quakespasm/Quake/snd_sdl.c

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/*
snd_sdl2.c
SDL audio driver for Hexen II: Hammer of Thyrion, based on the
implementations found in the quakeforge and quake3-icculus.org
projects.
$Id: snd_sdl2.c,v 1.8 2010/01/23 12:01:23 sezero Exp $
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.
51 Franklin St, Fifth Floor,
Boston, MA 02110-1301 USA
*/
#include "quakedef.h"
#include "SDL.h"
static int buffersize;
static void paint_audio (void *unused, Uint8 *stream, int len)
{
int pos, tobufend;
int len1, len2;
if (!shm)
{ /* shouldn't happen, but just in case */
memset(stream, 0, len);
return;
}
pos = (shm->samplepos * (shm->samplebits / 8));
if (pos >= buffersize)
shm->samplepos = pos = 0;
tobufend = buffersize - pos; /* bytes to buffer's end. */
len1 = len;
len2 = 0;
if (len1 > tobufend)
{
len1 = tobufend;
len2 = len - len1;
}
memcpy(stream, shm->buffer + pos, len1);
if (len2 <= 0)
{
shm->samplepos += (len1 / (shm->samplebits / 8));
}
else
{ /* wraparound? */
memcpy(stream + len1, shm->buffer, len2);
shm->samplepos = (len2 / (shm->samplebits / 8));
}
if (shm->samplepos >= buffersize)
shm->samplepos = 0;
}
qboolean SNDDMA_Init (void)
{
SDL_AudioSpec desired, obtained;
int tmp, val;
char drivername[128];
if (SDL_InitSubSystem(SDL_INIT_AUDIO) == -1)
{
Con_Printf("Couldn't init SDL audio: %s\n", SDL_GetError());
return false;
}
/* Set up the desired format */
desired.freq = tmp = sndspeed.value;
desired.format = (loadas8bit.value) ? AUDIO_U8 : AUDIO_S16SYS;
desired.channels = 2; /* = desired_channels; */
if (desired.freq <= 11025)
desired.samples = 256;
else if (desired.freq <= 22050)
desired.samples = 512;
else if (desired.freq <= 44100)
desired.samples = 1024;
else
desired.samples = 2048; /* shrug */
desired.callback = paint_audio;
desired.userdata = NULL;
/* Open the audio device */
if (SDL_OpenAudio(&desired, &obtained) == -1)
{
Con_Printf("Couldn't open SDL audio: %s\n", SDL_GetError());
SDL_QuitSubSystem(SDL_INIT_AUDIO);
return false;
}
/* Make sure we can support the audio format */
switch (obtained.format)
{
case AUDIO_U8:
case AUDIO_S16SYS:
/* Supported */
break;
default:
Con_Printf ("Unsupported audio format received (%u)\n", obtained.format);
SDL_CloseAudio();
SDL_QuitSubSystem(SDL_INIT_AUDIO);
return false;
}
memset ((void *) &sn, 0, sizeof(dma_t));
shm = &sn;
/* Fill the audio DMA information block */
shm->samplebits = (obtained.format & 0xFF); /* first byte of format is bits */
if (obtained.freq != tmp)
Con_Printf ("Warning: Rate set (%d) didn't match requested rate (%d)!\n", obtained.freq, tmp);
shm->speed = obtained.freq;
shm->channels = obtained.channels;
tmp = (obtained.samples * obtained.channels) * 10;
if (tmp & (tmp - 1))
{ /* make it a power of two */
val = 1;
while (val < tmp)
val <<= 1;
tmp = val;
}
shm->samples = tmp;
shm->samplepos = 0;
shm->submission_chunk = 1;
Con_Printf ("SDL audio spec : %d Hz, %d samples, %d channels\n",
obtained.freq, obtained.samples, obtained.channels);
if (SDL_AudioDriverName(drivername, sizeof(drivername)) == NULL)
strcpy(drivername, "(UNKNOWN)");
buffersize = shm->samples * (shm->samplebits / 8);
Con_Printf ("SDL audio driver: %s, %d bytes buffer\n", drivername, buffersize);
shm->buffer = (unsigned char *) calloc (1, buffersize);
if (!shm->buffer)
{
SDL_CloseAudio();
SDL_QuitSubSystem(SDL_INIT_AUDIO);
shm = NULL;
Con_Printf ("Failed allocating memory for SDL audio\n");
return false;
}
SDL_PauseAudio(0);
return true;
}
int SNDDMA_GetDMAPos (void)
{
return shm->samplepos;
}
void SNDDMA_Shutdown (void)
{
if (shm)
{
Con_Printf ("Shutting down SDL sound\n");
SDL_PauseAudio(1);
SDL_LockAudio ();
SDL_CloseAudio();
if (shm->buffer)
free (shm->buffer);
SDL_QuitSubSystem(SDL_INIT_AUDIO);
shm->buffer = NULL;
shm = NULL;
}
}
void SNDDMA_LockBuffer (void)
{
SDL_LockAudio ();
}
void SNDDMA_Submit (void)
{
SDL_UnlockAudio();
}
void SNDDMA_BlockSound (void)
{
SDL_PauseAudio(1);
}
void SNDDMA_UnblockSound (void)
{
SDL_PauseAudio(0);
}