ao_alsa.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 889 行 · 第 1/2 页

    mp_msg(MSGT_AO,MSGL_V,"alsa-init: using device %s\n", alsa_device);

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

    //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;
	  chunk_size = 1024;
	  break;
	}
    }

    if (!alsa_handler) {
      //modes = 0, SND_PCM_NONBLOCK, SND_PCM_ASYNC
      if ((err = try_open_device(alsa_device, open_mode, format == AF_FORMAT_AC3)) < 0)
	{
	  if (err != -EBUSY && ao_noblock) {
	    mp_msg(MSGT_AO,MSGL_INFO,MSGTR_AO_ALSA_OpenInNonblockModeFailed);
	    if ((err = try_open_device(alsa_device, 0, format == AF_FORMAT_AC3)) < 0) {
	      mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_PlaybackOpenError, snd_strerror(err));
	      return(0);
	    }
	  } else {
	    mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_PlaybackOpenError, snd_strerror(err));
	    return(0);
	  }
	}

      if ((err = snd_pcm_nonblock(alsa_handler, 0)) < 0) {
         mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_ErrorSetBlockMode, snd_strerror(err));
      } else {
	mp_msg(MSGT_AO,MSGL_V,"alsa-init: pcm opened in blocking mode\n");
      }

      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,MSGTR_AO_ALSA_UnableToGetInitialParameters,
		 snd_strerror(err));
	  return(0);
	}
    
      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,MSGTR_AO_ALSA_UnableToSetAccessType, 
	       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,
		MSGTR_AO_ALSA_FormatNotSupportedByHardware, af_fmt2str_short(format));
         alsa_format = SND_PCM_FORMAT_S16_LE;
         ao_data.format = AF_FORMAT_S16_LE;
      }

      if ((err = snd_pcm_hw_params_set_format(alsa_handler, alsa_hwparams,
					      alsa_format)) < 0)
	{
	  mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetFormat,
		 snd_strerror(err));
	  return(0);
	}

      if ((err = snd_pcm_hw_params_set_channels_near(alsa_handler, alsa_hwparams,
						     &ao_data.channels)) < 0)
	{
	  mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetChannels,
		 snd_strerror(err));
	  return(0);
	}

      /* workaround for buggy rate plugin (should be fixed in ALSA 1.0.11)
         prefer our own resampler */
#if SND_LIB_VERSION >= 0x010009
      if ((err = snd_pcm_hw_params_set_rate_resample(alsa_handler, alsa_hwparams,
						     0)) < 0)
	{
	  mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToDisableResampling,
		 snd_strerror(err));
	  return(0);
	}
#endif

      if ((err = snd_pcm_hw_params_set_rate_near(alsa_handler, alsa_hwparams, 
						 &ao_data.samplerate, NULL)) < 0) 
        {
	  mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetSamplerate2,
		 snd_strerror(err));
	  return(0);
        }

      bytes_per_sample = snd_pcm_format_physical_width(alsa_format) / 8;
      bytes_per_sample *= ao_data.channels;
      ao_data.bps = ao_data.samplerate * bytes_per_sample;

#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, NULL)) < 0)
	  {
	    mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetBufferTimeNear,
		   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, NULL)) < 0)
	  /* original: alsa_buffer_time/ao_data.bps */
	  {
	    mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetPeriodTime,
		   snd_strerror(err));
	    return 0;
	  }
	mp_msg(MSGT_AO,MSGL_INFO,MSGTR_AO_ALSA_BufferTimePeriodTime,
	       alsa_buffer_time, err);
      } 
#endif//end SET_BUFFERTIME

#ifdef SET_CHUNKSIZE
      {
	//set chunksize
	if ((err = snd_pcm_hw_params_set_period_size_near(alsa_handler, alsa_hwparams, 
							  &chunk_size, NULL)) < 0)
	  {
	    mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetPeriodSize,
			    chunk_size, snd_strerror(err));
	    return 0;
	  }
	else {
	  mp_msg(MSGT_AO,MSGL_V,"alsa-init: chunksize set to %li\n", chunk_size);
	}
	if ((err = snd_pcm_hw_params_set_periods_near(alsa_handler, alsa_hwparams,
						      &alsa_fragcount, NULL)) < 0) {
	  mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetPeriods, 
		 snd_strerror(err));
	  return 0;
	}
	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,MSGTR_AO_ALSA_UnableToSetHwParameters,
		 snd_strerror(err));
	  return 0;
	}
      // 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,MSGTR_AO_ALSA_UnableToGetBufferSize, snd_strerror(err));
	  return 0;
	}
      else {
	ao_data.buffersize = bufsize * bytes_per_sample;
	  mp_msg(MSGT_AO,MSGL_V,"alsa-init: got buffersize=%i\n", ao_data.buffersize);
      }

      if ((err = snd_pcm_hw_params_get_period_size(alsa_hwparams, &chunk_size, NULL)) < 0) {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToGetPeriodSize, snd_strerror(err));
	return 0;
      } else {
	mp_msg(MSGT_AO,MSGL_V,"alsa-init: got period size %li\n", chunk_size);
      }
      ao_data.outburst = chunk_size * bytes_per_sample;

