aboutsummaryrefslogtreecommitdiffstats
path: root/distrib/sdl-1.2.15/src/audio/dsp
diff options
context:
space:
mode:
Diffstat (limited to 'distrib/sdl-1.2.15/src/audio/dsp')
-rw-r--r--distrib/sdl-1.2.15/src/audio/dsp/SDL_dspaudio.c340
-rw-r--r--distrib/sdl-1.2.15/src/audio/dsp/SDL_dspaudio.h53
2 files changed, 393 insertions, 0 deletions
diff --git a/distrib/sdl-1.2.15/src/audio/dsp/SDL_dspaudio.c b/distrib/sdl-1.2.15/src/audio/dsp/SDL_dspaudio.c
new file mode 100644
index 0000000..256c547
--- /dev/null
+++ b/distrib/sdl-1.2.15/src/audio/dsp/SDL_dspaudio.c
@@ -0,0 +1,340 @@
+/*
+ SDL - Simple DirectMedia Layer
+ Copyright (C) 1997-2012 Sam Lantinga
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 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
+ Lesser General Public License for more details.
+
+ 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
+
+ Sam Lantinga
+ slouken@libsdl.org
+
+ Modified in Oct 2004 by Hannu Savolainen
+ hannu@opensound.com
+*/
+#include "SDL_config.h"
+
+/* Allow access to a raw mixing buffer */
+
+#include <stdio.h> /* For perror() */
+#include <string.h> /* For strerror() */
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <sys/time.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+
+#if SDL_AUDIO_DRIVER_OSS_SOUNDCARD_H
+/* This is installed on some systems */
+#include <soundcard.h>
+#else
+/* This is recommended by OSS */
+#include <sys/soundcard.h>
+#endif
+
+#include "SDL_timer.h"
+#include "SDL_audio.h"
+#include "../SDL_audiomem.h"
+#include "../SDL_audio_c.h"
+#include "../SDL_audiodev_c.h"
+#include "SDL_dspaudio.h"
+
+/* The tag name used by DSP audio */
+#define DSP_DRIVER_NAME "dsp"
+
+/* 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, 0);
+ if ( fd >= 0 ) {
+ available = 1;
+ close(fd);
+ }
+ return(available);
+}
+
+static void Audio_DeleteDevice(SDL_AudioDevice *device)
+{
+ SDL_free(device->hidden);
+ SDL_free(device);
+}
+
+static SDL_AudioDevice *Audio_CreateDevice(int devindex)
+{
+ SDL_AudioDevice *this;
+
+ /* Initialize all variables that we clean on shutdown */
+ this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice));
+ if ( this ) {
+ SDL_memset(this, 0, (sizeof *this));
+ this->hidden = (struct SDL_PrivateAudioData *)
+ SDL_malloc((sizeof *this->hidden));
+ }
+ if ( (this == NULL) || (this->hidden == NULL) ) {
+ SDL_OutOfMemory();
+ if ( this ) {
+ SDL_free(this);
+ }
+ return(0);
+ }
+ SDL_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 DSP_bootstrap = {
+ DSP_DRIVER_NAME, "OSS /dev/dsp standard audio",
+ Audio_Available, Audio_CreateDevice
+};
+
+/* This function waits until it is possible to write a full sound buffer */
+static void DSP_WaitAudio(_THIS)
+{
+ /* Not needed at all since OSS handles waiting automagically */
+}
+
+static void DSP_PlayAudio(_THIS)
+{
+ if (write(audio_fd, mixbuf, mixlen)==-1)
+ {
+ perror("Audio write");
+ this->enabled = 0;
+ }
+
+#ifdef DEBUG_AUDIO
+ fprintf(stderr, "Wrote %d bytes of audio data\n", mixlen);
+#endif
+}
+
+static Uint8 *DSP_GetAudioBuf(_THIS)
+{
+ return(mixbuf);
+}
+
