summaryrefslogtreecommitdiff
path: root/src/i_sdlsound.c
blob: e10cb5ee7568892c347ad03f4c3316b336e69b81 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
// Emacs style mode select   -*- C++ -*- 
//-----------------------------------------------------------------------------
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005 Simon Howard
//
// 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.
//
// DESCRIPTION:
//	System interface for sound.
//
//-----------------------------------------------------------------------------


#include <stdio.h>
#include <stdlib.h>
#include "SDL.h"
#include "SDL_mixer.h"

#include "deh_main.h"
#include "s_sound.h"
#include "m_argv.h"
#include "w_wad.h"
#include "z_zone.h"

#include "doomdef.h"

#define NUM_CHANNELS 16

static boolean sound_initialised = false;

static Mix_Chunk sound_chunks[NUMSFX];
static int channels_playing[NUM_CHANNELS];

static int mixer_freq;
static Uint16 mixer_format;
static int mixer_channels;

// When a sound stops, check if it is still playing.  If it is not, 
// we can mark the sound data as CACHE to be freed back for other
// means.

static void ReleaseSoundOnChannel(int channel)
{
    int i;
    int id = channels_playing[channel];

    if (!id)
    {
        return;
    }

    channels_playing[channel] = sfx_None;
    
    for (i=0; i<NUM_CHANNELS; ++i)
    {
        // Playing on this channel? if so, don't release.

        if (channels_playing[i] == id)
            return;
    }

    // Not used on any channel, and can be safely released
    
    Z_ChangeTag(sound_chunks[id].abuf, PU_CACHE);
}

static boolean ConvertibleRatio(int freq1, int freq2)
{
    int ratio;

    if (freq1 > freq2)
    {
        return ConvertibleRatio(freq2, freq1);
    }
    else if ((freq2 % freq1) != 0)
    {
        // Not in a direct ratio

        return false;
    }
    else
    {
        // Check the ratio is a power of 2

        ratio = freq2 / freq1;

        while ((ratio & 1) == 0)
        {
            ratio = ratio >> 1;
        }

        return ratio == 1;
    }
}

// Generic sound expansion function for any sample rate

static void ExpandSoundData(byte *data,
                            int samplerate,
                            int length,
                            Mix_Chunk *destination)
{
    SDL_AudioCVT convertor;
    
    if (samplerate <= mixer_freq
     && ConvertibleRatio(samplerate, mixer_freq)
     && SDL_BuildAudioCVT(&convertor,
                          AUDIO_U8, 1, samplerate,
                          mixer_format, mixer_channels, mixer_freq))
    {
        convertor.buf = destination->abuf;
        convertor.len = length;
        memcpy(convertor.buf, data, length);

        SDL_ConvertAudio(&convertor);
    }
    else
    {
        Sint16 *expanded = (Sint16 *) destination->abuf;
        int expanded_length;
        int expand_ratio;
        int i;

        // Generic expansion if conversion does not work:
        //
        // SDL's audio conversion only works for rate conversions that are
        // powers of 2; if the two formats are not in a direct power of 2
        // ratio, do this naive conversion instead.

        // number of samples in the converted sound

        expanded_length = ((uint64_t) length * mixer_freq) / samplerate;
        expand_ratio = (length << 8) / expanded_length;

        for (i=0; i<expanded_length; ++i)
        {
            Sint16 sample;
            int src;

            src = (i * expand_ratio) >> 8;

            sample = data[src] | (data[src] << 8);
            sample -= 32768;

            // expand 8->16 bits, mono->stereo

            expanded[i * 2] = expanded[i * 2 + 1] = sample;
        }
    }
}

// Load and convert a sound effect
// Returns true if successful

static boolean CacheSFX(int sound)
{
    int lumpnum;
    unsigned int lumplen;
    int samplerate;
    unsigned int length;
    unsigned int expanded_length;
    byte *data;

    // need to load the sound

    lumpnum = S_sfx[sound].lumpnum;
    data = W_CacheLumpNum(lumpnum, PU_STATIC);
    lumplen = W_LumpLength(lumpnum);

    // Check the header, and ensure this is a valid sound

    if (lumplen < 8
     || data[0] != 0x03 || data[1] != 0x00)
    {
        // Invalid sound

        return false;
    }

    // 16 bit sample rate field, 32 bit length field

    samplerate = (data[3] << 8) | data[2];
    length = (data[7] << 24) | (data[6] << 16) | (data[5] << 8) | data[4];

    // If the header specifies that the length of the sound is greater than
    // the length of the lump itself, this is an invalid sound lump

    if (length > lumplen - 8)
    {
        return false;
    }

    // Sample rate conversion

    expanded_length = (uint32_t) ((((uint64_t) length) * mixer_freq) / samplerate);

    // Double up twice: 8 -> 16 bit and mono -> stereo

    expanded_length *= 4;

    sound_chunks[sound].allocated = 1;
    sound_chunks[sound].alen = expanded_length;
    sound_chunks[sound].abuf 
        = Z_Malloc(expanded_length, PU_STATIC, &sound_chunks[sound].abuf);
    sound_chunks[sound].volume = MIX_MAX_VOLUME;

    ExpandSoundData(data + 8, 
                    samplerate, 
                    length, 
                    &sound_chunks[sound]);

    // don't need the original lump any more
  
    Z_ChangeTag(data, PU_CACHE);

    return true;
}

static Mix_Chunk *GetSFXChunk(int sound_id)
{
    if (sound_chunks[sound_id].abuf == NULL)
    {
        if (!CacheSFX(sound_id))
            return NULL;
    }
    else
    {
        // don't free the sound while it is playing!
   
