diff src/audio/sun/SDL_sunaudio.c @ 0:74212992fb08

Initial revision
author Sam Lantinga <slouken@lokigames.com>
date Thu, 26 Apr 2001 16:45:43 +0000
parents
children 8758b8d42cd9
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/audio/sun/SDL_sunaudio.c	Thu Apr 26 16:45:43 2001 +0000
@@ -0,0 +1,439 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997, 1998, 1999, 2000, 2001  Sam Lantinga
+
+    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
+
+    Sam Lantinga
+    slouken@devolution.com
+*/
+
+#ifdef SAVE_RCSID
+static char rcsid =
+ "@(#) $Id$";
+#endif
+
+/* Allow access to a raw mixing buffer */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#ifdef __NetBSD__
+#include <sys/ioctl.h>
+#include <sys/audioio.h>
+#endif
+#ifdef __SVR4
+#include <sys/audioio.h>
+#else
+#include <sys/time.h>
+#include <sys/types.h>
+#endif
+#include <unistd.h>
+
+#include "SDL_endian.h"
+#include "SDL_audio.h"
+#include "SDL_audiomem.h"
+#include "SDL_audiodev_c.h"
+#include "SDL_sunaudio.h"
+#include "SDL_audio_c.h"
+#include "SDL_timer.h"
+
+/* Open the audio device for playback, and don't block if busy */
+#define OPEN_FLAGS	(O_WRONLY|O_NONBLOCK)
+
+/* Audio driver functions */
+static int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec);
+static void DSP_WaitAudio(_THIS);
+static void DSP_PlayAudio(_THIS);
+static Uint8 *DSP_GetAudioBuf(_THIS);
+static void DSP_CloseAudio(_THIS);
+
+/* Audio driver bootstrap functions */
+
+static int Audio_Available(void)
+{
+	int fd;
+	int available;
+
+	available = 0;
+	fd = SDL_OpenAudioPath(NULL, 0, OPEN_FLAGS, 1);
+	if ( fd >= 0 ) {
+		available = 1;
+		close(fd);
+	}
+	return(available);
+}
+
+static void Audio_DeleteDevice(SDL_AudioDevice *device)
+{
+	free(device->hidden);
+	free(device);
+}
+
+static SDL_AudioDevice *Audio_CreateDevice(int devindex)
+{
+	SDL_AudioDevice *this;
+
+	/* Initialize all variables that we clean on shutdown */
+	this = (SDL_AudioDevice *)malloc(sizeof(SDL_AudioDevice));
+	if ( this ) {
+		memset(this, 0, (sizeof *this));
+		this->hidden = (struct SDL_PrivateAudioData *)
+				malloc((sizeof *this->hidden));
+	}
+	if ( (this == NULL) || (this->hidden == NULL) ) {
+		SDL_OutOfMemory();
+		if ( this ) {
+			free(this);
+		}
+		return(0);
+	}
+	memset(this->hidden, 0, (sizeof *this->hidden));
+	audio_fd = -1;
+
+	/* Set the function pointers */
+	this->OpenAudio = DSP_OpenAudio;
+	this->WaitAudio = DSP_WaitAudio;
+	this->PlayAudio = DSP_PlayAudio;
+	this->GetAudioBuf = DSP_GetAudioBuf;
+	this->CloseAudio = DSP_CloseAudio;
+
+	this->free = Audio_DeleteDevice;
+
+	return this;
+}
+
+AudioBootStrap AUDIO_bootstrap = {
+	"audio", "UNIX /dev/audio interface",
+	Audio_Available, Audio_CreateDevice
+};
+
+#ifdef DEBUG_AUDIO
+void CheckUnderflow(_THIS)
+{
+#ifdef AUDIO_GETINFO
+	audio_info_t info;
+	int left;
+
+	ioctl(audio_fd, AUDIO_GETINFO, &info);
+	left = (written - info.play.samples);
+	if ( written && (left == 0) ) {
+		fprintf(stderr, "audio underflow!\n");
+	}
+#endif
+}
+#endif
+
+void DSP_WaitAudio(_THIS)
+{
+#ifdef AUDIO_GETINFO
+#define SLEEP_FUDGE	10		/* 10 ms scheduling fudge factor */
+	audio_info_t info;
+	Sint32 left;
+
+	ioctl(audio_fd, AUDIO_GETINFO, &info);
+	left = (written - info.play.samples);
+	if ( left > fragsize ) {
+		Sint32 sleepy;
+
+		sleepy = ((left - fragsize)/frequency);
+		sleepy -= SLEEP_FUDGE;
+		if ( sleepy > 0 ) {
+			SDL_Delay(sleepy);
+		}
+	}
+#else
+	fd_set fdset;
+
+	FD_ZERO(&fdset);
+	FD_SET(audio_fd, &fdset);
+	select(audio_fd+1, NULL, &fdset, NULL, NULL);
+#endif
+}
+
+void DSP_PlayAudio(_THIS)
+{
