ao_alsa.c

自己移植的linux下的流媒体播放器原代码,支持mms协议,支持ftp和http协议.

	  IEC958_AES1_CON_PCM_CODER;
	s[2] = 0;
	s[3] = IEC958_AES3_CON_FS_48000;

	snprintf(alsa_device, ALSA_DEVICE_SIZE,
		"iec958:{CARD 0 AES0 0x%02x AES1 0x%02x AES2 0x%02x AES3 0x%02x}", 
 		s[0], s[1], s[2], s[3]);
	device.str = alsa_device;

	mp_msg(MSGT_AO,MSGL_V,"alsa-spdif-init: playing AC3, %i channels\n", channels);
    }
  else
        /* in any case for multichannel playback we should select
         * appropriate device
         */
        switch (channels) {
	case 1:
	case 2:
	  device.str = "default";
	  mp_msg(MSGT_AO,MSGL_V,"alsa-init: setup for 1/2 channel(s)\n");
	  break;
	case 4:
	  if (alsa_format == SND_PCM_FORMAT_FLOAT_LE)
	    // hack - use the converter plugin
	    device.str = "plug:surround40";
	  else
	    device.str = "surround40";
	  mp_msg(MSGT_AO,MSGL_V,"alsa-init: device set to surround40\n");
	  break;
	case 6:
	  if (alsa_format == SND_PCM_FORMAT_FLOAT_LE)
	    device.str = "plug:surround51";
	  else
	    device.str = "surround51";
	  mp_msg(MSGT_AO,MSGL_V,"alsa-init: device set to surround51\n");
	  break;
	default:
	  device.str = "default";
	  mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: %d channels are not supported\n",channels);
        }
    device.len = strlen(device.str);
    if (subopt_parse(ao_subdevice, subopts) != 0) {
        print_help();
        return 0;
    }
    ao_noblock = !block;
    parse_device(alsa_device, device.str, device.len);

	mp_msg(MSGT_AO,MSGL_INFO,"alsa-init: %d soundcard%s found, using: %s\n", cards+1,(cards >= 0) ? "" : "s", alsa_device);

    //setting modes for block or nonblock-mode
    if (ao_noblock) {
      open_mode = SND_PCM_NONBLOCK;
      set_block_mode = 1;
      str_block_mode = "nonblock-mode";
    }
    else {
      open_mode = 0;
      set_block_mode = 0;
      str_block_mode = "block-mode";
    }

    //sets buff/chunksize if its set manually
    if (ao_data.buffersize) {
      switch (ao_data.buffersize)
	{
	case 1:
	  alsa_fragcount = 16;
	  chunk_size = 512;
	    mp_msg(MSGT_AO,MSGL_V,"alsa-init: buffersize set manually to 8192\n");
	    mp_msg(MSGT_AO,MSGL_V,"alsa-init: chunksize set manually to 512\n");
	  break;
	case 2:
	  alsa_fragcount = 8;
	  chunk_size = 1024;
	    mp_msg(MSGT_AO,MSGL_V,"alsa-init: buffersize set manually to 8192\n");
	    mp_msg(MSGT_AO,MSGL_V,"alsa-init: chunksize set manually to 1024\n");
	  break;
	case 3:
	  alsa_fragcount = 32;
	  chunk_size = 512;
	    mp_msg(MSGT_AO,MSGL_V,"alsa-init: buffersize set manually to 16384\n");
	    mp_msg(MSGT_AO,MSGL_V,"alsa-init: chunksize set manually to 512\n");
	  break;
	case 4:
	  alsa_fragcount = 16;
	  chunk_size = 1024;
	    mp_msg(MSGT_AO,MSGL_V,"alsa-init: buffersize set manually to 16384\n");
	    mp_msg(MSGT_AO,MSGL_V,"alsa-init: chunksize set manually to 1024\n");
	  break;
	default:
	  alsa_fragcount = 16;
	  if (ao_mmap)
	    chunk_size = 512;
	  else
	    chunk_size = 1024;
	  break;
	}
    }

    if (!alsa_handler) {
      //modes = 0, SND_PCM_NONBLOCK, SND_PCM_ASYNC
      if ((err = snd_pcm_open(&alsa_handler, alsa_device, SND_PCM_STREAM_PLAYBACK, open_mode)) < 0)
	{
	  if (err != -EBUSY && ao_noblock) {
	    mp_msg(MSGT_AO,MSGL_INFO,"alsa-init: open in nonblock-mode failed, trying to open in block-mode\n");
	    if ((err = snd_pcm_open(&alsa_handler, alsa_device, SND_PCM_STREAM_PLAYBACK, 0)) < 0) {
	      mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: playback open error: %s\n", snd_strerror(err));
	      return(0);
	    } else {
	      set_block_mode = 0;
	      str_block_mode = "block-mode";
	    }
	  } else {
	    mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: playback open error: %s\n", snd_strerror(err));
	    return(0);
	  }
	}

      if ((err = snd_pcm_nonblock(alsa_handler, set_block_mode)) < 0) {
         mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: error set block-mode %s\n", snd_strerror(err));
      } else {
	mp_msg(MSGT_AO,MSGL_V,"alsa-init: pcm opend in %s\n", str_block_mode);
      }

      snd_pcm_hw_params_alloca(&alsa_hwparams);
      snd_pcm_sw_params_alloca(&alsa_swparams);

