src/SDL/audio_sdl.cpp

/*
 *  audio_sdl.cpp - Audio support, SDL implementation
 *
 *  Basilisk II (C) 1997-2004 Christian Bauer
 *
 *  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 the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "sysdeps.h"
#include "cpu_emulation.h"
#include "main.h"
#include "prefs.h"
#include "user_strings.h"
#include "audio.h"
#include "audio_defs.h"

#include <SDL_mutex.h>
#include <SDL_audio.h>

#define DEBUG 0
#include "debug.h"


// The currently selected audio parameters (indices in audio_sample_rates[] etc. vectors)
static int audio_sample_rate_index = 0;
static int audio_sample_size_index = 0;
static int audio_channel_count_index = 0;

// Global variables
static SDL_sem *audio_irq_done_sem = NULL;                      // Signal from interrupt to streaming thread: data block read
static uint8 silence_byte;                                                      // Byte value to use to fill sound buffers with silence

// Prototypes
static void stream_func(void *arg, uint8 *stream, int stream_len);


/*
 *  Initialization
 */

// Set AudioStatus to reflect current audio stream format
static void set_audio_status_format(void)
{
        AudioStatus.sample_rate = audio_sample_rates[audio_sample_rate_index];
        AudioStatus.sample_size = audio_sample_sizes[audio_sample_size_index];
        AudioStatus.channels = audio_channel_counts[audio_channel_count_index];
}

// Init SDL audio system
static bool open_sdl_audio(void)
{
        // SDL supports a variety of twisted little audio formats, all different
        if (audio_sample_sizes.empty()) {
                audio_sample_rates.push_back(11025 << 16);
                audio_sample_rates.push_back(22050 << 16);
                audio_sample_rates.push_back(44100 << 16);
                audio_sample_sizes.push_back(8);
                audio_sample_sizes.push_back(16);
                audio_channel_counts.push_back(1);
                audio_channel_counts.push_back(2);

                // Default to highest supported values
                audio_sample_rate_index = audio_sample_rates.size() - 1;
                audio_sample_size_index = audio_sample_sizes.size() - 1;
                audio_channel_count_index = audio_channel_counts.size() - 1;
        }

        SDL_AudioSpec audio_spec;
        audio_spec.freq = audio_sample_rates[audio_sample_rate_index] >> 16;
        audio_spec.format = (audio_sample_sizes[audio_sample_size_index] == 8) ? AUDIO_U8 : AUDIO_S16MSB;
        audio_spec.channels = audio_channel_counts[audio_channel_count_index];
        audio_spec.samples = 4096;
        audio_spec.callback = stream_func;
        audio_spec.userdata = NULL;

        // Open the audio device, forcing the desired format
        if (SDL_OpenAudio(&audio_spec, NULL) < 0) {
                fprintf(stderr, "WARNING: Cannot open audio: %s\n", SDL_GetError());
                return false;
        }

        char driver_name[32];
        printf("Using SDL/%s audio output\n", SDL_AudioDriverName(driver_name, sizeof(driver_name) - 1));
        silence_byte = audio_spec.silence;
        SDL_PauseAudio(0);

        // Sound buffer size = 4096 frames
        audio_frames_per_block = audio_spec.samples;
        return true;
}

static bool open_audio(void)
{
        // Try to open SDL audio
        if (!open_sdl_audio()) {
                WarningAlert(GetString(STR_NO_AUDIO_WARN));
                return false;
        }

        // Device opened, set AudioStatus
        set_audio_status_format();

        // Everything went fine
        audio_open = true;
        return true;
}

void AudioInit(void)
{
        // Init audio status and feature flags
        AudioStatus.sample_rate = 44100 << 16;
        AudioStatus.sample_size = 16;
        AudioStatus.channels = 2;
        AudioStatus.mixer = 0;
        AudioStatus.num_sources = 0;
        audio_component_flags = cmpWantsRegisterMessage | kStereoOut | k16BitOut;

        // Sound disabled in prefs? Then do nothing
        if (PrefsFindBool("nosound"))
                return;

        // Init semaphore
        audio_irq_done_sem = SDL_CreateSemaphore(0);

        // Open and initialize audio device
        open_audio();
}


/*
 *  Deinitialization
 */

static void close_audio(void)
{
        // Close audio device
        SDL_CloseAudio();
        audio_open = false;
}

void AudioExit(void)
{
        // Close audio device
        close_audio();

        // Delete semaphore
        if (audio_irq_done_sem)
                SDL_DestroySemaphore(audio_irq_done_sem);
}


