stream_decoder.c 48.7 KB
Newer Older
1
/* libFLAC - Free Lossless Audio Codec library
Josh Coalson's avatar
Josh Coalson committed
2
 * Copyright (C) 2000,2001  Josh Coalson
Josh Coalson's avatar
Josh Coalson committed
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA  02111-1307, USA.
 */

#include <assert.h>
#include <stdio.h>
#include <stdlib.h> /* for malloc() */
Josh Coalson's avatar
Josh Coalson committed
23
#include <string.h> /* for memset/memcpy() */
Josh Coalson's avatar
Josh Coalson committed
24
25
26
27
28
29
30
31
#include "FLAC/stream_decoder.h"
#include "private/bitbuffer.h"
#include "private/crc.h"
#include "private/fixed.h"
#include "private/lpc.h"

typedef struct FLAC__StreamDecoderPrivate {
	FLAC__StreamDecoderReadStatus (*read_callback)(const FLAC__StreamDecoder *decoder, byte buffer[], unsigned *bytes, void *client_data);
32
	FLAC__StreamDecoderWriteStatus (*write_callback)(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const int32 *buffer[], void *client_data);
Josh Coalson's avatar
Josh Coalson committed
33
34
35
36
37
	void (*metadata_callback)(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetaData *metadata, void *client_data);
	void (*error_callback)(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
	void *client_data;
	FLAC__BitBuffer input;
	int32 *output[FLAC__MAX_CHANNELS];
38
	int32 *residual[FLAC__MAX_CHANNELS];
39
	unsigned output_capacity, output_channels;
Josh Coalson's avatar
Josh Coalson committed
40
41
	uint32 last_frame_number;
	uint64 samples_decoded;
42
43
44
	bool has_stream_info, has_seek_table;
	FLAC__StreamMetaData stream_info;
	FLAC__StreamMetaData seek_table;
45
	FLAC__Frame frame;
46
47
48
	byte header_warmup[2]; /* contains the sync code and reserved bits */
	byte lookahead; /* temp storage when we need to look ahead one byte in the stream */
	bool cached; /* true if there is a byte in lookahead */
Josh Coalson's avatar
Josh Coalson committed
49
50
51
52
} FLAC__StreamDecoderPrivate;

static byte ID3V2_TAG_[3] = { 'I', 'D', '3' };

53
static bool stream_decoder_allocate_output_(FLAC__StreamDecoder *decoder, unsigned size, unsigned channels);
Josh Coalson's avatar
Josh Coalson committed
54
55
56
57
58
59
static bool stream_decoder_find_metadata_(FLAC__StreamDecoder *decoder);
static bool stream_decoder_read_metadata_(FLAC__StreamDecoder *decoder);
static bool stream_decoder_skip_id3v2_tag_(FLAC__StreamDecoder *decoder);
static bool stream_decoder_frame_sync_(FLAC__StreamDecoder *decoder);
static bool stream_decoder_read_frame_(FLAC__StreamDecoder *decoder, bool *got_a_frame);
static bool stream_decoder_read_frame_header_(FLAC__StreamDecoder *decoder);
60
61
62
63
64
static bool stream_decoder_read_subframe_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps);
static bool stream_decoder_read_subframe_constant_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps);
static bool stream_decoder_read_subframe_fixed_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps, const unsigned order);
static bool stream_decoder_read_subframe_lpc_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps, const unsigned order);
static bool stream_decoder_read_subframe_verbatim_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps);
65
static bool stream_decoder_read_residual_partitioned_rice_(FLAC__StreamDecoder *decoder, unsigned predictor_order, unsigned partition_order, int32 *residual);
Josh Coalson's avatar
Josh Coalson committed
66
67
68
static bool stream_decoder_read_zero_padding_(FLAC__StreamDecoder *decoder);
static bool read_callback_(byte buffer[], unsigned *bytes, void *client_data);

Josh Coalson's avatar
Josh Coalson committed
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
const char *FLAC__StreamDecoderStateString[] = {
	"FLAC__STREAM_DECODER_SEARCH_FOR_METADATA",
	"FLAC__STREAM_DECODER_READ_METADATA",
	"FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC",
	"FLAC__STREAM_DECODER_READ_FRAME",
	"FLAC__STREAM_DECODER_END_OF_STREAM",
	"FLAC__STREAM_DECODER_ABORTED",
	"FLAC__STREAM_DECODER_UNPARSEABLE_STREAM",
	"FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR",
	"FLAC__STREAM_DECODER_UNINITIALIZED"
};

const char *FLAC__StreamDecoderReadStatusString[] = {
	"FLAC__STREAM_DECODER_READ_CONTINUE",
	"FLAC__STREAM_DECODER_READ_END_OF_STREAM",
	"FLAC__STREAM_DECODER_READ_ABORT"
};

const char *FLAC__StreamDecoderWriteStatusString[] = {
	"FLAC__STREAM_DECODER_WRITE_CONTINUE",
	"FLAC__STREAM_DECODER_WRITE_ABORT"
};

const char *FLAC__StreamDecoderErrorStatusString[] = {
93
94
95
	"FLAC__STREAM_DECODER_ERROR_LOST_SYNC",
	"FLAC__STREAM_DECODER_ERROR_BAD_HEADER",
	"FLAC__STREAM_DECODER_ERROR_FRAME_CRC_MISMATCH"
Josh Coalson's avatar
Josh Coalson committed
96
97
};

Josh Coalson's avatar
Josh Coalson committed
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
FLAC__StreamDecoder *FLAC__stream_decoder_get_new_instance()
{
	FLAC__StreamDecoder *decoder = (FLAC__StreamDecoder*)malloc(sizeof(FLAC__StreamDecoder));
	if(decoder != 0) {
		decoder->state = FLAC__STREAM_DECODER_UNINITIALIZED;
		decoder->guts = 0;
	}
	return decoder;
}

void FLAC__stream_decoder_free_instance(FLAC__StreamDecoder *decoder)
{
	free(decoder);
}

FLAC__StreamDecoderState FLAC__stream_decoder_init(
	FLAC__StreamDecoder *decoder,
	FLAC__StreamDecoderReadStatus (*read_callback)(const FLAC__StreamDecoder *decoder, byte buffer[], unsigned *bytes, void *client_data),
116
	FLAC__StreamDecoderWriteStatus (*write_callback)(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const int32 *buffer[], void *client_data),
Josh Coalson's avatar
Josh Coalson committed
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
	void (*metadata_callback)(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetaData *metadata, void *client_data),
	void (*error_callback)(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data),
	void *client_data
)
{
	unsigned i;

	assert(sizeof(int) >= 4); /* we want to die right away if this is not true */
	assert(decoder != 0);
	assert(read_callback != 0);
	assert(write_callback != 0);
	assert(metadata_callback != 0);
	assert(error_callback != 0);
	assert(decoder->state == FLAC__STREAM_DECODER_UNINITIALIZED);
	assert(decoder->guts == 0);

	decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_METADATA;

	decoder->guts = (FLAC__StreamDecoderPrivate*)malloc(sizeof(FLAC__StreamDecoderPrivate));
	if(decoder->guts == 0)
		return decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;

	decoder->guts->read_callback = read_callback;
	decoder->guts->write_callback = write_callback;
	decoder->guts->metadata_callback = metadata_callback;
	decoder->guts->error_callback = error_callback;
	decoder->guts->client_data = client_data;

