5 files changed, 385 insertions, 0 deletions
diff --git a/shell/audio/alsa/sound_output.c b/shell/audio/alsa/sound_output.c
new file mode 100644
index 0000000..4da70a7
--- /dev/null
+++ b/shell/audio/alsa/sound_output.c
@@ -0,0 +1,146 @@
+#include <sys/ioctl.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <alsa/asoundlib.h>
+
+#include "sound_output.h"
+
+static snd_pcm_t *handle;
+
+uint32_t Audio_Init()
+{
+	snd_pcm_hw_params_t *params;
+	uint32_t val;
+	int32_t dir = -1;
+	snd_pcm_uframes_t frames;
+	
+	/* Open PCM device for playback. */
+	int32_t rc = snd_pcm_open(&handle, "default", SND_PCM_STREAM_PLAYBACK, 0);
+
+	if (rc < 0)
+		rc = snd_pcm_open(&handle, "plughw:0,0,0", SND_PCM_STREAM_PLAYBACK, 0);
+
+	if (rc < 0)
+		rc = snd_pcm_open(&handle, "plughw:0,0", SND_PCM_STREAM_PLAYBACK, 0);
+		
+	if (rc < 0)
+		rc = snd_pcm_open(&handle, "plughw:1,0,0", SND_PCM_STREAM_PLAYBACK, 0);
+
+	if (rc < 0)
+		rc = snd_pcm_open(&handle, "plughw:1,0", SND_PCM_STREAM_PLAYBACK, 0);
+
+	if (rc < 0)
+	{
+		fprintf(stderr, "unable to open PCM device: %s\n", snd_strerror(rc));
+		return 1;
+	}
+
+	/* Allocate a hardware parameters object. */
+	snd_pcm_hw_params_alloca(&params);
+
+	/* Fill it in with default values. */
+	rc = snd_pcm_hw_params_any(handle, params);
+	if (rc < 0)
+	{
+		fprintf(stderr, "Error:snd_pcm_hw_params_any %s\n", snd_strerror(rc));
+		return 1;
+	}
+
+	/* Set the desired hardware parameters. */
+
+	/* Interleaved mode */
+	rc = snd_pcm_hw_params_set_access(handle, params, SND_PCM_ACCESS_RW_INTERLEAVED);
+	if (rc < 0)
+	{
+		fprintf(stderr, "Error:snd_pcm_hw_params_set_access %s\n", snd_strerror(rc));
+		return 1;
+	}
+
+	/* Signed 16-bit little-endian format */
+	rc = snd_pcm_hw_params_set_format(handle, params, SND_PCM_FORMAT_S16_LE);
+	if (rc < 0)
+	{
+		fprintf(stderr, "Error:snd_pcm_hw_params_set_format %s\n", snd_strerror(rc));
+		return 1;
+	}
+
+	/* Two channels (stereo) */
+	rc = snd_pcm_hw_params_set_channels(handle, params, 2);
+	if (rc < 0)
+	{
+		fprintf(stderr, "Error:snd_pcm_hw_params_set_channels %s\n", snd_strerror(rc));
+		return 1;
+	}
+	
+	val = SOUND_OUTPUT_FREQUENCY;
+	rc = snd_pcm_hw_params_set_rate_near(handle, params, &val, &dir);
+	if (rc < 0)
+	{
+		fprintf(stderr, "Error:snd_pcm_hw_params_set_rate_near %s\n", snd_strerror(rc));
+		return 1;
+	}
+
+	/* Set period size to settings.aica.BufferSize frames. */
+	frames = SOUND_SAMPLES_SIZE;
+	rc = snd_pcm_hw_params_set_period_size_near(handle, params, &frames, &dir);
+	if (rc < 0)
+	{
+		fprintf(stderr, "Error:snd_pcm_hw_params_set_buffer_size_near %s\n", snd_strerror(rc));
+		return 1;
+	}
+	frames *= 4;
+	rc = snd_pcm_hw_params_set_buffer_size_near(handle, params, &frames);
+	if (rc < 0)
+	{
+		fprintf(stderr, "Error:snd_pcm_hw_params_set_buffer_size_near %s\n", snd_strerror(rc));
+		return 1;
+	}
+
+	/* Write the parameters to the driver */
+	rc = snd_pcm_hw_params(handle, params);
+	if (rc < 0)
+	{
+		fprintf(stderr, "Unable to set hw parameters: %s\n", snd_strerror(rc));
+		return 1;
+	}
+	
+	return 0;
+}
+
+void Audio_Write(int16_t* restrict buffer, uint32_t buffer_size)
