audio/sdlaudio.c - qemu - Git at Google

 /*
  * QEMU SDL audio output driver
  *
  * Copyright (c) 2004 Vassili Karpov (malc)
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
 #include <SDL/SDL.h>
 #include <SDL/SDL_thread.h>
 #include "vl.h"

 #define AUDIO_CAP "sdl"
 #include "audio/audio.h"
 #include "audio/sdlaudio.h"

 #define QC_SDL_SAMPLES "QEMU_SDL_SAMPLES"

 #define errstr() SDL_GetError ()

 static struct {
     int nb_samples;
 } conf = {
     1024
 };

 struct SDLAudioState {
     int exit;
     SDL_mutex *mutex;
     SDL_sem *sem;
     int initialized;
 } glob_sdl;
 typedef struct SDLAudioState SDLAudioState;

 static void sdl_hw_run (HWVoice *hw)
 {
     (void) hw;
 }

 static int sdl_lock (SDLAudioState *s)
 {
     if (SDL_LockMutex (s->mutex)) {
         dolog ("SDL_LockMutex failed\nReason: %s\n", errstr ());
         return -1;
     }
     return 0;
 }

 static int sdl_unlock (SDLAudioState *s)
 {
     if (SDL_UnlockMutex (s->mutex)) {
         dolog ("SDL_UnlockMutex failed\nReason: %s\n", errstr ());
         return -1;
     }
     return 0;
 }

 static int sdl_post (SDLAudioState *s)
 {
     if (SDL_SemPost (s->sem)) {
         dolog ("SDL_SemPost failed\nReason: %s\n", errstr ());
         return -1;
     }
     return 0;
 }

 static int sdl_wait (SDLAudioState *s)
 {
     if (SDL_SemWait (s->sem)) {
         dolog ("SDL_SemWait failed\nReason: %s\n", errstr ());
         return -1;
     }
     return 0;
 }

 static int sdl_unlock_and_post (SDLAudioState *s)
 {
     if (sdl_unlock (s))
         return -1;

     return sdl_post (s);
 }

 static int sdl_hw_write (SWVoice *sw, void *buf, int len)
 {
     int ret;
     SDLAudioState *s = &glob_sdl;
     sdl_lock (s);
     ret = pcm_hw_write (sw, buf, len);
     sdl_unlock_and_post (s);
     return ret;
 }

 static int AUD_to_sdlfmt (audfmt_e fmt, int *shift)
 {
     *shift = 0;
     switch (fmt) {
     case AUD_FMT_S8: return AUDIO_S8;
     case AUD_FMT_U8: return AUDIO_U8;
     case AUD_FMT_S16: *shift = 1; return AUDIO_S16LSB;
     case AUD_FMT_U16: *shift = 1; return AUDIO_U16LSB;
     default:
         dolog ("Internal logic error: Bad audio format %d\nAborting\n", fmt);
         exit (EXIT_FAILURE);
     }
 }

 static int sdl_to_audfmt (int fmt)
 {
     switch (fmt) {
     case AUDIO_S8: return AUD_FMT_S8;
     case AUDIO_U8: return AUD_FMT_U8;
     case AUDIO_S16LSB: return AUD_FMT_S16;
     case AUDIO_U16LSB: return AUD_FMT_U16;
     default:
         dolog ("Internal logic error: Unrecognized SDL audio format %d\n"
                "Aborting\n", fmt);
         exit (EXIT_FAILURE);
     }
 }

 static int sdl_open (SDL_AudioSpec *req, SDL_AudioSpec *obt)
 {
     int status;

     status = SDL_OpenAudio (req, obt);
     if (status) {
         dolog ("SDL_OpenAudio failed\nReason: %s\n", errstr ());
     }
     return status;
 }

 static void sdl_close (SDLAudioState *s)
 {
     if (s->initialized) {
         sdl_lock (s);
         s->exit = 1;
         sdl_unlock_and_post (s);
         SDL_PauseAudio (1);
         SDL_CloseAudio ();
         s->initialized = 0;
     }
 }

 static void sdl_callback (void *opaque, Uint8 *buf, int len)
 {
     SDLVoice *sdl = opaque;
     SDLAudioState *s = &glob_sdl;
     HWVoice *hw = &sdl->hw;
     int samples = len >> hw->shift;

     if (s->exit) {
         return;
     }

     while (samples) {
         int to_mix, live, decr;