	FLAC__bitbuffer_init(&decoder->guts->input);

147
	for(i = 0; i < FLAC__MAX_CHANNELS; i++) {
Josh Coalson's avatar
Josh Coalson committed
148
		decoder->guts->output[i] = 0;
149
150
		decoder->guts->residual[i] = 0;
	}
Josh Coalson's avatar
Josh Coalson committed
151
152

	decoder->guts->output_capacity = 0;
153
	decoder->guts->output_channels = 0;
Josh Coalson's avatar
Josh Coalson committed
154
155
	decoder->guts->last_frame_number = 0;
	decoder->guts->samples_decoded = 0;
156
157
	decoder->guts->has_stream_info = false;
	decoder->guts->has_seek_table = false;
158
	decoder->guts->cached = false;
Josh Coalson's avatar
Josh Coalson committed
159
160
161
162
163
164
165
166
167
168
169

	return decoder->state;
}

void FLAC__stream_decoder_finish(FLAC__StreamDecoder *decoder)
{
	unsigned i;
	assert(decoder != 0);
	if(decoder->state == FLAC__STREAM_DECODER_UNINITIALIZED)
		return;
	if(decoder->guts != 0) {
170
171
172
173
		if(decoder->guts->has_seek_table) {
			free(decoder->guts->seek_table.data.seek_table.points);
			decoder->guts->seek_table.data.seek_table.points = 0;
		}
Josh Coalson's avatar
Josh Coalson committed
174
175
176
177
178
179
		FLAC__bitbuffer_free(&decoder->guts->input);
		for(i = 0; i < FLAC__MAX_CHANNELS; i++) {
			if(decoder->guts->output[i] != 0) {
				free(decoder->guts->output[i]);
				decoder->guts->output[i] = 0;
			}
180
181
182
183
			if(decoder->guts->residual[i] != 0) {
				free(decoder->guts->residual[i]);
				decoder->guts->residual[i] = 0;
			}
Josh Coalson's avatar
Josh Coalson committed
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
		}
		free(decoder->guts);
		decoder->guts = 0;
	}
	decoder->state = FLAC__STREAM_DECODER_UNINITIALIZED;
}

bool FLAC__stream_decoder_flush(FLAC__StreamDecoder *decoder)
{
	assert(decoder != 0);

	if(!FLAC__bitbuffer_clear(&decoder->guts->input)) {
		decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
		return false;
	}

	return true;
}

bool FLAC__stream_decoder_reset(FLAC__StreamDecoder *decoder)
{
	assert(decoder != 0);

	if(!FLAC__stream_decoder_flush(decoder)) {
		decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
		return false;
	}
	decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_METADATA;

	return true;
}

bool FLAC__stream_decoder_process_whole_stream(FLAC__StreamDecoder *decoder)
{
	bool dummy;
	assert(decoder != 0);

	if(decoder->state == FLAC__STREAM_DECODER_END_OF_STREAM)
		return true;

	assert(decoder->state == FLAC__STREAM_DECODER_SEARCH_FOR_METADATA);

	if(!FLAC__stream_decoder_reset(decoder)) {
		decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
		return false;
	}

	while(1) {
		switch(decoder->state) {
			case FLAC__STREAM_DECODER_SEARCH_FOR_METADATA:
				if(!stream_decoder_find_metadata_(decoder))
					return false; /* above function sets the status for us */
				break;
			case FLAC__STREAM_DECODER_READ_METADATA:
				if(!stream_decoder_read_metadata_(decoder))
					return false; /* above function sets the status for us */
				break;
			case FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC:
				if(!stream_decoder_frame_sync_(decoder))
					return true; /* above function sets the status for us */
				break;
			case FLAC__STREAM_DECODER_READ_FRAME:
				if(!stream_decoder_read_frame_(decoder, &dummy))
					return false; /* above function sets the status for us */
				break;
			case FLAC__STREAM_DECODER_END_OF_STREAM:
				return true;
			default:
				assert(0);
		}
	}
}

bool FLAC__stream_decoder_process_metadata(FLAC__StreamDecoder *decoder)
{
	assert(decoder != 0);

	if(decoder->state == FLAC__STREAM_DECODER_END_OF_STREAM)
		return true;

	assert(decoder->state == FLAC__STREAM_DECODER_SEARCH_FOR_METADATA);

	if(!FLAC__stream_decoder_reset(decoder)) {
		decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
		return false;
	}

	while(1) {
		switch(decoder->state) {
			case FLAC__STREAM_DECODER_SEARCH_FOR_METADATA:
				if(!stream_decoder_find_metadata_(decoder))
					return false; /* above function sets the status for us */
				break;
			case FLAC__STREAM_DECODER_READ_METADATA:
				if(!stream_decoder_read_metadata_(decoder))
					return false; /* above function sets the status for us */
				break;
			case FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC:
				return true;
				break;
			case FLAC__STREAM_DECODER_END_OF_STREAM:
				return true;
			default:
				assert(0);
		}
	}
}

bool FLAC__stream_decoder_process_one_frame(FLAC__StreamDecoder *decoder)
{
	bool got_a_frame;
	assert(decoder != 0);

	if(decoder->state == FLAC__STREAM_DECODER_END_OF_STREAM)
		return true;

	assert(decoder->state == FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC);

	while(1) {
		switch(decoder->state) {
			case FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC:
				if(!stream_decoder_frame_sync_(decoder))
					return true; /* above function sets the status for us */
				break;
			case FLAC__STREAM_DECODER_READ_FRAME:
				if(!stream_decoder_read_frame_(decoder, &got_a_frame))
					return false; /* above function sets the status for us */
				if(got_a_frame)
					return true; /* above function sets the status for us */
				break;
			case FLAC__STREAM_DECODER_END_OF_STREAM:
				return true;
			default:
				assert(0);
		}
	}
}

bool FLAC__stream_decoder_process_remaining_frames(FLAC__StreamDecoder *decoder)
{
	bool dummy;
	assert(decoder != 0);

	if(decoder->state == FLAC__STREAM_DECODER_END_OF_STREAM)
		return true;

	assert(decoder->state == FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC);

	while(1) {
		switch(decoder->state) {
			case FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC:
				if(!stream_decoder_frame_sync_(decoder))
					return true; /* above function sets the status for us */
				break;
			case FLAC__STREAM_DECODER_READ_FRAME:
				if(!stream_decoder_read_frame_(decoder, &dummy))
					return false; /* above function sets the status for us */
				break;
			case FLAC__STREAM_DECODER_END_OF_STREAM:
				return true;
			default:
				assert(0);
		}
	}
}

unsigned FLAC__stream_decoder_input_bytes_unconsumed(FLAC__StreamDecoder *decoder)
{
	assert(decoder != 0);
	return decoder->guts->input.bytes - decoder->guts->input.consumed_bytes;
}

356
bool stream_decoder_allocate_output_(FLAC__StreamDecoder *decoder, unsigned size, unsigned channels)
Josh Coalson's avatar
Josh Coalson committed
357
358
359
360
{
	unsigned i;
	int32 *tmp;

361
	if(size <= decoder->guts->output_capacity && channels <= decoder->guts->output_channels)
Josh Coalson's avatar
Josh Coalson committed
362
363
		return true;

