bitwriter.c 26.7 KB
Newer Older
1
/* libFLAC - Free Lossless Audio Codec library
Josh Coalson's avatar
Josh Coalson committed
2
 * Copyright (C) 2000,2001,2002,2003,2004,2005,2006,2007,2008,2009  Josh Coalson
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
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the Xiph.org Foundation nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#if HAVE_CONFIG_H
#  include <config.h>
#endif

36
37
#include <stdlib.h>
#include <string.h>
38
39
40
#include "private/bitwriter.h"
#include "private/crc.h"
#include "FLAC/assert.h"
41
#include "share/alloc.h"
42
#include "share/endswap.h"
43
44
45
46
47
48
49
50
51
52
53
54

/* Things should be fastest when this matches the machine word size */
/* WATCHOUT: if you change this you must also change the following #defines down to SWAP_BE_WORD_TO_HOST below to match */
/* WATCHOUT: there are a few places where the code will not work unless bwword is >= 32 bits wide */
typedef FLAC__uint32 bwword;
#define FLAC__BYTES_PER_WORD 4
#define FLAC__BITS_PER_WORD 32
#define FLAC__WORD_ALL_ONES ((FLAC__uint32)0xffffffff)
/* SWAP_BE_WORD_TO_HOST swaps bytes in a bwword (which is always big-endian) if necessary to match host byte order */
#if WORDS_BIGENDIAN
#define SWAP_BE_WORD_TO_HOST(x) (x)
#else
55
#define SWAP_BE_WORD_TO_HOST(x) ENDSWAP_32(x)
56
#endif
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

/*
 * The default capacity here doesn't matter too much.  The buffer always grows
 * to hold whatever is written to it.  Usually the encoder will stop adding at
 * a frame or metadata block, then write that out and clear the buffer for the
 * next one.
 */
static const unsigned FLAC__BITWRITER_DEFAULT_CAPACITY = 32768u / sizeof(bwword); /* size in words */
/* When growing, increment 4K at a time */
static const unsigned FLAC__BITWRITER_DEFAULT_INCREMENT = 4096u / sizeof(bwword); /* size in words */

#define FLAC__WORDS_TO_BITS(words) ((words) * FLAC__BITS_PER_WORD)
#define FLAC__TOTAL_BITS(bw) (FLAC__WORDS_TO_BITS((bw)->words) + (bw)->bits)

#ifdef min
#undef min
#endif
#define min(x,y) ((x)<(y)?(x):(y))

/* adjust for compilers that can't understand using LLU suffix for uint64_t literals */
#ifdef _MSC_VER
#define FLAC__U64L(x) x
#else
#define FLAC__U64L(x) x##LLU
#endif

#ifndef FLaC__INLINE
#define FLaC__INLINE
#endif

struct FLAC__BitWriter {
	bwword *buffer;
	bwword accum; /* accumulator; bits are right-justified; when full, accum is appended to buffer */
	unsigned capacity; /* capacity of buffer in words */
	unsigned words; /* # of complete words in buffer */
	unsigned bits; /* # of used bits in accum */
};

/* * WATCHOUT: The current implementation only grows the buffer. */
static FLAC__bool bitwriter_grow_(FLAC__BitWriter *bw, unsigned bits_to_add)
{
	unsigned new_capacity;
	bwword *new_buffer;

	FLAC__ASSERT(0 != bw);
	FLAC__ASSERT(0 != bw->buffer);

	/* calculate total words needed to store 'bits_to_add' additional bits */
	new_capacity = bw->words + ((bw->bits + bits_to_add + FLAC__BITS_PER_WORD - 1) / FLAC__BITS_PER_WORD);

	/* it's possible (due to pessimism in the growth estimation that
	 * leads to this call) that we don't actually need to grow
	 */
	if(bw->capacity >= new_capacity)
		return true;

	/* round up capacity increase to the nearest FLAC__BITWRITER_DEFAULT_INCREMENT */
	if((new_capacity - bw->capacity) % FLAC__BITWRITER_DEFAULT_INCREMENT)
		new_capacity += FLAC__BITWRITER_DEFAULT_INCREMENT - ((new_capacity - bw->capacity) % FLAC__BITWRITER_DEFAULT_INCREMENT);
	/* make sure we got everything right */
	FLAC__ASSERT(0 == (new_capacity - bw->capacity) % FLAC__BITWRITER_DEFAULT_INCREMENT);
	FLAC__ASSERT(new_capacity > bw->capacity);
	FLAC__ASSERT(new_capacity >= bw->words + ((bw->bits + bits_to_add + FLAC__BITS_PER_WORD - 1) / FLAC__BITS_PER_WORD));

