Recherche avancée

Sur d’autres sites (3886)

• Streaming audio with ffmpeg library in C++/CLR, avcodec_fill_audio_frame returning -22 error code

  31 janvier 2018, par Sherl0ck_H

  Good morning.
  So I am working on a project where I need to stream realtime video & audio in C++ over an RTMP connection using FFmpeg’s libraries. As far as I understand, the video & audio use two different streams so I am now trying to create an audio only stream.

  MY PROBLEM : When calling FFmpeg’s avcodec_fill_audio_frame() I receive an error code -22. This tells me nothing seeing as the FFmpeg library’s documentation...leaves a great deal to be desired.

  My MainForm.h has the following (relevant) members

  private: NAudio::CoreAudioApi::MMDevice^ waveDevice_chat;
  
  private: NAudio::Wave::WaveIn^ waveInput_chat;
  
  private: NAudio::Wave::IWavePlayer^ waveOutput_chat;
  
  private: NAudio::Wave::BufferedWaveProvider^ waveProvider_chat;

  Fist step is to connect the mic :

  System::Void MainForm::btnConnectMic_Click(System::Object^  sender, System::EventArgs^  e) {
  
      msclr::interop::marshal_context context;
  
      waveEnumerator_chat = gcnew NAudio::CoreAudioApi::MMDeviceEnumerator();
  
      System::Collections::Generic::List^ wavePorts_chat = System::Linq::Enumerable::ToList(waveEnumerator_chat->EnumerateAudioEndPoints(DataFlow::Capture, DeviceState::Active));
  
  
  
      if (wavePorts_chat->Count > 0) {
  
          waveDevice_chat = (NAudio::CoreAudioApi::MMDevice^)(wavePorts_chat[0]);
  
          waveDevice_chat->AudioEndpointVolume->Mute = false;
  
  
  
          waveInput_chat = gcnew WaveIn();
  
          waveInput_chat->BufferMilliseconds = 50;
  
          waveInput_chat->DeviceNumber = 0;
  
          waveInput_chat->WaveFormat = gcnew NAudio::Wave::WaveFormat(44100, 1);
  
          waveInput_chat->DataAvailable += gcnew System::EventHandler(this, &MainForm::waveInput_data_available);
  
          waveInput_chat->StartRecording();
  
  
  
          waveProvider_chat = gcnew BufferedWaveProvider(gcnew NAudio::Wave::WaveFormat(44100, 1));
  
          waveProvider_chat->DiscardOnBufferOverflow;
  
      }
  
  }

  Here is the code for the EventHandler which is called by NAudio when data is available

  void MainForm::waveInput_data_available(System::Object^ sender, WaveInEventArgs^ e) {
  
      if (waveProvider_chat->BufferedBytes + e->BytesRecorded > waveProvider_chat->BufferLength)
  
          waveProvider_chat->ClearBuffer();
  
      else
  
          waveProvider_chat->AddSamples(e->Buffer, 0, e->BytesRecorded);
  
  }

  And finally, here is the code snippet that is supposed to fill my audio frame (this is runnign in a loop in a background worker)

  uint8_t* new_buffer;
  
  int result
  
  AVFrame* a_frame = av_frame_alloc();
  
  AVStream* astrm;
  
  AVCodec* acodec = avcodec_find_encoder(AVCodecID::AV_CODEC_ID_AAC);
  
  
  
  /*
  
   *
  
   *
  
   *
  
   */
  
  
  
  in the loop
  
  
  
      if (read_buffer->Length <= 0)
  
          continue;
  
  
  
      new_buffer = (uint8_t*)av_malloc((size_t)waveProvider_chat->BufferedBytes);
  
      for (int i = 0; i < waveProvider_chat->BufferedBytes; i++)
  
          new_buffer[i] = (uint8_t)read_buffer[i];
  
  
  
      AVPacket a_pkt;
  
      av_init_packet(&a_pkt);
  
      a_pkt.data = nullptr;
  
      a_pkt.size = 0;
  
      int got_a_packet = 0;
  
  
  
      int a_encode = avcodec_fill_audio_frame(a_frame, astrm->codec->channels, astrm->codec->sample_fmt, new_buffer, read_buffer->Length, 0);
  
      std::cout << "[FILL] encoded response: " << a_encode << std::endl;

