fluidsynth/src/drivers/fluid_portaudio.c

/* FluidSynth - A Software Synthesizer
 *
 * Copyright (C) 2003  Peter Hanappe and others.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 */

/* fluid_portaudio.c
 *
 * Drivers for the PortAudio API : www.portaudio.com
 * Implementation files for PortAudio on each platform have to be added
 *
 * Stephane Letz  (letz@grame.fr)  Grame
 * 12/20/01 Adapdation for new audio drivers
 *
 * Josh Green <jgreen@users.sourceforge.net>
 * 2009-01-28 Overhauled for PortAudio 19 API and current FluidSynth API (was broken)
 */

#include "fluid_synth.h"
#include "fluid_settings.h"
#include "fluid_adriver.h"

#if PORTAUDIO_SUPPORT

#include <portaudio.h>


/** fluid_portaudio_driver_t
 *
 * This structure should not be accessed directly. Use audio port
 * functions instead.
 */
typedef struct
{
  fluid_audio_driver_t driver;
  fluid_synth_t *synth;
  fluid_audio_callback_t read;
  PaStream *stream;
} fluid_portaudio_driver_t;

static int
fluid_portaudio_run (const void *input, void *output, unsigned long frameCount,
                     const PaStreamCallbackTimeInfo* timeInfo,
                     PaStreamCallbackFlags statusFlags, void *userData);
void delete_fluid_portaudio_driver (fluid_audio_driver_t *p);

#define PORTAUDIO_DEFAULT_DEVICE "PortAudio Default"

/**
 * Checks if device_num is a valid device and returns the name of the portaudio device.
 * A device is valid if it is an output device with at least 2 channels.
 * 
 * @param device_num index of the portaudio device to check.
 * @param name_ptr if device_num is valid, set to a unique device name, ignored otherwise
 *
 * The name returned is unique for each num_device index, so this 
 * name is useful to identify any available host audio device.
 * This name is convenient for audio.portaudio.device setting.
 *
 * The format of the name is: device_index:host_api_name:host_device_name
 *   
 *   example: 5:MME:SB PCI
 *   
 *   5: is the portaudio device index.
 *   MME: is the host API name.
 *   SB PCI: is the host device name.
 * 
 * @return #FLUID_OK if device_num is a valid output device, #FLUID_FAILED otherwise.
 * When #FLUID_OK, the name is returned in allocated memory. The caller must check
 * the name pointer for a valid memory allocation and should free the memory.
 */
static int fluid_portaudio_get_device_name(int device_num, char **name_ptr)
{
  	const PaDeviceInfo *deviceInfo =  Pa_GetDeviceInfo (device_num);

	if( deviceInfo->maxOutputChannels >= 2 )
	{
		const PaHostApiInfo *hostInfo = Pa_GetHostApiInfo( deviceInfo->hostApi );
		/* The size of the buffer name for the following format:
		   device_index:host_api_name:host_device_name.
		*/
		int i =  device_num;
		int size = 0;
		do {size++; i = i/10 ;} while(i);		/*  index size */ 
		/* host API size +  host device size + 2 separators + zero termination */
		size += strlen(hostInfo->name) + strlen(deviceInfo->name) + 3;
		*name_ptr = FLUID_MALLOC (size);
		if (*name_ptr)
		{   /* the name is filled if allocation is successful */
			FLUID_SPRINTF(*name_ptr,"%d:%s:%s",device_num, 
							hostInfo->name, deviceInfo->name);
		}
		return FLUID_OK; /* device_num is a valid device */
	}
	else return FLUID_FAILED; /* device_num is an invalid device */
}

/**
 * Initializes "audio.portaudio.device" setting with an options list of unique device names
 * of available sound card devices.
 * @param settings pointer to settings.
 */
void
fluid_portaudio_driver_settings (fluid_settings_t *settings)
{
  int numDevices;
  PaError err;
  int i;

  fluid_settings_register_str (settings, "audio.portaudio.device", PORTAUDIO_DEFAULT_DEVICE, 0);
  fluid_settings_add_option (settings, "audio.portaudio.device", PORTAUDIO_DEFAULT_DEVICE);

  err = Pa_Initialize();

  if (err != paNoError)
  {
    FLUID_LOG (FLUID_ERR, "Error initializing PortAudio driver: %s",
               Pa_GetErrorText (err));
    return;
  }

  numDevices = Pa_GetDeviceCount();

  if (numDevices < 0)
  {
      FLUID_LOG (FLUID_ERR, "PortAudio returned unexpected device count %d", numDevices);
  }
  else   for (i = 0; i < numDevices; i++)
  {
    char * name;
    if(fluid_portaudio_get_device_name(i, &name) == FLUID_OK)
    {
        /* the device i is a valid output device */
        if(name)
        {
            /* registers this name in the option list */
            fluid_settings_add_option (settings, "audio.portaudio.device", name);
            FLUID_FREE (name);
        }
        else
        {
            FLUID_LOG (FLUID_ERR, "Out of memory");
            break;
        }
    }
    }

  /* done with PortAudio for now, may get reopened later */
  err = Pa_Terminate();

  if (err != paNoError)
    printf ("PortAudio termination error: %s\n", Pa_GetErrorText (err) );
}

