SDL  2.0
SDL_wave.c File Reference
#include "../SDL_internal.h"
#include "SDL_audio.h"
#include "SDL_wave.h"
+ Include dependency graph for SDL_wave.c:

Go to the source code of this file.

Data Structures

struct  MS_ADPCM_decodestate
 
struct  MS_ADPCM_decoder
 
struct  IMA_ADPCM_decodestate
 
struct  IMA_ADPCM_decoder
 

Functions

static int ReadChunk (SDL_RWops *src, Chunk *chunk)
 
static int InitMS_ADPCM (WaveFMT *format)
 
static Sint32 MS_ADPCM_nibble (struct MS_ADPCM_decodestate *state, Uint8 nybble, Sint16 *coeff)
 
static int MS_ADPCM_decode (Uint8 **audio_buf, Uint32 *audio_len)
 
static int InitIMA_ADPCM (WaveFMT *format)
 
static Sint32 IMA_ADPCM_nibble (struct IMA_ADPCM_decodestate *state, Uint8 nybble)
 
static void Fill_IMA_ADPCM_block (Uint8 *decoded, Uint8 *encoded, int channel, int numchannels, struct IMA_ADPCM_decodestate *state)
 
static int IMA_ADPCM_decode (Uint8 **audio_buf, Uint32 *audio_len)
 
SDL_AudioSpecSDL_LoadWAV_RW (SDL_RWops *src, int freesrc, SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len)
 
void SDL_FreeWAV (Uint8 *audio_buf)
 

Variables

static struct MS_ADPCM_decoder MS_ADPCM_state
 
static struct IMA_ADPCM_decoder IMA_ADPCM_state
 

Function Documentation

static void Fill_IMA_ADPCM_block ( Uint8 decoded,
Uint8 encoded,
int  channel,
int  numchannels,
struct IMA_ADPCM_decodestate state 
)
static

Definition at line 309 of file SDL_wave.c.

References i, and IMA_ADPCM_nibble().

Referenced by IMA_ADPCM_decode().

312 {
313  int i;
314  Sint8 nybble;
315  Sint32 new_sample;
316 
317  decoded += (channel * 2);
318  for (i = 0; i < 4; ++i) {
319  nybble = (*encoded) & 0x0F;
320  new_sample = IMA_ADPCM_nibble(state, nybble);
321  decoded[0] = new_sample & 0xFF;
322  new_sample >>= 8;
323  decoded[1] = new_sample & 0xFF;
324  decoded += 2 * numchannels;
325 
326  nybble = (*encoded) >> 4;
327  new_sample = IMA_ADPCM_nibble(state, nybble);
328  decoded[0] = new_sample & 0xFF;
329  new_sample >>= 8;
330  decoded[1] = new_sample & 0xFF;
331  decoded += 2 * numchannels;
332 
333  ++encoded;
334  }
335 }
int8_t Sint8
A signed 8-bit integer type.
Definition: SDL_stdinc.h:135
int32_t Sint32
A signed 32-bit integer type.
Definition: SDL_stdinc.h:151
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int in i)
Definition: SDL_x11sym.h:42
static Sint32 IMA_ADPCM_nibble(struct IMA_ADPCM_decodestate *state, Uint8 nybble)
Definition: SDL_wave.c:254
static int IMA_ADPCM_decode ( Uint8 **  audio_buf,
Uint32 audio_len 
)
static

Definition at line 338 of file SDL_wave.c.

References WaveFMT::blockalign, WaveFMT::channels, Fill_IMA_ADPCM_block(), IMA_ADPCM_state, IMA_ADPCM_decodestate::index, NULL, IMA_ADPCM_decodestate::sample, SDL_arraysize, SDL_free(), SDL_malloc, SDL_OutOfMemory, SDL_SetError, state, IMA_ADPCM_decoder::state, IMA_ADPCM_decoder::wavefmt, and IMA_ADPCM_decoder::wSamplesPerBlock.

Referenced by SDL_LoadWAV_RW().

