demux_audio.c

来自「君正早期ucos系统(只有早期的才不没有打包成库),MPLAYER,文件系统,图」· C语言 代码 · 共 796 行 · 第 1/2 页

     //F("mp3_totaltime = %d count = %d\n",(unsigned int)(mp3_totaltime *1000.0),dcount);
     //F("s->eof = %d\n",s->eof);
    free(mp3_found);
    mp3_found = NULL;
    //F("BBBBB\n");
    if(s->end_pos) {
      char tag[4];
    //F("AAAAAAAA\n");
      stream_seek(s,s->end_pos-128);
      stream_read(s,tag,3);
      tag[3] = '\0';
      if(strcmp(tag,"TAG"))
	{
		demuxer->movi_end = s->end_pos;
		
   }   else {
	char buf[31];
	uint8_t g;
	demuxer->movi_end = stream_tell(s)-3;
//	F("demuxer->movi_end = %d demuxer->movi_start = %d sh_audio->i_bps = %d\n",demuxer->movi_end,demuxer->movi_start,sh_audio->i_bps);
	stream_read(s,buf,30);
	buf[30] = '\0';
	demux_info_add(demuxer,"Title",buf);
	stream_read(s,buf,30);
	buf[30] = '\0';
	demux_info_add(demuxer,"Artist",buf);
	stream_read(s,buf,30);
	buf[30] = '\0';
	demux_info_add(demuxer,"Album",buf);
	stream_read(s,buf,4);
	buf[4] = '\0';
	demux_info_add(demuxer,"Year",buf);
	stream_read(s,buf,30);
	buf[30] = '\0';
	demux_info_add(demuxer,"Comment",buf);
	if(buf[28] == 0 && buf[29] != 0) {
	  uint8_t trk = (uint8_t)buf[29];
	  sprintf(buf,"%d",trk);
	  demux_info_add(demuxer,"Track",buf);
	}
	g = stream_read_char(s);
	demux_info_add(demuxer,"Genre",genres[g]);
      }
    }
    break;
  case WAV: {
    unsigned int chunk_type;
    unsigned int chunk_size;
    WAVEFORMATEX* w;
    int l;
    l = stream_read_dword_le(s);
    if(l < 16) {
      mp_msg(MSGT_DEMUX,MSGL_ERR,"[demux_audio] Bad wav header length: too short (%d)!!!\n",l);
      l = 16;
    }
    if(l > MAX_WAVHDR_LEN) {
      mp_msg(MSGT_DEMUX,MSGL_ERR,"[demux_audio] Bad wav header length: too long (%d)!!!\n",l);
      l = 16;
    }
    sh_audio->wf = w = malloc(l > sizeof(WAVEFORMATEX) ? l : sizeof(WAVEFORMATEX));
    w->wFormatTag = sh_audio->format = stream_read_word_le(s);
    w->nChannels = sh_audio->channels = stream_read_word_le(s);
    w->nSamplesPerSec = sh_audio->samplerate = stream_read_dword_le(s);
    w->nAvgBytesPerSec = stream_read_dword_le(s);
    w->nBlockAlign = stream_read_word_le(s);
    w->wBitsPerSample = stream_read_word_le(s);
    sh_audio->samplesize = (w->wBitsPerSample + 7) / 8;
    w->cbSize = 0;
    sh_audio->i_bps = sh_audio->wf->nAvgBytesPerSec;
    l -= 16;
    if (l > 0) {
    w->cbSize = stream_read_word_le(s);
    l -= 2;
     if (w->cbSize > 0) {
      if (l < w->cbSize) {
        mp_msg(MSGT_DEMUX,MSGL_ERR,"[demux_audio] truncated extradata (%d < %d)\n",
	l,w->cbSize);
        stream_read(s,(char*)((char*)(w)+sizeof(WAVEFORMATEX)),l);
        l = 0;
      } else {
        stream_read(s,(char*)((char*)(w)+sizeof(WAVEFORMATEX)),w->cbSize);
        l -= w->cbSize;
      }
     }
    }