+{
+	uint32_t i;
+	long ret, len;
+
+	if (!handle) return;
+	
+	len = buffer_size;
+	
+	ret = snd_pcm_writei(handle, buffer, len);
+	while(ret != len) 
+	{
+		if (ret < 0) 
+		{
+			snd_pcm_prepare( handle );
+		}
+		else 
+		{
+			len -= ret;
+		}
+		ret = snd_pcm_writei(handle, buffer, len);
+	}
+}
+
+bool Audio_Underrun_Likely() {
+	return false;
+}
+
+void Audio_Close()
+{
+	if (handle)
+	{
+		snd_pcm_drain(handle);
+		snd_pcm_close(handle);
+	}
+}
diff --git a/shell/audio/oss/sound_output.c b/shell/audio/oss/sound_output.c
new file mode 100644
index 0000000..39a7ba3
--- /dev/null
+++ b/shell/audio/oss/sound_output.c
@@ -0,0 +1,63 @@
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/soundcard.h>
+
+#include "sound_output.h"
+
+static int32_t oss_audio_fd = -1;
+
+uint32_t Audio_Init()
+{
+	uint32_t channels = 2;
+	uint32_t format = AFMT_S16_LE;
+	uint32_t tmp = SOUND_OUTPUT_FREQUENCY;
+	int32_t err_ret;
+
+	oss_audio_fd = open("/dev/dsp", O_WRONLY | O_NONBLOCK);
+	if (oss_audio_fd < 0)
+	{
+		printf("Couldn't open /dev/dsp.\n");
+		return 1;
+	}
+	
+	err_ret = ioctl(oss_audio_fd, SNDCTL_DSP_SPEED,&tmp);
+	if (err_ret == -1)
+	{
+		printf("Could not set sound frequency\n");
+		return 1;
+	}
+	err_ret = ioctl(oss_audio_fd, SNDCTL_DSP_CHANNELS, &channels);
+	if (err_ret == -1)
+	{
+		printf("Could not set channels\n");
+		return 1;
+	}
+	err_ret = ioctl(oss_audio_fd, SNDCTL_DSP_SETFMT, &format);
+	if (err_ret == -1)
+	{
+		printf("Could not set sound format\n");
+		return 1;
+	}
+	return 0;
+}
+
+void Audio_Write(int16_t* restrict buffer, uint32_t buffer_size)
+{
+	write(oss_audio_fd, buffer, buffer_size * 4 );
+}
+
+bool Audio_Underrun_Likely() {
+	return false;
+}
+
+void Audio_Close()
+{
+	if (oss_audio_fd >= 0)
+	{
+		close(oss_audio_fd);
+		oss_audio_fd = -1;
+	}
+}
diff --git a/shell/audio/portaudio/sound_output.c b/shell/audio/portaudio/sound_output.c
new file mode 100644
index 0000000..0c03c93
--- /dev/null
+++ b/shell/audio/portaudio/sound_output.c
@@ -0,0 +1,45 @@
+#include <portaudio.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#include "shared.h"
+
+static PaStream *apu_stream;
+
+uint32_t Audio_Init()
+{
+	Pa_Initialize();
+	
+	PaStreamParameters outputParameters;
+	
+	outputParameters.device = Pa_GetDefaultOutputDevice();
+	
+	if (outputParameters.device == paNoDevice) 
+	{
+		printf("No sound output\n");
+		return 1;
+	}
+
+	outputParameters.channelCount = 2;
+	outputParameters.sampleFormat = paInt16;
+	outputParameters.hostApiSpecificStreamInfo = NULL;
+	
+	Pa_OpenStream( &apu_stream, NULL, &outputParameters, SOUND_OUTPUT_FREQUENCY, SOUND_SAMPLES_SIZE, paNoFlag, NULL, NULL);
+	Pa_StartStream( apu_stream );
+	
+	return 0;
+}
+
+void Audio_Write(int16_t* restrict buffer, uint32_t buffer_size)
+{
+	Pa_WriteStream( apu_stream, buffer, buffer_size);
+}
+
+bool Audio_Underrun_Likely() {
+	return false;
+}
+
+void Audio_Close()
+{
+	//Pa_Close();
+}
diff --git a/shell/audio/sdl/sound_output.c b/shell/audio/sdl/sound_output.c
new file mode 100644
index 0000000..0758718
--- /dev/null
+++ b/shell/audio/sdl/sound_output.c
@@ -0,0 +1,119 @@