339 {
341  Uint8 *freeable, *encoded, *decoded;
342  Sint32 encoded_len, samplesleft;
343  unsigned int c, channels;
344 
345  /* Check to make sure we have enough variables in the state array */
346  channels = IMA_ADPCM_state.wavefmt.channels;
347  if (channels > SDL_arraysize(IMA_ADPCM_state.state)) {
348  SDL_SetError("IMA ADPCM decoder can only handle %u channels",
349  (unsigned int)SDL_arraysize(IMA_ADPCM_state.state));
350  return (-1);
351  }
352  state = IMA_ADPCM_state.state;
353 
354  /* Allocate the proper sized output buffer */
355  encoded_len = *audio_len;
356  encoded = *audio_buf;
357  freeable = *audio_buf;
358  *audio_len = (encoded_len / IMA_ADPCM_state.wavefmt.blockalign) *
361  *audio_buf = (Uint8 *) SDL_malloc(*audio_len);
362  if (*audio_buf == NULL) {
363  return SDL_OutOfMemory();
364  }
365  decoded = *audio_buf;
366 
367  /* Get ready... Go! */
368  while (encoded_len >= IMA_ADPCM_state.wavefmt.blockalign) {
369  /* Grab the initial information for this block */
370  for (c = 0; c < channels; ++c) {
371  /* Fill the state information for this block */
372  state[c].sample = ((encoded[1] << 8) | encoded[0]);
373  encoded += 2;
374  if (state[c].sample & 0x8000) {
375  state[c].sample -= 0x10000;
376  }
377  state[c].index = *encoded++;
378  /* Reserved byte in buffer header, should be 0 */
379  if (*encoded++ != 0) {
380  /* Uh oh, corrupt data? Buggy code? */ ;
381  }
382 
383  /* Store the initial sample we start with */
384  decoded[0] = (Uint8) (state[c].sample & 0xFF);
385  decoded[1] = (Uint8) (state[c].sample >> 8);
386  decoded += 2;
387  }
388 
389  /* Decode and store the other samples in this block */
390  samplesleft = (IMA_ADPCM_state.wSamplesPerBlock - 1) * channels;
391  while (samplesleft > 0) {
392  for (c = 0; c < channels; ++c) {
393  Fill_IMA_ADPCM_block(decoded, encoded,
394  c, channels, &state[c]);
395  encoded += 4;
396  samplesleft -= 8;
397  }
398  decoded += (channels * 8 * 2);
399  }
400  encoded_len -= IMA_ADPCM_state.wavefmt.blockalign;
401  }
402  SDL_free(freeable);
403  return (0);
404 }
Uint16 blockalign
Definition: SDL_wave.h:55
static void Fill_IMA_ADPCM_block(Uint8 *decoded, Uint8 *encoded, int channel, int numchannels, struct IMA_ADPCM_decodestate *state)
Definition: SDL_wave.c:309
struct xkb_state * state
static struct IMA_ADPCM_decoder IMA_ADPCM_state
WaveFMT wavefmt
Definition: SDL_wave.c:225
Uint16 channels
Definition: SDL_wave.h:52
uint8_t Uint8
An unsigned 8-bit integer type.
Definition: SDL_stdinc.h:139
void SDL_free(void *mem)
struct IMA_ADPCM_decodestate state[2]
Definition: SDL_wave.c:228
const GLubyte * c
int32_t Sint32
A signed 32-bit integer type.
Definition: SDL_stdinc.h:151
#define NULL
Definition: begin_code.h:143
#define SDL_OutOfMemory()
Definition: SDL_error.h:52
#define SDL_SetError
#define SDL_arraysize(array)
Definition: SDL_stdinc.h:93
#define SDL_malloc
Uint16 wSamplesPerBlock
Definition: SDL_wave.c:226
int16_t Sint16
A signed 16-bit integer type.
Definition: SDL_stdinc.h:143
static Sint32 IMA_ADPCM_nibble ( struct IMA_ADPCM_decodestate state,
Uint8  nybble 
)
static

Definition at line 254 of file SDL_wave.c.

References IMA_ADPCM_decodestate::index, and IMA_ADPCM_decodestate::sample.

Referenced by Fill_IMA_ADPCM_block().

255 {
256  const Sint32 max_audioval = ((1 << (16 - 1)) - 1);
257  const Sint32 min_audioval = -(1 << (16 - 1));
258  const int index_table[16] = {
259  -1, -1, -1, -1,
260  2, 4, 6, 8,
261  -1, -1, -1, -1,
262  2, 4, 6, 8
263  };
264  const Sint32 step_table[89] = {
265  7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 19, 21, 23, 25, 28, 31,
266  34, 37, 41, 45, 50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130,
267  143, 157, 173, 190, 209, 230, 253, 279, 307, 337, 371, 408,
268  449, 494, 544, 598, 658, 724, 796, 876, 963, 1060, 1166, 1282,
269  1411, 1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024, 3327,
270  3660, 4026, 4428, 4871, 5358, 5894, 6484, 7132, 7845, 8630,
271  9493, 10442, 11487, 12635, 13899, 15289, 16818, 18500, 20350,
272  22385, 24623, 27086, 29794, 32767
273  };
274  Sint32 delta, step;
275 
276  /* Compute difference and new sample value */
277  if (state->index > 88) {
278  state->index = 88;
279  } else if (state->index < 0) {
280  state->index = 0;
281  }
282  /* explicit cast to avoid gcc warning about using 'char' as array index */
283  step = step_table[(int)state->index];
284  delta = step >> 3;
285  if (nybble & 0x04)
286  delta += step;
287  if (nybble & 0x02)
288  delta += (step >> 1);
289  if (nybble & 0x01)
290  delta += (step >> 2);
291  if (nybble & 0x08)
292  delta = -delta;
293  state->sample += delta;
294 
295  /* Update index value */
296  state->index += index_table[nybble];
297 
298  /* Clamp output sample */
299  if (state->sample > max_audioval) {
300  state->sample = max_audioval;
301  } else if (state->sample < min_audioval) {
302  state->sample = min_audioval;
303  }
304  return (state->sample);
305 }
int32_t Sint32
A signed 32-bit integer type.
Definition: SDL_stdinc.h:151
static int InitIMA_ADPCM ( WaveFMT format)
static

