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• av_free crashes application randomly - FFMPEG C++

  12 mai 2013, par Spamdark

  I am trying to create a simple media-player for an introduction to the world of ffmpeg, the problem is that every time that I call av_freep(void*ptr) the application crashes.

  If I don't call av_freep I get a memory leak and the memory used by the program increases up to 1000MB (Already measured), here is the code :

  int16_t* audioBuffer=(int16_t*)av_malloc(AVCODEC_MAX_AUDIO_FRAME_SIZE+FF_INPUT_BUFFER_PADDING_SIZE);
  
  
  
  if(!audioBuffer){
  
      MessageBox(0,"Error allocating in audioBuffer","Error: Mem",MB_ICONWARNING | MB_OK);
  
      return -1;
  
  }
  
  
  
  int sz = MEDIA->DecodeAudioFrame((void*)audioBuffer,0);
  
  
  
  Pa_WriteStream(MEDIA->output_stream,(int16_t*)audioBuffer,MEDIA->_audio_ccontext->frame_size);
  
  
  
  av_freep(audioBuffer);

  Here is my 'DecodeAudioFrame' function code :

  int WbMedia::DecodeAudioFrame(void *audio_buf, int buf_size){
  
  static AVFrame frame;
  
  static AVPacket pkt;
  
  static uint8_t *audio_pkt_data = NULL;
  
  static int audio_pkt_size = 0;
  
  
  
  int len1=0;
  
  
  
  for(;;){
  
      bool do_rt = false;
  
  
  
  
  
      while(audio_pkt_size > 0){
  
          int obt_frame = 0;
  
  
  
          len1 = avcodec_decode_audio4(_audio_ccontext,&frame,&obt_frame,&pkt);
  
          if(len1 < 0){
  
              audio_pkt_size = 0;
  
              break;
  
          }
  
  
  
          audio_pkt_data+=len1;
  
          audio_pkt_size-=len1;
  
  
  
          if(obt_frame){
  
              data_size = av_samples_get_buffer_size(frame.linesize,channel_count,sample_fr,_audio_ccontext->sample_fmt,1);
  
              memcpy(audio_buf,frame.data[0],data_size);
  
          }
  
  
  
          if(data_size < 0){
  
              continue;
  
          }
  
  
  
          if(pkt.data){
  
              av_free_packet(&pkt);
  
          }
  
          return data_size;
  
  
  
      }
  
  
  
      if(pkt.data){
  
          av_free_packet(&pkt);
  
      }
  
  
  
      if(do_rt){
  
          return data_size;
  
      }
  
  
  
      // Try to get a new packet
  
      if(!audio_packets.empty()){
  
          WaitForSingleObject(Queue_Audio_Mutex,INFINITE);
  
              pkt = audio_packets.front();
  
              audio_packets.pop();
  
          ReleaseMutex(Queue_Audio_Mutex);
  
  
  
          audio_pkt_size = pkt.size;
  
          audio_pkt_data = pkt.data;
  
      }else{
  
          return -1;
  
      }
  
  }
  
  return 0;
  
  }

  I need help with this issue, I don't know if it is a bug or what I need to do. What's happening there ? Why does it crashes on the av_freep call ? How can I fix it ?

  Thanks

• lavc/aacenc_utils : replace powf(x,y) by expf(logf(x), y)

  8 mars 2016, par Ganesh Ajjanagadde

  lavc/aacenc_utils : replace powf(x,y) by expf(logf(x), y)
  This is 2x faster for y not an integer on Haswell+GCC, and should
  
  generally be faster due to the fact that anyway powf essentially does
  
  this under the hood. Made an inline function in lavu/internal.h for this
  
  purpose.
  Note that there are some accuracy differences, that should generally be
  
  negligible. In particular, FATE still passes on this platform.
  Results in 7% speedup in aac encoding with -march=native, Haswell+GCC.
  
  before :
  
  ffmpeg -i sin.flac -acodec aac -y sin_new.aac  6.05s user 0.06s system 104% cpu 5.821 total
  after :
  
  ffmpeg -i sin.flac -acodec aac -y sin_new.aac  5.67s user 0.03s system 105% cpu 5.416 total
  This is also faster than an alternative approach that pulls in powf, gets rid of
  
  the crufty NaN checks and other special cases, exploits knowledge about the intervals, etc.
  
  This of course does not exclude smarter approaches ; just suggests that
  
  there would need to be significant work on this front of lower utility than
  
  searches for hotspots elsewhere.
  Reviewed-by : Reimar Döffinger <Reimar.Doeffinger@gmx.de>
  
  Reviewed-by : Ronald S. Bultje <rsbultje@gmail.com>
  
  Signed-off-by : Ganesh Ajjanagadde <gajjanag@gmail.com>
  

  • [DH] libavcodec/aacenc_utils.h
  • [DH] libavutil/internal.h

• FFMPEG - Concat 3 videos with one of the videos becoming a picture in picture overlay

  7 décembre 2022, par John

  I have been getting to grips with FFMPEG for the last few days...so please excuse my lack of knowledge. It's very much early days.

  


  I need to join 3 video elements together with one of the videos becoming an overlay at a specific time.

  


  intro.mp4

  


  mainvideo.mp4

  


  endboard.mp4

  


  I need the intro.mp4 to bolt on to the front of the mainvideo.mp4 and then ideally with 20 seconds to go before the end of the mainvideo.mp4, I need the endboard.mp4 video to be bolted on to the sequence and take over the frame. When this happens, I then need the mainvideo.mp4 to be overlayed in the top left corner and continue playing seamlessly through the transition.

  


  I also need the audio from the main video to play until the end of the video.

  


  I currently achieve this but putting all of the video elements into Premiere and exporting them out but I know this process can be much quicker with FFMPEG. For reference, here is an example of how it looks. If you skip to the end of the video below (just after 45 mins into the video) as the credits are rolling you will see the main video transition to the picture in picture overlay, and the endboard video take over the main frame.

  


  https://www.youtube.com/watch?v=RtgIvWxZUwM&t=2723s

  


  There will be lots of mainvideo.mp4 files that this will be applied to individually, and the lengths of these videos will always be different. I am hoping that there is a way to have the transition to the endboard.mp4 happen relative to 20secs before the end of the files. If not I guess I would have to manually input the time I want this change over transition to happen.

  


  I roughly understand in theory what needs to be done, but being so new to this world I am really unsure of how something this complicated would be pieced together.

  


  If there is anyone out there that can help me , it would be greatly appreciated !

  


  I have got my head around the process of merging videos together with a simple concat command and I can see that overlaying a video in the top left corner of the frame is also possible...but my brain cannot figure out the sequence of events that needs to happen to bolt the intro video on to the main video....and then have the main video transition into the picture in picture overlay video at a specific time, while also bolting on the endboard video for the main video to overlay onto.

  


  Any help for a complete newb would be so unbelievably appreciated !