[Ffmpeg-devel] Using libavformat and libavcodec(help me Martin Böhme)

Chang Min Jeon jcm1981
Tue May 31 15:54:50 CEST 2005


hello, I'm student in South Korea.

I read Martin B?hme's article about using libavcodec and libavformat
in ffmpeg doc.

So I can read video frame from video file, Wow amazing.~

Now I'm trying to read audio stream.

 

How to read raw audio stream from video file ?

 

//find the first audio stream.

 m_nAudioStream = -1;

 for(j=0; j<m_pFormatCtx->nb_streams; j++)
  if(m_pFormatCtx->streams[j]->codec.codec_type == CODEC_TYPE_AUDIO)
  {
   m_nAudioStream =j;
   break;
  }

// didn't find a video stream
 if(m_nAudioStream==-1)
  return -1;
  
 // get a pointer to the codec context for the audio stream.
 m_pAudioCtx=&m_pFormatCtx->streams[m_nAudioStream]->codec;
 

// fine the decoder for the audio stream
 pAudioCodec=avcodec_find_decoder(m_pAudioCtx->codec_id);
 if(pAudioCodec==NULL)
  return -1;


// open audio codec

 if(avcodec_open(m_pAudioCtx, pAudioCodec) <0)
  return -1;

 

............

............

 

???????

 

Thanks in advance :)





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