Definition at line 232 of file SDL_wave.c.

References WaveFMT::bitspersample, WaveFMT::blockalign, WaveFMT::byterate, WaveFMT::channels, WaveFMT::encoding, WaveFMT::frequency, IMA_ADPCM_state, SDL_SwapLE16, SDL_SwapLE32, IMA_ADPCM_decoder::wavefmt, and IMA_ADPCM_decoder::wSamplesPerBlock.

Referenced by SDL_LoadWAV_RW().

233 {
234  Uint8 *rogue_feel;
235 
236  /* Set the rogue pointer to the IMA_ADPCM specific data */
243  SDL_SwapLE16(format->bitspersample);
244  rogue_feel = (Uint8 *) format + sizeof(*format);
245  if (sizeof(*format) == 16) {
246  /* const Uint16 extra_info = ((rogue_feel[1] << 8) | rogue_feel[0]); */
247  rogue_feel += sizeof(Uint16);
248  }
249  IMA_ADPCM_state.wSamplesPerBlock = ((rogue_feel[1] << 8) | rogue_feel[0]);
250  return (0);
251 }
Uint16 blockalign
Definition: SDL_wave.h:55
static struct IMA_ADPCM_decoder IMA_ADPCM_state
Uint16 encoding
Definition: SDL_wave.h:51
WaveFMT wavefmt
Definition: SDL_wave.c:225
Uint16 channels
Definition: SDL_wave.h:52
uint8_t Uint8
An unsigned 8-bit integer type.
Definition: SDL_stdinc.h:139
#define SDL_SwapLE32(X)
Definition: SDL_endian.h:212
uint16_t Uint16
An unsigned 16-bit integer type.
Definition: SDL_stdinc.h:147
Uint16 wSamplesPerBlock
Definition: SDL_wave.c:226
Uint32 frequency
Definition: SDL_wave.h:53
Uint16 bitspersample
Definition: SDL_wave.h:56
#define SDL_SwapLE16(X)
Definition: SDL_endian.h:211
Uint32 byterate
Definition: SDL_wave.h:54
static int InitMS_ADPCM ( WaveFMT format)
static

Definition at line 49 of file SDL_wave.c.

References MS_ADPCM_decoder::aCoeff, WaveFMT::bitspersample, WaveFMT::blockalign, WaveFMT::byterate, WaveFMT::channels, WaveFMT::encoding, WaveFMT::frequency, i, MS_ADPCM_state, SDL_SetError, SDL_SwapLE16, SDL_SwapLE32, MS_ADPCM_decoder::wavefmt, MS_ADPCM_decoder::wNumCoef, and MS_ADPCM_decoder::wSamplesPerBlock.

Referenced by SDL_LoadWAV_RW().