121
	new_buffer = (bwword*)safe_realloc_mul_2op_(bw->buffer, sizeof(bwword), /*times*/new_capacity);
122
123
124
125
126
127
128
129
130
131
132
133
134
135
	if(new_buffer == 0)
		return false;
	bw->buffer = new_buffer;
	bw->capacity = new_capacity;
	return true;
}


/***********************************************************************
 *
 * Class constructor/destructor
 *
 ***********************************************************************/

136
FLAC__BitWriter *FLAC__bitwriter_new(void)
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
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
{
	FLAC__BitWriter *bw = (FLAC__BitWriter*)calloc(1, sizeof(FLAC__BitWriter));
	/* note that calloc() sets all members to 0 for us */
	return bw;
}

void FLAC__bitwriter_delete(FLAC__BitWriter *bw)
{
	FLAC__ASSERT(0 != bw);

	FLAC__bitwriter_free(bw);
	free(bw);
}

/***********************************************************************
 *
 * Public class methods
 *
 ***********************************************************************/

FLAC__bool FLAC__bitwriter_init(FLAC__BitWriter *bw)
{
	FLAC__ASSERT(0 != bw);

	bw->words = bw->bits = 0;
	bw->capacity = FLAC__BITWRITER_DEFAULT_CAPACITY;
	bw->buffer = (bwword*)malloc(sizeof(bwword) * bw->capacity);
	if(bw->buffer == 0)
		return false;

	return true;
}

void FLAC__bitwriter_free(FLAC__BitWriter *bw)
{
	FLAC__ASSERT(0 != bw);

	if(0 != bw->buffer)
		free(bw->buffer);
	bw->buffer = 0;
	bw->capacity = 0;
	bw->words = bw->bits = 0;
}

void FLAC__bitwriter_clear(FLAC__BitWriter *bw)
{
	bw->words = bw->bits = 0;
}

void FLAC__bitwriter_dump(const FLAC__BitWriter *bw, FILE *out)
{
	unsigned i, j;
	if(bw == 0) {
		fprintf(out, "bitwriter is NULL\n");
	}
	else {
		fprintf(out, "bitwriter: capacity=%u words=%u bits=%u total_bits=%u\n", bw->capacity, bw->words, bw->bits, FLAC__TOTAL_BITS(bw));

		for(i = 0; i < bw->words; i++) {
			fprintf(out, "%08X: ", i);
			for(j = 0; j < FLAC__BITS_PER_WORD; j++)
				fprintf(out, "%01u", bw->buffer[i] & (1 << (FLAC__BITS_PER_WORD-j-1)) ? 1:0);
			fprintf(out, "\n");
		}
		if(bw->bits > 0) {
			fprintf(out, "%08X: ", i);
			for(j = 0; j < bw->bits; j++)
				fprintf(out, "%01u", bw->accum & (1 << (bw->bits-j-1)) ? 1:0);
			fprintf(out, "\n");
		}
	}
}

FLAC__bool FLAC__bitwriter_get_write_crc16(FLAC__BitWriter *bw, FLAC__uint16 *crc)
{
	const FLAC__byte *buffer;
	size_t bytes;

	FLAC__ASSERT((bw->bits & 7) == 0); /* assert that we're byte-aligned */

	if(!FLAC__bitwriter_get_buffer(bw, &buffer, &bytes))
		return false;

	*crc = (FLAC__uint16)FLAC__crc16(buffer, bytes);
	FLAC__bitwriter_release_buffer(bw);
	return true;
}

FLAC__bool FLAC__bitwriter_get_write_crc8(FLAC__BitWriter *bw, FLAC__byte *crc)
{
	const FLAC__byte *buffer;
	size_t bytes;

	FLAC__ASSERT((bw->bits & 7) == 0); /* assert that we're byte-aligned */

	if(!FLAC__bitwriter_get_buffer(bw, &buffer, &bytes))
		return false;

	*crc = FLAC__crc8(buffer, bytes);
	FLAC__bitwriter_release_buffer(bw);
	return true;
}

FLAC__bool FLAC__bitwriter_is_byte_aligned(const FLAC__BitWriter *bw)
{
	return ((bw->bits & 7) == 0);
}

unsigned FLAC__bitwriter_get_input_bits_unconsumed(const FLAC__BitWriter *bw)
{
	return FLAC__TOTAL_BITS(bw);
}