    if( mp_msg_test(MSGT_DEMUX,MSGL_V) ) print_wave_header(w, MSGL_V);
    if(l)
      stream_skip(s,l);
    do
    {
      chunk_type = stream_read_fourcc(demuxer->stream);
      chunk_size = stream_read_dword_le(demuxer->stream);
      if (chunk_type != mmioFOURCC('d', 'a', 't', 'a'))
        stream_skip(demuxer->stream, chunk_size);
    } while (!s->eof && chunk_type != mmioFOURCC('d', 'a', 't', 'a'));
    demuxer->movi_start = stream_tell(s);
    demuxer->movi_end = chunk_size ? demuxer->movi_start + chunk_size : s->end_pos;
//    printf("wav: %X .. %X\n",(int)demuxer->movi_start,(int)demuxer->movi_end);
    // Check if it contains dts audio
    if((w->wFormatTag == 0x01) && (w->nChannels == 2) && (w->nSamplesPerSec == 44100)) {
	unsigned char buf[16384]; // vlc uses 16384*4 (4 dts frames)
	unsigned int i;
	stream_read(s, buf, sizeof(buf));
	for (i = 0; i < sizeof(buf) - 5; i += 2) {
	    // DTS, 14 bit, LE
	    if((buf[i] == 0xff) && (buf[i+1] == 0x1f) && (buf[i+2] == 0x00) &&
	       (buf[i+3] == 0xe8) && ((buf[i+4] & 0xfe) == 0xf0) && (buf[i+5] == 0x07)) {
		sh_audio->format = 0x2001;
		mp_msg(MSGT_DEMUX,MSGL_V,"[demux_audio] DTS audio in wav, 14 bit, LE\n");
		break;
	    }
	    // DTS, 14 bit, BE
	    if((buf[i] == 0x1f) && (buf[i+1] == 0xff) && (buf[i+2] == 0xe8) &&
	       (buf[i+3] == 0x00) && (buf[i+4] == 0x07) && ((buf[i+5] & 0xfe) == 0xf0)) {
		sh_audio->format = 0x2001;
		mp_msg(MSGT_DEMUX,MSGL_V,"[demux_audio] DTS audio in wav, 14 bit, BE\n");
		break;
	    }
	    // DTS, 16 bit, BE
	    if((buf[i] == 0x7f) && (buf[i+1] == 0xfe) && (buf[i+2] == 0x80) &&
	       (buf[i+3] == 0x01)) {
		sh_audio->format = 0x2001;
		mp_msg(MSGT_DEMUX,MSGL_V,"[demux_audio] DTS audio in wav, 16 bit, BE\n");
		break;
	    }
	    // DTS, 16 bit, LE
	    if((buf[i] == 0xfe) && (buf[i+1] == 0x7f) && (buf[i+2] == 0x01) &&
	       (buf[i+3] == 0x80)) {
		sh_audio->format = 0x2001;
		mp_msg(MSGT_DEMUX,MSGL_V,"[demux_audio] DTS audio in wav, 16 bit, LE\n");
		break;
	    }
	}
	if (sh_audio->format == 0x2001)
	    mp_msg(MSGT_DEMUX,MSGL_DBG2,"[demux_audio] DTS sync offset = %u\n", i);

    }
    stream_seek(s,demuxer->movi_start);
  } break;
  case fLaC:
	    sh_audio->format = mmioFOURCC('f', 'L', 'a', 'C');
	    demuxer->movi_start = stream_tell(s) - 4;
	    demuxer->movi_end = s->end_pos;
	    if (demuxer->movi_end > demuxer->movi_start) {
	      // try to find out approx. bitrate
	      int64_t size = demuxer->movi_end - demuxer->movi_start;
	      int64_t num_samples = 0;
	      int32_t srate = 0;
	      stream_skip(s, 14);
	      stream_read(s, (char *)&srate, 3);
	      srate = be2me_32(srate) >> 12;
	      stream_read(s, (char *)&num_samples, 5);
	      num_samples = (be2me_64(num_samples) >> 24) & 0xfffffffffULL;
	      if (num_samples && srate)
	        sh_audio->i_bps = size * srate / num_samples;
	    }
	    if (sh_audio->i_bps < 1) // guess value to prevent crash
	      sh_audio->i_bps = 64 * 1024;
	    get_flac_metadata (demuxer);
	    break;
  }