50 {
51  Uint8 *rogue_feel;
52  int i;
53 
54  /* Set the rogue pointer to the MS_ADPCM specific data */
61  SDL_SwapLE16(format->bitspersample);
62  rogue_feel = (Uint8 *) format + sizeof(*format);
63  if (sizeof(*format) == 16) {
64  /* const Uint16 extra_info = ((rogue_feel[1] << 8) | rogue_feel[0]); */
65  rogue_feel += sizeof(Uint16);
66  }
67  MS_ADPCM_state.wSamplesPerBlock = ((rogue_feel[1] << 8) | rogue_feel[0]);
68  rogue_feel += sizeof(Uint16);
69  MS_ADPCM_state.wNumCoef = ((rogue_feel[1] << 8) | rogue_feel[0]);
70  rogue_feel += sizeof(Uint16);
71  if (MS_ADPCM_state.wNumCoef != 7) {
72  SDL_SetError("Unknown set of MS_ADPCM coefficients");
73  return (-1);
74  }
75  for (i = 0; i < MS_ADPCM_state.wNumCoef; ++i) {
76  MS_ADPCM_state.aCoeff[i][0] = ((rogue_feel[1] << 8) | rogue_feel[0]);
77  rogue_feel += sizeof(Uint16);
78  MS_ADPCM_state.aCoeff[i][1] = ((rogue_feel[1] << 8) | rogue_feel[0]);
79  rogue_feel += sizeof(Uint16);
80  }
81  return (0);
82 }
Uint16 wNumCoef
Definition: SDL_wave.c:42
Uint16 wSamplesPerBlock
Definition: SDL_wave.c:41
Uint16 blockalign
Definition: SDL_wave.h:55
Uint16 encoding
Definition: SDL_wave.h:51
Uint16 channels
Definition: SDL_wave.h:52
uint8_t Uint8
An unsigned 8-bit integer type.
Definition: SDL_stdinc.h:139
#define SDL_SwapLE32(X)
Definition: SDL_endian.h:212
Sint16 aCoeff[7][2]
Definition: SDL_wave.c:43
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int in i)
Definition: SDL_x11sym.h:42
#define SDL_SetError
uint16_t Uint16
An unsigned 16-bit integer type.
Definition: SDL_stdinc.h:147
Uint32 frequency
Definition: SDL_wave.h:53
Uint16 bitspersample
Definition: SDL_wave.h:56
#define SDL_SwapLE16(X)
Definition: SDL_endian.h:211
Uint32 byterate
Definition: SDL_wave.h:54
WaveFMT wavefmt
Definition: SDL_wave.c:40
static struct MS_ADPCM_decoder MS_ADPCM_state
static int MS_ADPCM_decode ( Uint8 **  audio_buf,
Uint32 audio_len 
)
static

Definition at line 119 of file SDL_wave.c.

References MS_ADPCM_decoder::aCoeff, WaveFMT::blockalign, WaveFMT::channels, MS_ADPCM_decodestate::hPredictor, MS_ADPCM_decodestate::iDelta, MS_ADPCM_decodestate::iSamp1, MS_ADPCM_decodestate::iSamp2, MS_ADPCM_nibble(), MS_ADPCM_state, NULL, SDL_free(), SDL_malloc, SDL_OutOfMemory, MS_ADPCM_decoder::state, state, MS_ADPCM_decoder::wavefmt, and MS_ADPCM_decoder::wSamplesPerBlock.

Referenced by SDL_LoadWAV_RW().