         /* dolog ("in callback samples=%d\n", samples); */
         sdl_wait (s);
         if (s->exit) {
             return;
         }

         sdl_lock (s);
         live = pcm_hw_get_live (hw);
         if (live <= 0)
             goto again;

         /* dolog ("in callback live=%d\n", live); */
         to_mix = audio_MIN (samples, live);
         decr = to_mix;
         while (to_mix) {
             int chunk = audio_MIN (to_mix, hw->samples - hw->rpos);
             st_sample_t *src = hw->mix_buf + hw->rpos;

             /* dolog ("in callback to_mix %d, chunk %d\n", to_mix, chunk); */
             hw->clip (buf, src, chunk);
             memset (src, 0, chunk * sizeof (st_sample_t));
             hw->rpos = (hw->rpos + chunk) % hw->samples;
             to_mix -= chunk;
             buf += chunk << hw->shift;
         }
         samples -= decr;
         pcm_hw_dec_live (hw, decr);

     again:
         sdl_unlock (s);
     }
     /* dolog ("done len=%d\n", len); */
 }

 static void sdl_hw_fini (HWVoice *hw)
 {
     ldebug ("sdl_hw_fini %d fixed=%d\n",
              glob_sdl.initialized, audio_conf.fixed_format);
     sdl_close (&glob_sdl);
 }

 static int sdl_hw_init (HWVoice *hw, int freq, int nchannels, audfmt_e fmt)
 {
     SDLVoice *sdl = (SDLVoice *) hw;
     SDLAudioState *s = &glob_sdl;
     SDL_AudioSpec req, obt;
     int shift;

     ldebug ("sdl_hw_init %d freq=%d fixed=%d\n",
             s->initialized, freq, audio_conf.fixed_format);

     if (nchannels != 2) {
         dolog ("Bogus channel count %d\n", nchannels);
         return -1;
     }

     req.freq = freq;
     req.format = AUD_to_sdlfmt (fmt, &shift);
     req.channels = nchannels;
     req.samples = conf.nb_samples;
     shift <<= nchannels == 2;

     req.callback = sdl_callback;
     req.userdata = sdl;

     if (sdl_open (&req, &obt))
         return -1;

     hw->freq = obt.freq;
     hw->fmt = sdl_to_audfmt (obt.format);
     hw->nchannels = obt.channels;
     hw->bufsize = obt.samples << shift;

     s->initialized = 1;
     s->exit = 0;
     SDL_PauseAudio (0);
     return 0;
 }

 static int sdl_hw_ctl (HWVoice *hw, int cmd, ...)
 {
     (void) hw;

     switch (cmd) {
     case VOICE_ENABLE:
         SDL_PauseAudio (0);
         break;

     case VOICE_DISABLE:
         SDL_PauseAudio (1);
         break;
     }
     return 0;
 }

 static void *sdl_audio_init (void)
 {
     SDLAudioState *s = &glob_sdl;
     conf.nb_samples = audio_get_conf_int (QC_SDL_SAMPLES, conf.nb_samples);

     if (SDL_InitSubSystem (SDL_INIT_AUDIO)) {
         dolog ("SDL failed to initialize audio subsystem\nReason: %s\n",
                errstr ());
         return NULL;
     }

     s->mutex = SDL_CreateMutex ();
     if (!s->mutex) {
         dolog ("Failed to create SDL mutex\nReason: %s\n", errstr ());
         SDL_QuitSubSystem (SDL_INIT_AUDIO);
         return NULL;
     }

     s->sem = SDL_CreateSemaphore (0);
     if (!s->sem) {
         dolog ("Failed to create SDL semaphore\nReason: %s\n", errstr ());
         SDL_DestroyMutex (s->mutex);
         SDL_QuitSubSystem (SDL_INIT_AUDIO);
         return NULL;
     }

     return s;
 }

 static void sdl_audio_fini (void *opaque)
 {
     SDLAudioState *s = opaque;
     sdl_close (s);
     SDL_DestroySemaphore (s->sem);
     SDL_DestroyMutex (s->mutex);
     SDL_QuitSubSystem (SDL_INIT_AUDIO);
 }

 struct pcm_ops sdl_pcm_ops = {
     sdl_hw_init,
     sdl_hw_fini,
     sdl_hw_run,
     sdl_hw_write,
     sdl_hw_ctl
 };

 struct audio_output_driver sdl_output_driver = {
     "sdl",
     sdl_audio_init,
     sdl_audio_fini,
     &sdl_pcm_ops,
     1,
     1,
     sizeof (SDLVoice)
 };
	/*
	* QEMU SDL audio output driver
	*
	* Copyright (c) 2004 Vassili Karpov (malc)
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/
	#include <SDL/SDL.h>
	#include <SDL/SDL_thread.h>
	#include "vl.h"