364
365
	/* @@@ should change to use realloc() */

Josh Coalson's avatar
Josh Coalson committed
366
367
368
369
370
	for(i = 0; i < FLAC__MAX_CHANNELS; i++) {
		if(decoder->guts->output[i] != 0) {
			free(decoder->guts->output[i]);
			decoder->guts->output[i] = 0;
		}
371
372
373
374
		if(decoder->guts->residual[i] != 0) {
			free(decoder->guts->residual[i]);
			decoder->guts->residual[i] = 0;
		}
Josh Coalson's avatar
Josh Coalson committed
375
376
	}

377
	for(i = 0; i < channels; i++) {
Josh Coalson's avatar
Josh Coalson committed
378
379
380
381
382
383
		tmp = (int32*)malloc(sizeof(int32)*size);
		if(tmp == 0) {
			decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
			return false;
		}
		decoder->guts->output[i] = tmp;
384
385
386
387
388
389
390

		tmp = (int32*)malloc(sizeof(int32)*size);
		if(tmp == 0) {
			decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
			return false;
		}
		decoder->guts->residual[i] = tmp;
Josh Coalson's avatar
Josh Coalson committed
391
392
393
	}

	decoder->guts->output_capacity = size;
394
	decoder->guts->output_channels = channels;
Josh Coalson's avatar
Josh Coalson committed
395
396
397
398
399
400
401
402

	return true;
}

bool stream_decoder_find_metadata_(FLAC__StreamDecoder *decoder)
{
	uint32 x;
	unsigned i, id;
403
	bool first = true;
Josh Coalson's avatar
Josh Coalson committed
404
405
406
407

	assert(decoder->guts->input.consumed_bits == 0); /* make sure we're byte aligned */

	for(i = id = 0; i < 4; ) {
408
409
410
411
412
413
414
415
		if(decoder->guts->cached) {
			x = (uint32)decoder->guts->lookahead;
			decoder->guts->cached = false;
		}
		else {
			if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
				return false; /* the read_callback_ sets the state for us */
		}
Josh Coalson's avatar
Josh Coalson committed
416
		if(x == FLAC__STREAM_SYNC_STRING[i]) {
417
			first = true;
Josh Coalson's avatar
Josh Coalson committed
418
419
420
421
422
423
424
425
426
427
428
429
430
431
			i++;
			id = 0;
			continue;
		}
		if(x == ID3V2_TAG_[id]) {
			id++;
			i = 0;
			if(id == 3) {
				if(!stream_decoder_skip_id3v2_tag_(decoder))
					return false; /* the read_callback_ sets the state for us */
			}
			continue;
		}
		if(x == 0xff) { /* MAGIC NUMBER for the first 8 frame sync bits */
432
433
			decoder->guts->header_warmup[0] = (byte)x;
			if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
434
				return false; /* the read_callback_ sets the state for us */
435
436
437
438
439
440
441
442
443

			/* we have to check if we just read two 0xff's in a row; the second may actually be the beginning of the sync code */
			/* else we have to check if the second byte is the end of a sync code */
			if(x == 0xff) { /* MAGIC NUMBER for the first 8 frame sync bits */
				decoder->guts->lookahead = (byte)x;
				decoder->guts->cached = true;
			}
			else if(x >> 2 == 0x3e) { /* MAGIC NUMBER for the last 6 sync bits */
				decoder->guts->header_warmup[1] = (byte)x;
Josh Coalson's avatar
Josh Coalson committed
444
445
446
447
448
449
450
				decoder->state = FLAC__STREAM_DECODER_READ_FRAME;
				return true;
			}
		}
		i = 0;
		if(first) {
			decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
451
			first = false;
Josh Coalson's avatar
Josh Coalson committed
452
453
454
455
456
457
458
459
460
461
		}
	}

	decoder->state = FLAC__STREAM_DECODER_READ_METADATA;
	return true;
}

bool stream_decoder_read_metadata_(FLAC__StreamDecoder *decoder)
{
	uint32 i, x, last_block, type, length;
462
	uint64 xx;
Josh Coalson's avatar
Josh Coalson committed
463
464
465
466
467
468
469
470
471

	assert(decoder->guts->input.consumed_bits == 0); /* make sure we're byte aligned */

	if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &last_block, FLAC__STREAM_METADATA_IS_LAST_LEN, read_callback_, decoder))
		return false; /* the read_callback_ sets the state for us */
	if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &type, FLAC__STREAM_METADATA_TYPE_LEN, read_callback_, decoder))
		return false; /* the read_callback_ sets the state for us */
	if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &length, FLAC__STREAM_METADATA_LENGTH_LEN, read_callback_, decoder))
		return false; /* the read_callback_ sets the state for us */
Josh Coalson's avatar
Josh Coalson committed
472
	if(type == FLAC__METADATA_TYPE_STREAMINFO) {
473
		unsigned used_bits = 0;
474
475
476
		decoder->guts->stream_info.type = type;
		decoder->guts->stream_info.is_last = last_block;
		decoder->guts->stream_info.length = length;
477

Josh Coalson's avatar
Josh Coalson committed
478
		if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
479
			return false; /* the read_callback_ sets the state for us */
480
		decoder->guts->stream_info.data.stream_info.min_blocksize = x;
Josh Coalson's avatar
Josh Coalson committed
481
		used_bits += FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN;
482

Josh Coalson's avatar
Josh Coalson committed
483
		if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
484
			return false; /* the read_callback_ sets the state for us */
485
		decoder->guts->stream_info.data.stream_info.max_blocksize = x;
Josh Coalson's avatar
Josh Coalson committed
486
		used_bits += FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN;
487

Josh Coalson's avatar
Josh Coalson committed
488
		if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
489
			return false; /* the read_callback_ sets the state for us */
490
		decoder->guts->stream_info.data.stream_info.min_framesize = x;
Josh Coalson's avatar
Josh Coalson committed
491
		used_bits += FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN;
492

Josh Coalson's avatar
Josh Coalson committed
493
		if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
494
			return false; /* the read_callback_ sets the state for us */
495
		decoder->guts->stream_info.data.stream_info.max_framesize = x;
Josh Coalson's avatar
Josh Coalson committed
496
		used_bits += FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN;
497

Josh Coalson's avatar
Josh Coalson committed
498
		if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
499
			return false; /* the read_callback_ sets the state for us */
500
		decoder->guts->stream_info.data.stream_info.sample_rate = x;
Josh Coalson's avatar
Josh Coalson committed
501
		used_bits += FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN;
502

Josh Coalson's avatar
Josh Coalson committed
503
		if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
504
			return false; /* the read_callback_ sets the state for us */
505
		decoder->guts->stream_info.data.stream_info.channels = x+1;
Josh Coalson's avatar
Josh Coalson committed
506
		used_bits += FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN;
507

Josh Coalson's avatar
Josh Coalson committed
508
		if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
509
			return false; /* the read_callback_ sets the state for us */
510
		decoder->guts->stream_info.data.stream_info.bits_per_sample = x+1;
Josh Coalson's avatar
Josh Coalson committed
511
		used_bits += FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN;
512

513
		if(!FLAC__bitbuffer_read_raw_uint64(&decoder->guts->input, &decoder->guts->stream_info.data.stream_info.total_samples, FLAC__STREAM_METADATA_STREAMINFO_TOTAL_SAMPLES_LEN, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
514
			return false; /* the read_callback_ sets the state for us */
Josh Coalson's avatar
Josh Coalson committed
515
		used_bits += FLAC__STREAM_METADATA_STREAMINFO_TOTAL_SAMPLES_LEN;
516

