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• Strange performance of avcodec_decode_video2

  26 janvier 2014, par John Simpson

  I am developing an Android video player. I use ffmpeg in native code to decode video frame. In the native code, I have a thread called decode_thread that calls avcodec_decode_video2()

  int decode_thread(void *arg) { 
  
     avcodec_decode_video2(codecCtx, pFrame, &frameFinished,pkt);
  
  }

  I have another thread called display_thread that uses aNativeWindow to display a decoded frame on a SurfaceView.

  The problem is that if I let the decode_thread run continuously without a delay. It significantly reduces the performance of avcodec_decode_video2(). Sometimes it takes about 0.1 seconds to decode a frame. However if I put a delay on the decode_thread. Something likes this.

  int decode_thread(void *arg) { 
  
      avcodec_decode_video2(codecCtx, pFrame, &frameFinished,pkt);
  
      usleep(20*1000);
  
  }

  The performance of avcodec_decode_video2() is really good, about 0.001 seconds. However putting a delay on the decode_thread is not a good solution because it affects the playback. Could anyone explain the behavior of avcodec_decode_video2() and suggest me a solution ?

• 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

• Concat two mp4 files with MP4Box error : Bad Parameter [on hold]

  6 février 2014, par user3279646

  I'm trying to concat two mp4 files. But I get an error : Bad Parameter

  Can someone help me with this problem ?

  I'm using de debian packages. On a previously version it worked fine. I moved from a old debian version to the new one and I also had to change the ffmpeg to avconv which I use to create these mp4 files. I also had to change the audio codec to '-acodec aac -strict experimental'

  Kind Regards,
  Marcel

      MP4Box -force-cat -cat conv1-1391608417314.mp4 -add conv1-1391608417345.mp4 -new output.mp4
  
      IsoMedia import - track ID 1 - Video (size 384 x 288)
  
      Error importing conv1-1391608417345.mp4: Bad Parameter

  ---

      MP4Box -info conv1-1391608417314.mp4
  
      Movie Info 
  
      Timescale 1000 - Duration 00:00:23.985
  
      Fragmented File no - 2 track(s)
  
      File Brand isom - version 512
  
      Created: UNKNOWN DATE
  
      File has root IOD (9 bytes)
  
      Scene PL 0xff - Graphics PL 0xff - OD PL 0xff
  
      Visual PL: Not part of MPEG-4 Visual profiles (0xfe)
  
      Audio PL: Not part of MPEG-4 audio profiles (0xfe)
  
      No streams included in root OD
  
  
  
      iTunes Info:
  
      Encoder Software: Lavf53.21.1
  
  
  
      Track # 1 Info - TrackID 1 - TimeScale 1000 - Duration 00:00:23.985
  
      Media Info: Language "Undetermined" - Type "vide:avc1" - 23988 samples
  
      Visual Track layout: x=0 y=0 width=384 height=288
  
      MPEG-4 Config: Visual Stream - ObjectTypeIndication 0x21
  
      AVC/H264 Video - Visual Size 384 x 288
  
      AVC Info: 1 SPS - 1 PPS - Profile High @ Level 4.2
  
      NAL Unit length bits: 32
  
      Self-synchronized
  
  
  
      Track # 2 Info - TrackID 2 - TimeScale 44100 - Duration 00:00:23.962
  
      Media Info: Language "Undetermined" - Type "soun:mp4a" - 1032 samples
  
      MPEG-4 Config: Audio Stream - ObjectTypeIndication 0x40
  
      MPEG-4 Audio MPEG-4 Audio AAC LC - 2 Channel(s) - SampleRate 44100
  
      Synchronized on stream 1
  
      Alternate Group ID 1

  ---

      MP4Box -version
  
      MP4Box - GPAC version 0.5.0-rev
  
      GPAC Copyright: (c) Jean Le Feuvre 2000-2005
  
      (c) ENST 2005-200X
  
      GPAC Configuration: --build=x86_64-linux-gnu --prefix=/usr --includedir=${prefix}/include --mandir=${prefix}/share/man --infodir=${prefix}/share/info --sysconfdir=/etc --localstatedir=/var --libdir=${prefix}/lib/x86_64-linux-gnu --libexecdir=${prefix}/lib/x86_64-linux-gnu --disable-maintainer-mode --disable-dependency-tracking --prefix=/usr --mandir=${prefix}/share/man --libdir=lib/x86_64-linux-gnu --extra-cflags='-Wall -fPIC -DPIC -I/usr/include/mozjs -DXP_UNIX' --enable-joystick --enable-debug --disable-ssl
  
      Features: GPAC_HAS_JPEG GPAC_HAS_PNG