by
  derf -0.085%
  stdhd -0.103%

  Change-Id : If304f26d42e6412152a84c3dd7b02635c38444f4

• Elimination compression from videos generated from images using ffmpeg ?

  5 novembre 2011, par Magz

  So I'm using ffmpeg to generate videos from a series of images. Unfortunately every video I've generated so far becomes compressed about halfway through (these are about 10-30 second videos). I've tried a lot of different options, but here's an example and the resulting output.

  Any suggestions ?

  ffmpeg -minrate 5000k -maxrate 5000k -bufsize 1835k -b 5000k -s 480x480 \
  
  -f image2 -r 10 -i 'dms-%05d.jpeg' output.flv
  
  
  
  
  
  ffmpeg version 0.8.1, Copyright (c) 2000-2011 the FFmpeg developers
  
    built on Jul 29 2011 14:13:56 with gcc 4.2.1 (Apple Inc. build 5664)
  
    configuration: --enable-libmp3lame --enable-shared --disable-mmx --arch=x86_64
  
    libavutil    51.  9. 1 / 51.  9. 1
  
    libavcodec   53.  7. 0 / 53.  7. 0
  
    libavformat  53.  4. 0 / 53.  4. 0
  
    libavdevice  53.  1. 1 / 53.  1. 1
  
    libavfilter   2. 23. 0 /  2. 23. 0
  
    libswscale    2.  0. 0 /  2.  0. 0
  
  [image2 @ 0x101007c00] max_analyze_duration 5000000 reached at 5000000
  
  Input #0, image2, from 'dms-%05d.jpeg':
  
    Duration: 00:00:10.00, start: 0.000000, bitrate: N/A
  
      Stream #0.0: Video: mjpeg, yuvj444p, 559x480 [PAR 1:1 DAR 559:480], 10 fps, 10 tbr, 10 tbn, 10 tbc
  
  Incompatible pixel format 'yuvj444p' for codec 'flv', auto-selecting format 'yuv420p'
  
  [buffer @ 0x100d00230] w:559 h:480 pixfmt:yuvj444p tb:1/1000000 sar:1/1 sws_param:
  
  [buffersink @ 0x100d02160] auto-inserting filter 'auto-inserted scaler 0' between the filter 'src' and the filter 'out'
  
  [scale @ 0x100d023a0] w:559 h:480 fmt:yuvj444p -> w:559 h:480 fmt:yuv420p flags:0x4
  
  Output #0, flv, to 'output.flv':
  
    Metadata:
  
      encoder         : Lavf53.4.0
  
      Stream #0.0: Video: flv, yuv420p, 559x480 [PAR 1:1 DAR 559:480], q=2-31, 200 kb/s, 1k tbn, 10 tbc
  
  Stream mapping:
  
    Stream #0.0 -> #0.0
  
  Press [q] to stop, [?] for help
  
  [buffer @ 0x100d00230] Buffer video input changed from size:559x480 fmt:yuvj444p to size:480x480 fmt:yuvj420p
  
  [scale @ 0x100d023a0] w:480 h:480 fmt:yuvj420p -> w:559 h:480 fmt:yuv420p flags:0x2
  
  [buffer @ 0x100d00230] Buffer video input changed from size:480x480 fmt:yuvj420p to size:559x480 fmt:yuvj444p
  
  [scale @ 0x100d023a0] w:559 h:480 fmt:yuvj444p -> w:559 h:480 fmt:yuv420p flags:0x2
  
  [buffer @ 0x100d00230] Buffer video input changed from size:559x480 fmt:yuvj444p to size:480x480 fmt:yuvj420p
  
  [scale @ 0x100d023a0] w:480 h:480 fmt:yuvj420p -> w:559 h:480 fmt:yuv420p flags:0x2
  
  [buffer @ 0x100d00230] Buffer video input changed from size:480x480 fmt:yuvj420p to size:559x480 fmt:yuvj444p
  
  [scale @ 0x100d023a0] w:559 h:480 fmt:yuvj444p -> w:559 h:480 fmt:yuv420p flags:0x2
  
  [buffer @ 0x100d00230] Buffer video input changed from size:559x480 fmt:yuvj444p to size:480x480 fmt:yuvj420p
  
  [scale @ 0x100d023a0] w:480 h:480 fmt:yuvj420p -> w:559 h:480 fmt:yuv420p flags:0x2
  
  [buffer @ 0x100d00230] Buffer video input changed from size:480x480 fmt:yuvj420p to size:559x480 fmt:yuvj444p
  
  [scale @ 0x100d023a0] w:559 h:480 fmt:yuvj444p -> w:559 h:480 fmt:yuv420p flags:0x2
  
  frame=  100 fps= 35 q=24.8 Lsize=    1062kB time=00:00:10.00 bitrate= 870.2kbits/s    
  
  video:1060kB audio:0kB global headers:0kB muxing overhead 0.166586%

• FFmpeg avcodec_find_encoder problem

  13 novembre 2012, par net

  I'm newbie in ffmpeg.

  my problem is "avcodec_find_encoder(CODEC_ID_H264) ;" func always returning null.

  ffmpeg configure is below on my ubuntu system.

  ./ffmpeg
  
  FFmpeg version SVN-r26306, Copyright (c) 2000-2011 the FFmpeg developers
  
    built on Jan 11 2011 10:34:49 with gcc 4.4.5
  
    configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-postproc --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-x11grab
  
    libavutil     50.36. 0 / 50.36. 0
  
    libavcore      0.16. 0 /  0.16. 0
  
    libavcodec    52.108. 0 / 52.108. 0
  
    libavformat   52.92. 0 / 52.92. 0
  
    libavdevice   52. 2. 3 / 52. 2. 3
  
    libavfilter    1.72. 0 /  1.72. 0
  
    libswscale     0.12. 0 /  0.12. 0
  
    libpostproc   51. 2. 0 / 51. 2. 0

  as you can see, configuration contains —enable-libx264

  so I think avcodec_find_encoder(CODEC_ID_H264) ; have to return something not null...
  please let me know how to solve this problem ?

  ps) I call avcodec_init() and av_register_all() in my program.

  when I compile my test program, using below

  gcc -o test test.c -lavutil -lavformat -lavcodec -lx264 -lz -lm

  thanks