quakeforge/libs/audio/targets/snd_sdl.c

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/*
snd_sdl.c
(description)
Copyright (C) 1996-1997 Id Software, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to:
Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston, MA 02111-1307, USA
$Id$
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <SDL_audio.h>
#include <SDL_byteorder.h>
#include <stdlib.h>
#include "QF/cmd.h"
#include "QF/console.h"
#include "QF/qargs.h"
#include "QF/sound.h"
#include "QF/sys.h"
static dma_t the_shm;
static int snd_inited;
extern int desired_speed;
extern int desired_bits;
static void
paint_audio (void *unused, Uint8 * stream, int len)
{
int streamsamples;
int sampleposbytes;
int samplesbytes;
if (shm) {
streamsamples = len / (shm->samplebits / 8);
sampleposbytes = shm->samplepos * (shm->samplebits / 8);
samplesbytes = shm->samples * (shm->samplebits / 8);
shm->samplepos += streamsamples;
if (shm->samplepos >= shm->samples)
shm->samplepos -= shm->samples;
S_PaintChannels (soundtime + streamsamples);
if (shm->samplepos + streamsamples <= shm->samples)
memcpy (stream, shm->buffer + sampleposbytes, len);
else {
memcpy (stream, shm->buffer + sampleposbytes, samplesbytes - sampleposbytes);
memcpy (stream + samplesbytes - sampleposbytes, shm->buffer, len - (samplesbytes - sampleposbytes));
}
soundtime += streamsamples;
}
}
qboolean
SNDDMA_Init (void)
{
SDL_AudioSpec desired, obtained;
snd_inited = 0;
/* Set up the desired format */
desired.freq = desired_speed;
switch (desired_bits) {
case 8:
desired.format = AUDIO_U8;
break;
case 16:
if (SDL_BYTEORDER == SDL_BIG_ENDIAN)
desired.format = AUDIO_S16MSB;
else
desired.format = AUDIO_S16LSB;
break;
default:
Con_Printf ("Unknown number of audio bits: %d\n", desired_bits);
return 0;
}
desired.channels = 2;
desired.samples = 512;
desired.callback = paint_audio;
/* Open the audio device */
if (SDL_OpenAudio (&desired, &obtained) < 0) {
Con_Printf ("Couldn't open SDL audio: %s\n", SDL_GetError ());
return 0;
}
/* Make sure we can support the audio format */
switch (obtained.format) {
case AUDIO_U8:
/* Supported */
break;
case AUDIO_S16LSB:
case AUDIO_S16MSB:
if (((obtained.format == AUDIO_S16LSB) &&
(SDL_BYTEORDER == SDL_LIL_ENDIAN)) ||
((obtained.format == AUDIO_S16MSB) &&
(SDL_BYTEORDER == SDL_BIG_ENDIAN))) {
/* Supported */
break;
}
/* Unsupported, fall through */ ;
default:
/* Not supported -- force SDL to do our bidding */
SDL_CloseAudio ();
if (SDL_OpenAudio (&desired, NULL) < 0) {
Con_Printf ("Couldn't open SDL audio: %s\n", SDL_GetError ());
return 0;
}
memcpy (&obtained, &desired, sizeof (desired));
break;
}
SDL_LockAudio();
SDL_PauseAudio (0);
/* Fill the audio DMA information block */
shm = &the_shm;
shm->splitbuffer = 0;
shm->samplebits = (obtained.format & 0xFF);
shm->speed = obtained.freq;
shm->channels = obtained.channels;
shm->samples = obtained.samples * 4;
shm->samplepos = 0;
shm->submission_chunk = 1;
shm->buffer = calloc(shm->samples * (shm->samplebits / 8), 1);
if (!shm->buffer)
{
Sys_Error ("Failed to allocate buffer for sound!\n");
}
snd_inited = 1;
return 1;
}
int
SNDDMA_GetDMAPos (void)
{
return shm->samplepos;
}
void
SNDDMA_Shutdown (void)
{
if (snd_inited) {
SDL_PauseAudio (1);
SDL_UnlockAudio ();
SDL_CloseAudio ();
snd_inited = 0;
shm = NULL;
}
}
/*
SNDDMA_Submit
Send sound to device if buffer isn't really the dma buffer
*/
void
SNDDMA_Submit (void)
{
SDL_UnlockAudio();
SDL_LockAudio();
}