Josh Coalson's avatar
Josh Coalson committed
517
518
519
		for(i = 0; i < 16; i++) {
			if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
				return false; /* the read_callback_ sets the state for us */
520
			decoder->guts->stream_info.data.stream_info.md5sum[i] = (byte)x;
Josh Coalson's avatar
Josh Coalson committed
521
		}
522
		used_bits += i*8;
Josh Coalson's avatar
Josh Coalson committed
523

524
525
526
527
528
529
530
531
		/* skip the rest of the block */
		assert(used_bits % 8 == 0);
		length -= (used_bits / 8);
		for(i = 0; i < length; i++) {
			if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
				return false; /* the read_callback_ sets the state for us */
		}

532
533
534
535
		decoder->guts->has_stream_info = true;
		decoder->guts->metadata_callback(decoder, &decoder->guts->stream_info, decoder->guts->client_data);
	}
	else if(type == FLAC__METADATA_TYPE_SEEKTABLE) {
Josh Coalson's avatar
Josh Coalson committed
536
537
		unsigned real_points;

538
539
540
541
542
543
544
545
546
547
		decoder->guts->seek_table.type = type;
		decoder->guts->seek_table.is_last = last_block;
		decoder->guts->seek_table.length = length;

		decoder->guts->seek_table.data.seek_table.num_points = length / FLAC__STREAM_METADATA_SEEKPOINT_LEN;

		if(0 == (decoder->guts->seek_table.data.seek_table.points = (FLAC__StreamMetaData_SeekPoint*)malloc(decoder->guts->seek_table.data.seek_table.num_points * sizeof(FLAC__StreamMetaData_SeekPoint)))) {
			decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
			return false;
		}
Josh Coalson's avatar
Josh Coalson committed
548
		for(i = real_points = 0; i < decoder->guts->seek_table.data.seek_table.num_points; i++) {
549
550
			if(!FLAC__bitbuffer_read_raw_uint64(&decoder->guts->input, &xx, FLAC__STREAM_METADATA_SEEKPOINT_SAMPLE_NUMBER_LEN, read_callback_, decoder))
				return false; /* the read_callback_ sets the state for us */
Josh Coalson's avatar
Josh Coalson committed
551
			decoder->guts->seek_table.data.seek_table.points[real_points].sample_number = xx;
552
553
554

			if(!FLAC__bitbuffer_read_raw_uint64(&decoder->guts->input, &xx, FLAC__STREAM_METADATA_SEEKPOINT_STREAM_OFFSET_LEN, read_callback_, decoder))
				return false; /* the read_callback_ sets the state for us */
Josh Coalson's avatar
Josh Coalson committed
555
			decoder->guts->seek_table.data.seek_table.points[real_points].stream_offset = xx;
556

Josh Coalson's avatar
Josh Coalson committed
557
			if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_SEEKPOINT_FRAME_SAMPLES_LEN, read_callback_, decoder))
558
				return false; /* the read_callback_ sets the state for us */
Josh Coalson's avatar
Josh Coalson committed
559
560
561
562
			decoder->guts->seek_table.data.seek_table.points[real_points].frame_samples = x;

			if(decoder->guts->seek_table.data.seek_table.points[real_points].sample_number != FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER)
				real_points++;
563
		}
Josh Coalson's avatar
Josh Coalson committed
564
		decoder->guts->seek_table.data.seek_table.num_points = real_points;
565
566
567

		decoder->guts->has_seek_table = true;
		decoder->guts->metadata_callback(decoder, &decoder->guts->seek_table, decoder->guts->client_data);
Josh Coalson's avatar
Josh Coalson committed
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
	}
	else {
		/* skip other metadata blocks */
		for(i = 0; i < length; i++) {
			if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
				return false; /* the read_callback_ sets the state for us */
		}
	}

	if(last_block)
		decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;

	return true;
}

bool stream_decoder_skip_id3v2_tag_(FLAC__StreamDecoder *decoder)
{
	uint32 x;
	unsigned i, skip;

	/* skip the version and flags bytes */
	if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 24, read_callback_, decoder))
		return false; /* the read_callback_ sets the state for us */
	/* get the size (in bytes) to skip */
	skip = 0;
	for(i = 0; i < 4; i++) {
		if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
			return false; /* the read_callback_ sets the state for us */
		skip <<= 7;
		skip |= (x & 0x7f);
	}
	/* skip the rest of the tag */
	for(i = 0; i < skip; i++) {
		if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
			return false; /* the read_callback_ sets the state for us */
	}
	return true;
}

bool stream_decoder_frame_sync_(FLAC__StreamDecoder *decoder)
{
	uint32 x;
610
	bool first = true;
Josh Coalson's avatar
Josh Coalson committed
611
612
613

	/* If we know the total number of samples in the stream, stop if we've read that many. */
	/* This will stop us, for example, from wasting time trying to sync on an ID3V1 tag. */
614
615
	if(decoder->guts->has_stream_info && decoder->guts->stream_info.data.stream_info.total_samples) {
		if(decoder->guts->samples_decoded >= decoder->guts->stream_info.data.stream_info.total_samples) {
Josh Coalson's avatar
Josh Coalson committed
616
617
618
619
620
621
622
623
624
625
626
627
			decoder->state = FLAC__STREAM_DECODER_END_OF_STREAM;
			return true;
		}
	}

	/* make sure we're byte aligned */
	if(decoder->guts->input.consumed_bits != 0) {
		if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8-decoder->guts->input.consumed_bits, read_callback_, decoder))
			return false; /* the read_callback_ sets the state for us */
	}

	while(1) {
628
629
630
631
632
633
634
635
		if(decoder->guts->cached) {
			x = (uint32)decoder->guts->lookahead;
			decoder->guts->cached = false;
		}
		else {
			if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
				return false; /* the read_callback_ sets the state for us */
		}
Josh Coalson's avatar
Josh Coalson committed
636
		if(x == 0xff) { /* MAGIC NUMBER for the first 8 frame sync bits */
637
638
			decoder->guts->header_warmup[0] = (byte)x;
			if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
639
				return false; /* the read_callback_ sets the state for us */
640
641
642
643
644
645
646
647
648

			/* we have to check if we just read two 0xff's in a row; the second may actually be the beginning of the sync code */
			/* else we have to check if the second byte is the end of a sync code */
			if(x == 0xff) { /* MAGIC NUMBER for the first 8 frame sync bits */
				decoder->guts->lookahead = (byte)x;
				decoder->guts->cached = true;
			}
			else if(x >> 2 == 0x3e) { /* MAGIC NUMBER for the last 6 sync bits */
				decoder->guts->header_warmup[1] = (byte)x;
Josh Coalson's avatar
Josh Coalson committed
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
				decoder->state = FLAC__STREAM_DECODER_READ_FRAME;
				return true;
			}
		}
		if(first) {
			decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
			first = 0;
		}
	}

	return true;
}

bool stream_decoder_read_frame_(FLAC__StreamDecoder *decoder, bool *got_a_frame)
{
	unsigned channel;
	unsigned i;
	int32 mid, side, left, right;
667
668
	uint16 frame_crc; /* the one we calculate from the input stream */
	uint32 x;
Josh Coalson's avatar
Josh Coalson committed
669
670
671

	*got_a_frame = false;

