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• Running error, [h264 @ 0x10af4a0] AVC : nal size [big number]

  27 mars 2017, par Beanocean

  I am using libavformat apis to get video frame from a MP4 video file. My code (c++) runs good in my personal computer, but when I try to deploy it into computing server, there are something strange happens. In the function ’av_read_frame()’, some errors appear.

  [h264 @ 0x10af4a0] AVC: nal size 555453589
  
  [h264 @ 0x10af4a0] AVC: nal size 555453589
  
  [h264 @ 0x10af4a0] no frame!

  My code is like this :

  if (av_read_frame(_p_format_ctx, &_packet) < 0) {
  
      return false; 
  
  }

  But when this error occurs, the program doesn’t exit. But the final results are wrong.

  The OS of computing server is Linux, the kernel is 2.6.32.
  The version of FFmpeg is 3.2.4.
  The version of gcc is 4.8.2.

• ffmpeg python subprocess error only on ubuntu

  19 avril 2017, par Wonger

  Im working on an application that is splitting videos from youtube into images. I work on a macbook pro for development, but our app servers run on an ubuntu 12.04 server. The current code on our servers running right now is the following

  ffmpeg -i {video_file} -vf fps={fps}

  which we run via a subprocess Popen function call in python. This has very slow performance because it is essentially playing back the whole video file to get the frames. I found another SO post that said you could use -accurate_seek -ss to grab single frames at a specific time, but I am facing some issues with that. When i run the command via command line when SSH into our dev server, it works fine, but when i run it via a subprocess Popen call in python, i get the following error :

  (standard_in) 1: syntax error
  
  ffmpeg version 3.2.4-static http://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2017 the FFmpeg developers
  
    built with gcc 5.4.1 (Debian 5.4.1-5) 20170205
  
    configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc-5 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gray --enable-libass --enable-libfreetype --enable-libfribidi --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libzimg
  
    libavutil      55. 34.101 / 55. 34.101
  
    libavcodec     57. 64.101 / 57. 64.101
  
    libavformat    57. 56.101 / 57. 56.101
  
    libavdevice    57.  1.100 / 57.  1.100
  
    libavfilter     6. 65.100 /  6. 65.100
  
    libswscale      4.  2.100 /  4.  2.100
  
    libswresample   2.  3.100 /  2.  3.100
  
    libpostproc    54.  1.100 / 54.  1.100
  
  Option accurate_seek (enable/disable accurate seeking with -ss) cannot be applied to output url test.mkv -- you are trying to apply an input option to an output file or vice versa. Move this option before the file it belongs to.
  
  Error parsing options for output file test.mkv.
  
  Error opening output files: Invalid argument

  python code :

  import subprocess
  
  command = "for i in {0..3} ; do ffmpeg -accurate_seek -ss `echo $i*60.0 | bc` -i test.mkv -frames:v 1 images/test_img_$i.jpg ; done"
  
  process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr = subprocess.STDOUT, shell=True)
  
  output = process.communicate()
  
  print output[0].replace('\\n' , '\n')

  The thing is, when i run this on my OSX terminal, it works fine, but there is some issue with doing it in ubuntu. Does anyone have experience with this issue ?

  Output when i run the same exact code in osx :

  ffmpeg version 3.0.2 Copyright (c) 2000-2016 the FFmpeg developers
  
    built with Apple LLVM version 7.3.0 (clang-703.0.31)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.0.2 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libxvid --enable-libvpx --enable-vda
  
    libavutil      55. 17.103 / 55. 17.103
  
    libavcodec     57. 24.102 / 57. 24.102
  
    libavformat    57. 25.100 / 57. 25.100
  
    libavdevice    57.  0.101 / 57.  0.101
  
    libavfilter     6. 31.100 /  6. 31.100
  
    libavresample   3.  0.  0 /  3.  0.  0
  
    libswscale      4.  0.100 /  4.  0.100
  
    libswresample   2.  0.101 /  2.  0.101
  
    libpostproc    54.  0.100 / 54.  0.100
  
    Input #0, matroska,webm, from 'test.mkv':
  
    Metadata:
  
      COMPATIBLE_BRANDS: iso6avc1mp41
  
      MAJOR_BRAND     : dash
  
      MINOR_VERSION   : 0
  
      ENCODER         : Lavf57.25.100
  
    Duration: 00:02:10.20, start: 0.007000, bitrate: 2729 kb/s
  
      Stream #0:0: Video: h264 (High), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
  
      Metadata:
  
        HANDLER_NAME    : VideoHandler
  
        DURATION        : 00:02:10.172000000
  
      Stream #0:1(eng): Audio: opus, 48000 Hz, stereo, fltp (default)
  
      Metadata:
  
        DURATION        : 00:02:10.201000000
  
        [swscaler @ 0x7f9b4b008000] deprecated pixel format used, make sure you did set range correctly
  
  Output #0, image2, to 'images/test_img_0.jpg':
  
    Metadata:
  
      COMPATIBLE_BRANDS: iso6avc1mp41
  
      MAJOR_BRAND     : dash
  
      MINOR_VERSION   : 0
  
      encoder         : Lavf57.25.100
  
      Stream #0:0: Video: mjpeg, yuvj420p(pc), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 23.98 fps, 23.98 tbn, 23.98 tbc (default)
  
      Metadata:
  
        HANDLER_NAME    : VideoHandler
  
        DURATION        : 00:02:10.172000000
  
        encoder         : Lavc57.24.102 mjpeg
  
      Side data:
  
        unknown side data type 10 (24 bytes)
  
        Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 (native) -> mjpeg (native))
  
    Press [q] to stop, [?] for help
  
  frame=    1 fps=0.0 q=7.2 Lsize=N/A time=00:00:00.04 bitrate=N/A speed=   1x    
  
  video:73kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
  
  ....

  One thing i forgot to mention is that on my mac i used homebrew to install ffmpeg, where as on Ubuntu i used a static build

  other stack overflow reference : Fastest way to extract frames using ffmpeg ?

• qsvenc : Make sure the interlaced encoding works

  6 mai 2017, par Aaron Levinson

  qsvenc : Make sure the interlaced encoding works
  Purpose : qsvenc : make sure that interlaced encoding works.  Also,
  
  reduce the vertical alignment constraint when possible to reduce
  
  memory usage.
  Note : Most of this code used to be present in ffmpeg and was
  
  eliminated in revision 1f26a23 on Oct. 31, 2016 (qsv : Merge libav
  
  implementation, at
  
  https://github.com/FFmpeg/FFmpeg/commit/1f26a231bb065276cd80ce02957c759f3197
  
  edfa#diff-7d84a34d58597bb7aa4b8239dca1f9f8).  Already applied to
  
  libav.
  Reviewed-by : Luca Barbato <lu_zero@gentoo.org>
  
  (cherry picked from commit 8fd8f91e47f33cd82371a97ac81afc476144964f)
  
  Signed-off-by : Mark Thompson <sw@jkqxz.net>
  
  Signed-off-by : Aaron Levinson <alevinsn@aracnet.com>
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavcodec/qsvenc.c
  • [DH] libavcodec/qsvenc.h