      // setting hw-parameters
      if ((err = snd_pcm_hw_params_any(alsa_handler, alsa_hwparams)) < 0)
	{
	  mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: unable to get initial parameters: %s\n",
		 snd_strerror(err));
	  return(0);
	}
    
      if (ao_mmap) {
	snd_pcm_access_mask_t *mask = alloca(snd_pcm_access_mask_sizeof());
	snd_pcm_access_mask_none(mask);
	snd_pcm_access_mask_set(mask, SND_PCM_ACCESS_MMAP_INTERLEAVED);
	snd_pcm_access_mask_set(mask, SND_PCM_ACCESS_MMAP_NONINTERLEAVED);
	snd_pcm_access_mask_set(mask, SND_PCM_ACCESS_MMAP_COMPLEX);
	err = snd_pcm_hw_params_set_access_mask(alsa_handler, alsa_hwparams, mask);
	mp_msg(MSGT_AO,MSGL_INFO,"alsa-init: mmap set\n");
      } else {
	err = snd_pcm_hw_params_set_access(alsa_handler, alsa_hwparams,
					   SND_PCM_ACCESS_RW_INTERLEAVED);
      }
      if (err < 0) {
	mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: unable to set access type: %s\n", 
	       snd_strerror(err));
	return (0);
      }

      /* workaround for nonsupported formats
	 sets default format to S16_LE if the given formats aren't supported */
      if ((err = snd_pcm_hw_params_test_format(alsa_handler, alsa_hwparams,
                                             alsa_format)) < 0)
      {
         mp_msg(MSGT_AO,MSGL_INFO,
		"alsa-init: format %s are not supported by hardware, trying default\n", af_fmt2str_short(format));
         alsa_format = SND_PCM_FORMAT_S16_LE;
         ao_data.format = AF_FORMAT_S16_LE;
         ao_data.bps = channels * rate_hz * 2;
      }

      bytes_per_sample = ao_data.bps / ao_data.samplerate; //it should be here

    
      if ((err = snd_pcm_hw_params_set_format(alsa_handler, alsa_hwparams,
					      alsa_format)) < 0)
	{
	  mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: unable to set format: %s\n",
		 snd_strerror(err));
	}

      if ((err = snd_pcm_hw_params_set_channels(alsa_handler, alsa_hwparams,
						ao_data.channels)) < 0)
	{
	  mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: unable to set channels: %s\n",
		 snd_strerror(err));
	}

      if ((err = snd_pcm_hw_params_set_rate_near(alsa_handler, alsa_hwparams, 
						 &ao_data.samplerate, &dir)) < 0) 
        {
	  mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: unable to set samplerate-2: %s\n",
		 snd_strerror(err));
	  return(0);
        }

#ifdef BUFFERTIME
      {
	int alsa_buffer_time = 500000; /* original 60 */
	int alsa_period_time;
	alsa_period_time = alsa_buffer_time/4;
	if ((err = snd_pcm_hw_params_set_buffer_time_near(alsa_handler, alsa_hwparams, 
							  &alsa_buffer_time, &dir)) < 0)
	  {
	    mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: unable to set buffer time near: %s\n",
		   snd_strerror(err));
	    return(0);
	  } else
	    alsa_buffer_time = err;

	if ((err = snd_pcm_hw_params_set_period_time_near(alsa_handler, alsa_hwparams, 
							  &alsa_period_time, &dir)) < 0)
	  /* original: alsa_buffer_time/ao_data.bps */
	  {
	    mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: unable to set period time: %s\n",
		   snd_strerror(err));
	  }
	mp_msg(MSGT_AO,MSGL_INFO,"alsa-init: buffer_time: %d, period_time :%d\n",
	       alsa_buffer_time, err);
      } 
#endif//end SET_BUFFERTIME

#ifdef SET_CHUNKSIZE
      {
	//set chunksize
	dir=0;
	if ((err = snd_pcm_hw_params_set_period_size_near(alsa_handler, alsa_hwparams, 
							  &chunk_size, &dir)) < 0)
	  {
	    mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: unable to set periodsize(%d): %s\n",
			    chunk_size, snd_strerror(err));
	  }
	else {
	  mp_msg(MSGT_AO,MSGL_V,"alsa-init: chunksize set to %i\n", chunk_size);
	}
	if ((err = snd_pcm_hw_params_set_periods_near(alsa_handler, alsa_hwparams,
						      &alsa_fragcount, &dir)) < 0) {
	  mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: unable to set periods: %s\n", 
		 snd_strerror(err));
	}
	else {
	  mp_msg(MSGT_AO,MSGL_V,"alsa-init: fragcount=%i\n", alsa_fragcount);
	}
      }
#endif//end SET_CHUNKSIZE