672
673
674
675
676
677
	/* init the CRC */
	frame_crc = 0;
	FLAC__CRC16_UPDATE(decoder->guts->header_warmup[0], frame_crc);
	FLAC__CRC16_UPDATE(decoder->guts->header_warmup[1], frame_crc);
	FLAC__bitbuffer_init_read_crc16(&decoder->guts->input, frame_crc);

Josh Coalson's avatar
Josh Coalson committed
678
679
	if(!stream_decoder_read_frame_header_(decoder))
		return false;
680
	if(decoder->state == FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC)
Josh Coalson's avatar
Josh Coalson committed
681
		return true;
682
	if(!stream_decoder_allocate_output_(decoder, decoder->guts->frame.header.blocksize, decoder->guts->frame.header.channels))
Josh Coalson's avatar
Josh Coalson committed
683
		return false;
684
	for(channel = 0; channel < decoder->guts->frame.header.channels; channel++) {
685
686
687
688
689
690
691
692
693
		/*
		 * first figure the correct bits-per-sample of the subframe
		 */
		unsigned bps = decoder->guts->frame.header.bits_per_sample;
		switch(decoder->guts->frame.header.channel_assignment) {
			case FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT:
				/* no adjustment needed */
				break;
			case FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE:
Josh Coalson's avatar
Josh Coalson committed
694
				assert(decoder->guts->frame.header.channels == 2);
695
696
697
698
				if(channel == 1)
					bps++;
				break;
			case FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE:
Josh Coalson's avatar
Josh Coalson committed
699
				assert(decoder->guts->frame.header.channels == 2);
700
701
702
703
				if(channel == 0)
					bps++;
				break;
			case FLAC__CHANNEL_ASSIGNMENT_MID_SIDE:
Josh Coalson's avatar
Josh Coalson committed
704
				assert(decoder->guts->frame.header.channels == 2);
705
706
707
708
709
710
711
712
713
714
				if(channel == 1)
					bps++;
				break;
			default:
				assert(0);
		}
		/*
		 * now read it
		 */
		if(!stream_decoder_read_subframe_(decoder, channel, bps))
Josh Coalson's avatar
Josh Coalson committed
715
716
717
718
719
720
721
722
723
			return false;
		if(decoder->state != FLAC__STREAM_DECODER_READ_FRAME) {
			decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
			return true;
		}
	}
	if(!stream_decoder_read_zero_padding_(decoder))
		return false;

724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
	/*
	 * Read the frame CRC-16 from the footer and check
	 */
	frame_crc = decoder->guts->input.read_crc16;
	if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__FRAME_FOOTER_CRC_LEN, read_callback_, decoder))
		return false; /* the read_callback_ sets the state for us */
	if(frame_crc == (uint16)x) {
		/* Undo any special channel coding */
		switch(decoder->guts->frame.header.channel_assignment) {
			case FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT:
				/* do nothing */
				break;
			case FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE:
				assert(decoder->guts->frame.header.channels == 2);
				for(i = 0; i < decoder->guts->frame.header.blocksize; i++)
					decoder->guts->output[1][i] = decoder->guts->output[0][i] - decoder->guts->output[1][i];
				break;
			case FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE:
				assert(decoder->guts->frame.header.channels == 2);
				for(i = 0; i < decoder->guts->frame.header.blocksize; i++)
					decoder->guts->output[0][i] += decoder->guts->output[1][i];
				break;
			case FLAC__CHANNEL_ASSIGNMENT_MID_SIDE:
				assert(decoder->guts->frame.header.channels == 2);
				for(i = 0; i < decoder->guts->frame.header.blocksize; i++) {
					mid = decoder->guts->output[0][i];
					side = decoder->guts->output[1][i];
					mid <<= 1;
					if(side & 1) /* i.e. if 'side' is odd... */
						mid++;
					left = mid + side;
					right = mid - side;
					decoder->guts->output[0][i] = left >> 1;
					decoder->guts->output[1][i] = right >> 1;
				}
				break;
			default:
				assert(0);
				break;
		}
	}
	else {
		/* Bad frame, emit error and zero the output signal */
		decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_FRAME_CRC_MISMATCH, decoder->guts->client_data);
		for(channel = 0; channel < decoder->guts->frame.header.channels; channel++) {
			memset(decoder->guts->output[channel], 0, sizeof(int32) * decoder->guts->frame.header.blocksize);
		}
Josh Coalson's avatar
Josh Coalson committed
771
772
773
774
775
	}

	*got_a_frame = true;

	/* put the latest values into the public section of the decoder instance */
776
777
778
779
780
	decoder->channels = decoder->guts->frame.header.channels;
	decoder->channel_assignment = decoder->guts->frame.header.channel_assignment;
	decoder->bits_per_sample = decoder->guts->frame.header.bits_per_sample;
	decoder->sample_rate = decoder->guts->frame.header.sample_rate;
	decoder->blocksize = decoder->guts->frame.header.blocksize;
Josh Coalson's avatar
Josh Coalson committed
781

782
	decoder->guts->samples_decoded += decoder->guts->frame.header.blocksize;
Josh Coalson's avatar
Josh Coalson committed
783
784

	/* write it */
785
	/* NOTE: some versions of GCC can't figure out const-ness right and will give you an 'incompatible pointer type' warning on arg 3 here: */
786
	if(decoder->guts->write_callback(decoder, &decoder->guts->frame, decoder->guts->output, decoder->guts->client_data) != FLAC__STREAM_DECODER_WRITE_CONTINUE)
Josh Coalson's avatar
Josh Coalson committed
787
788
789
790
791
792
793
794
795
796
797
		return false;

	decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
	return true;
}

bool stream_decoder_read_frame_header_(FLAC__StreamDecoder *decoder)
{
	uint32 x;
	uint64 xx;
	unsigned i, blocksize_hint = 0, sample_rate_hint = 0;
798
	byte crc8, raw_header[16]; /* MAGIC NUMBER based on the maximum frame header size, including CRC */
Josh Coalson's avatar
Josh Coalson committed
799
800
	unsigned raw_header_len;
	bool is_unparseable = false;
801
802
	const bool is_known_variable_blocksize_stream = (decoder->guts->has_stream_info && decoder->guts->stream_info.data.stream_info.min_blocksize != decoder->guts->stream_info.data.stream_info.max_blocksize);
	const bool is_known_fixed_blocksize_stream = (decoder->guts->has_stream_info && decoder->guts->stream_info.data.stream_info.min_blocksize == decoder->guts->stream_info.data.stream_info.max_blocksize);
Josh Coalson's avatar
Josh Coalson committed
803
804
805

	assert(decoder->guts->input.consumed_bits == 0); /* make sure we're byte aligned */

806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
	/* init the raw header with the saved bits from synchronization */
	raw_header[0] = decoder->guts->header_warmup[0];
	raw_header[1] = decoder->guts->header_warmup[1];
	raw_header_len = 2;

	/*
	 * check to make sure that the reserved bits are 0
	 */
	if(raw_header[1] & 0x03) { /* MAGIC NUMBER */
		is_unparseable = true;
	}

	/*
	 * Note that along the way as we read the header, we look for a sync
	 * code inside.  If we find one it would indicate that our original
	 * sync was bad since there cannot be a sync code in a valid header.
	 */
Josh Coalson's avatar
Josh Coalson committed
823
824
825
826
827
828
829