120 {
121  struct MS_ADPCM_decodestate *state[2];
122  Uint8 *freeable, *encoded, *decoded;
123  Sint32 encoded_len, samplesleft;
124  Sint8 nybble;
125  Uint8 stereo;
126  Sint16 *coeff[2];
127  Sint32 new_sample;
128 
129  /* Allocate the proper sized output buffer */
130  encoded_len = *audio_len;
131  encoded = *audio_buf;
132  freeable = *audio_buf;
133  *audio_len = (encoded_len / MS_ADPCM_state.wavefmt.blockalign) *
136  *audio_buf = (Uint8 *) SDL_malloc(*audio_len);
137  if (*audio_buf == NULL) {
138  return SDL_OutOfMemory();
139  }
140  decoded = *audio_buf;
141 
142  /* Get ready... Go! */
143  stereo = (MS_ADPCM_state.wavefmt.channels == 2);
144  state[0] = &MS_ADPCM_state.state[0];
145  state[1] = &MS_ADPCM_state.state[stereo];
146  while (encoded_len >= MS_ADPCM_state.wavefmt.blockalign) {
147  /* Grab the initial information for this block */
148  state[0]->hPredictor = *encoded++;
149  if (stereo) {
150  state[1]->hPredictor = *encoded++;
151  }
152  state[0]->iDelta = ((encoded[1] << 8) | encoded[0]);
153  encoded += sizeof(Sint16);
154  if (stereo) {
155  state[1]->iDelta = ((encoded[1] << 8) | encoded[0]);
156  encoded += sizeof(Sint16);
157  }
158  state[0]->iSamp1 = ((encoded[1] << 8) | encoded[0]);
159  encoded += sizeof(Sint16);
160  if (stereo) {
161  state[1]->iSamp1 = ((encoded[1] << 8) | encoded[0]);
162  encoded += sizeof(Sint16);
163  }
164  state[0]->iSamp2 = ((encoded[1] << 8) | encoded[0]);
165  encoded += sizeof(Sint16);
166  if (stereo) {
167  state[1]->iSamp2 = ((encoded[1] << 8) | encoded[0]);
168  encoded += sizeof(Sint16);
169  }
170  coeff[0] = MS_ADPCM_state.aCoeff[state[0]->hPredictor];
171  coeff[1] = MS_ADPCM_state.aCoeff[state[1]->hPredictor];
172 
173  /* Store the two initial samples we start with */
174  decoded[0] = state[0]->iSamp2 & 0xFF;
175  decoded[1] = state[0]->iSamp2 >> 8;
176  decoded += 2;
177  if (stereo) {
178  decoded[0] = state[1]->iSamp2 & 0xFF;
179  decoded[1] = state[1]->iSamp2 >> 8;
180  decoded += 2;
181  }
182  decoded[0] = state[0]->iSamp1 & 0xFF;
183  decoded[1] = state[0]->iSamp1 >> 8;
184  decoded += 2;
185  if (stereo) {
186  decoded[0] = state[1]->iSamp1 & 0xFF;
187  decoded[1] = state[1]->iSamp1 >> 8;
188  decoded += 2;
189  }
190 
191  /* Decode and store the other samples in this block */
192  samplesleft = (MS_ADPCM_state.wSamplesPerBlock - 2) *
194  while (samplesleft > 0) {
195  nybble = (*encoded) >> 4;
196  new_sample = MS_ADPCM_nibble(state[0], nybble, coeff[0]);
197  decoded[0] = new_sample & 0xFF;
198  new_sample >>= 8;
199  decoded[1] = new_sample & 0xFF;
200  decoded += 2;
201 
202  nybble = (*encoded) & 0x0F;
203  new_sample = MS_ADPCM_nibble(state[1], nybble, coeff[1]);
204  decoded[0] = new_sample & 0xFF;
205  new_sample >>= 8;
206  decoded[1] = new_sample & 0xFF;
207  decoded += 2;
208 
209  ++encoded;
210  samplesleft -= 2;
211  }
212  encoded_len -= MS_ADPCM_state.wavefmt.blockalign;
213  }
214  SDL_free(freeable);
215  return (0);
216 }
Uint16 wSamplesPerBlock
Definition: SDL_wave.c:41
Uint16 blockalign
Definition: SDL_wave.h:55
struct xkb_state * state
struct MS_ADPCM_decodestate state[2]
Definition: SDL_wave.c:45
static Sint32 MS_ADPCM_nibble(struct MS_ADPCM_decodestate *state, Uint8 nybble, Sint16 *coeff)
Definition: SDL_wave.c:85
Uint16 channels
Definition: SDL_wave.h:52
int8_t Sint8
A signed 8-bit integer type.
Definition: SDL_stdinc.h:135
uint8_t Uint8
An unsigned 8-bit integer type.
Definition: SDL_stdinc.h:139
void SDL_free(void *mem)
Sint16 aCoeff[7][2]
Definition: SDL_wave.c:43
int32_t Sint32
A signed 32-bit integer type.
Definition: SDL_stdinc.h:151
#define NULL
Definition: begin_code.h:143
#define SDL_OutOfMemory()
Definition: SDL_error.h:52
#define SDL_malloc
WaveFMT wavefmt
Definition: SDL_wave.c:40
int16_t Sint16
A signed 16-bit integer type.
Definition: SDL_stdinc.h:143
static struct MS_ADPCM_decoder MS_ADPCM_state
static Sint32 MS_ADPCM_nibble ( struct MS_ADPCM_decodestate state,
Uint8  nybble,
Sint16 coeff 
)
static

Definition at line 85 of file SDL_wave.c.

References MS_ADPCM_decodestate::iDelta, MS_ADPCM_decodestate::iSamp1, and MS_ADPCM_decodestate::iSamp2.

Referenced by MS_ADPCM_decode().

87 {
88  const Sint32 max_audioval = ((1 << (16 - 1)) - 1);
89  const Sint32 min_audioval = -(1 << (16 - 1));
90  const Sint32 adaptive[] = {
91  230, 230, 230, 230, 307, 409, 512, 614,
92  768, 614, 512, 409, 307, 230, 230, 230
93  };
94  Sint32 new_sample, delta;
95 
96  new_sample = ((state->iSamp1 * coeff[0]) +
97  (state->iSamp2 * coeff[1])) / 256;
98  if (nybble & 0x08) {
99  new_sample += state->iDelta * (nybble - 0x10);
100  } else {
101  new_sample += state->iDelta * nybble;
102  }
103  if (new_sample < min_audioval) {
104  new_sample = min_audioval;
105  } else if (new_sample > max_audioval) {
106  new_sample = max_audioval;
107  }
108  delta = ((Sint32) state->iDelta * adaptive[nybble]) / 256;
109  if (delta < 16) {
110  delta = 16;
111  }
112  state->iDelta = (Uint16) delta;
113  state->iSamp2 = state->iSamp1;
114  state->iSamp1 = (Sint16) new_sample;
115  return (new_sample);
116 }
int32_t Sint32
A signed 32-bit integer type.
Definition: SDL_stdinc.h:151
uint16_t Uint16
An unsigned 16-bit integer type.
Definition: SDL_stdinc.h:147
int16_t Sint16
A signed 16-bit integer type.
Definition: SDL_stdinc.h:143
static int ReadChunk ( SDL_RWops src,
Chunk chunk 
)
static

Definition at line 608 of file SDL_wave.c.