      /* finally install hardware parameters */
      if ((err = snd_pcm_hw_params(alsa_handler, alsa_hwparams)) < 0)
	{
	  mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: unable to set hw-parameters: %s\n",
		 snd_strerror(err));
	}
      // end setting hw-params


      // gets buffersize for control
      if ((err = snd_pcm_hw_params_get_buffer_size(alsa_hwparams, &bufsize)) < 0)
	{
	  mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: unable to get buffersize: %s\n", snd_strerror(err));
	}
      else {
	ao_data.buffersize = bufsize * bytes_per_sample;
	  mp_msg(MSGT_AO,MSGL_V,"alsa-init: got buffersize=%i\n", ao_data.buffersize);
      }

      // setting sw-params (only avail-min) if noblocking mode was choosed
      if (ao_noblock)
	{

	  if ((err = snd_pcm_sw_params_current(alsa_handler, alsa_swparams)) < 0)
	    {
	      mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: unable to get parameters: %s\n",
		     snd_strerror(err));

	    }

	  //set min available frames to consider pcm ready (4)
	  //increased for nonblock-mode should be set dynamically later
	  if ((err = snd_pcm_sw_params_set_avail_min(alsa_handler, alsa_swparams, 4)) < 0)
	    {
	      mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: unable to set avail_min %s\n",
		     snd_strerror(err));
	    }

	  if ((err = snd_pcm_sw_params(alsa_handler, alsa_swparams)) < 0)
	    {
	      mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: unable to install sw-params\n");
	    }

	  bits_per_sample = snd_pcm_format_physical_width(alsa_format);
	  bits_per_frame = bits_per_sample * channels;
	  chunk_bytes = chunk_size * bits_per_frame / 8;

	    mp_msg(MSGT_AO,MSGL_V,"alsa-init: bits per sample (bps)=%i, bits per frame (bpf)=%i, chunk_bytes=%i\n",bits_per_sample,bits_per_frame,chunk_bytes);}
	//end swparams

      if ((err = snd_pcm_prepare(alsa_handler)) < 0)
	{
	  mp_msg(MSGT_AO,MSGL_ERR,"alsa-init: pcm prepare error: %s\n", snd_strerror(err));
	}

      mp_msg(MSGT_AO,MSGL_INFO,"alsa: %d Hz/%d channels/%d bpf/%d bytes buffer/%s\n",
	     ao_data.samplerate, ao_data.channels, bytes_per_sample, ao_data.buffersize,
	     snd_pcm_format_description(alsa_format));

    } // end switch alsa_handler (spdif)
    alsa_can_pause = snd_pcm_hw_params_can_pause(alsa_hwparams);
    return(1);
} // end init


/* close audio device */
static void uninit(int immed)
{

  if (alsa_handler) {
    int err;

    if (!immed)
      snd_pcm_drain(alsa_handler);

    if (!ao_noblock) {
      if ((err = snd_pcm_drop(alsa_handler)) < 0)
	{
	  mp_msg(MSGT_AO,MSGL_ERR,"alsa-uninit: pcm drop error: %s\n", snd_strerror(err));
	  return;
	}
    }

    if ((err = snd_pcm_close(alsa_handler)) < 0)
      {
	mp_msg(MSGT_AO,MSGL_ERR,"alsa-uninit: pcm close error: %s\n", snd_strerror(err));
	return;
      }
    else {
      alsa_handler = NULL;
      mp_msg(MSGT_AO,MSGL_INFO,"alsa-uninit: pcm closed\n");
    }
  }
  else {
    mp_msg(MSGT_AO,MSGL_ERR,"alsa-uninit: no handler defined!\n");
  }
}

static void audio_pause()
{
    int err;

    if (alsa_can_pause) {
        if ((err = snd_pcm_pause(alsa_handler, 1)) < 0)
        {
            mp_msg(MSGT_AO,MSGL_ERR,"alsa-pause: pcm pause error: %s\n", snd_strerror(err));
            return;
        }
          mp_msg(MSGT_AO,MSGL_V,"alsa-pause: pause supported by hardware\n");
    } else {
        if ((err = snd_pcm_drop(alsa_handler)) < 0)
        {
            mp_msg(MSGT_AO,MSGL_ERR,"alsa-pause: pcm drop error: %s\n", snd_strerror(err));
            return;
        }
    }
}

static void audio_resume()
{
    int err;

    if (alsa_can_pause) {
        if ((err = snd_pcm_pause(alsa_handler, 0)) < 0)
        {
            mp_msg(MSGT_AO,MSGL_ERR,"alsa-resume: pcm resume error: %s\n", snd_strerror(err));
            return;
        }
          mp_msg(MSGT_AO,MSGL_V,"alsa-resume: resume supported by hardware\n");
    } else {
        if ((err = snd_pcm_prepare(alsa_handler)) < 0)
        {
           mp_msg(MSGT_AO,MSGL_ERR,"alsa-resume: pcm prepare error: %s\n", snd_strerror(err));
            return;
        }