libmp4.c

aac解码器源程序在Visual C++下的实现

      //guint		avgBitrate;
      //MP4Duration	duration;
      int		msDuration;
      int		numSamples;
      int		sampleID = 0;
      unsigned int	framesize;
      mp4AudioSpecificConfig mp4ASC;
      gchar		*xmmstitle;

      decoder = NeAACDecOpen();
      mp4ff_get_decoder_config(infile, mp4track, &buffer, &bufferSize);
      if(NeAACDecInit2(decoder, buffer, bufferSize, &samplerate, &channels)<0){
          goto end;
      }
      if(buffer){
	framesize = 1024;
	if(NeAACDecAudioSpecificConfig(buffer, bufferSize, &mp4ASC) >= 0){
	  if(mp4ASC.frameLengthFlag == 1) framesize = 960;
	  if(mp4ASC.sbr_present_flag == 1) framesize *= 2;
	}
	g_free(buffer);
      }
      if(channels == 0){
	g_print("Number of Channels not supported\n");
	goto end;
      }

      //duration = MP4GetTrackDuration(mp4file, mp4track);
      //msDuration = MP4ConvertFromTrackDuration(mp4file, mp4track,
      //				       duration,MP4_MSECS_TIME_SCALE);

      //msDuration = mp4ff_get_track_duration(infile, mp4track);
      //printf("%d\n", msDuration);

      //numSamples = MP4GetTrackNumberOfSamples(mp4file, mp4track);
      numSamples = mp4ff_num_samples(infile, mp4track);
      {
	float f = 1024.0;
	if(mp4ASC.sbr_present_flag == 1)
	  f = f * 2.0;
	msDuration = ((float)numSamples*(float)(f-1.0)/
		      (float)samplerate)*1000;
      }
      xmmstitle = getMP4title(infile, args);
      mp4_ip.output->open_audio(FMT_S16_NE, samplerate, channels);
      mp4_ip.output->flush(0);
      mp4_ip.set_info(xmmstitle, msDuration, -1, samplerate/1000, channels);
      g_print("MP4 - %d channels @ %ld Hz\n", channels, samplerate);

      while(bPlaying){
	void*			sampleBuffer;
	faacDecFrameInfo	frameInfo;
	gint			rc;

	if(seekPosition!=-1){
	  /*
	  duration = MP4ConvertToTrackDuration(mp4file,
					       mp4track,
					       seekPosition*1000,
					       MP4_MSECS_TIME_SCALE);
	  sampleID = MP4GetSampleIdFromTime(mp4file, mp4track, duration, 0);
          */
          float f = 1024.0;
	  if(mp4ASC.sbr_present_flag == 1)
	    f = f * 2.0;
          sampleID = (float)seekPosition*(float)samplerate/(float)(f-1.0);
	  mp4_ip.output->flush(seekPosition*1000);
	  seekPosition = -1;
	}
	buffer=NULL;
	bufferSize=0;
	rc = mp4ff_read_sample(infile, mp4track, sampleID++,
			       &buffer, &bufferSize);
	//g_print("%d/%d\n", sampleID-1, numSamples);
	if((rc==0) || (buffer== NULL)){
	  g_print("MP4: read error\n");
	  sampleBuffer = NULL;
	  sampleID=0;
	  mp4_ip.output->buffer_free();
            goto end;
	}else{
	  sampleBuffer = NeAACDecDecode(decoder, &frameInfo, buffer, bufferSize);
	  if(frameInfo.error > 0){
	    g_print("MP4: %s\n",
		    faacDecGetErrorMessage(frameInfo.error));
	    goto end;
	  }
	  if(buffer){
	    g_free(buffer); buffer=NULL; bufferSize=0;
	  }
	  while(bPlaying && mp4_ip.output->buffer_free()<frameInfo.samples<<1)
	    xmms_usleep(30000);
	}
	mp4_ip.add_vis_pcm(mp4_ip.output->written_time(),
			   FMT_S16_NE,
			   channels,
			   frameInfo.samples<<1,
			   sampleBuffer);
	mp4_ip.output->write_audio(sampleBuffer, frameInfo.samples<<1);
	if(sampleID >= numSamples){
          break;
	}
      }
      while(bPlaying && mp4_ip.output->buffer_playing() && mp4_ip.output->buffer_free()){
	xmms_usleep(10000);
      }
end:
      mp4_ip.output->close_audio();
      g_free(args);
      NeAACDecClose(decoder);
      if(infile) mp4ff_close(infile);
      if(mp4cb) g_free(mp4cb);
      bPlaying = FALSE;
      fclose(mp4file);
      pthread_mutex_unlock(&mutex);
      pthread_exit(NULL);
    }
  }else{
    // WE ARE READING AN AAC FILE
    FILE		*file = NULL;
    NeAACDecHandle	decoder = 0;
    guchar		*buffer = 0;
    gulong		bufferconsumed = 0;
    gulong		samplerate = 0;
    guchar		channels;
    gulong		buffervalid = 0;
    TitleInput*		input;
    gchar		*temp = g_strdup(args);
    gchar		*ext  = strrchr(temp, '.');
    gchar		*xmmstitle = NULL;
    NeAACDecConfigurationPtr config;