References Chunk::data, Chunk::length, Chunk::magic, NULL, SDL_EFREAD, SDL_Error, SDL_free(), SDL_malloc, SDL_OutOfMemory, SDL_ReadLE32, and SDL_RWread.

Referenced by SDL_LoadWAV_RW().

609 {
610  chunk->magic = SDL_ReadLE32(src);
611  chunk->length = SDL_ReadLE32(src);
612  chunk->data = (Uint8 *) SDL_malloc(chunk->length);
613  if (chunk->data == NULL) {
614  return SDL_OutOfMemory();
615  }
616  if (SDL_RWread(src, chunk->data, chunk->length, 1) != 1) {
617  SDL_free(chunk->data);
618  chunk->data = NULL;
619  return SDL_Error(SDL_EFREAD);
620  }
621  return (chunk->length);
622 }
#define SDL_ReadLE32
#define SDL_RWread(ctx, ptr, size, n)
Definition: SDL_rwops.h:187
Uint32 length
Definition: SDL_wave.h:63
#define SDL_Error
uint8_t Uint8
An unsigned 8-bit integer type.
Definition: SDL_stdinc.h:139
void SDL_free(void *mem)
Uint8 * data
Definition: SDL_wave.h:64
#define NULL
Definition: begin_code.h:143
#define SDL_OutOfMemory()
Definition: SDL_error.h:52
Uint32 magic
Definition: SDL_wave.h:62
#define SDL_malloc
void SDL_FreeWAV ( Uint8 audio_buf)

This function frees data previously allocated with SDL_LoadWAV_RW()

Definition at line 602 of file SDL_wave.c.

References SDL_free().

603 {
604  SDL_free(audio_buf);
605 }
void SDL_free(void *mem)
SDL_AudioSpec* SDL_LoadWAV_RW ( SDL_RWops src,
int  freesrc,
SDL_AudioSpec spec,
Uint8 **  audio_buf,
Uint32 audio_len 
)

This function loads a WAVE from the data source, automatically freeing that source if freesrc is non-zero. For example, to load a WAVE file, you could do:

1 SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, ...);

If this function succeeds, it returns the given SDL_AudioSpec, filled with the audio data format of the wave data, and sets *audio_buf to a malloc()'d buffer containing the audio data, and sets *audio_len to the length of that audio buffer, in bytes. You need to free the audio buffer with SDL_FreeWAV() when you are done with it.

This function returns NULL and sets the SDL error message if the wave file cannot be opened, uses an unknown data format, or is corrupt. Currently raw and MS-ADPCM WAVE files are supported.

Definition at line 407 of file SDL_wave.c.

References AUDIO_F32, AUDIO_S16, AUDIO_S32, AUDIO_U8, BEXT, WaveFMT::bitspersample, WaveFMT::channels, SDL_AudioSpec::channels, DATA, Chunk::data, done, WaveFMT::encoding, FACT, FMT, SDL_AudioSpec::format, SDL_AudioSpec::freq, WaveFMT::frequency, IEEE_FLOAT_CODE, IMA_ADPCM_CODE, IMA_ADPCM_decode(), InitIMA_ADPCM(), InitMS_ADPCM(), JUNK, Chunk::length, LIST, Chunk::magic, MP3_CODE, MS_ADPCM_CODE, MS_ADPCM_decode(), NULL, PCM_CODE, ReadChunk(), RIFF, RW_SEEK_CUR, SDL_AudioSpec::samples, SDL_AUDIO_BITSIZE, SDL_free(), SDL_memset, SDL_ReadLE32, SDL_RWclose, SDL_RWseek, SDL_SetError, SDL_SwapLE16, SDL_SwapLE32, SDL_zero, and WAVE.