      /* setting software parameters */
      if ((err = snd_pcm_sw_params_current(alsa_handler, alsa_swparams)) < 0) {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToGetSwParameters,
	       snd_strerror(err));
	return 0;
      }
#if SND_LIB_VERSION >= 0x000901
      if ((err = snd_pcm_sw_params_get_boundary(alsa_swparams, &boundary)) < 0) {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToGetBoundary,
	       snd_strerror(err));
	return 0;
      }
#else
      boundary = 0x7fffffff;
#endif
      /* start playing when one period has been written */
      if ((err = snd_pcm_sw_params_set_start_threshold(alsa_handler, alsa_swparams, chunk_size)) < 0) {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetStartThreshold,
	       snd_strerror(err));
	return 0;
      }
      /* disable underrun reporting */
      if ((err = snd_pcm_sw_params_set_stop_threshold(alsa_handler, alsa_swparams, boundary)) < 0) {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetStopThreshold,
	       snd_strerror(err));
	return 0;
      }
#if SND_LIB_VERSION >= 0x000901
      /* play silence when there is an underrun */
      if ((err = snd_pcm_sw_params_set_silence_size(alsa_handler, alsa_swparams, boundary)) < 0) {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToSetSilenceSize,
	       snd_strerror(err));
	return 0;
      }
#endif
      if ((err = snd_pcm_sw_params(alsa_handler, alsa_swparams)) < 0) {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToGetSwParameters,
	       snd_strerror(err));
	return 0;
      }
      /* end setting sw-params */

      mp_msg(MSGT_AO,MSGL_V,"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 ((err = snd_pcm_close(alsa_handler)) < 0)
      {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_PcmCloseError, snd_strerror(err));
	return;
      }
    else {
      alsa_handler = NULL;
      mp_msg(MSGT_AO,MSGL_V,"alsa-uninit: pcm closed\n");
    }
  }
  else {
    mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_NoHandlerDefined);
  }
}

static void audio_pause(void)
{
    int err;

    if (alsa_can_pause) {
        if ((err = snd_pcm_pause(alsa_handler, 1)) < 0)
        {
            mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_PcmPauseError, 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,MSGTR_AO_ALSA_PcmDropError, snd_strerror(err));
            return;
        }
    }
}

static void audio_resume(void)
{
    int err;

    if (alsa_can_pause) {
        if ((err = snd_pcm_pause(alsa_handler, 0)) < 0)
        {
            mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_PcmResumeError, 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,MSGTR_AO_ALSA_PcmPrepareError, snd_strerror(err));
            return;
        }
    }
}

/* stop playing and empty buffers (for seeking/pause) */
static void reset(void)
{
    int err;

    if ((err = snd_pcm_drop(alsa_handler)) < 0)
    {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_PcmPrepareError, snd_strerror(err));
	return;
    }
    if ((err = snd_pcm_prepare(alsa_handler)) < 0)
    {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_PcmPrepareError, snd_strerror(err));
	return;
    }
    return;
}

/*
    plays 'len' bytes of 'data'
    returns: number of bytes played
    modified last at 29.06.02 by jp
    thanxs for marius <[e-mail]> for giving us the light ;)
*/

static int play(void* data, int len, int flags)
{
  int num_frames = len / bytes_per_sample;
  snd_pcm_sframes_t res = 0;

  //mp_msg(MSGT_AO,MSGL_ERR,"alsa-play: frames=%i, len=%i\n",num_frames,len);

  if (!alsa_handler) {
    mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_DeviceConfigurationError);
    return 0;
  }

  if (num_frames == 0)
    return 0;

  do {
    res = snd_pcm_writei(alsa_handler, data, num_frames);

      if (res == -EINTR) {
	/* nothing to do */
	res = 0;
      }
      else if (res == -ESTRPIPE) {	/* suspend */
	mp_msg(MSGT_AO,MSGL_INFO,MSGTR_AO_ALSA_PcmInSuspendModeTryingResume);
	while ((res = snd_pcm_resume(alsa_handler)) == -EAGAIN)
	  sleep(1);
      }
      if (res < 0) {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_WriteError, snd_strerror(res));
	mp_msg(MSGT_AO,MSGL_INFO,MSGTR_AO_ALSA_TryingToResetSoundcard);
	if ((res = snd_pcm_prepare(alsa_handler)) < 0) {
	  mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_PcmPrepareError, snd_strerror(res));
	  return(0);
	  break;
	}
      }
  } while (res == 0);

  return res < 0 ? res : res * bytes_per_sample;
}

/* how many byes are free in the buffer */
static int get_space(void)
{
    snd_pcm_status_t *status;
    int ret;
    
    snd_pcm_status_alloca(&status);
    
    if ((ret = snd_pcm_status(alsa_handler, status)) < 0)
    {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_CannotGetPcmStatus, snd_strerror(ret));
	return(0);
    }
    
    ret = snd_pcm_status_get_avail(status) * bytes_per_sample;
    if (ret > ao_data.buffersize)  // Buffer underrun?
	ret = ao_data.buffersize;
    return(ret);
}

/* delay in seconds between first and last sample in buffer */
static float get_delay(void)
{
  if (alsa_handler) {
    snd_pcm_sframes_t delay;
    
    if (snd_pcm_delay(alsa_handler, &delay) < 0)
      return 0;
    
    if (delay < 0) {
      /* underrun - move the application pointer forward to catch up */
#if SND_LIB_VERSION >= 0x000901 /* snd_pcm_forward() exists since 0.9.0rc8 */
      snd_pcm_forward(alsa_handler, -delay);
#endif
      delay = 0;
    }
    return (float)delay / (float)ao_data.samplerate;
  } else {
    return(0);
  }
}