+	static Uint8 snd2au(int sample);
+	/* Write the audio data */
+	if ( ulaw_only ) {
+		/* Assuming that this->spec.freq >= 8000 Hz */
+		int accum, incr, pos;
+		Uint8 *aubuf;
+
+		accum = 0;
+		incr  = this->spec.freq/8;
+		aubuf = ulaw_buf;
+		switch (audio_fmt & 0xFF) {
+			case 8: {
+				Uint8 *sndbuf;
+
+				sndbuf = mixbuf;
+				for ( pos=0; pos < fragsize; ++pos ) {
+					*aubuf = snd2au((0x80-*sndbuf)*64);
+					accum += incr;
+					while ( accum > 0 ) {
+						accum -= 1000;
+						sndbuf += 1;
+					}
+					aubuf += 1;
+				}
+			}
+			break;
+			case 16: {
+				Sint16 *sndbuf;
+
+				sndbuf = (Sint16 *)mixbuf;
+				for ( pos=0; pos < fragsize; ++pos ) {
+					*aubuf = snd2au(*sndbuf/4);
+					accum += incr;
+					while ( accum > 0 ) {
+						accum -= 1000;
+						sndbuf += 1;
+					}
+					aubuf += 1;
+				}
+			}
+			break;
+		}
+#ifdef DEBUG_AUDIO
+		CheckUnderflow(this);
+#endif
+		if ( write(audio_fd, ulaw_buf, fragsize) < 0 ) {
+			/* Assume fatal error, for now */
+			this->enabled = 0;
+		}
+		written += fragsize;
+	} else {
+#ifdef DEBUG_AUDIO
+		CheckUnderflow(this);
+#endif
+		if ( write(audio_fd, mixbuf, this->spec.size) < 0 ) {
+			/* Assume fatal error, for now */
+			this->enabled = 0;
+		}
+		written += fragsize;
+	}
+}
+
+Uint8 *DSP_GetAudioBuf(_THIS)
+{
+	return(mixbuf);
+}
+
+void DSP_CloseAudio(_THIS)
+{
+	if ( mixbuf != NULL ) {
+		SDL_FreeAudioMem(mixbuf);
+		mixbuf = NULL;
+	}
+	if ( ulaw_buf != NULL ) {
+		free(ulaw_buf);
+		ulaw_buf = NULL;
+	}
+	close(audio_fd);
+}
+
+int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec)
+{
+	char audiodev[1024];
+#ifdef AUDIO_SETINFO
+	int enc;
+#endif
+	int desired_freq = spec->freq;
+
+	/* Initialize our freeable variables, in case we fail*/
+	audio_fd = -1;
+	mixbuf = NULL;
+	ulaw_buf = NULL;
+
+	/* Determine the audio parameters from the AudioSpec */
+	switch ( spec->format & 0xFF ) {
+
+		case 8: { /* Unsigned 8 bit audio data */
+			spec->format = AUDIO_U8;
+#ifdef AUDIO_SETINFO
+			enc = AUDIO_ENCODING_LINEAR8;
+#endif
+		}
+		break;
+
+		case 16: { /* Signed 16 bit audio data */
+		        spec->format = AUDIO_S16SYS;
+#ifdef AUDIO_SETINFO
+			enc = AUDIO_ENCODING_LINEAR;
+#endif
+		}
+		break;
+
+		default: {
+			SDL_SetError("Unsupported audio format");
+			return(-1);
+		}
+	}
+	audio_fmt = spec->format;
+
+	/* Open the audio device */
+	audio_fd = SDL_OpenAudioPath(audiodev, sizeof(audiodev), OPEN_FLAGS, 1);
+	if ( audio_fd < 0 ) {
+		SDL_SetError("Couldn't open %s: %s", audiodev,
+			     strerror(errno));
+		return(-1);
+	}
+
+	ulaw_only = 0;		/* modern Suns do support linear audio */
+#ifdef AUDIO_SETINFO
+	for(;;) {
+	    audio_info_t info;
+	    AUDIO_INITINFO(&info); /* init all fields to "no change" */
+
+	    /* Try to set the requested settings */
+	    info.play.sample_rate = spec->freq;
+	    info.play.channels = spec->channels;
+	    info.play.precision = (enc == AUDIO_ENCODING_ULAW)
+		                  ? 8 : spec->format & 0xff;
+	    info.play.encoding = enc;
+	    if( ioctl(audio_fd, AUDIO_SETINFO, &info) == 0 ) {
+
+		/* Check to be sure we got what we wanted */
+		if(ioctl(audio_fd, AUDIO_GETINFO, &info) < 0) {
+		    SDL_SetError("Error getting audio parameters: %s",
+				 strerror(errno));
+		    return -1;
+		}
+		if(info.play.encoding == enc
+		   && info.play.precision == (spec->format & 0xff)
+		   && info.play.channels == spec->channels) {
+		    /* Yow! All seems to be well! */
+		    spec->freq = info.play.sample_rate;
+		    break;
+		}
+	    }
+
+	    switch(enc) {
+	    case AUDIO_ENCODING_LINEAR8:
+		/* unsigned 8bit apparently not supported here */
+		enc = AUDIO_ENCODING_LINEAR;
+		spec->format = AUDIO_S16SYS;
+		break;	/* try again */
+
+	    case AUDIO_ENCODING_LINEAR:
+		/* linear 16bit didn't work either, resort to µ-law */
+		enc = AUDIO_ENCODING_ULAW;
+		spec->channels = 1;
+		spec->freq = 8000;
+		spec->format = AUDIO_U8;
+		ulaw_only = 1;
+		break;
+
+	    default:
+		/* oh well... */
+		SDL_SetError("Error setting audio parameters: %s",
+			     strerror(errno));
+		return -1;
+	    }
+	}
+#endif /* AUDIO_SETINFO */
+	written = 0;
+
+	/* We can actually convert on-the-fly to U-Law */
+	if ( ulaw_only ) {
+	        spec->freq = desired_freq;
+		fragsize = (spec->samples*1000)/(spec->freq/8);
+		frequency = 8;
+		ulaw_buf = (Uint8 *)malloc(fragsize);
+		if ( ulaw_buf == NULL ) {
+			SDL_OutOfMemory();
+			return(-1);
+		}
+		spec->channels = 1;
+	} else {
+		fragsize = spec->samples;
+		frequency = spec->freq/1000;
+	}
+#ifdef DEBUG_AUDIO
+	fprintf(stderr, "Audio device %s U-Law only\n", 
+				ulaw_only ? "is" : "is not");
+	fprintf(stderr, "format=0x%x chan=%d freq=%d\n",
+		spec->format, spec->channels, spec->freq);
+#endif
+
+	/* Update the fragment size as size in bytes */
+	SDL_CalculateAudioSpec(spec);
+
+	/* Allocate mixing buffer */
+	mixbuf = (Uint8 *)SDL_AllocAudioMem(spec->size);
+	if ( mixbuf == NULL ) {
+		SDL_OutOfMemory();
+		return(-1);
+	}
+	memset(mixbuf, spec->silence, spec->size);
+
+	/* We're ready to rock and roll. :-) */
+	return(0);
+}
+
+/************************************************************************/
+/* This function (snd2au()) copyrighted:                                */
+/************************************************************************/
+/*      Copyright 1989 by Rich Gopstein and Harris Corporation          */
+/*                                                                      */
+/*      Permission to use, copy, modify, and distribute this software   */
+/*      and its documentation for any purpose and without fee is        */
+/*      hereby granted, provided that the above copyright notice        */
+/*      appears in all copies and that both that copyright notice and   */
+/*      this permission notice appear in supporting documentation, and  */
+/*      that the name of Rich Gopstein and Harris Corporation not be    */
+/*      used in advertising or publicity pertaining to distribution     */
+/*      of the software without specific, written prior permission.     */
+/*      Rich Gopstein and Harris Corporation make no representations    */
+/*      about the suitability of this software for any purpose.  It     */
+/*      provided "as is" without express or implied warranty.           */
+/************************************************************************/
+
+static Uint8 snd2au(int sample)
+{
+
+	int mask;
+
+	if (sample < 0) {
+		sample = -sample;
+		mask = 0x7f;
+	} else {
+		mask = 0xff;
+	}
+
+	if (sample < 32) {
+		sample = 0xF0 | (15 - sample / 2);
+	} else if (sample < 96) {
+		sample = 0xE0 | (15 - (sample - 32) / 4);
+	} else if (sample < 224) {
+		sample = 0xD0 | (15 - (sample - 96) / 8);
+	} else if (sample < 480) {
+		sample = 0xC0 | (15 - (sample - 224) / 16);
+	} else if (sample < 992) {
+		sample = 0xB0 | (15 - (sample - 480) / 32);
+	} else if (sample < 2016) {
+		sample = 0xA0 | (15 - (sample - 992) / 64);
+	} else if (sample < 4064) {
+		sample = 0x90 | (15 - (sample - 2016) / 128);
+	} else if (sample < 8160) {
+		sample = 0x80 | (15 - (sample - 4064) /  256);
+	} else {
+		sample = 0x80;
+	}
+	return (mask & sample);
+}