	/*
	 * read in the raw header as bytes so we can CRC it, and parse it on the way
	 */
	for(i = 0; i < 2; i++) {
		if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
			return false; /* the read_callback_ sets the state for us */
830
		if(x == 0xff) { /* MAGIC NUMBER for the first 8 frame sync bits */
Josh Coalson's avatar
Josh Coalson committed
831
			/* if we get here it means our original sync was erroneous since the sync code cannot appear in the header */
832
833
834
835
836
			decoder->guts->lookahead = (byte)x;
			decoder->guts->cached = true;
			decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_BAD_HEADER, decoder->guts->client_data);
			decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
			return true;
Josh Coalson's avatar
Josh Coalson committed
837
838
839
840
		}
		raw_header[raw_header_len++] = (byte)x;
	}

841
	switch(x = raw_header[2] >> 4) {
Josh Coalson's avatar
Josh Coalson committed
842
		case 0:
843
			if(is_known_fixed_blocksize_stream)
844
				decoder->guts->frame.header.blocksize = decoder->guts->stream_info.data.stream_info.min_blocksize;
Josh Coalson's avatar
Josh Coalson committed
845
846
847
848
			else
				is_unparseable = true;
			break;
		case 1:
849
			decoder->guts->frame.header.blocksize = 192;
Josh Coalson's avatar
Josh Coalson committed
850
851
852
853
854
			break;
		case 2:
		case 3:
		case 4:
		case 5:
855
			decoder->guts->frame.header.blocksize = 576 << (x-2);
Josh Coalson's avatar
Josh Coalson committed
856
857
858
859
860
			break;
		case 6:
		case 7:
			blocksize_hint = x;
			break;
861
862
863
864
865
866
867
868
869
870
		case 8:
		case 9:
		case 10:
		case 11:
		case 12:
		case 13:
		case 14:
		case 15:
			decoder->guts->frame.header.blocksize = 256 << (x-8);
			break;
Josh Coalson's avatar
Josh Coalson committed
871
872
873
874
875
		default:
			assert(0);
			break;
	}

876
	switch(x = raw_header[2] & 0x0f) {
Josh Coalson's avatar
Josh Coalson committed
877
		case 0:
878
879
			if(decoder->guts->has_stream_info)
				decoder->guts->frame.header.sample_rate = decoder->guts->stream_info.data.stream_info.sample_rate;
Josh Coalson's avatar
Josh Coalson committed
880
881
882
883
884
885
886
887
888
			else
				is_unparseable = true;
			break;
		case 1:
		case 2:
		case 3:
			is_unparseable = true;
			break;
		case 4:
889
			decoder->guts->frame.header.sample_rate = 8000;
Josh Coalson's avatar
Josh Coalson committed
890
891
			break;
		case 5:
892
			decoder->guts->frame.header.sample_rate = 16000;
Josh Coalson's avatar
Josh Coalson committed
893
894
			break;
		case 6:
895
			decoder->guts->frame.header.sample_rate = 22050;
Josh Coalson's avatar
Josh Coalson committed
896
897
			break;
		case 7:
898
			decoder->guts->frame.header.sample_rate = 24000;
Josh Coalson's avatar
Josh Coalson committed
899
900
			break;
		case 8:
901
			decoder->guts->frame.header.sample_rate = 32000;
Josh Coalson's avatar
Josh Coalson committed
902
903
			break;
		case 9:
904
			decoder->guts->frame.header.sample_rate = 44100;
Josh Coalson's avatar
Josh Coalson committed
905
906
			break;
		case 10:
907
			decoder->guts->frame.header.sample_rate = 48000;
Josh Coalson's avatar
Josh Coalson committed
908
909
			break;
		case 11:
910
			decoder->guts->frame.header.sample_rate = 96000;
Josh Coalson's avatar
Josh Coalson committed
911
912
913
914
915
916
917
			break;
		case 12:
		case 13:
		case 14:
			sample_rate_hint = x;
			break;
		case 15:
918
			decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_BAD_HEADER, decoder->guts->client_data);
Josh Coalson's avatar
Josh Coalson committed
919
920
921
922
923
924
			decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
			return true;
		default:
			assert(0);
	}

925
	x = (unsigned)(raw_header[3] >> 4);
Josh Coalson's avatar
Josh Coalson committed
926
	if(x & 8) {
927
		decoder->guts->frame.header.channels = 2;
Josh Coalson's avatar
Josh Coalson committed
928
929
		switch(x & 7) {
			case 0:
930
				decoder->guts->frame.header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE;
Josh Coalson's avatar
Josh Coalson committed
931
932
				break;
			case 1:
933
				decoder->guts->frame.header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE;
Josh Coalson's avatar
Josh Coalson committed
934
935
				break;
			case 2:
936
				decoder->guts->frame.header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_MID_SIDE;
Josh Coalson's avatar
Josh Coalson committed
937
938
939
940
941
942
943
				break;
			default:
				is_unparseable = true;
				break;
		}
	}
	else {
944
945
		decoder->guts->frame.header.channels = (unsigned)x + 1;
		decoder->guts->frame.header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT;
Josh Coalson's avatar
Josh Coalson committed
946
947
	}

948
	switch(x = (unsigned)(raw_header[3] & 0x0e) >> 1) {
Josh Coalson's avatar
Josh Coalson committed
949
		case 0:
950
951
			if(decoder->guts->has_stream_info)
				decoder->guts->frame.header.bits_per_sample = decoder->guts->stream_info.data.stream_info.bits_per_sample;
Josh Coalson's avatar
Josh Coalson committed
952
953
954
955
			else
				is_unparseable = true;
			break;
		case 1:
956
			decoder->guts->frame.header.bits_per_sample = 8;
Josh Coalson's avatar
Josh Coalson committed
957
958
			break;
		case 2:
959
			decoder->guts->frame.header.bits_per_sample = 12;
Josh Coalson's avatar
Josh Coalson committed
960
961
			break;
		case 4:
962
			decoder->guts->frame.header.bits_per_sample = 16;
Josh Coalson's avatar
Josh Coalson committed
963
964
			break;
		case 5:
965
			decoder->guts->frame.header.bits_per_sample = 20;
Josh Coalson's avatar
Josh Coalson committed
966
967
			break;
		case 6:
968
			decoder->guts->frame.header.bits_per_sample = 24;
Josh Coalson's avatar
Josh Coalson committed
969
970
971
972
973
974
975
976
977
978
			break;
		case 3:
		case 7:
			is_unparseable = true;
			break;
		default:
			assert(0);
			break;
	}

979
980
	if(raw_header[3] & 0x01) { /* this should be a zero padding bit */
		decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_BAD_HEADER, decoder->guts->client_data);
Josh Coalson's avatar
Josh Coalson committed
981
982
983
984
		decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
		return true;
	}