FLAC__bool FLAC__bitwriter_get_buffer(FLAC__BitWriter *bw, const FLAC__byte **buffer, size_t *bytes)
{
	FLAC__ASSERT((bw->bits & 7) == 0);
	/* double protection */
	if(bw->bits & 7)
		return false;
	/* if we have bits in the accumulator we have to flush those to the buffer first */
	if(bw->bits) {
		FLAC__ASSERT(bw->words <= bw->capacity);
		if(bw->words == bw->capacity && !bitwriter_grow_(bw, FLAC__BITS_PER_WORD))
			return false;
		/* append bits as complete word to buffer, but don't change bw->accum or bw->bits */
		bw->buffer[bw->words] = SWAP_BE_WORD_TO_HOST(bw->accum << (FLAC__BITS_PER_WORD-bw->bits));
	}
	/* now we can just return what we have */
	*buffer = (FLAC__byte*)bw->buffer;
	*bytes = (FLAC__BYTES_PER_WORD * bw->words) + (bw->bits >> 3);
	return true;
}

void FLAC__bitwriter_release_buffer(FLAC__BitWriter *bw)
{
	/* nothing to do.  in the future, strict checking of a 'writer-is-in-
	 * get-mode' flag could be added everywhere and then cleared here
	 */
	(void)bw;
}

FLaC__INLINE FLAC__bool FLAC__bitwriter_write_zeroes(FLAC__BitWriter *bw, unsigned bits)
{
	unsigned n;

	FLAC__ASSERT(0 != bw);
	FLAC__ASSERT(0 != bw->buffer);

	if(bits == 0)
		return true;
	/* slightly pessimistic size check but faster than "<= bw->words + (bw->bits+bits+FLAC__BITS_PER_WORD-1)/FLAC__BITS_PER_WORD" */
	if(bw->capacity <= bw->words + bits && !bitwriter_grow_(bw, bits))
		return false;
	/* first part gets to word alignment */
	if(bw->bits) {
		n = min(FLAC__BITS_PER_WORD - bw->bits, bits);
		bw->accum <<= n;
		bits -= n;
		bw->bits += n;
		if(bw->bits == FLAC__BITS_PER_WORD) {
			bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum);
			bw->bits = 0;
		}
		else
			return true;
	}
	/* do whole words */
	while(bits >= FLAC__BITS_PER_WORD) {
		bw->buffer[bw->words++] = 0;
		bits -= FLAC__BITS_PER_WORD;
	}
	/* do any leftovers */
	if(bits > 0) {
		bw->accum = 0;
		bw->bits = bits;
	}
	return true;
}

FLaC__INLINE FLAC__bool FLAC__bitwriter_write_raw_uint32(FLAC__BitWriter *bw, FLAC__uint32 val, unsigned bits)
{
	register unsigned left;

	/* WATCHOUT: code does not work with <32bit words; we can make things much faster with this assertion */
	FLAC__ASSERT(FLAC__BITS_PER_WORD >= 32);

	FLAC__ASSERT(0 != bw);
	FLAC__ASSERT(0 != bw->buffer);

	FLAC__ASSERT(bits <= 32);
	if(bits == 0)
		return true;

	/* slightly pessimistic size check but faster than "<= bw->words + (bw->bits+bits+FLAC__BITS_PER_WORD-1)/FLAC__BITS_PER_WORD" */
	if(bw->capacity <= bw->words + bits && !bitwriter_grow_(bw, bits))
		return false;

	left = FLAC__BITS_PER_WORD - bw->bits;
	if(bits < left) {
		bw->accum <<= bits;
		bw->accum |= val;
		bw->bits += bits;
	}
	else if(bw->bits) { /* WATCHOUT: if bw->bits == 0, left==FLAC__BITS_PER_WORD and bw->accum<<=left is a NOP instead of setting to 0 */
		bw->accum <<= left;
		bw->accum |= val >> (bw->bits = bits - left);
		bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum);
		bw->accum = val;
	}
	else {
		bw->accum = val;
		bw->bits = 0;
		bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(val);
	}

	return true;
}

FLaC__INLINE FLAC__bool FLAC__bitwriter_write_raw_int32(FLAC__BitWriter *bw, FLAC__int32 val, unsigned bits)
{
	/* zero-out unused bits */
	if(bits < 32)
		val &= (~(0xffffffff << bits));

	return FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)val, bits);
}

FLaC__INLINE FLAC__bool FLAC__bitwriter_write_raw_uint64(FLAC__BitWriter *bw, FLAC__uint64 val, unsigned bits)
{
	/* this could be a little faster but it's not used for much */
	if(bits > 32) {
		return
			FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)(val>>32), bits-32) &&
			FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)val, 32);
	}
	else
		return FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)val, bits);
}

FLaC__INLINE FLAC__bool FLAC__bitwriter_write_raw_uint32_little_endian(FLAC__BitWriter *bw, FLAC__uint32 val)
{
	/* this doesn't need to be that fast as currently it is only used for vorbis comments */

	if(!FLAC__bitwriter_write_raw_uint32(bw, val & 0xff, 8))
		return false;
	if(!FLAC__bitwriter_write_raw_uint32(bw, (val>>8) & 0xff, 8))
		return false;
	if(!FLAC__bitwriter_write_raw_uint32(bw, (val>>16) & 0xff, 8))
		return false;
	if(!FLAC__bitwriter_write_raw_uint32(bw, val>>24, 8))
		return false;

	return true;
}

FLaC__INLINE FLAC__bool FLAC__bitwriter_write_byte_block(FLAC__BitWriter *bw, const FLAC__byte vals[], unsigned nvals)
{
	unsigned i;