• FFMPEG to OpenGL Texture

  23 avril 2014, par Spamdark

  I was here to ask, how can I convert an AVFrame to an opengl texture. Actually, I created a renderer the outputs me the audio (Audio is working) and the video, but the video is not outputing. Here is my code :

  Texture creation :

  glGenTextures(1,&_texture);
  
  glBindTexture(GL_TEXTURE_2D,_texture);
  
  glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  
  
  
  glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR ); 
  
  glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );

  Code Info : _texture variable is a GLuint that keeps the texture ID

  Function that gets the AVFrame and convert it to OpenGL Texture :

  int VideoGL::NextVideoFrame(){
  
  // Get a packet from the queue
  
  AVPacket *videopacket = this->DEQUEUE(VIDEO);
  
  int frameFinished;
  
  if(videopacket!=0){
  
      avcodec_decode_video2(_codec_context_video, _std_frame,&frameFinished,videopacket);
  
  
  
      if(frameFinished){
  
  
  
          sws_scale(sws_ctx, _std_frame->data, _std_frame->linesize, 0, _codec_context_video->height, _rgb_frame->data, _rgb_frame->linesize);
  
  
  
          if(_firstrendering){
  
          glBindTexture(GL_TEXTURE_2D,_texture);
  
          glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, _codec_context_video->width,_codec_context_video->height,0,GL_RGB,GL_UNSIGNED_BYTE,_rgb_frame->data[0]);
  
  
  
          _firstrendering = false;
  
  
  
          }else{
  
  
  
              glActiveTexture(_texture);
  
              glBindTexture(GL_TEXTURE_2D,_texture);
  
              glTexSubImage2D(GL_TEXTURE_2D,0,0,0,_codec_context_video->width,_codec_context_video->height,GL_RGB,GL_UNSIGNED_BYTE,_rgb_frame->data[0]);
  
  
  
          }
  
          av_free_packet(videopacket);
  
          return 0;
  
      }else{
  
  
  
          av_free_packet(videopacket);
  
          return -1;
  
      }
  
  
  
  }else{
  
      return -1;
  
  }
  
  return 0;
  
  }

  Code Information : There is a queue where a thread store the AVFrames, this function is frequently called to get the AVFrames, until it gets a NULL it stops to being called.

  That’s actually not working. (I tried to look at some questions in stack overflow, it’s still not working)
  Any example, or someone that helps me to correct any error there ?

  Additional Data : I tried to change the GL_RGB to GL_RGBA and started to play with the formats, anyway it crashes when I try GL_RGBA (Because the width and height are very big, anyway I tried to resize them). I have tried to change the sizes to Power Of 2, stills not working.

  1 Edit :

  Thread function :

  DWORD WINAPI VideoGL::VidThread(LPVOID myparam){
  
  
  
  VideoGL * instance = (VideoGL*) myparam;
  
  instance->wave_audio->Start();
  
  
  
  int quantity=0;
  
  
  
  AVPacket packet;
  
  while(av_read_frame(instance->_format_context,&packet) >= 0){
  
      if(packet.stream_index==instance->videoStream){
  
          instance->ENQUEUE(VIDEO,&packet);
  
      }
  
      if(packet.stream_index==instance->audioStream){
  
          instance->ENQUEUE(AUDIO,&packet);
  
      }
  
  }
  
  
  
  instance->ENQUEUE(AUDIO,NULL);
  
  instance->ENQUEUE(VIDEO,NULL);
  
  
  
  return 0;
  
  }

  Thread creation function :

  CreateThread(NULL, 0, VidThread, this, NULL, NULL);

  Where this refers to the class that contains the NextVideoFrame, and the _texture members.

  Solved :

  I followed some of the datenwolf tips, and now the video is displaying correctly with the audio/video :

  

• How do I access the ipod-library for decoding ffmpeg ?

  16 janvier 2014, par M_On

  Thank you to look at my question.

  There is a problem with too slow to access the music file using ffmpeg.

  Get the URL of the music that is in the ipod-library by using the 'valueForProperty:MPMediaItemPropertyAssetURL' method.

  Use the (AVAssetExportSession Class) TSLibraryImport.m, extract the music files from ipod-library.

  However, I took the extraction time is too long. (4 seconds of the 3GS iPhone, iPhone 5 is 1 second)

  It was not possible to be decoded using FFmpeg If you do not the Export.

  In order to use FFmpeg, it's AVPlayer can not be used.

  I will never forget the grace if you can answer if you folded to know how other maybe.