	#define AUDIO_CAP "sdl"
	#include "audio/audio.h"
	#include "audio/sdlaudio.h"

	#define QC_SDL_SAMPLES "QEMU_SDL_SAMPLES"

	#define errstr() SDL_GetError ()

	static struct {
	int nb_samples;
	} conf = {
	1024
	};

	struct SDLAudioState {
	int exit;
	SDL_mutex *mutex;
	SDL_sem *sem;
	int initialized;
	} glob_sdl;
	typedef struct SDLAudioState SDLAudioState;

	static void sdl_hw_run (HWVoice *hw)
	{
	(void) hw;
	}

	static int sdl_lock (SDLAudioState *s)
	{
	if (SDL_LockMutex (s->mutex)) {
	dolog ("SDL_LockMutex failed\nReason: %s\n", errstr ());
	return -1;
	}
	return 0;
	}

	static int sdl_unlock (SDLAudioState *s)
	{
	if (SDL_UnlockMutex (s->mutex)) {
	dolog ("SDL_UnlockMutex failed\nReason: %s\n", errstr ());
	return -1;
	}
	return 0;
	}

	static int sdl_post (SDLAudioState *s)
	{
	if (SDL_SemPost (s->sem)) {
	dolog ("SDL_SemPost failed\nReason: %s\n", errstr ());
	return -1;
	}
	return 0;
	}

	static int sdl_wait (SDLAudioState *s)
	{
	if (SDL_SemWait (s->sem)) {
	dolog ("SDL_SemWait failed\nReason: %s\n", errstr ());
	return -1;
	}
	return 0;
	}

	static int sdl_unlock_and_post (SDLAudioState *s)
	{
	if (sdl_unlock (s))
	return -1;

	return sdl_post (s);
	}

	static int sdl_hw_write (SWVoice sw, void buf, int len)
	{
	int ret;
	SDLAudioState *s = &glob_sdl;
	sdl_lock (s);
	ret = pcm_hw_write (sw, buf, len);
	sdl_unlock_and_post (s);
	return ret;
	}

	static int AUD_to_sdlfmt (audfmt_e fmt, int *shift)
	{
	*shift = 0;
	switch (fmt) {
	case AUD_FMT_S8: return AUDIO_S8;
	case AUD_FMT_U8: return AUDIO_U8;
	case AUD_FMT_S16: *shift = 1; return AUDIO_S16LSB;
	case AUD_FMT_U16: *shift = 1; return AUDIO_U16LSB;
	default:
	dolog ("Internal logic error: Bad audio format %d\nAborting\n", fmt);
	exit (EXIT_FAILURE);
	}
	}

	static int sdl_to_audfmt (int fmt)
	{
	switch (fmt) {
	case AUDIO_S8: return AUD_FMT_S8;
	case AUDIO_U8: return AUD_FMT_U8;
	case AUDIO_S16LSB: return AUD_FMT_S16;
	case AUDIO_U16LSB: return AUD_FMT_U16;
	default:
	dolog ("Internal logic error: Unrecognized SDL audio format %d\n"
	"Aborting\n", fmt);
	exit (EXIT_FAILURE);
	}
	}

	static int sdl_open (SDL_AudioSpec req, SDL_AudioSpec obt)
	{
	int status;

	status = SDL_OpenAudio (req, obt);
	if (status) {
	dolog ("SDL_OpenAudio failed\nReason: %s\n", errstr ());
	}
	return status;
	}

	static void sdl_close (SDLAudioState *s)
	{
	if (s->initialized) {
	sdl_lock (s);
	s->exit = 1;
	sdl_unlock_and_post (s);
	SDL_PauseAudio (1);
	SDL_CloseAudio ();
	s->initialized = 0;
	}
	}

	static void sdl_callback (void opaque, Uint8 buf, int len)
	{
	SDLVoice *sdl = opaque;
	SDLAudioState *s = &glob_sdl;
	HWVoice *hw = &sdl->hw;
	int samples = len >> hw->shift;

	if (s->exit) {
	return;
	}

	while (samples) {
	int to_mix, live, decr;