/*
 *  First source added, start audio stream
 */

void audio_enter_stream()
{
}


/*
 *  Last source removed, stop audio stream
 */

void audio_exit_stream()
{
}


/*
 *  Streaming function
 */

static void stream_func(void *arg, uint8 *stream, int stream_len)
{
        if (AudioStatus.num_sources) {

                // Trigger audio interrupt to get new buffer
                D(bug("stream: triggering irq\n"));
                SetInterruptFlag(INTFLAG_AUDIO);
                TriggerInterrupt();
                D(bug("stream: waiting for ack\n"));
                SDL_SemWait(audio_irq_done_sem);
                D(bug("stream: ack received\n"));

                // Get size of audio data
                uint32 apple_stream_info = ReadMacInt32(audio_data + adatStreamInfo);
                if (apple_stream_info) {
                        int work_size = ReadMacInt32(apple_stream_info + scd_sampleCount) * (AudioStatus.sample_size >> 3) * AudioStatus.channels;
                        D(bug("stream: work_size %d\n", work_size));
                        if (work_size > stream_len)
                                work_size = stream_len;
                        if (work_size == 0)
                                goto silence;

                        // Send data to audio device
                        Mac2Host_memcpy(stream, ReadMacInt32(apple_stream_info + scd_buffer), work_size);
                        if (work_size != stream_len)
                                memset((uint8 *)stream + work_size, silence_byte, stream_len - work_size);
                        D(bug("stream: data written\n"));
                } else
                        goto silence;

        } else {

                // Audio not active, play silence
silence: memset(stream, silence_byte, stream_len);
        }
}


/*
 *  MacOS audio interrupt, read next data block
 */

void AudioInterrupt(void)
{
        D(bug("AudioInterrupt\n"));

        // Get data from apple mixer
        if (AudioStatus.mixer) {
                M68kRegisters r;
                r.a[0] = audio_data + adatStreamInfo;
                r.a[1] = AudioStatus.mixer;
                Execute68k(audio_data + adatGetSourceData, &r);
                D(bug(" GetSourceData() returns %08lx\n", r.d[0]));
        } else
                WriteMacInt32(audio_data + adatStreamInfo, 0);

        // Signal stream function
        SDL_SemPost(audio_irq_done_sem);
        D(bug("AudioInterrupt done\n"));
}


/*
 *  Set sampling parameters
 *  "index" is an index into the audio_sample_rates[] etc. vectors
 *  It is guaranteed that AudioStatus.num_sources == 0
 */

bool audio_set_sample_rate(int index)
{
        close_audio();
        audio_sample_rate_index = index;
        return open_audio();
}

bool audio_set_sample_size(int index)
{
        close_audio();
        audio_sample_size_index = index;
        return open_audio();
}

bool audio_set_channels(int index)
{
        close_audio();
        audio_channel_count_index = index;
        return open_audio();
}


/*
 *  Get/set volume controls (volume values received/returned have the left channel
 *  volume in the upper 16 bits and the right channel volume in the lower 16 bits;
 *  both volumes are 8.8 fixed point values with 0x0100 meaning "maximum volume"))
 */