985
	if(blocksize_hint && is_known_variable_blocksize_stream) {
Josh Coalson's avatar
Josh Coalson committed
986
987
		if(!FLAC__bitbuffer_read_utf8_uint64(&decoder->guts->input, &xx, read_callback_, decoder, raw_header, &raw_header_len))
			return false; /* the read_callback_ sets the state for us */
988
989
990
991
992
993
		if(xx == 0xffffffffffffffff) { /* i.e. non-UTF8 code... */
			decoder->guts->lookahead = raw_header[raw_header_len-1]; /* back up as much as we can */
			decoder->guts->cached = true;
			decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_BAD_HEADER, decoder->guts->client_data);
			decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
			return true;
Josh Coalson's avatar
Josh Coalson committed
994
		}
995
		decoder->guts->frame.header.number.sample_number = xx;
Josh Coalson's avatar
Josh Coalson committed
996
997
998
999
	}
	else {
		if(!FLAC__bitbuffer_read_utf8_uint32(&decoder->guts->input, &x, read_callback_, decoder, raw_header, &raw_header_len))
			return false; /* the read_callback_ sets the state for us */
1000
1001
1002
1003
1004
1005
		if(x == 0xffffffff) { /* i.e. non-UTF8 code... */
			decoder->guts->lookahead = raw_header[raw_header_len-1]; /* back up as much as we can */
			decoder->guts->cached = true;
			decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_BAD_HEADER, decoder->guts->client_data);
			decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
			return true;
Josh Coalson's avatar
Josh Coalson committed
1006
1007
		}
		decoder->guts->last_frame_number = x;
1008
1009
		if(decoder->guts->has_stream_info) {
			decoder->guts->frame.header.number.sample_number = (int64)decoder->guts->stream_info.data.stream_info.min_blocksize * (int64)x;
Josh Coalson's avatar
Josh Coalson committed
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
		}
		else {
			is_unparseable = true;
		}
	}

	if(blocksize_hint) {
		if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
			return false; /* the read_callback_ sets the state for us */
		raw_header[raw_header_len++] = (byte)x;
		if(blocksize_hint == 7) {
			uint32 _x;
			if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &_x, 8, read_callback_, decoder))
				return false; /* the read_callback_ sets the state for us */
			raw_header[raw_header_len++] = (byte)_x;
			x = (x << 8) | _x;
		}
1027
		decoder->guts->frame.header.blocksize = x+1;
Josh Coalson's avatar
Josh Coalson committed
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
	}

	if(sample_rate_hint) {
		if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
			return false; /* the read_callback_ sets the state for us */
		raw_header[raw_header_len++] = (byte)x;
		if(sample_rate_hint != 12) {
			uint32 _x;
			if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &_x, 8, read_callback_, decoder))
				return false; /* the read_callback_ sets the state for us */
			raw_header[raw_header_len++] = (byte)_x;
			x = (x << 8) | _x;
		}
		if(sample_rate_hint == 12)
1042
			decoder->guts->frame.header.sample_rate = x*1000;
Josh Coalson's avatar
Josh Coalson committed
1043
		else if(sample_rate_hint == 13)
1044
			decoder->guts->frame.header.sample_rate = x;
Josh Coalson's avatar
Josh Coalson committed
1045
		else
1046
			decoder->guts->frame.header.sample_rate = x*10;
Josh Coalson's avatar
Josh Coalson committed
1047
1048
	}

1049
	/* read the CRC-8 byte */
Josh Coalson's avatar
Josh Coalson committed
1050
1051
	if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
		return false; /* the read_callback_ sets the state for us */
1052
	crc8 = (byte)x;
Josh Coalson's avatar
Josh Coalson committed
1053

1054
1055
	if(FLAC__crc8(raw_header, raw_header_len) != crc8) {
		decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_BAD_HEADER, decoder->guts->client_data);
Josh Coalson's avatar
Josh Coalson committed
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
		decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
		return true;
	}

	if(is_unparseable) {
		decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
		return false;
	}

	return true;
}

1068
bool stream_decoder_read_subframe_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps)
Josh Coalson's avatar
Josh Coalson committed
1069
1070
{
	uint32 x;
1071
	bool wasted_bits;
Josh Coalson's avatar
Josh Coalson committed
1072

1073
	if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder)) /* MAGIC NUMBER */
Josh Coalson's avatar
Josh Coalson committed
1074
		return false; /* the read_callback_ sets the state for us */
1075
1076
1077
1078
1079
1080
1081
1082
1083

	wasted_bits = (x & 1);
	x &= 0xfe;

	if(wasted_bits) {
		unsigned u;
		if(!FLAC__bitbuffer_read_unary_unsigned(&decoder->guts->input, &u, read_callback_, decoder))
			return false; /* the read_callback_ sets the state for us */
		decoder->guts->frame.subframes[channel].wasted_bits = u+1;
1084
		bps -= decoder->guts->frame.subframes[channel].wasted_bits;
1085
1086
1087
1088
	}
	else
		decoder->guts->frame.subframes[channel].wasted_bits = 0;

1089
1090
1091
	/*
	 * Lots of magic numbers here
	 */
1092
	if(x & 0x80) {
Josh Coalson's avatar
Josh Coalson committed
1093
1094
1095
1096
1097
		decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
		decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
		return true;
	}
	else if(x == 0) {
1098
1099
		if(!stream_decoder_read_subframe_constant_(decoder, channel, bps))
			return false;
Josh Coalson's avatar
Josh Coalson committed
1100
1101
	}
	else if(x == 2) {
1102
1103
		if(!stream_decoder_read_subframe_verbatim_(decoder, channel, bps))
			return false;
Josh Coalson's avatar
Josh Coalson committed
1104
1105
1106
1107
1108
1109
	}
	else if(x < 16) {
		decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
		return false;
	}
	else if(x <= 24) {
1110
1111
		if(!stream_decoder_read_subframe_fixed_(decoder, channel, bps, (x>>1)&7))
			return false;
Josh Coalson's avatar
Josh Coalson committed
1112
1113
1114
1115
1116
1117
	}
	else if(x < 64) {
		decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
		return false;
	}
	else {
1118
1119
		if(!stream_decoder_read_subframe_lpc_(decoder, channel, bps, ((x>>1)&31)+1))
			return false;
Josh Coalson's avatar
Josh Coalson committed
1120
	}
1121
1122

	if(wasted_bits) {
1123
1124
1125
1126
		unsigned i;
		x = decoder->guts->frame.subframes[channel].wasted_bits;
		for(i = 0; i < decoder->guts->frame.header.blocksize; i++)
			decoder->guts->output[channel][i] <<= x;
1127
	}
1128

1129
	return true;
Josh Coalson's avatar
Josh Coalson committed
1130
1131
}

1132
bool stream_decoder_read_subframe_constant_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps)
Josh Coalson's avatar
Josh Coalson committed
1133
{
1134
	FLAC__Subframe_Constant *subframe = &decoder->guts->frame.subframes[channel].data.constant;
Josh Coalson's avatar
Josh Coalson committed
1135
1136
	int32 x;
	unsigned i;
1137
	int32 *output = decoder->guts->output[channel];
Josh Coalson's avatar
Josh Coalson committed
1138

1139
1140
	decoder->guts->frame.subframes[channel].type = FLAC__SUBFRAME_TYPE_CONSTANT;

1141
	if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &x, bps, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
1142
1143
		return false; /* the read_callback_ sets the state for us */

1144
1145
1146
1147
1148
	subframe->value = x;

	/* decode the subframe */
	for(i = 0; i < decoder->guts->frame.header.blocksize; i++)
		output[i] = x;
Josh Coalson's avatar
Josh Coalson committed
1149
1150
1151
1152

	return true;
}

1153
bool stream_decoder_read_subframe_fixed_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps, const unsigned order)
Josh Coalson's avatar
Josh Coalson committed
1154
{
1155
	FLAC__Subframe_Fixed *subframe = &decoder->guts->frame.subframes[channel].data.fixed;
Josh Coalson's avatar
Josh Coalson committed
1156
1157
1158
1159
	int32 i32;
	uint32 u32;
	unsigned u;

