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• 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.

• How to get the latest frames in ffmpeg, not the next frame

  6 novembre 2014, par LawfulEvil

  I have an application which connects to an RTSP camera and processes some of the frames of video. Depending on the camera resolution and frame rate, I don’t need to process all the frames and sometimes my processing takes a while. I’ve designed things so that when the frame is read, its passed off to a work queue for another thread to deal with. However, depending on system load/resolution/frame rate/network/file system/etc, I occasionally will find cases where the program doesn’t keep up with the camera.

  I’ve found that with ffmpeg(I’m using the latest git drop from mid october and running on windows) that being a couple seconds behind is fine and you keep getting the next frame, next frame, etc. However, once you get, say, 15-20 seconds behind that frames you get from ffmpeg occasionally have corruption. That is, what is returned as the next frame often has graphical glitches (streaking of the bottom of the frame, etc).

  What I’d like to do is put in a check, somehow, to detect if I’m more than X frames behind the live stream and if so, flush the caches frames out and start fetching the latest/current frames.

  My current snippet of my frame buffer reading thread (C++) :

  while(runThread)
  
  {
  
      av_init_packet(&(newPacket));
  
  
  
      int errorCheck = av_read_frame(context, &(newPacket));
  
      if (errorCheck < 0)
  
      {
  
          // error
  
      }
  
      else
  
      {
  
  
  
          int frameFinished = 0;
  
          int decodeCode = avcodec_decode_video2(ccontext, actualFrame, &frameFinished, &newPacket);
  
  
  
          if (decodeCode <0)
  
          {
  
              // error
  
          }
  
          else
  
          if (decodeCode == 0)
  
          {
  
              // no frame could be decompressed / decoded / etc
  
          }
  
          else
  
          if ((decodeCode > 0) && (frameFinished))
  
          {
  
              // do my processing / copy the frame off for later processing / etc
  
          }
  
          else
  
          {
  
              // decoded some data, but frame was not finished...
  
              // Save data and reconstitute the pieces somehow??
  
              // Given that we free the packet, I doubt there is any way to use this partial information
  
          }
  
          av_free_packet(&(newPacket));
  
      }
  
  }

  I’ve google’d and looked through the ffmpeg documents for some function I can call to flush things and enable me to catch up but I can’t seem to find anything. This same sort of solution would be needed if you wanted to only occasionally monitor a video source(eg, if you only wanted to snag one frame per second or per minute). The only thing I could come up with is disconnecting from the camera and reconnecting. However, I still need a way to detect if the frames I am receiving are old.

  Ideally, I’d be able to do something like this :

  while(runThread)
  
  {
  
      av_init_packet(&(newPacket));
  
  
  
      // Not a real function, but I'd like to do something like this
  
      if (av_check_frame_buffer_size(context) > 30_frames)
  
      {
  
          // flush frame buffer.
  
          av_frame_buffer_flush(context);
  
      }
  
  
  
      int errorCheck = av_read_frame(context, &(newPacket));
  
  
  
      ...
  
      }
  
  }

• avfilter/interlace : add complex vertical low-pass filter

  20 avril 2017, par Thomas Mundt

  avfilter/interlace : add complex vertical low-pass filter
  This complex (-1 2 6 2 -1) filter slightly less reduces interlace 'twitter' but better retain detail and subjective sharpness impression compared to the linear (1 2 1) filter.
  Signed-off-by : Thomas Mundt <tmundt75@gmail.com>
  
  Signed-off-by : James Almer <jamrial@gmail.com>
  

  • [DH] doc/filters.texi
  • [DH] libavfilter/interlace.h
  • [DH] libavfilter/tinterlace.h
  • [DH] libavfilter/vf_interlace.c
  • [DH] libavfilter/vf_tinterlace.c
  • [DH] libavfilter/x86/vf_interlace.asm
  • [DH] libavfilter/x86/vf_interlace_init.c
  • [DH] libavfilter/x86/vf_tinterlace_init.c
  • [DH] tests/fate/filter-video.mak
  • [DH] tests/ref/fate/filter-interlace-complex