Recherche avancée

Sur d’autres sites (5341)

• ffmpeg mod if case in source code

  5 février 2014, par Stephan Pokorny

  I'm working on a specific ffmpeg mod where I have to auto execute an extension within the binary call.

  Specific it is the extension -isync -af aresample=async=1000

  The binary is called by another compiled tool which escapes my input.

  For that reason I wanna rewrite the filter rule to execude in any case.

  if (audio_sync_method > 0) {
  
      char args[256] = {0};
  
  
  
      av_strlcatf(args, sizeof(args), "async=%d", audio_sync_method);
  
      if (audio_drift_threshold != 0.1)
  
          av_strlcatf(args, sizeof(args), ":min_hard_comp=%f", audio_drift_threshold);
  
      if (!fg->reconfiguration)
  
          av_strlcatf(args, sizeof(args), ":first_pts=0");
  
      AUTO_INSERT_FILTER_INPUT("-async", "aresample", args);
  
  }

  Can somebody help me to execute this AUTO_INSERT_FILTER in any case which could happen.

  I already played around to answer any if loop with the AUTO_INSERT_FILTER_INPUT("-async", "aresample", 1000) ;

  When I launch I can see that it is calling the fresh compiled version of ffmpeg but not activating the filter

  Thanks

  Stephan

• ffmpeg pipe:0 : could not find codec parameters

  13 octobre 2016, par dre

  When i run this command i get an error. If i run without the pipe, it works.

  With Pipe

  cat mymovie.m4v | ffmpeg -i pipe:0 -an -analyzeduration 1000000 -f image2 -vf 
  
  "select='eq(pict_type,PICT_TYPE_I)'" -vsync vfr 'public/files/thumb%04d.png'

  Without Pipe (Works)

  ffmpeg -i mymovie.m4v -an -analyzeduration 2147483647 -probesize 2147483647 -f image2 -vf 
  
  "select='eq(pict_type,PICT_TYPE_I)'" -vsync vfr 'public/files/thumb%04d.png'

  Output

  ffmpeg version 2.2 Copyright (c) 2000-2014 the FFmpeg developers
  
  built on Apr 10 2014 17:50:46 with Apple LLVM version 5.1 (clang-503.0.38) 
  
  (based on LLVM 3.4svn)
  
  configuration: --prefix=/usr/local/Cellar/ffmpeg/2.2 
  
  --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-nonfree 
  
  --enable-hardcoded-tables --enable-avresample --enable-vda --cc=clang 
  
  --host-cflags= --host-ldflags= --enable-libx264 --enable-libfaac --enable-libmp3lame 
  
  --enable-libxvid --enable-libfreetype --enable-libtheora --enable-libvorbis 
  
  --enable-libvpx --enable-librtmp --enable-libopencore-amrnb --enable-libopencore-amrwb
  
  --enable-libvo-aacenc --enable-libass --enable-ffplay --enable-libspeex 
  
  --enable-libschroedinger --enable-libfdk-aac --enable-libopus --enable-frei0r 
  
  --enable-libopenjpeg --extra-cflags='-
  
  
  
  I/usr/local/Cellar/openjpeg/1.5.1_1/include/openjpeg-1.5 '
  
    libavutil      52. 66.100 / 52. 66.100
  
    libavcodec     55. 52.102 / 55. 52.102
  
    libavformat    55. 33.100 / 55. 33.100
  
    libavdevice    55. 10.100 / 55. 10.100
  
    libavfilter     4.  2.100 /  4.  2.100
  
    libavresample   1.  2.  0 /  1.  2.  0
  
    libswscale      2.  5.102 /  2.  5.102
  
    libswresample   0. 18.100 /  0. 18.100
  
    libpostproc    52.  3.100 / 52.  3.100
  
  
  
  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fd87b80f000] stream 0, offset 0x2c: partial file
  
  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fd87b80f000] Could not find codec parameters for stream 0
  
  (Video: h264 (avc1 / 0x31637661), 1280x720, 3310 kb/s): unspecified pixel format

  Consider increasing the value for the ’analyzeduration’ and ’probesize’ options
  pipe:0 : could not find codec parameters

  I have tried setting (link)

  -analyzeduration100 -probesize 10000000 
  
  -analyzeduration 2147483647 -probesize 2147483647

  Still didn’t work.

• c# Create NAL unit from following structure

  30 mai 2014, par user1411499

  Im wanting to send my desktop as an avc h.264 stream.

  The pseudocode would go something like :

  1) Capture screen as bitmap
  2) Encode bitmap into h.264
  3) Create NALU header
  4) Send header and payload
  5) Rinse and repeat.
  

  My questions are :
  How would I go about creating the payload ? Would I use FFMPEG to convert the Bitmap into h.264 format ?

  I have the following spec for creating the NALU :

  

  How would I go about creating this in a c# array of bytes ? (Im not that familiar with bit shifting operations) e.g ByteArray[0] = value, ByteArray1 = value

  Im fairly new to this streaming thing so any help/code samples would be great. Im not looking for references to ISO standards(I understand they are an important part), after doing a few hours of searching I found this link http://aviadr1.blogspot.co.nz/2010/05/h264-extradata-partially-explained-for.html and it was a breath of fresh air as it was someone explaining it from the beginning !

  I am also not searching for a library to do this for me as I need learn the fundamentals.

  Any help would be great thanks !