  priv = malloc(sizeof(da_priv_t));
  priv->frmt = frmt;
  priv->next_pts = 0;
  demuxer->priv = priv;
  demuxer->audio->id = 0;
  demuxer->audio->sh = sh_audio;
  sh_audio->ds = demuxer->audio;
  sh_audio->samplerate = sh_audio->audio.dwRate;

  if(stream_tell(s) != demuxer->movi_start)
  {
    mp_msg(MSGT_DEMUX, MSGL_V, "demux_audio: seeking from 0x%X to start pos 0x%X\n",
            (int)stream_tell(s), (int)demuxer->movi_start);
    stream_seek(s,demuxer->movi_start);
    if (stream_tell(s) != demuxer->movi_start) {
      mp_msg(MSGT_DEMUX, MSGL_V, "demux_audio: seeking failed, now at 0x%X!\n",
              (int)stream_tell(s));
      if (next_frame_pos) {
        mp_msg(MSGT_DEMUX, MSGL_V, "demux_audio: seeking to 0x%X instead\n",
                (int)next_frame_pos);
        stream_seek(s, next_frame_pos);
      }
    }
  }

  mp_msg(MSGT_DEMUX,MSGL_V,"demux_audio: audio data 0x%X - 0x%X  \n",(int)demuxer->movi_start,(int)demuxer->movi_end);

  return DEMUXER_TYPE_AUDIO;
}


static int demux_audio_fill_buffer(demuxer_t *demuxer, demux_stream_t *ds) {
  int l;
  demux_packet_t* dp;
  sh_audio_t* sh_audio = ds->sh;
  demuxer_t* demux = ds->demuxer;
  da_priv_t* priv = demux->priv;
  double this_pts = priv->next_pts;
  stream_t* s = demux->stream;
	int mp3_freq, mp3_chans, mp3_flen, mpa_layer, mpa_spf, mpa_br;

  if(s->eof)
    return 0;

  switch(priv->frmt) {
  case MP3 :
    
    while(1) {
      uint8_t hdr[4];
      stream_read(s,hdr,4);
      if (s->eof)
        return 0;
      
      l = mp_get_mp3_header(hdr, &mp3_chans, &mp3_freq,
                                &mpa_spf, &mpa_layer, &mpa_br);
                              
      //l = mp_decode_mp3_header(hdr);
      if(l < 0) {
	if (demux->movi_end && stream_tell(s) >= demux->movi_end)
	  return 0; // might be ID3 tag, i.e. EOF
	stream_skip(s,-3);
      } else {
	dp = new_demux_packet(l);
	memcpy(dp->buffer,hdr,4);
	if (stream_read(s,dp->buffer + 4,l-4) != l-4)
	{
	  free_demux_packet(dp);
	  return 0;
	}
	//priv->next_pts += sh_audio->audio.dwScale/(double)sh_audio->samplerate;
	priv->next_pts += (double)mpa_spf / (double)mp3_freq;
	
	
	break;
      }
    } break;
  case WAV : {
    unsigned align = sh_audio->wf->nBlockAlign;
    l = sh_audio->wf->nAvgBytesPerSec;
    if (demux->movi_end && l > demux->movi_end - stream_tell(s)) {
      // do not read beyond end, there might be junk after data chunk
      l = demux->movi_end - stream_tell(s);
      if (l <= 0) return 0;
    }
    if (align)
      l = (l + align - 1) / align * align;
    dp = new_demux_packet(l);
    l = stream_read(s,dp->buffer,l);
    priv->next_pts += l/(double)sh_audio->i_bps;
    break;
  }
  case fLaC: {
    l = 65535;
    dp = new_demux_packet(l);
    l = stream_read(s,dp->buffer,l);
    /* FLAC is not a constant-bitrate codec. These values will be wrong. */
    priv->next_pts += l/(double)sh_audio->i_bps;
    break;
  }
  default:
    mp_msg(MSGT_DEMUXER,MSGL_WARN,MSGTR_MPDEMUX_AUDIO_UnknownFormat,priv->frmt);
    return 0;
  }

  resize_demux_packet(dp, l);
  dp->pts = this_pts;
  sh_audio->pts = this_pts;
	ds_add_packet(ds, dp);
  return 1;
}

