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• doc/filters : change subtitles example to hint at correct color syntax

  9 juin 2018, par Gyan Doshi

  doc/filters : change subtitles example to hint at correct color syntax
  libass changed their color syntax in 2015 to TBGR
  

  • [DH] doc/filters.texi

• h.264 lossless video in python with ffmpeg

  7 mars 2015, par Ojtwist

  I have raw video files which I encoded via ffmpeg (lossless) :

  ffmpeg -i test.avi -c:v libx264 -preset veryslow -crf 0 output.mkv

  Now I tried to read these in python :

      FFMPEG_BIN = "ffmpeg"
  
  
  
      command = [FFMPEG_BIN,
  
                     '-i',path,
  
                     '-f', 'image2pipe',
  
                     '-pix_fmt','yuv444p',
  
                     '-r',framerate,
  
                     '-ss',startposition,
  
                     '-vcodec','rawvideo','-']
  
  
  
      pipe = sp.Popen(command,stdout=sp.PIPE,bufsize=10**8)
  
  
  
      while True:
  
          raw_image = pipe.stdout.read(640*480*3)
  
  
  
          image = np.fromstring(raw_image,dtype='uint8')
  
  
  
          image = image.reshape((480,640,3))

  I can’t find the good command to get the video lossless in python. If I try it as mentioned above and show it with matplotlib, I get :
  

  If I set -vcodec to libx264 I get noise.

  

  If i set -pix_fmt to rgb24, I get a normal looking image, but I can see some artifact due to the color conversion.

  What is the command I am looking for ?

  ---

  extra info, the output of the encoding (initial raw video ==> lossless h.264) :

  worker@worklati:~/data/DMG/test$ ffmpeg -i test.avi -c:v libx264 -preset veryslow -crf 0 output.mkv
  
  ffmpeg version 2.5.3 Copyright (c) 2000-2015 the FFmpeg developers
  
    built on Jan 11 2015 17:53:45 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
  
    configuration: --extra-libs=-ldl --prefix=/opt/ffmpeg --enable-avresample --disable-debug --enable-nonfree --enable-gpl --enable-version3 --enable-libpulse --enable-libopencore-amrnb --enable-libopencore-amrwb --disable-decoder=amrnb --disable-decoder=amrwb --enable-libx264 --enable-libx265 --enable-libfdk-aac --enable-libvorbis --enable-libmp3lame --enable-libopus --enable-libvpx --enable-libspeex --enable-libass --enable-avisynth --enable-libsoxr --enable-libxvid --enable-libvo-aacenc --enable-libvidstab
  
    libavutil      54. 15.100 / 54. 15.100
  
    libavcodec     56. 13.100 / 56. 13.100
  
    libavformat    56. 15.102 / 56. 15.102
  
    libavdevice    56.  3.100 / 56.  3.100
  
    libavfilter     5.  2.103 /  5.  2.103
  
    libavresample   2.  1.  0 /  2.  1.  0
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  1.100 /  1.  1.100
  
    libpostproc    53.  3.100 / 53.  3.100
  
  Input #0, avi, from 'test.avi':
  
    Duration: 00:10:25.17, start: 0.000000, bitrate: 44237 kb/s
  
      Stream #0:0: Video: rawvideo, bgr24, 640x480, 6 fps, 6 tbr, 6 tbn, 6 tbc
  
  File 'output.mkv' already exists. Overwrite ? [y/N] y
  
  No pixel format specified, yuv444p for H.264 encoding chosen.
  
  Use -pix_fmt yuv420p for compatibility with outdated media players.
  
  [libx264 @ 0x1fd7160] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX AVX2 FMA3 LZCNT BMI2
  
  [libx264 @ 0x1fd7160] profile High 4:4:4 Predictive, level 3.2, 4:4:4 8-bit
  
  [libx264 @ 0x1fd7160] 264 - core 142 r2389 956c8d8 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - http://www.videolan.org/x264.html - options: cabac=1 ref=16 deblock=1:0:0 analyse=0x3:0x133 me=umh subme=9 psy=0 mixed_ref=1 me_range=24 chroma_me=1 trellis=0 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=0 chroma_qp_offset=0 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=2 keyint=250 keyint_min=6 scenecut=40 intra_refresh=0 rc=cqp mbtree=0 qp=0
  
  Output #0, matroska, to 'output.mkv':
  
    Metadata:
  
      encoder         : Lavf56.15.102
  
      Stream #0:0: Video: h264 (libx264) (H264 / 0x34363248), yuv444p, 640x480, q=-1--1, 6 fps, 1k tbn, 6 tbc
  
      Metadata:
  
        encoder         : Lavc56.13.100 libx264
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264))
  
  Press [q] to stop, [?] for help
  
  frame= 3751 fps= 40 q=-1.0 Lsize=  133724kB time=00:10:25.16 bitrate=1752.3kbits/s    
  
  video:133691kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.024307%
  
  [libx264 @ 0x1fd7160] frame I:16    Avg QP: 0.00  size: 58298
  
  [libx264 @ 0x1fd7160] frame P:3735  Avg QP: 0.00  size: 36403
  
  [libx264 @ 0x1fd7160] mb I  I16..4: 65.3%  6.9% 27.7%
  
  [libx264 @ 0x1fd7160] mb P  I16..4:  3.0%  2.1%  0.2%  P16..4: 71.2%  0.8% 22.4%  0.0%  0.0%    skip: 0.1%
  
  [libx264 @ 0x1fd7160] 8x8 transform intra:36.9% inter:49.5%
  
  [libx264 @ 0x1fd7160] coded y,u,v intra: 79.3% 0.0% 0.0% inter: 97.6% 0.0% 0.0%
  
  [libx264 @ 0x1fd7160] i16 v,h,dc,p: 20%  3% 76%  1%
  
  [libx264 @ 0x1fd7160] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu:  5%  8% 80%  1%  1%  2%  1%  1%  1%
  
  [libx264 @ 0x1fd7160] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 23% 28% 16%  5%  7%  8%  5%  4%  5%
  
  [libx264 @ 0x1fd7160] Weighted P-Frames: Y:0.2% UV:0.0%
  
  [libx264 @ 0x1fd7160] ref P L0: 63.2%  0.0% 14.2%  5.3%  4.0%  3.2%  2.6%  1.1%  1.0%  1.0%  0.9%  1.1%  0.7%  0.6%  0.6%  0.6%
  
  [libx264 @ 0x1fd7160] kb/s:1751.85

• configure : Make compilable with VS2015

  6 mars 2015, par Peter Tissen

  configure : Make compilable with VS2015
  So Visual Studio 2015 has some breaking changes regarding the C
  
  runtime. In short, they made C99 compatable runtime.
  
  Refer to http://blogs.msdn.com/b/vcblog/archive/2014/06/18/crt-features-fixes-and-breaking-changes-in-visual-studio-14-ctp1.aspx
  Made-Seriously-Happy : "Ronald S. Bultje" <rsbultje@gmail.com>
  
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] configure