+static void DSP_CloseAudio(_THIS)
+{
+ if ( mixbuf != NULL ) {
+ SDL_FreeAudioMem(mixbuf);
+ mixbuf = NULL;
+ }
+ if ( audio_fd >= 0 ) {
+ close(audio_fd);
+ audio_fd = -1;
+ }
+}
+
+static int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec)
+{
+ char audiodev[1024];
+ int format;
+ int value;
+ int frag_spec;
+ Uint16 test_format;
+
+ /* Make sure fragment size stays a power of 2, or OSS fails. */
+ /* I don't know which of these are actually legal values, though... */
+ if (spec->channels > 8)
+ spec->channels = 8;
+ else if (spec->channels > 4)
+ spec->channels = 4;
+ else if (spec->channels > 2)
+ spec->channels = 2;
+
+ /* Open the audio device */
+ audio_fd = SDL_OpenAudioPath(audiodev, sizeof(audiodev), OPEN_FLAGS, 0);
+ if ( audio_fd < 0 ) {
+ SDL_SetError("Couldn't open %s: %s", audiodev, strerror(errno));
+ return(-1);
+ }
+ mixbuf = NULL;
+
+ /* Make the file descriptor use blocking writes with fcntl() */
+ { long flags;
+ flags = fcntl(audio_fd, F_GETFL);
+ flags &= ~O_NONBLOCK;
+ if ( fcntl(audio_fd, F_SETFL, flags) < 0 ) {
+ SDL_SetError("Couldn't set audio blocking mode");
+ DSP_CloseAudio(this);
+ return(-1);
+ }
+ }
+
+ /* Get a list of supported hardware formats */
+ if ( ioctl(audio_fd, SNDCTL_DSP_GETFMTS, &value) < 0 ) {
+ perror("SNDCTL_DSP_GETFMTS");
+ SDL_SetError("Couldn't get audio format list");
+ DSP_CloseAudio(this);
+ return(-1);
+ }
+
+ /* Try for a closest match on audio format */
+ format = 0;
+ for ( test_format = SDL_FirstAudioFormat(spec->format);
+ ! format && test_format; ) {
+#ifdef DEBUG_AUDIO
+ fprintf(stderr, "Trying format 0x%4.4x\n", test_format);
+#endif
+ switch ( test_format ) {
+ case AUDIO_U8:
+ if ( value & AFMT_U8 ) {
+ format = AFMT_U8;
+ }
+ break;
+ case AUDIO_S16LSB:
+ if ( value & AFMT_S16_LE ) {
+ format = AFMT_S16_LE;
+ }
+ break;
+ case AUDIO_S16MSB:
+ if ( value & AFMT_S16_BE ) {
+ format = AFMT_S16_BE;
+ }
+ break;
+#if 0
+/*
+ * These formats are not used by any real life systems so they are not
+ * needed here.
+ */
+ case AUDIO_S8:
+ if ( value & AFMT_S8 ) {
+ format = AFMT_S8;
+ }
+ break;
+ case AUDIO_U16LSB:
+ if ( value & AFMT_U16_LE ) {
+ format = AFMT_U16_LE;
+ }
+ break;
+ case AUDIO_U16MSB:
+ if ( value & AFMT_U16_BE ) {
+ format = AFMT_U16_BE;
+ }
+ break;
+#endif
+ default:
+ format = 0;
+ break;
+ }
+ if ( ! format ) {
+ test_format = SDL_NextAudioFormat();
+ }
+ }
+ if ( format == 0 ) {
+ SDL_SetError("Couldn't find any hardware audio formats");
+ DSP_CloseAudio(this);
+ return(-1);
+ }
+ spec->format = test_format;
+
+ /* Set the audio format */
+ value = format;
+ if ( (ioctl(audio_fd, SNDCTL_DSP_SETFMT, &value) < 0) ||
+ (value != format) ) {
+ perror("SNDCTL_DSP_SETFMT");
+ SDL_SetError("Couldn't set audio format");
+ DSP_CloseAudio(this);
+ return(-1);
+ }
+
+ /* Set the number of channels of output */
+ value = spec->channels;
+ if ( ioctl(audio_fd, SNDCTL_DSP_CHANNELS, &value) < 0 ) {
+ perror("SNDCTL_DSP_CHANNELS");
+ SDL_SetError("Cannot set the number of channels");
+ DSP_CloseAudio(this);
+ return(-1);
+ }
+ spec->channels = value;
+
