/**
 * $Id:$
 * ***** BEGIN GPL/BL DUAL LICENSE BLOCK *****
 *
 * The contents of this file may be used under the terms of either the GNU
 * General Public License Version 2 or later (the "GPL", see
 * http://www.gnu.org/licenses/gpl.html ), or the Blender License 1.0 or
 * later (the "BL", see http://www.blender.org/BL/ ) which has to be
 * bought from the Blender Foundation to become active, in which case the
 * above mentioned GPL option does not apply.
 *
 * The Original Code is Copyright (C) 1997 by Ton Roosendaal, Frank van Beek and Joeri Kassenaar.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL/BL DUAL LICENSE BLOCK *****
 */

/*

 * alInit.c: Does libaudio (audio library) initializations)
 *
 * 
 * Silicon Graphics Inc., June 1994
 */

#include "play.h"

static void setAudioFrameRate (void);
static int AudioOutputHardwareInUse(double rate);
static long GetAudioHardwareOutputRate(void);
static long GetAudioHardwareInputRate(void);


void alInit ()
{
	int sampleWidth;

	if (!audio.isTrack)
		return;

	/* initialize audio hardware output port */

	if ((audio.config = ALnewconfig()) == NULL) {
		fprintf (stderr, "Unable to initialise an ALconfig structure\n");
		exit (-1);
	}

	/* attempt to set audio hardware output sampling rate to file rate */
	setAudioFrameRate ();

	if (ALsetqueuesize(audio.config, audio.queueSize) == -1) {
		fprintf (stderr, "Unable to set Queue size for the audio port.\n");
		exit (-1);
	}
	if (audio.sampleWidth <= 8) {
		sampleWidth = AL_SAMPLE_8;
	} else if (audio.sampleWidth <= 16) {
		sampleWidth = AL_SAMPLE_16;
	} else {
		sampleWidth = AL_SAMPLE_24;
	}
	if (ALsetwidth(audio.config, sampleWidth)) {
		fprintf (stderr, "Unable to set audio sample width.\n");
		exit (-1);
	}

	if (ALsetchannels(audio.config, audio.channelCount)) {
		fprintf (stderr, "Unable to set number of audio channels\n.");
		exit (-1);
	}
	if ((audio.outPort = ALopenport("play", "w", audio.config)) == NULL) {
		printf("Sorry, no audio output.\n");
	}

}


/*** All the routines below are for setting audio frame rate ***/

void setAudioFrameRate ()
{
	int audioHardwareInUse;

#define RUDE_AUDIO
#ifdef RUDE_AUDIO
	int doNotRudelyChangeSamplingRate = 0;
#else  
	int doNotRudelyChangeSamplingRate = 1;
#endif /*RUDE_AUDIO*/
	long currentHardwareRate;
	long buffer[2];

	/* turn off AL error handler during first half of this funtion */
	ALerrfunc oldErrorHandler = ALseterrorhandler(NULL);


	currentHardwareRate = GetAudioHardwareOutputRate();
	if (currentHardwareRate != audio.frameRate)
	{
		audioHardwareInUse = AudioOutputHardwareInUse(audio.frameRate);
		/* if no one else is using audio output hardware, change sampling rate */
		if ((!audioHardwareInUse)||
		    (!doNotRudelyChangeSamplingRate))
		{
			buffer[0] = AL_OUTPUT_RATE;
			buffer[1] = (long) audio.frameRate;
			ALsetparams(AL_DEFAULT_DEVICE, buffer, 2);
		}

		/* hardware will use nearest supported rate.  */
		/* warn about unsupported rates (outside the Audio Driver 
	       rate set) */
		currentHardwareRate = GetAudioHardwareOutputRate();
		if ((currentHardwareRate != AL_RATE_UNDEFINED)&&
		    (currentHardwareRate != (long) audio.frameRate))
		{
			if (audioHardwareInUse) {
				fprintf (stderr, 
				    "Audio Hardware in Use. Playing at ");
				fprintf (stderr,"%d Hz, not file rate %g Hz\n", 
				    currentHardwareRate, audio.frameRate);
				fprintf (stderr, "Shutting off audio\n");
				/*
                         * we won't play the audio track because we
                         * can't change the output sample rate
                         * another audio app is already running
                         */
				audio.isTrack = 0;
			} else {
				fprintf (stderr, "File rate %g Hz unsupported. ");
				fprintf (stderr, "Playing at %d Hz\n", 
				    audio.frameRate, currentHardwareRate);
			}
		}
	}
	/* restore AL error handler */
	ALseterrorhandler(oldErrorHandler);
}

/* ******************************************************************
 * GetAudioHardwareOutputRate	acquire audio hardware output sampling rate	
 * ****************************************************************** */
static long 
GetAudioHardwareOutputRate(void)
{
	long	buffer[4];

	buffer[0] = AL_OUTPUT_RATE;
	buffer[2] = AL_DIGITAL_INPUT_RATE;
	ALgetparams(AL_DEFAULT_DEVICE, buffer, 4);

	/* output rate is in Hertz */
	if	(buffer[1] > 0)
		return (buffer[1]);

		/* output rate is input rate */
	else if (AL_RATE_INPUTRATE == buffer[1])
		return (GetAudioHardwareInputRate());

		/* for input rate AES word clock and machine has ability to read digital input sampling rate, return 
	AL_DIGITAL_INPUT_RATE */
	else if (ALgetdefault(AL_DEFAULT_DEVICE, AL_DIGITAL_INPUT_RATE) >= 0)
		return (buffer[3]);

		/* could not determine sampling rate */
	else
		return (AL_RATE_UNDEFINED);
} /* ---- end GetAudioHardwareOutputRate() ---- */

/* ******************************************************************
 * AudioOutputHardwareInUse    any output ports open or monitor on?  
 * ****************************************************************** */
int
AudioOutputHardwareInUse(double rate)
{
	long	buffer[4];

	buffer[0] = AL_OUTPUT_COUNT;
	buffer[2] = AL_MONITOR_CTL;
	ALgetparams(AL_DEFAULT_DEVICE, buffer, 4);

	/* no open audio output ports and monitor off */
	if ((0 == buffer[1]) && (AL_MONITOR_OFF == buffer[3]))
		return (FALSE);

	return (TRUE);
} /* ---- end AudioOutputHardwareInUse() ---- */

/*
 * GetAudioHardwareInputRate:    acquire audio hardware input sampling rate
 * -------------------------------------------------------------------- */
long 
GetAudioHardwareInputRate(void)
{
	long buffer[6];

	/* acquire state variables of audio hardware */
	buffer[0] = AL_INPUT_RATE;
	buffer[2] = AL_INPUT_SOURCE;
	buffer[4] = AL_DIGITAL_INPUT_RATE;
	ALgetparams(AL_DEFAULT_DEVICE, buffer, 6);

	/* for input sources microphone or line and input rate not AES word clock */
	if	((buffer[3] != AL_INPUT_DIGITAL)&&(buffer[1] > 0))
		return (buffer[1]);

		/* for input rate AES word clock and machine has ability to read digital input sampling rate, return 
	AL_DIGITAL_INPUT_RATE */
	else if (ALgetdefault(AL_DEFAULT_DEVICE, AL_DIGITAL_INPUT_RATE) >= 0)
		return (buffer[5]);

		/* could not determine sampling rate */
	else
		return (AL_RATE_UNDEFINED);
}   /* ---- end GetAudioHardwareInputRate() ---- */