midi

开发平台：
C/C++

fluid_aufile.c：源码内容
							/* 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 Library General Public License
 * as published by the Free Software Foundation; either version 2 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 * 02111-1307, USA
 */
/* fluid_aufile.c
 *
 * Audio driver, outputs the audio to a file (non real-time)
 *
 */
#include "fluid_adriver.h"
#include "fluid_settings.h"
#include "fluid_sys.h"
#include "config.h"
#include <stdio.h>
/** fluid_file_audio_driver_t
 *
 * This structure should not be accessed directly. Use audio port
 * functions instead.
 */
typedef struct {
	fluid_audio_driver_t driver;
	fluid_audio_func_t callback;
	void* data;
	fluid_file_renderer_t* renderer;
	int period_size;
	double sample_rate;
	fluid_timer_t* timer;
	unsigned int samples;
} fluid_file_audio_driver_t;
fluid_audio_driver_t* new_fluid_file_audio_driver(fluid_settings_t* settings,
						  fluid_synth_t* synth);
int delete_fluid_file_audio_driver(fluid_audio_driver_t* p);
static int fluid_file_audio_run_s16(void* d, unsigned int msec);
/**************************************************************
 *
 *        'file' audio driver
 * 
 */
fluid_audio_driver_t*
new_fluid_file_audio_driver(fluid_settings_t* settings,
			    fluid_synth_t* synth)
{
	fluid_file_audio_driver_t* dev;
	int msec;
	dev = FLUID_NEW(fluid_file_audio_driver_t);
	if (dev == NULL) {
		FLUID_LOG(FLUID_ERR, "Out of memory");
		return NULL;
	}
	FLUID_MEMSET(dev, 0, sizeof(fluid_file_audio_driver_t));
	fluid_settings_getint(settings, "audio.period-size", &dev->period_size);
	fluid_settings_getnum(settings, "synth.sample-rate", &dev->sample_rate);
	dev->data = synth;
	dev->callback = (fluid_audio_func_t) fluid_synth_process;
	dev->samples = 0;
	dev->renderer = new_fluid_file_renderer(synth);
	if (dev->renderer == NULL)
		goto error_recovery;
	msec = (int) (0.5 + dev->period_size / dev->sample_rate * 1000.0);
	dev->timer = new_fluid_timer(msec, fluid_file_audio_run_s16, (void*) dev, TRUE, FALSE, TRUE);
	if (dev->timer == NULL) {
		FLUID_LOG(FLUID_PANIC, "Couldn't create the audio thread.");
		goto error_recovery;
	}
	return (fluid_audio_driver_t*) dev;
 error_recovery:
	delete_fluid_file_audio_driver((fluid_audio_driver_t*) dev);
	return NULL;
}
int delete_fluid_file_audio_driver(fluid_audio_driver_t* p)
{
	fluid_file_audio_driver_t* dev = (fluid_file_audio_driver_t*) p;
	if (dev == NULL) {
		return FLUID_OK;
	}
	if (dev->timer != NULL) {
		delete_fluid_timer(dev->timer);
	}
	
	if (dev->renderer != NULL) {
		delete_fluid_file_renderer(dev->renderer);
	}
	FLUID_FREE(dev);
	return FLUID_OK;
}
static int fluid_file_audio_run_s16(void* d, unsigned int clock_time)
{
	fluid_file_audio_driver_t* dev = (fluid_file_audio_driver_t*) d;
	unsigned int sample_time;
	sample_time = (unsigned int) (dev->samples / dev->sample_rate * 1000.0);
	if (sample_time > clock_time) {
		return 1;
	}
	dev->samples += dev->period_size;
	return fluid_file_renderer_process_block(dev->renderer) == FLUID_OK ? 1 : 0;
}

						