+#include <sys/ioctl.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <SDL/SDL.h>
+
+#include "sound_output.h"
+
+#define UNDERRUN_THRESHOLD 0.5
+
+static int32_t BUFFSIZE;
+static uint8_t *buffer;
+static uint32_t buf_read_pos = 0;
+static uint32_t buf_write_pos = 0;
+static int32_t buffered_bytes = 0;
+
+static int32_t sdl_read_buffer(uint8_t* data, int32_t len)
+{
+	if (buffered_bytes >= len) 
+	{
+		if(buf_read_pos + len <= BUFFSIZE ) 
+		{
+			memcpy(data, buffer + buf_read_pos, len);
+		} 
+		else 
+		{
+			int32_t tail = BUFFSIZE - buf_read_pos;
+			memcpy(data, buffer + buf_read_pos, tail);
+			memcpy(data + tail, buffer, len - tail);
+		}
+		buf_read_pos = (buf_read_pos + len) % BUFFSIZE;
+		buffered_bytes -= len;
+	}
+
+	return len;
+}
+
+
+static void sdl_write_buffer(uint8_t* data, int32_t len)
+{
+	SDL_LockAudio();
+	for(uint32_t i = 0; i < len; i += 4) 
+	{
+		while (buffered_bytes == BUFFSIZE) {
+			SDL_UnlockAudio();
+			usleep(1000);
+			SDL_LockAudio();
+		}
+		*(int32_t*)((char*)(buffer + buf_write_pos)) = *(int32_t*)((char*)(data + i));
+		//memcpy(buffer + buf_write_pos, data + i, 4);
+		buf_write_pos = (buf_write_pos + 4) % BUFFSIZE;
+		buffered_bytes += 4;
+	}
+	SDL_UnlockAudio();
+}
+
+void sdl_callback(void *unused, uint8_t *stream, int32_t len)
+{
+	sdl_read_buffer((uint8_t *)stream, len);
+}
+uint32_t Audio_Init()
+{
+	SDL_AudioSpec aspec, obtained;
+
+	BUFFSIZE = (SOUND_SAMPLES_SIZE * 2 * 2) * 4;
+	buffer = (uint8_t *) malloc(BUFFSIZE);
+
+	/* Add some silence to the buffer */
+	buffered_bytes = 0;
+	buf_read_pos = 0;
+	buf_write_pos = 0;
+
+	aspec.format   = AUDIO_S16SYS;
+	aspec.freq     = SOUND_OUTPUT_FREQUENCY;
+	aspec.channels = 2;
+	aspec.samples  = SOUND_SAMPLES_SIZE;
+	aspec.callback = (sdl_callback);
+	aspec.userdata = NULL;
+
+	/* initialize the SDL Audio system */
+	if (SDL_InitSubSystem (SDL_INIT_AUDIO | SDL_INIT_NOPARACHUTE)) 
+	{
+		printf("SDL: Initializing of SDL Audio failed: %s.\n", SDL_GetError());
+		return 1;
+	}
+
+	/* Open the audio device and start playing sound! */
+	if(SDL_OpenAudio(&aspec, &obtained) < 0) 
+	{
+		printf("SDL: Unable to open audio: %s\n", SDL_GetError());
+		return 1;
+	}
+	
+	SDL_PauseAudio(0);
+	
+	return 0;
+}
+
+void Audio_Write(int16_t* restrict buffer, uint32_t buffer_size)
+{
+	sdl_write_buffer(buffer, buffer_size * 4);
+}
+
+bool Audio_Underrun_Likely() {
+	bool underrun_likely = false;
+	SDL_LockAudio();
+	underrun_likely = buffered_bytes < BUFFSIZE * UNDERRUN_THRESHOLD;
+	SDL_UnlockAudio();
+	return underrun_likely;
+}
+
+void Audio_Close()
+{
+	SDL_PauseAudio(1);
+	SDL_CloseAudio();
+	SDL_QuitSubSystem(SDL_INIT_AUDIO);
+	buffer = NULL;
+}
diff --git a/shell/audio/sound_output.h b/shell/audio/sound_output.h
new file mode 100644
index 0000000..b770fbe
--- /dev/null
+++ b/shell/audio/sound_output.h
@@ -0,0 +1,12 @@
+#ifndef SOUND_OUTPUT_H
+#define SOUND_OUTPUT_H
+
+#include <stdbool.h>
+#include "shared.h"
+
+extern uint32_t Audio_Init();
+extern void Audio_Write(int16_t* restrict buffer, uint32_t buffer_size);
+extern bool Audio_Underrun_Likely();
+extern void Audio_Close();
+
+#endif