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SDL_artsaudio.c
354 lines (302 loc) · 10 KB
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2006 Sam Lantinga
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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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
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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Sam Lantinga
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slouken@libsdl.org
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*/
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#include "SDL_config.h"
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/* Allow access to a raw mixing buffer */
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#include "SDL_timer.h"
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#include "SDL_audio.h"
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#include "../SDL_audiomem.h"
#include "../SDL_audio_c.h"
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#include "SDL_artsaudio.h"
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#ifdef SDL_AUDIO_DRIVER_ARTS_DYNAMIC
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#include "SDL_name.h"
#include "SDL_loadso.h"
#else
#define SDL_NAME(X) X
#endif
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/* The tag name used by artsc audio */
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#define ARTS_DRIVER_NAME "arts"
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#ifdef SDL_AUDIO_DRIVER_ARTS_DYNAMIC
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static const char *arts_library = SDL_AUDIO_DRIVER_ARTS_DYNAMIC;
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static void *arts_handle = NULL;
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/* !!! FIXME: I hate this SDL_NAME clutter...it makes everything so messy! */
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static int (*SDL_NAME(arts_init)) (void);
static void (*SDL_NAME(arts_free)) (void);
static arts_stream_t(*SDL_NAME(arts_play_stream)) (int rate, int bits,
int channels,
const char *name);
static int (*SDL_NAME(arts_stream_set)) (arts_stream_t s,
arts_parameter_t param, int value);
static int (*SDL_NAME(arts_stream_get)) (arts_stream_t s,
arts_parameter_t param);
static int (*SDL_NAME(arts_write)) (arts_stream_t s, const void *buffer,
int count);
static void (*SDL_NAME(arts_close_stream)) (arts_stream_t s);
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static void (*SDL_NAME(arts_close_stream)) (arts_stream_t s);
static const char *(*SDL_NAME(arts_error_text)) (int errorcode);
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#define SDL_ARTS_SYM(x) { #x, (void **) (char *) &SDL_NAME(x) }
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static struct
{
const char *name;
void **func;
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} arts_functions[] = {
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SDL_ARTS_SYM(arts_init),
SDL_ARTS_SYM(arts_free),
SDL_ARTS_SYM(arts_play_stream),
SDL_ARTS_SYM(arts_stream_set),
SDL_ARTS_SYM(arts_stream_get),
SDL_ARTS_SYM(arts_write),
SDL_ARTS_SYM(arts_close_stream), SDL_ARTS_SYM(arts_error_text),};
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#undef SDL_ARTS_SYM
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static void
UnloadARTSLibrary()
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{
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if (arts_handle != NULL) {
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SDL_UnloadObject(arts_handle);
arts_handle = NULL;
}
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}
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static int
LoadARTSLibrary(void)
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{
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int i, retval = -1;
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if (arts_handle == NULL) {
arts_handle = SDL_LoadObject(arts_library);
if (arts_handle != NULL) {
retval = 0;
for (i = 0; i < SDL_arraysize(arts_functions); ++i) {
*arts_functions[i].func =
SDL_LoadFunction(arts_handle, arts_functions[i].name);
if (!*arts_functions[i].func) {
retval = -1;
UnloadARTSLibrary();
break;
}
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}
}
}
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return retval;
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}
#else
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static void
UnloadARTSLibrary()
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{
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return;
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}
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static int
LoadARTSLibrary(void)
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{
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return 0;
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}
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#endif /* SDL_AUDIO_DRIVER_ARTS_DYNAMIC */
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/* This function waits until it is possible to write a full sound buffer */
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static void
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ARTS_WaitDevice(_THIS)
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{
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Sint32 ticks;
/* Check to see if the thread-parent process is still alive */
{
static int cnt = 0;
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/* Note that this only works with thread implementations
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that use a different process id for each thread.