bool audio_get_main_mute(void)
{
        return false;
}

uint32 audio_get_main_volume(void)
{
        return 0x01000100;
}

bool audio_get_speaker_mute(void)
{
        return false;
}

uint32 audio_get_speaker_volume(void)
{
        return 0x01000100;
}

void audio_set_main_mute(bool mute)
{
}

void audio_set_main_volume(uint32 vol)
{
}

void audio_set_speaker_mute(bool mute)
{
}

void audio_set_speaker_volume(uint32 vol)
{
}
Revision:	1.1
Committed:	2004-07-19T19:25:06Z (20 years, 4 months ago) by gbeauche
Branch:	MAIN
Log Message:	SDL audio support
#	User	Rev	Content
1	gbeauche	1.1	/*
2			* audio_sdl.cpp - Audio support, SDL implementation
3			*
4			* Basilisk II (C) 1997-2004 Christian Bauer
5			*
6			* This program is free software; you can redistribute it and/or modify
7			* it under the terms of the GNU General Public License as published by
8			* the Free Software Foundation; either version 2 of the License, or
9			* (at your option) any later version.
10			*
11			* This program is distributed in the hope that it will be useful,
12			* but WITHOUT ANY WARRANTY; without even the implied warranty of
13			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			* GNU General Public License for more details.
15			*
16			* You should have received a copy of the GNU General Public License
17			* along with this program; if not, write to the Free Software
18			* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19			*/
20
21			#include "sysdeps.h"
22			#include "cpu_emulation.h"
23			#include "main.h"
24			#include "prefs.h"
25			#include "user_strings.h"
26			#include "audio.h"
27			#include "audio_defs.h"
28
29			#include <SDL_mutex.h>
30			#include <SDL_audio.h>
31
32			#define DEBUG 0
33			#include "debug.h"
34
35
36			// The currently selected audio parameters (indices in audio_sample_rates[] etc. vectors)
37			static int audio_sample_rate_index = 0;
38			static int audio_sample_size_index = 0;
39			static int audio_channel_count_index = 0;
40
41			// Global variables
42			static SDL_sem *audio_irq_done_sem = NULL; // Signal from interrupt to streaming thread: data block read
43			static uint8 silence_byte; // Byte value to use to fill sound buffers with silence
44
45			// Prototypes
46			static void stream_func(void arg, uint8 stream, int stream_len);
47
48
49			/*
50			* Initialization
51			*/
52
53			// Set AudioStatus to reflect current audio stream format
54			static void set_audio_status_format(void)
55			{
56			AudioStatus.sample_rate = audio_sample_rates[audio_sample_rate_index];
57			AudioStatus.sample_size = audio_sample_sizes[audio_sample_size_index];
58			AudioStatus.channels = audio_channel_counts[audio_channel_count_index];
59			}
60
61			// Init SDL audio system
62			static bool open_sdl_audio(void)
63			{
64			// SDL supports a variety of twisted little audio formats, all different
65			if (audio_sample_sizes.empty()) {
66			audio_sample_rates.push_back(11025 << 16);
67			audio_sample_rates.push_back(22050 << 16);
68			audio_sample_rates.push_back(44100 << 16);
69			audio_sample_sizes.push_back(8);
70			audio_sample_sizes.push_back(16);
71			audio_channel_counts.push_back(1);
72			audio_channel_counts.push_back(2);
73
74			// Default to highest supported values
75			audio_sample_rate_index = audio_sample_rates.size() - 1;
76			audio_sample_size_index = audio_sample_sizes.size() - 1;
77			audio_channel_count_index = audio_channel_counts.size() - 1;
78			}
79
80			SDL_AudioSpec audio_spec;
81			audio_spec.freq = audio_sample_rates[audio_sample_rate_index] >> 16;
82			audio_spec.format = (audio_sample_sizes[audio_sample_size_index] == 8) ? AUDIO_U8 : AUDIO_S16MSB;
83			audio_spec.channels = audio_channel_counts[audio_channel_count_index];
84			audio_spec.samples = 4096;
85			audio_spec.callback = stream_func;
86			audio_spec.userdata = NULL;
87
88			// Open the audio device, forcing the desired format
89			if (SDL_OpenAudio(&audio_spec, NULL) < 0) {
90			fprintf(stderr, "WARNING: Cannot open audio: %s\n", SDL_GetError());
91			return false;
92			}
93
94			char driver_name[32];
95			printf("Using SDL/%s audio output\n", SDL_AudioDriverName(driver_name, sizeof(driver_name) - 1));
96			silence_byte = audio_spec.silence;
97			SDL_PauseAudio(0);
98
99			// Sound buffer size = 4096 frames
100			audio_frames_per_block = audio_spec.samples;
101			return true;
102			}
103
104			static bool open_audio(void)
105			{
106			// Try to open SDL audio
107			if (!open_sdl_audio()) {
108			WarningAlert(GetString(STR_NO_AUDIO_WARN));
109			return false;
110			}
111
112			// Device opened, set AudioStatus
113			set_audio_status_format();
114
115			// Everything went fine
116			audio_open = true;
117			return true;
118			}
119