/**
 * Creates the portaudio driver and opens the portaudio device
 * indicated by audio.portaudio.device setting.
 *
 * @param settings pointer to settings
 * @param synth the synthesizer instance
 * @return pointer to the driver on success, NULL otherwise.
 */
fluid_audio_driver_t *
new_fluid_portaudio_driver (fluid_settings_t *settings, fluid_synth_t *synth)
{
  fluid_portaudio_driver_t *dev = NULL;
  PaStreamParameters outputParams;
  char *device = NULL; /* the portaudio device name to work with */
  double sample_rate;  /* intended sample rate */
  int period_size;     /* intended buffer size */
  PaError err;

  dev = FLUID_NEW (fluid_portaudio_driver_t);

  if (dev == NULL)
  {
    FLUID_LOG (FLUID_ERR, "Out of memory");
    return NULL;
  }

  err = Pa_Initialize ();

  if (err != paNoError)
  {
    FLUID_LOG (FLUID_ERR, "Error initializing PortAudio driver: %s",
               Pa_GetErrorText (err));
    FLUID_FREE (dev);
    return NULL;
  }

  FLUID_MEMSET (dev, 0, sizeof (fluid_portaudio_driver_t));

  dev->synth = synth;
  
  /* gets audio parameters from the settings */
  fluid_settings_getint (settings, "audio.period-size", &period_size);
  fluid_settings_getnum (settings, "synth.sample-rate", &sample_rate);
  fluid_settings_dupstr(settings, "audio.portaudio.device", &device);   /* ++ alloc device name */

  memset (&outputParams, 0, sizeof (outputParams));
  outputParams.channelCount = 2; /* For stereo output */
  outputParams.suggestedLatency = (PaTime)period_size / sample_rate;

  /* Locate the device if specified */
  if (FLUID_STRCMP (device, PORTAUDIO_DEFAULT_DEVICE) != 0)
  { /* The intended device is not the default device name, so we search
    a device among available devices */
    int numDevices;
    int i;

    numDevices = Pa_GetDeviceCount ();

    if (numDevices < 0)
    {
      FLUID_LOG (FLUID_ERR, "PortAudio returned unexpected device count %d", numDevices);
      goto error_recovery;
    }

    for (i = 0; i < numDevices; i++)
    {
        char * name;
        if(fluid_portaudio_get_device_name(i, &name) == FLUID_OK )
        {
            /* the device i is a valid output device */
            if(name)
            {
                /* We see if the name corresponds to audio.portaudio.device */
                char found = (FLUID_STRCMP (device, name) == 0);
                FLUID_FREE (name);

                if(found)
                {
                    /* the device index is found */
                    outputParams.device = i;
                    /* The search is finished */
                    break;
                }
            }
            else
            {
                FLUID_LOG (FLUID_ERR, "Out of memory");
                goto error_recovery;
            }
        }
    }
    
    if (i == numDevices)
    {
      FLUID_LOG (FLUID_ERR, "PortAudio device '%s' was not found", device);
      goto error_recovery;
    }
  }
  else
  { /* the default device will be used */
    outputParams.device = Pa_GetDefaultOutputDevice();
  }

  /* The device is found. We set the sample format and the audio rendering
     function suited to this format. 
  */
  if (fluid_settings_str_equal (settings, "audio.sample-format", "16bits"))
  {
    outputParams.sampleFormat = paInt16;
    dev->read = fluid_synth_write_s16;
  }
  else if (fluid_settings_str_equal (settings, "audio.sample-format", "float"))
  {
    outputParams.sampleFormat = paFloat32;
    dev->read = fluid_synth_write_float;
  }
  else
  {
    FLUID_LOG (FLUID_ERR, "Unknown sample format");
    goto error_recovery;
  }

  /* PortAudio section */

  /* Open an audio I/O stream. */
  err = Pa_OpenStream (&dev->stream,
                       NULL,              /* Input parameters */
                       &outputParams,     /* Output parameters */
                       sample_rate,
                       period_size,
                       paNoFlag,
                       fluid_portaudio_run, /* callback */
                       dev);

  if (err != paNoError)
  {
    FLUID_LOG (FLUID_ERR, "Error opening PortAudio stream: %s",
               Pa_GetErrorText (err));
    goto error_recovery;
  }

  err = Pa_StartStream (dev->stream); /* starts the I/O stream */

  if (err != paNoError)
  {
    FLUID_LOG (FLUID_ERR, "Error starting PortAudio stream: %s",
               Pa_GetErrorText (err));
    goto error_recovery;
  }

  if (device) FLUID_FREE (device);      /* -- free device name */
  
  return (fluid_audio_driver_t *)dev;

error_recovery:
  if (device) FLUID_FREE (device);      /* -- free device name */
  delete_fluid_portaudio_driver ((fluid_audio_driver_t *)dev);
  return NULL;
}

/* PortAudio callback
 * fluid_portaudio_run
 */
static int
fluid_portaudio_run (const void *input, void *output, unsigned long frameCount,
                     const PaStreamCallbackTimeInfo* timeInfo,
                     PaStreamCallbackFlags statusFlags, void *userData)
{
  fluid_portaudio_driver_t *dev = (fluid_portaudio_driver_t *)userData;
  /* it's as simple as that: */
  dev->read (dev->synth, frameCount, output, 0, 2, output, 1, 2);
  return 0;
}

/*
 * delete_fluid_portaudio_driver
 */
void
delete_fluid_portaudio_driver(fluid_audio_driver_t *p)
{
  fluid_portaudio_driver_t* dev = (fluid_portaudio_driver_t*)p;
  PaError err;
  fluid_return_if_fail(dev != NULL);

  /* PortAudio section */
  if (dev->stream) Pa_CloseStream (dev->stream);

  err = Pa_Terminate();

  if (err != paNoError)
    printf ("PortAudio termination error: %s\n", Pa_GetErrorText (err) );

  FLUID_FREE (dev);
}

#endif /* PORTAUDIO_SUPPORT */