        Z_ChangeTag(sound_chunks[sound_id].abuf, PU_STATIC);
    }

    return &sound_chunks[sound_id];
}


//
// Retrieve the raw data lump index
//  for a given SFX name.
//

static int I_SDL_GetSfxLumpNum(sfxinfo_t* sfx)
{
    char namebuf[9];

    sprintf(namebuf, "ds%s", DEH_String(sfx->name));
    
    return W_GetNumForName(namebuf);
}

static void I_SDL_UpdateSoundParams(int handle, int vol, int sep)
{
    int left, right;

    if (!sound_initialised)
    {
        return;
    }

    left = ((254 - sep) * vol) / 127;
    right = ((sep) * vol) / 127;

    Mix_SetPanning(handle, left, right);
}


//
// Starting a sound means adding it
//  to the current list of active sounds
//  in the internal channels.
// As the SFX info struct contains
//  e.g. a pointer to the raw data,
//  it is ignored.
// As our sound handling does not handle
//  priority, it is ignored.
// Pitching (that is, increased speed of playback)
//  is set, but currently not used by mixing.
//

static int I_SDL_StartSound(int id, int channel, int vol, int sep)
{
    Mix_Chunk *chunk;

    if (!sound_initialised)
    {
        return -1;
    }

    // Release a sound effect if there is already one playing
    // on this channel

    ReleaseSoundOnChannel(channel);

    // Get the sound data

    chunk = GetSFXChunk(id);

    if (chunk == NULL)
    {
        return -1;
    }

    // play sound

    Mix_PlayChannelTimed(channel, chunk, 0, -1);

    channels_playing[channel] = id;

    // set separation, etc.
 
    I_SDL_UpdateSoundParams(channel, vol, sep);

    return channel;
}

static void I_SDL_StopSound (int handle)
{
    if (!sound_initialised)
    {
        return;
    }

    Mix_HaltChannel(handle);

    // Sound data is no longer needed; release the
    // sound data being used for this channel

    ReleaseSoundOnChannel(handle);
}


static boolean I_SDL_SoundIsPlaying(int handle)
{
    if (handle < 0)
    {
        return false;
    }

    return Mix_Playing(handle);
}

// 
// Periodically called to update the sound system
//

static void I_SDL_UpdateSound(void)
{
    int i;

    // Check all channels to see if a sound has finished

    for (i=0; i<NUM_CHANNELS; ++i)
    {
        if (channels_playing[i] && !I_SDL_SoundIsPlaying(i))
        {
            // Sound has finished playing on this channel,
            // but sound data has not been released to cache
            
            ReleaseSoundOnChannel(i);
        }
    }
}

static void I_SDL_ShutdownSound(void)
{    
    if (!sound_initialised)
    {
        return;
    }

    Mix_CloseAudio();
    SDL_QuitSubSystem(SDL_INIT_AUDIO);

    sound_initialised = false;
}

static boolean I_SDL_InitSound()
{ 
    int i;
    
    // No sounds yet

    for (i=0; i<NUMSFX; ++i)
    {
        sound_chunks[i].abuf = NULL;
    }

    for (i=0; i<NUM_CHANNELS; ++i)
    {
        channels_playing[i] = sfx_None;
    }

    if (SDL_Init(SDL_INIT_AUDIO) < 0)
    {
        fprintf(stderr, "Unable to set up sound.\n");
        return false;
    }

    if (Mix_OpenAudio(snd_samplerate, AUDIO_S16SYS, 2, 1024) < 0)
    {
        fprintf(stderr, "Error initialising SDL_mixer: %s\n", Mix_GetError());
        return false;
    }

    Mix_QuerySpec(&mixer_freq, &mixer_format, &mixer_channels);

    Mix_AllocateChannels(NUM_CHANNELS);
    
    SDL_PauseAudio(0);

    sound_initialised = true;

    return true;
}

static snddevice_t sound_sdl_devices[] = 
{
    SNDDEVICE_SB,
    SNDDEVICE_PAS,
    SNDDEVICE_GUS,
    SNDDEVICE_WAVEBLASTER,
    SNDDEVICE_SOUNDCANVAS,
    SNDDEVICE_AWE32,
};

sound_module_t sound_sdl_module = 
{
    sound_sdl_devices,
    arrlen(sound_sdl_devices),
    I_SDL_InitSound,
    I_SDL_ShutdownSound,
    I_SDL_GetSfxLumpNum,
    I_SDL_UpdateSound,
    I_SDL_UpdateSoundParams,
    I_SDL_StartSound,
    I_SDL_StopSound,
    I_SDL_SoundIsPlaying,
};