120			void AudioInit(void)
121			{
122			// Init audio status and feature flags
123			AudioStatus.sample_rate = 44100 << 16;
124			AudioStatus.sample_size = 16;
125			AudioStatus.channels = 2;
126			AudioStatus.mixer = 0;
127			AudioStatus.num_sources = 0;
128			audio_component_flags = cmpWantsRegisterMessage \| kStereoOut \| k16BitOut;
129
130			// Sound disabled in prefs? Then do nothing
131			if (PrefsFindBool("nosound"))
132			return;
133
134			// Init semaphore
135			audio_irq_done_sem = SDL_CreateSemaphore(0);
136
137			// Open and initialize audio device
138			open_audio();
139			}
140
141
142			/*
143			* Deinitialization
144			*/
145
146			static void close_audio(void)
147			{
148			// Close audio device
149			SDL_CloseAudio();
150			audio_open = false;
151			}
152
153			void AudioExit(void)
154			{
155			// Close audio device
156			close_audio();
157
158			// Delete semaphore
159			if (audio_irq_done_sem)
160			SDL_DestroySemaphore(audio_irq_done_sem);
161			}
162
163
164			/*
165			* First source added, start audio stream
166			*/
167
168			void audio_enter_stream()
169			{
170			}
171
172
173			/*
174			* Last source removed, stop audio stream
175			*/
176
177			void audio_exit_stream()
178			{
179			}
180
181
182			/*
183			* Streaming function
184			*/
185
186			static void stream_func(void arg, uint8 stream, int stream_len)
187			{
188			if (AudioStatus.num_sources) {
189
190			// Trigger audio interrupt to get new buffer
191			D(bug("stream: triggering irq\n"));
192			SetInterruptFlag(INTFLAG_AUDIO);
193			TriggerInterrupt();
194			D(bug("stream: waiting for ack\n"));
195			SDL_SemWait(audio_irq_done_sem);
196			D(bug("stream: ack received\n"));
197
198			// Get size of audio data
199			uint32 apple_stream_info = ReadMacInt32(audio_data + adatStreamInfo);
200			if (apple_stream_info) {
201			int work_size = ReadMacInt32(apple_stream_info + scd_sampleCount) * (AudioStatus.sample_size >> 3) * AudioStatus.channels;
202			D(bug("stream: work_size %d\n", work_size));
203			if (work_size > stream_len)
204			work_size = stream_len;
205			if (work_size == 0)
206			goto silence;
207
208			// Send data to audio device
209			Mac2Host_memcpy(stream, ReadMacInt32(apple_stream_info + scd_buffer), work_size);
210			if (work_size != stream_len)
211			memset((uint8 *)stream + work_size, silence_byte, stream_len - work_size);
212			D(bug("stream: data written\n"));
213			} else
214			goto silence;
215
216			} else {
217
218			// Audio not active, play silence
219			silence: memset(stream, silence_byte, stream_len);
220			}
221			}
222
223
224			/*
225			* MacOS audio interrupt, read next data block
226			*/
227
228			void AudioInterrupt(void)
229			{
230			D(bug("AudioInterrupt\n"));
231
232			// Get data from apple mixer
233			if (AudioStatus.mixer) {
234			M68kRegisters r;
235			r.a[0] = audio_data + adatStreamInfo;
236			r.a[1] = AudioStatus.mixer;
237			Execute68k(audio_data + adatGetSourceData, &r);
238			D(bug(" GetSourceData() returns %08lx\n", r.d[0]));
239			} else
240			WriteMacInt32(audio_data + adatStreamInfo, 0);
241
242			// Signal stream function
243			SDL_SemPost(audio_irq_done_sem);
244			D(bug("AudioInterrupt done\n"));
245			}
246
247
248			/*
249			* Set sampling parameters
250			* "index" is an index into the audio_sample_rates[] etc. vectors
251			* It is guaranteed that AudioStatus.num_sources == 0
252			*/
253
254			bool audio_set_sample_rate(int index)
255			{
256			close_audio();
257			audio_sample_rate_index = index;
258			return open_audio();
259			}
260
261			bool audio_set_sample_size(int index)
262			{
263			close_audio();
264			audio_sample_size_index = index;
265			return open_audio();
266			}
267
268			bool audio_set_channels(int index)
269			{
270			close_audio();
271			audio_channel_count_index = index;
272			return open_audio();
273			}
274
275
276			/*
277			* Get/set volume controls (volume values received/returned have the left channel
278			* volume in the upper 16 bits and the right channel volume in the lower 16 bits;
279			* both volumes are 8.8 fixed point values with 0x0100 meaning "maximum volume"))
280			*/
281
282			bool audio_get_main_mute(void)
283			{
284			return false;
285			}
286
287			uint32 audio_get_main_volume(void)
288			{
289			return 0x01000100;
290			}
291
292			bool audio_get_speaker_mute(void)
293			{
294			return false;
295			}
296
297			uint32 audio_get_speaker_volume(void)
298			{
299			return 0x01000100;
300			}
301
302			void audio_set_main_mute(bool mute)
303			{
304			}
305
306			void audio_set_main_volume(uint32 vol)
307			{
308			}
309
310			void audio_set_speaker_mute(bool mute)
311			{
312			}
313
314			void audio_set_speaker_volume(uint32 vol)
315			{
316			}