    if((file = fopen(args, "rb")) == 0){
      g_print("AAC: can't find file %s\n", args);
      bPlaying = FALSE;
      pthread_mutex_unlock(&mutex);
      pthread_exit(NULL);
    }
    if((decoder = NeAACDecOpen()) == NULL){
      g_print("AAC: Open Decoder Error\n");
      fclose(file);
      bPlaying = FALSE;
      pthread_mutex_unlock(&mutex);
      pthread_exit(NULL);
    }
    config = NeAACDecGetCurrentConfiguration(decoder);
    config->useOldADTSFormat = 0;
    NeAACDecSetConfiguration(decoder, config);
    if((buffer = g_malloc(BUFFER_SIZE)) == NULL){
      g_print("AAC: error g_malloc\n");
      fclose(file);
      bPlaying = FALSE;
      NeAACDecClose(decoder);
      pthread_mutex_unlock(&mutex);
      pthread_exit(NULL);
    }
    if((buffervalid = fread(buffer, 1, BUFFER_SIZE, file))==0){
      g_print("AAC: Error reading file\n");
      g_free(buffer);
      fclose(file);
      bPlaying = FALSE;
      NeAACDecClose(decoder);
      pthread_mutex_unlock(&mutex);
      pthread_exit(NULL);
    }
    XMMS_NEW_TITLEINPUT(input);
    input->file_name = g_basename(temp);
    input->file_ext = ext ? ext+1 : NULL;
    input->file_path = temp;
    if(!strncmp(buffer, "ID3", 3)){
      gint size = 0;

      fseek(file, 0, SEEK_SET);
      size = (buffer[6]<<21) | (buffer[7]<<14) | (buffer[8]<<7) | buffer[9];
      size+=10;
      fread(buffer, 1, size, file);
      buffervalid = fread(buffer, 1, BUFFER_SIZE, file);
    }
    xmmstitle = xmms_get_titlestring(xmms_get_gentitle_format(), input);
    if(xmmstitle == NULL)
      xmmstitle = g_strdup(input->file_name);
    if(temp) g_free(temp);
    if(input->performer) g_free(input->performer);
    if(input->album_name) g_free(input->album_name);
    if(input->track_name) g_free(input->track_name);
    if(input->genre) g_free(input->genre);
    g_free(input);
    bufferconsumed = NeAACDecInit(decoder,
				 buffer,
				 buffervalid,
				 &samplerate,
				 &channels);
    if(mp4_ip.output->open_audio(FMT_S16_NE,samplerate,channels) == FALSE){
      g_print("AAC: Output Error\n");
      g_free(buffer); buffer=0;
      faacDecClose(decoder);
      fclose(file);
      mp4_ip.output->close_audio();
      /*
      if(positionTable){
	g_free(positionTable); positionTable=0;
      }
      */
      g_free(xmmstitle);
      bPlaying = FALSE;
      pthread_mutex_unlock(&mutex);
      pthread_exit(NULL);
    }
    //if(bSeek){
    //mp4_ip.set_info(xmmstitle, lenght*1000, -1, samplerate, channels);
      //}else{
    mp4_ip.set_info(xmmstitle, -1, -1, samplerate, channels);
      //}
    mp4_ip.output->flush(0);

    while(bPlaying && buffervalid > 0){
      NeAACDecFrameInfo	finfo;
      unsigned long	samplesdecoded;
      char*		sample_buffer = NULL;
      /*
	if(bSeek && seekPosition!=-1){
	fseek(file, positionTable[seekPosition], SEEK_SET);
	bufferconsumed=0;
	buffervalid = fread(buffer, 1, BUFFER_SIZE, file);
	aac_ip.output->flush(seekPosition*1000);
	seekPosition=-1;
	}
      */
      if(bufferconsumed > 0){
	memmove(buffer, &buffer[bufferconsumed], buffervalid-bufferconsumed);
	buffervalid -= bufferconsumed;
	buffervalid += fread(&buffer[buffervalid], 1,
			     BUFFER_SIZE-buffervalid, file);
	bufferconsumed = 0;
      }
      sample_buffer = NeAACDecDecode(decoder, &finfo, buffer, buffervalid);
      if(finfo.error){
	config = NeAACDecGetCurrentConfiguration(decoder);
	if(config->useOldADTSFormat != 1){
	  NeAACDecClose(decoder);
	  decoder = NeAACDecOpen();
	  config = NeAACDecGetCurrentConfiguration(decoder);
	  config->useOldADTSFormat = 1;
	  NeAACDecSetConfiguration(decoder, config);
	  finfo.bytesconsumed=0;
	  finfo.samples = 0;
	  NeAACDecInit(decoder,
		      buffer,
		      buffervalid,
		      &samplerate,
		      &channels);
	}else{
	  g_print("FAAD2 Warning %s\n", NeAACDecGetErrorMessage(finfo.error));
	  buffervalid = 0;
	}
      }
      bufferconsumed += finfo.bytesconsumed;
      samplesdecoded = finfo.samples;
      if((samplesdecoded<=0) && !sample_buffer){
	g_print("AAC: error sample decoding\n");
	continue;
      }
      while(bPlaying && mp4_ip.output->buffer_free() < (samplesdecoded<<1)){
	xmms_usleep(10000);
      }
      mp4_ip.add_vis_pcm(mp4_ip.output->written_time(),
			 FMT_S16_LE, channels,
			 samplesdecoded<<1, sample_buffer);
      mp4_ip.output->write_audio(sample_buffer, samplesdecoded<<1);
    }
    while(bPlaying && mp4_ip.output->buffer_playing()){
      xmms_usleep(10000);
    }
    mp4_ip.output->buffer_free();
    mp4_ip.output->close_audio();
    bPlaying = FALSE;
    g_free(buffer);
    NeAACDecClose(decoder);
    g_free(xmmstitle);
    fclose(file);
    seekPosition = -1;
    /*
    if(positionTable){
      g_free(positionTable); positionTable=0;
    }
    */
    bPlaying = FALSE;
    pthread_mutex_unlock(&mutex);
    pthread_exit(NULL);

  }
}