static void high_res_mp3_seek(demuxer_t *demuxer,float time) {
  uint8_t hdr[4];
  int len,nf;
  da_priv_t* priv = demuxer->priv;
  sh_audio_t* sh = (sh_audio_t*)demuxer->audio->sh;
  int mp3_freq, mp3_chans, mp3_flen, mpa_layer, mpa_spf, mpa_br;  
  nf = time*sh->samplerate/sh->audio.dwScale;
  while(nf > 0) {
    stream_read(demuxer->stream,hdr,4);
    len =  mp_get_mp3_header(hdr, &mp3_chans, &mp3_freq,
                                &mpa_spf, &mpa_layer, &mpa_br);
    if(len < 0) {
      stream_skip(demuxer->stream,-3);
      continue;
    }
    stream_skip(demuxer->stream,len-4);
    priv->next_pts += (double)mpa_spf / (double)mp3_freq;
    nf--;
  }
  sh->pts = priv->next_pts; 
}

static void demux_audio_seek(demuxer_t *demuxer,float rel_seek_secs,float audio_delay,int flags){
  sh_audio_t* sh_audio;
  stream_t* s;
  int base,pos;
  float len;
  da_priv_t* priv;

  if(!(sh_audio = demuxer->audio->sh))
    return;
  s = demuxer->stream;
  priv = demuxer->priv;
  if(priv->frmt == MP3 && hr_mp3_seek && !(flags & 2)) {
    len = (flags & 1) ? rel_seek_secs - priv->next_pts : rel_seek_secs;
    if(len < 0) {
      stream_seek(s,demuxer->movi_start);
      len = priv->next_pts + len;
      priv->next_pts = 0;
    }
    if(len > 0)
      high_res_mp3_seek(demuxer,len);
    return;
  }

  base = flags&1 ? demuxer->movi_start : stream_tell(s);
  if(flags&2)
    pos = base + ((demuxer->movi_end - demuxer->movi_start)*rel_seek_secs);
  else
    pos = base + (rel_seek_secs*sh_audio->i_bps);

  if(demuxer->movi_end && pos >= demuxer->movi_end) {
     pos = demuxer->movi_end;
  } else if(pos < demuxer->movi_start)
    pos = demuxer->movi_start;

  priv->next_pts = (pos-demuxer->movi_start)/(double)sh_audio->i_bps;
  
  switch(priv->frmt) {
  case WAV:
    pos -= (pos - demuxer->movi_start) %
            (sh_audio->wf->nBlockAlign ? sh_audio->wf->nBlockAlign :
             (sh_audio->channels * sh_audio->samplesize));
    break;
  }

  stream_seek(s,pos);
}

static void demux_close_audio(demuxer_t* demuxer) {
  da_priv_t* priv = demuxer->priv;

  if(!priv)
    return;
  free(priv);
  mp3_totaltime = 0;
}

static int demux_audio_control(demuxer_t *demuxer,int cmd, void *arg){
    sh_audio_t *sh_audio=demuxer->audio->sh;
    //int audio_length = demuxer->movi_end / sh_audio->i_bps;
    
    float audio_length;
    if(mp3_totaltime > 0)
    	audio_length = mp3_totaltime;
    else	
    	audio_length = (float)(demuxer->movi_end - demuxer->movi_start)/ sh_audio->i_bps;
  	
    da_priv_t* priv = demuxer->priv;
	    
    switch(cmd) {
	case DEMUXER_CTRL_GET_TIME_LENGTH:
	    if (audio_length<=0) return DEMUXER_CTRL_DONTKNOW;
	    *((double *)arg)=(double)audio_length;
	    return DEMUXER_CTRL_GUESS;

	case DEMUXER_CTRL_GET_PERCENT_POS:
	    if (audio_length<=0) 
    		return DEMUXER_CTRL_DONTKNOW;
    	    *((int *)arg)=(int)( (priv->next_pts*100)  / audio_length);
	    return DEMUXER_CTRL_OK;

	default:
	    return DEMUXER_CTRL_NOTIMPL;
    }
}


demuxer_desc_t demuxer_desc_audio = {
  "Audio demuxer",
  "audio",
  "Audio file",
  "?",
  "Audio only files",
  DEMUXER_TYPE_AUDIO,
  0, // unsafe autodetect
  demux_audio_open,
  demux_audio_fill_buffer,
  NULL,
  demux_close_audio,
  demux_audio_seek,
  demux_audio_control
};