1160
1161
1162
1163
	decoder->guts->frame.subframes[channel].type = FLAC__SUBFRAME_TYPE_FIXED;

	subframe->residual = decoder->guts->residual[channel];
	subframe->order = order;
Josh Coalson's avatar
Josh Coalson committed
1164
1165
1166

	/* read warm-up samples */
	for(u = 0; u < order; u++) {
1167
		if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, bps, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
1168
			return false; /* the read_callback_ sets the state for us */
1169
		subframe->warmup[u] = i32;
Josh Coalson's avatar
Josh Coalson committed
1170
1171
1172
1173
1174
	}

	/* read entropy coding method info */
	if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_TYPE_LEN, read_callback_, decoder))
		return false; /* the read_callback_ sets the state for us */
1175
1176
	subframe->entropy_coding_method.type = u32;
	switch(subframe->entropy_coding_method.type) {
Josh Coalson's avatar
Josh Coalson committed
1177
1178
1179
		case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
			if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN, read_callback_, decoder))
				return false; /* the read_callback_ sets the state for us */
1180
			subframe->entropy_coding_method.data.partitioned_rice.order = u32;
Josh Coalson's avatar
Josh Coalson committed
1181
1182
1183
1184
1185
1186
1187
			break;
		default:
			decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
			return false;
	}

	/* read residual */
1188
	switch(subframe->entropy_coding_method.type) {
Josh Coalson's avatar
Josh Coalson committed
1189
		case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
1190
			if(!stream_decoder_read_residual_partitioned_rice_(decoder, order, subframe->entropy_coding_method.data.partitioned_rice.order, decoder->guts->residual[channel]))
Josh Coalson's avatar
Josh Coalson committed
1191
1192
1193
1194
1195
1196
1197
				return false;
			break;
		default:
			assert(0);
	}

	/* decode the subframe */
1198
1199
	memcpy(decoder->guts->output[channel], subframe->warmup, sizeof(int32) * order);
	FLAC__fixed_restore_signal(decoder->guts->residual[channel], decoder->guts->frame.header.blocksize-order, order, decoder->guts->output[channel]+order);
Josh Coalson's avatar
Josh Coalson committed
1200
1201
1202
1203

	return true;
}

1204
bool stream_decoder_read_subframe_lpc_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps, const unsigned order)
Josh Coalson's avatar
Josh Coalson committed
1205
{
1206
	FLAC__Subframe_LPC *subframe = &decoder->guts->frame.subframes[channel].data.lpc;
Josh Coalson's avatar
Josh Coalson committed
1207
1208
1209
1210
	int32 i32;
	uint32 u32;
	unsigned u;

1211
1212
1213
1214
	decoder->guts->frame.subframes[channel].type = FLAC__SUBFRAME_TYPE_LPC;

	subframe->residual = decoder->guts->residual[channel];
	subframe->order = order;
Josh Coalson's avatar
Josh Coalson committed
1215
1216
1217

	/* read warm-up samples */
	for(u = 0; u < order; u++) {
1218
		if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, bps, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
1219
			return false; /* the read_callback_ sets the state for us */
1220
		subframe->warmup[u] = i32;
Josh Coalson's avatar
Josh Coalson committed
1221
1222
1223
	}

	/* read qlp coeff precision */
1224
	if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
1225
		return false; /* the read_callback_ sets the state for us */
Josh Coalson's avatar
Josh Coalson committed
1226
	if(u32 == (1u << FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN) - 1) {
Josh Coalson's avatar
Josh Coalson committed
1227
1228
1229
1230
		decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
		decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
		return true;
	}
1231
	subframe->qlp_coeff_precision = u32+1;
Josh Coalson's avatar
Josh Coalson committed
1232
1233

	/* read qlp shift */
1234
	if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
1235
		return false; /* the read_callback_ sets the state for us */
1236
	subframe->quantization_level = i32;
Josh Coalson's avatar
Josh Coalson committed
1237
1238
1239

	/* read quantized lp coefficiencts */
	for(u = 0; u < order; u++) {
1240
		if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, subframe->qlp_coeff_precision, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
1241
			return false; /* the read_callback_ sets the state for us */
1242
		subframe->qlp_coeff[u] = i32;
Josh Coalson's avatar
Josh Coalson committed
1243
1244
1245
1246
1247
	}

	/* read entropy coding method info */
	if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_TYPE_LEN, read_callback_, decoder))
		return false; /* the read_callback_ sets the state for us */
1248
1249
	subframe->entropy_coding_method.type = u32;
	switch(subframe->entropy_coding_method.type) {
Josh Coalson's avatar
Josh Coalson committed
1250
1251
1252
		case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
			if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN, read_callback_, decoder))
				return false; /* the read_callback_ sets the state for us */
1253
			subframe->entropy_coding_method.data.partitioned_rice.order = u32;
Josh Coalson's avatar
Josh Coalson committed
1254
1255
1256
1257
1258
1259
1260
			break;
		default:
			decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
			return false;
	}

	/* read residual */
1261
	switch(subframe->entropy_coding_method.type) {
Josh Coalson's avatar
Josh Coalson committed
1262
		case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
1263
			if(!stream_decoder_read_residual_partitioned_rice_(decoder, order, subframe->entropy_coding_method.data.partitioned_rice.order, decoder->guts->residual[channel]))
Josh Coalson's avatar
Josh Coalson committed
1264
1265
1266
1267
1268
1269
1270
				return false;
			break;
		default:
			assert(0);
	}

	/* decode the subframe */
1271
1272
	memcpy(decoder->guts->output[channel], subframe->warmup, sizeof(int32) * order);
	FLAC__lpc_restore_signal(decoder->guts->residual[channel], decoder->guts->frame.header.blocksize-order, subframe->qlp_coeff, order, subframe->quantization_level, decoder->guts->output[channel]+order);
Josh Coalson's avatar
Josh Coalson committed
1273
1274
1275
1276

	return true;
}

1277
bool stream_decoder_read_subframe_verbatim_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps)
Josh Coalson's avatar
Josh Coalson committed
1278
{
1279
	FLAC__Subframe_Verbatim *subframe = &decoder->guts->frame.subframes[channel].data.verbatim;
1280
	int32 x, *residual = decoder->guts->residual[channel];
Josh Coalson's avatar
Josh Coalson committed
1281
1282
	unsigned i;

1283
1284
	decoder->guts->frame.subframes[channel].type = FLAC__SUBFRAME_TYPE_VERBATIM;

1285
	subframe->data = residual;
1286
1287

	for(i = 0; i < decoder->guts->frame.header.blocksize; i++) {
1288
		if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &x, bps, read_callback_, decoder))
Josh Coalson's avatar
Josh Coalson committed
1289
			return false; /* the read_callback_ sets the state for us */
1290
		residual[i] = x;
Josh Coalson's avatar
Josh Coalson committed
1291
1292
	}

1293
1294
1295
	/* decode the subframe */
	memcpy(decoder->guts->output[channel], subframe->data, sizeof(int32) * decoder->guts->frame.header.blocksize);

Josh Coalson's avatar
Josh Coalson committed
1296
1297
1298
	return true;
}