409 {
410  int was_error;
411  Chunk chunk;
412  int lenread;
413  int IEEE_float_encoded, MS_ADPCM_encoded, IMA_ADPCM_encoded;
414  int samplesize;
415 
416  /* WAV magic header */
417  Uint32 RIFFchunk;
418  Uint32 wavelen = 0;
419  Uint32 WAVEmagic;
420  Uint32 headerDiff = 0;
421 
422  /* FMT chunk */
423  WaveFMT *format = NULL;
424 
425  SDL_zero(chunk);
426 
427  /* Make sure we are passed a valid data source */
428  was_error = 0;
429  if (src == NULL) {
430  was_error = 1;
431  goto done;
432  }
433 
434  /* Check the magic header */
435  RIFFchunk = SDL_ReadLE32(src);
436  wavelen = SDL_ReadLE32(src);
437  if (wavelen == WAVE) { /* The RIFFchunk has already been read */
438  WAVEmagic = wavelen;
439  wavelen = RIFFchunk;
440  RIFFchunk = RIFF;
441  } else {
442  WAVEmagic = SDL_ReadLE32(src);
443  }
444  if ((RIFFchunk != RIFF) || (WAVEmagic != WAVE)) {
445  SDL_SetError("Unrecognized file type (not WAVE)");
446  was_error = 1;
447  goto done;
448  }
449  headerDiff += sizeof(Uint32); /* for WAVE */
450 
451  /* Read the audio data format chunk */
452  chunk.data = NULL;
453  do {
454  SDL_free(chunk.data);
455  chunk.data = NULL;
456  lenread = ReadChunk(src, &chunk);
457  if (lenread < 0) {
458  was_error = 1;
459  goto done;
460  }
461  /* 2 Uint32's for chunk header+len, plus the lenread */
462  headerDiff += lenread + 2 * sizeof(Uint32);
463  } while ((chunk.magic == FACT) || (chunk.magic == LIST) || (chunk.magic == BEXT) || (chunk.magic == JUNK));
464 
465  /* Decode the audio data format */
466  format = (WaveFMT *) chunk.data;
467  if (chunk.magic != FMT) {
468  SDL_SetError("Complex WAVE files not supported");
469  was_error = 1;
470  goto done;
471  }
472  IEEE_float_encoded = MS_ADPCM_encoded = IMA_ADPCM_encoded = 0;
473  switch (SDL_SwapLE16(format->encoding)) {
474  case PCM_CODE:
475  /* We can understand this */
476  break;
477  case IEEE_FLOAT_CODE:
478  IEEE_float_encoded = 1;
479  /* We can understand this */
480  break;
481  case MS_ADPCM_CODE:
482  /* Try to understand this */
483  if (InitMS_ADPCM(format) < 0) {
484  was_error = 1;
485  goto done;
486  }
487  MS_ADPCM_encoded = 1;
488  break;
489  case IMA_ADPCM_CODE:
490  /* Try to understand this */
491  if (InitIMA_ADPCM(format) < 0) {
492  was_error = 1;
493  goto done;
494  }
495  IMA_ADPCM_encoded = 1;
496  break;
497  case MP3_CODE:
498  SDL_SetError("MPEG Layer 3 data not supported");
499  was_error = 1;
500  goto done;
501  default:
502  SDL_SetError("Unknown WAVE data format: 0x%.4x",
503  SDL_SwapLE16(format->encoding));
504  was_error = 1;
505  goto done;
506  }
507  SDL_memset(spec, 0, (sizeof *spec));
508  spec->freq = SDL_SwapLE32(format->frequency);
509 
510  if (IEEE_float_encoded) {
511  if ((SDL_SwapLE16(format->bitspersample)) != 32) {
512  was_error = 1;
513  } else {
514  spec->format = AUDIO_F32;
515  }
516  } else {
517  switch (SDL_SwapLE16(format->bitspersample)) {
518  case 4:
519  if (MS_ADPCM_encoded || IMA_ADPCM_encoded) {
520  spec->format = AUDIO_S16;
521  } else {
522  was_error = 1;
523  }
524  break;
525  case 8:
526  spec->format = AUDIO_U8;
527  break;
528  case 16:
529  spec->format = AUDIO_S16;
530  break;
531  case 32:
532  spec->format = AUDIO_S32;
533  break;
534  default:
535  was_error = 1;
536  break;
537  }
538  }
539 
540  if (was_error) {
541  SDL_SetError("Unknown %d-bit PCM data format",
542  SDL_SwapLE16(format->bitspersample));
543  goto done;
544  }
545  spec->channels = (Uint8) SDL_SwapLE16(format->channels);
546  spec->samples = 4096; /* Good default buffer size */
547 
548  /* Read the audio data chunk */
549  *audio_buf = NULL;
550  do {
551  SDL_free(*audio_buf);
552  *audio_buf = NULL;
553  lenread = ReadChunk(src, &chunk);