	/* dolog ("in callback samples=%d\n", samples); */
	sdl_wait (s);
	if (s->exit) {
	return;
	}

	sdl_lock (s);
	live = pcm_hw_get_live (hw);
	if (live <= 0)
	goto again;

	/* dolog ("in callback live=%d\n", live); */
	to_mix = audio_MIN (samples, live);
	decr = to_mix;
	while (to_mix) {
	int chunk = audio_MIN (to_mix, hw->samples - hw->rpos);
	st_sample_t *src = hw->mix_buf + hw->rpos;

	/* dolog ("in callback to_mix %d, chunk %d\n", to_mix, chunk); */
	hw->clip (buf, src, chunk);
	memset (src, 0, chunk * sizeof (st_sample_t));
	hw->rpos = (hw->rpos + chunk) % hw->samples;
	to_mix -= chunk;
	buf += chunk << hw->shift;
	}
	samples -= decr;
	pcm_hw_dec_live (hw, decr);

	again:
	sdl_unlock (s);
	}
	/* dolog ("done len=%d\n", len); */
	}

	static void sdl_hw_fini (HWVoice *hw)
	{
	ldebug ("sdl_hw_fini %d fixed=%d\n",
	glob_sdl.initialized, audio_conf.fixed_format);
	sdl_close (&glob_sdl);
	}

	static int sdl_hw_init (HWVoice *hw, int freq, int nchannels, audfmt_e fmt)
	{
	SDLVoice sdl = (SDLVoice ) hw;
	SDLAudioState *s = &glob_sdl;
	SDL_AudioSpec req, obt;
	int shift;

	ldebug ("sdl_hw_init %d freq=%d fixed=%d\n",
	s->initialized, freq, audio_conf.fixed_format);

	if (nchannels != 2) {
	dolog ("Bogus channel count %d\n", nchannels);
	return -1;
	}

	req.freq = freq;
	req.format = AUD_to_sdlfmt (fmt, &shift);
	req.channels = nchannels;
	req.samples = conf.nb_samples;
	shift <<= nchannels == 2;

	req.callback = sdl_callback;
	req.userdata = sdl;

	if (sdl_open (&req, &obt))
	return -1;

	hw->freq = obt.freq;
	hw->fmt = sdl_to_audfmt (obt.format);
	hw->nchannels = obt.channels;
	hw->bufsize = obt.samples << shift;

	s->initialized = 1;
	s->exit = 0;
	SDL_PauseAudio (0);
	return 0;
	}

	static int sdl_hw_ctl (HWVoice *hw, int cmd, ...)
	{
	(void) hw;

	switch (cmd) {
	case VOICE_ENABLE:
	SDL_PauseAudio (0);
	break;

	case VOICE_DISABLE:
	SDL_PauseAudio (1);
	break;
	}
	return 0;
	}

	static void *sdl_audio_init (void)
	{
	SDLAudioState *s = &glob_sdl;
	conf.nb_samples = audio_get_conf_int (QC_SDL_SAMPLES, conf.nb_samples);

	if (SDL_InitSubSystem (SDL_INIT_AUDIO)) {
	dolog ("SDL failed to initialize audio subsystem\nReason: %s\n",
	errstr ());
	return NULL;
	}

	s->mutex = SDL_CreateMutex ();
	if (!s->mutex) {
	dolog ("Failed to create SDL mutex\nReason: %s\n", errstr ());
	SDL_QuitSubSystem (SDL_INIT_AUDIO);
	return NULL;
	}

	s->sem = SDL_CreateSemaphore (0);
	if (!s->sem) {
	dolog ("Failed to create SDL semaphore\nReason: %s\n", errstr ());
	SDL_DestroyMutex (s->mutex);
	SDL_QuitSubSystem (SDL_INIT_AUDIO);
	return NULL;
	}

	return s;
	}

	static void sdl_audio_fini (void *opaque)
	{
	SDLAudioState *s = opaque;
	sdl_close (s);
	SDL_DestroySemaphore (s->sem);
	SDL_DestroyMutex (s->mutex);
	SDL_QuitSubSystem (SDL_INIT_AUDIO);
	}

	struct pcm_ops sdl_pcm_ops = {
	sdl_hw_init,
	sdl_hw_fini,
	sdl_hw_run,
	sdl_hw_write,
	sdl_hw_ctl
	};

	struct audio_output_driver sdl_output_driver = {
	"sdl",
	sdl_audio_init,
	sdl_audio_fini,
	&sdl_pcm_ops,
	1,
	1,
	sizeof (SDLVoice)
	};