*/
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/* Check every 10 loops */
if (this->hidden->parent && (((++cnt) % 10) == 0)) {
if (kill(this->hidden->parent, 0) < 0) {
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this->enabled = 0;
}
}
}
/* Use timer for general audio synchronization */
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ticks =
((Sint32) (this->hidden->next_frame - SDL_GetTicks())) - FUDGE_TICKS;
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if (ticks > 0) {
SDL_Delay(ticks);
}
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}
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static void
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ARTS_PlayDevice(_THIS)
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{
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/* Write the audio data */
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int written = SDL_NAME(arts_write) (this->hidden->stream,
this->hidden->mixbuf,
this->hidden->mixlen);
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/* If timer synchronization is enabled, set the next write frame */
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if (this->hidden->frame_ticks) {
this->hidden->next_frame += this->hidden->frame_ticks;
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}
/* If we couldn't write, assume fatal error for now */
if (written < 0) {
this->enabled = 0;
}
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#ifdef DEBUG_AUDIO
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fprintf(stderr, "Wrote %d bytes of audio data\n", written);
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#endif
}
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static void
ARTS_WaitDone(_THIS)
{
/* !!! FIXME: camp here until buffer drains... SDL_Delay(???); */
}
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static Uint8 *
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ARTS_GetDeviceBuf(_THIS)
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{
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return (this->hidden->mixbuf);
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}
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static void
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ARTS_CloseDevice(_THIS)
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{
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if (this->hidden != NULL) {
if (this->hidden->mixbuf != NULL) {
SDL_FreeAudioMem(this->hidden->mixbuf);
this->hidden->mixbuf = NULL;
}
if (this->hidden->stream) {
SDL_NAME(arts_close_stream) (this->hidden->stream);
this->hidden->stream = 0;
}
SDL_NAME(arts_free) ();
SDL_free(this->hidden);
this->hidden = NULL;
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}
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}
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static int
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ARTS_OpenDevice(_THIS, const char *devname, int iscapture)
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{
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int rc = 0;
int bits = 0, frag_spec = 0;
SDL_AudioFormat test_format = 0, format = 0;
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/* Initialize all variables that we clean on shutdown */
this->hidden = (struct SDL_PrivateAudioData *)
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SDL_malloc((sizeof *this->hidden));
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if (this->hidden == NULL) {
SDL_OutOfMemory();
return 0;
}
SDL_memset(this->hidden, 0, (sizeof *this->hidden));
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/* Try for a closest match on audio format */
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for (test_format = SDL_FirstAudioFormat(this->spec.format);
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!format && test_format;) {
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#ifdef DEBUG_AUDIO
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fprintf(stderr, "Trying format 0x%4.4x\n", test_format);
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#endif
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switch (test_format) {
case AUDIO_U8:
bits = 8;
format = 1;
break;
case AUDIO_S16LSB:
bits = 16;
format = 1;
break;
default:
format = 0;
break;
}
if (!format) {
test_format = SDL_NextAudioFormat();
}
}
if (format == 0) {
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ARTS_CloseDevice(this);
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SDL_SetError("Couldn't find any hardware audio formats");
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return 0;
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}
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this->spec.format = test_format;
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if ((rc = SDL_NAME(arts_init) ()) != 0) {
ARTS_CloseDevice(this);
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SDL_SetError("Unable to initialize ARTS: %s",
SDL_NAME(arts_error_text) (rc));
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return 0;
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}
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this->hidden->stream = SDL_NAME(arts_play_stream) (this->spec.freq,
bits,
this->spec.channels,
"SDL");
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/* Calculate the final parameters for this audio specification */
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SDL_CalculateAudioSpec(&this->spec);
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/* Determine the power of two of the fragment size */
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for (frag_spec = 0; (0x01 << frag_spec) < this->spec.size; ++frag_spec);
if ((0x01 << frag_spec) != this->spec.size) {
ARTS_CloseDevice(this);
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SDL_SetError("Fragment size must be a power of two");
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return 0;
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}
frag_spec |= 0x00020000; /* two fragments, for low latency */
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#ifdef ARTS_P_PACKET_SETTINGS
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SDL_NAME(arts_stream_set) (this->hidden->stream,
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ARTS_P_PACKET_SETTINGS, frag_spec);
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#else
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SDL_NAME(arts_stream_set) (this->hidden->stream, ARTS_P_PACKET_SIZE,
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frag_spec & 0xffff);
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SDL_NAME(arts_stream_set) (this->hidden->stream, ARTS_P_PACKET_COUNT,
frag_spec >> 16);
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#endif
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this->spec.size = SDL_NAME(arts_stream_get) (this->hidden->stream,
ARTS_P_PACKET_SIZE);
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/* Allocate mixing buffer */
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this->hidden->mixlen = this->spec.size;
this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen);
if (this->hidden->mixbuf == NULL) {
ARTS_CloseDevice(this);
SDL_OutOfMemory();
return 0;
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}
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SDL_memset(this->hidden->mixbuf, this->spec.silence, this->spec.size);
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/* Get the parent process id (we're the parent of the audio thread) */
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this->hidden->parent = getpid();
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/* We're ready to rock and roll. :-) */
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return 1;
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}
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static void
ARTS_Deinitialize(void)
{
UnloadARTSLibrary();
}
static int
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ARTS_Init(SDL_AudioDriverImpl * impl)
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{
if (LoadARTSLibrary() < 0) {
return 0;
} else {
if (SDL_NAME(arts_init) () != 0) {
UnloadARTSLibrary();
SDL_SetError("ARTS: arts_init failed (no audio server?)");
return 0;
}
/* Play a stream so aRts doesn't crash */
arts_stream_t stream;
stream = SDL_NAME(arts_play_stream) (44100, 16, 2, "SDL");
SDL_NAME(arts_write) (stream, "", 0);
SDL_NAME(arts_close_stream) (stream);
SDL_NAME(arts_free) ();
}
/* Set the function pointers */
impl->OpenDevice = ARTS_OpenDevice;
impl->PlayDevice = ARTS_PlayDevice;
impl->WaitDevice = ARTS_WaitDevice;
impl->GetDeviceBuf = ARTS_GetDeviceBuf;
impl->CloseDevice = ARTS_CloseDevice;
impl->WaitDone = ARTS_WaitDone;
impl->Deinitialize = ARTS_Deinitialize;
impl->OnlyHasDefaultOutputDevice = 1;
return 1;
}
AudioBootStrap ARTS_bootstrap = {
ARTS_DRIVER_NAME, "Analog RealTime Synthesizer", ARTS_Init, 0
};
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/* vi: set ts=4 sw=4 expandtab: */