sgi.c

mips上编译过的mpg 运行正常 环境：AU12

/*
	sgi: audio output on SGI boxen

	copyright ?-2006 by the mpg123 project - free software under the terms of the LGPL 2.1
	see COPYING and AUTHORS files in distribution or http://mpg123.org
	initially written (as it seems) by Thomas Woerner
*/

#include <fcntl.h>

/* #include <audio.h> */
#include <dmedia/audio.h>

#include "mpg123app.h"
#include "debug.h"


/* Analog output constant */
static const char analog_output_res_name[] = ".AnalogOut";


static int set_rate(audio_output_t *ao, ALconfig config)
{
	int dev = alGetDevice(config);
	ALpv params[1];
	
	/* Make sure the device is OK */
	if (dev < 0)
	{
		error1("set_rate: %s",alGetErrorString(oserror()));
		return 1;      
	}
	
	params[0].param = AL_OUTPUT_RATE;
	params[0].value.ll = alDoubleToFixed(ao->rate);
	
	if (alSetParams(dev, params,1) < 0)
		error1("set_rate: %s",alGetErrorString(oserror()));
	
	return 0;
}


static int set_channels(audio_output_t *ao, ALconfig config)
{
	int ret;
	
	if(ao->channels == 2)
		ret = alSetChannels(config, AL_STEREO);
	else
		ret = alSetChannels(config, AL_MONO);
	
	if (ret < 0)
		error1("set_channels : %s",alGetErrorString(oserror()));
	
	return 0;
}

static int set_format(audio_output_t *ao, ALconfig config)
{
	if (alSetSampFmt(config,AL_SAMPFMT_TWOSCOMP) < 0)
		error1("set_format : %s",alGetErrorString(oserror()));
	
	if (alSetWidth(config,AL_SAMPLE_16) < 0)
		error1("set_format : %s",alGetErrorString(oserror()));
	
	return 0;
}


static int open_sgi(audio_output_t *ao)
{
	int dev = AL_DEFAULT_OUTPUT;
	ALconfig config = alNewConfig();
	ALport port = NULL;
	
	/* Test for correct completion */
	if (config == 0) {
		error1("open_sgi: %s",alGetErrorString(oserror()));
		return -1;
	}
	
	/* Set port parameters */
	if(ao->channels == 2)
		alSetChannels(config, AL_STEREO);
	else
		alSetChannels(config, AL_MONO);
	
	alSetWidth(config, AL_SAMPLE_16);
	alSetSampFmt(config,AL_SAMPFMT_TWOSCOMP);
	alSetQueueSize(config, 131069);
	
	/* Setup output device to specified module. If there is no module
	specified in ao structure, use the default four output */
	if ((ao->device) != NULL) {
		char *dev_name;
		
		dev_name=malloc((strlen(ao->device) + strlen(analog_output_res_name) + 1) *
		  sizeof(char));
		
		strcpy(dev_name,ao->device);
		strcat(dev_name,analog_output_res_name);
		
		/* Find the asked device resource */
		dev=alGetResourceByName(AL_SYSTEM,dev_name,AL_DEVICE_TYPE);
		
		/* Free allocated space */
		free(dev_name);
		
		if (!dev) {
			error2("Invalid audio resource: %s (%s)",dev_name, alGetErrorString(oserror()));
			return -1;
		}
	}
	
	/* Set the device */
	if (alSetDevice(config,dev) < 0)
	{
		error1("open_sgi: %s",alGetErrorString(oserror()));
		return -1;
	}
	
	/* Open the audio port */
	port = alOpenPort("mpg123-VSC", "w", config);
	if(port == NULL) {
		error1("Unable to open audio channel: %s", alGetErrorString(oserror()));
		return -1;
	}
	
	ao->handle = (void*)port;
	
	
	set_format(ao, config);
	set_channels(ao, config);
	set_rate(ao, config);
	
	
	alFreeConfig(config);
	
	return 1;
}


static int get_formats_sgi(output_t *ao)
{
	return MPG123_ENC_SIGNED_16;
}


static int write_sgi(audio_output_t *ao,unsigned char *buf,int len)
{
	ALport port = (ALport)ao->handle;
	
	if(ao->format == MPG123_ENC_SIGNED_8)
		alWriteFrames(port, buf, len>>1);
	else
		alWriteFrames(port, buf, len>>2);
	
	return len;
}


int close_sgi(audio_output_t *ao)
{
	ALport port = (ALport)ao->handle;
	
	if (port) {
		while(alGetFilled(port) > 0) sginap(1);  
		alClosePort(port);
		ao->handle=NULL;
	}
	
	return 0;
}

void flush_sgi(audio_output_t *ao)
{
}


static int init_sgi(audio_output_t* ao)
{
	if (ao==NULL) return -1;

	/* Set callbacks */
	ao->open = open_sgi;
	ao->flush = flush_sgi;
	ao->write = write_sgi;
	ao->get_formats = get_formats_sgi;
	ao->close = close_sgi;

	/* Success */
	return 0;
}





/* 
	Module information data structure
*/
mpg123_module_t mpg123_output_module_info = {
	/* api_version */	MPG123_MODULE_API_VERSION,
	/* name */			"sgi",						
	/* description */	"Audio output for SGI.",
	/* revision */		"$Rev:$",						
	/* handle */		NULL,
	
	/* init_output */	init_sgi,						
};