+ /* Set the DSP frequency */
+ value = spec->freq;
+ if ( ioctl(audio_fd, SNDCTL_DSP_SPEED, &value) < 0 ) {
+ perror("SNDCTL_DSP_SPEED");
+ SDL_SetError("Couldn't set audio frequency");
+ DSP_CloseAudio(this);
+ return(-1);
+ }
+ spec->freq = value;
+
+ /* Calculate the final parameters for this audio specification */
+ SDL_CalculateAudioSpec(spec);
+
+ /* Determine the power of two of the fragment size */
+ for ( frag_spec = 0; (0x01U<<frag_spec) < spec->size; ++frag_spec );
+ if ( (0x01U<<frag_spec) != spec->size ) {
+ SDL_SetError("Fragment size must be a power of two");
+ DSP_CloseAudio(this);
+ return(-1);
+ }
+ frag_spec |= 0x00020000; /* two fragments, for low latency */
+
+ /* Set the audio buffering parameters */
+#ifdef DEBUG_AUDIO
+ fprintf(stderr, "Requesting %d fragments of size %d\n",
+ (frag_spec >> 16), 1<<(frag_spec&0xFFFF));
+#endif
+ if ( ioctl(audio_fd, SNDCTL_DSP_SETFRAGMENT, &frag_spec) < 0 ) {
+ perror("SNDCTL_DSP_SETFRAGMENT");
+ }
+#ifdef DEBUG_AUDIO
+ { audio_buf_info info;
+ ioctl(audio_fd, SNDCTL_DSP_GETOSPACE, &info);
+ fprintf(stderr, "fragments = %d\n", info.fragments);
+ fprintf(stderr, "fragstotal = %d\n", info.fragstotal);
+ fprintf(stderr, "fragsize = %d\n", info.fragsize);
+ fprintf(stderr, "bytes = %d\n", info.bytes);
+ }
+#endif
+
+ /* Allocate mixing buffer */
+ mixlen = spec->size;
+ mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen);
+ if ( mixbuf == NULL ) {
+ DSP_CloseAudio(this);
+ return(-1);
+ }
+ SDL_memset(mixbuf, spec->silence, spec->size);
+
+ /* Get the parent process id (we're the parent of the audio thread) */
+ parent = getpid();
+
+ /* We're ready to rock and roll. :-) */
+ return(0);
+}
diff --git a/distrib/sdl-1.2.15/src/audio/dsp/SDL_dspaudio.h b/distrib/sdl-1.2.15/src/audio/dsp/SDL_dspaudio.h
new file mode 100644
index 0000000..382544f
--- /dev/null
+++ b/distrib/sdl-1.2.15/src/audio/dsp/SDL_dspaudio.h
@@ -0,0 +1,53 @@
+/*
+ SDL - Simple DirectMedia Layer
+ Copyright (C) 1997-2012 Sam Lantinga
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 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
+ Lesser General Public License for more details.
+
+ 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
+
+ Sam Lantinga
+ slouken@libsdl.org
+*/
+#include "SDL_config.h"
+
+#ifndef _SDL_dspaudio_h
+#define _SDL_dspaudio_h
+
+#include "../SDL_sysaudio.h"
+
+/* Hidden "this" pointer for the video functions */
+#define _THIS SDL_AudioDevice *this
+
+struct SDL_PrivateAudioData {
+ /* The file descriptor for the audio device */
+ int audio_fd;
+
+ /* The parent process id, to detect when application quits */
+ pid_t parent;
+
+ /* Raw mixing buffer */
+ Uint8 *mixbuf;
+ int mixlen;
+};
+#define FUDGE_TICKS 10 /* The scheduler overhead ticks per frame */
+
+/* Old variable names */
+#define audio_fd (this->hidden->audio_fd)
+#define parent (this->hidden->parent)
+#define mixbuf (this->hidden->mixbuf)
+#define mixlen (this->hidden->mixlen)
+#define frame_ticks (this->hidden->frame_ticks)
+#define next_frame (this->hidden->next_frame)
+
+#endif /* _SDL_dspaudio_h */