554  if (lenread < 0) {
555  was_error = 1;
556  goto done;
557  }
558  *audio_len = lenread;
559  *audio_buf = chunk.data;
560  if (chunk.magic != DATA)
561  headerDiff += lenread + 2 * sizeof(Uint32);
562  } while (chunk.magic != DATA);
563  headerDiff += 2 * sizeof(Uint32); /* for the data chunk and len */
564 
565  if (MS_ADPCM_encoded) {
566  if (MS_ADPCM_decode(audio_buf, audio_len) < 0) {
567  was_error = 1;
568  goto done;
569  }
570  }
571  if (IMA_ADPCM_encoded) {
572  if (IMA_ADPCM_decode(audio_buf, audio_len) < 0) {
573  was_error = 1;
574  goto done;
575  }
576  }
577 
578  /* Don't return a buffer that isn't a multiple of samplesize */
579  samplesize = ((SDL_AUDIO_BITSIZE(spec->format)) / 8) * spec->channels;
580  *audio_len &= ~(samplesize - 1);
581 
582  done:
583  SDL_free(format);
584  if (src) {
585  if (freesrc) {
586  SDL_RWclose(src);
587  } else {
588  /* seek to the end of the file (given by the RIFF chunk) */
589  SDL_RWseek(src, wavelen - chunk.length - headerDiff, RW_SEEK_CUR);
590  }
591  }
592  if (was_error) {
593  spec = NULL;
594  }
595  return (spec);
596 }
static int InitIMA_ADPCM(WaveFMT *format)
Definition: SDL_wave.c:232
#define PCM_CODE
Definition: SDL_wave.h:36
#define RIFF
Definition: SDL_wave.h:28
#define LIST
Definition: SDL_wave.h:31
uint32_t Uint32
An unsigned 32-bit integer type.
Definition: SDL_stdinc.h:155
#define MP3_CODE
Definition: SDL_wave.h:40
Definition: SDL_wave.h:60
#define SDL_ReadLE32
Uint32 length
Definition: SDL_wave.h:63
Uint16 samples
Definition: SDL_audio.h:174
Uint16 encoding
Definition: SDL_wave.h:51
static int MS_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
Definition: SDL_wave.c:119
Uint16 channels
Definition: SDL_wave.h:52
#define FMT
Definition: SDL_wave.h:34
#define SDL_RWseek(ctx, offset, whence)
Definition: SDL_rwops.h:185
#define AUDIO_U8
Definition: SDL_audio.h:89
#define DATA
Definition: SDL_wave.h:35
#define FACT
Definition: SDL_wave.h:30
Uint8 channels
Definition: SDL_audio.h:172
static int IMA_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
Definition: SDL_wave.c:338
uint8_t Uint8
An unsigned 8-bit integer type.
Definition: SDL_stdinc.h:139
void SDL_free(void *mem)
#define SDL_AUDIO_BITSIZE(x)
Definition: SDL_audio.h:75
#define SDL_SwapLE32(X)
Definition: SDL_endian.h:212
int done
Definition: checkkeys.c:28
#define AUDIO_S32
Definition: SDL_audio.h:105
#define WAVE
Definition: SDL_wave.h:29
#define JUNK
Definition: SDL_wave.h:33
#define SDL_zero(x)
Definition: SDL_stdinc.h:355
Uint8 * data
Definition: SDL_wave.h:64
#define NULL
Definition: begin_code.h:143
#define IEEE_FLOAT_CODE
Definition: SDL_wave.h:38
#define SDL_RWclose(ctx)
Definition: SDL_rwops.h:189
#define IMA_ADPCM_CODE
Definition: SDL_wave.h:39
#define SDL_SetError
GLint GLint GLsizei GLsizei GLsizei GLint GLenum format
Definition: SDL_opengl.h:1565
SDL_AudioFormat format
Definition: SDL_audio.h:171
static int InitMS_ADPCM(WaveFMT *format)
Definition: SDL_wave.c:49
Uint32 magic
Definition: SDL_wave.h:62
#define AUDIO_S16
Definition: SDL_audio.h:96
Uint32 frequency
Definition: SDL_wave.h:53
#define RW_SEEK_CUR
Definition: SDL_rwops.h:175
Uint16 bitspersample
Definition: SDL_wave.h:56
#define AUDIO_F32
Definition: SDL_audio.h:114
#define SDL_SwapLE16(X)
Definition: SDL_endian.h:211
#define BEXT
Definition: SDL_wave.h:32
#define SDL_memset
static int ReadChunk(SDL_RWops *src, Chunk *chunk)
Definition: SDL_wave.c:608
#define MS_ADPCM_CODE
Definition: SDL_wave.h:37

Variable Documentation

struct IMA_ADPCM_decoder IMA_ADPCM_state
static

Referenced by IMA_ADPCM_decode(), and InitIMA_ADPCM().

struct MS_ADPCM_decoder MS_ADPCM_state
static

Referenced by InitMS_ADPCM(), and MS_ADPCM_decode().