	/* this could be faster but currently we don't need it to be since it's only used for writing metadata */
	for(i = 0; i < nvals; i++) {
		if(!FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)(vals[i]), 8))
			return false;
	}

	return true;
}

FLAC__bool FLAC__bitwriter_write_unary_unsigned(FLAC__BitWriter *bw, unsigned val)
{
	if(val < 32)
		return FLAC__bitwriter_write_raw_uint32(bw, 1, ++val);
	else
		return
			FLAC__bitwriter_write_zeroes(bw, val) &&
			FLAC__bitwriter_write_raw_uint32(bw, 1, 1);
}

unsigned FLAC__bitwriter_rice_bits(FLAC__int32 val, unsigned parameter)
{
	FLAC__uint32 uval;

	FLAC__ASSERT(parameter < sizeof(unsigned)*8);

	/* fold signed to unsigned; actual formula is: negative(v)? -2v-1 : 2v */
	uval = (val<<1) ^ (val>>31);

	return 1 + parameter + (uval >> parameter);
}

#if 0 /* UNUSED */
unsigned FLAC__bitwriter_golomb_bits_signed(int val, unsigned parameter)
{
	unsigned bits, msbs, uval;
	unsigned k;

	FLAC__ASSERT(parameter > 0);

	/* fold signed to unsigned */
	if(val < 0)
		uval = (unsigned)(((-(++val)) << 1) + 1);
	else
		uval = (unsigned)(val << 1);

	k = FLAC__bitmath_ilog2(parameter);
	if(parameter == 1u<<k) {
		FLAC__ASSERT(k <= 30);

		msbs = uval >> k;
		bits = 1 + k + msbs;
	}
	else {
		unsigned q, r, d;

		d = (1 << (k+1)) - parameter;
		q = uval / parameter;
		r = uval - (q * parameter);

		bits = 1 + q + k;
		if(r >= d)
			bits++;
	}
	return bits;
}

unsigned FLAC__bitwriter_golomb_bits_unsigned(unsigned uval, unsigned parameter)
{
	unsigned bits, msbs;
	unsigned k;

	FLAC__ASSERT(parameter > 0);

	k = FLAC__bitmath_ilog2(parameter);
	if(parameter == 1u<<k) {
		FLAC__ASSERT(k <= 30);

		msbs = uval >> k;
		bits = 1 + k + msbs;
	}
	else {
		unsigned q, r, d;

		d = (1 << (k+1)) - parameter;
		q = uval / parameter;
		r = uval - (q * parameter);

		bits = 1 + q + k;
		if(r >= d)
			bits++;
	}
	return bits;
}
#endif /* UNUSED */

FLAC__bool FLAC__bitwriter_write_rice_signed(FLAC__BitWriter *bw, FLAC__int32 val, unsigned parameter)
{
	unsigned total_bits, interesting_bits, msbs;
	FLAC__uint32 uval, pattern;

	FLAC__ASSERT(0 != bw);
	FLAC__ASSERT(0 != bw->buffer);
	FLAC__ASSERT(parameter < 8*sizeof(uval));

	/* fold signed to unsigned; actual formula is: negative(v)? -2v-1 : 2v */
	uval = (val<<1) ^ (val>>31);

	msbs = uval >> parameter;
	interesting_bits = 1 + parameter;
	total_bits = interesting_bits + msbs;
	pattern = 1 << parameter; /* the unary end bit */
	pattern |= (uval & ((1<<parameter)-1)); /* the binary LSBs */

	if(total_bits <= 32)
		return FLAC__bitwriter_write_raw_uint32(bw, pattern, total_bits);
	else
		return
			FLAC__bitwriter_write_zeroes(bw, msbs) && /* write the unary MSBs */
			FLAC__bitwriter_write_raw_uint32(bw, pattern, interesting_bits); /* write the unary end bit and binary LSBs */
}

FLAC__bool FLAC__bitwriter_write_rice_signed_block(FLAC__BitWriter *bw, const FLAC__int32 *vals, unsigned nvals, unsigned parameter)
{
	const FLAC__uint32 mask1 = FLAC__WORD_ALL_ONES << parameter; /* we val|=mask1 to set the stop bit above it... */
	const FLAC__uint32 mask2 = FLAC__WORD_ALL_ONES >> (31-parameter); /* ...then mask off the bits above the stop bit with val&=mask2*/
	FLAC__uint32 uval;
522
	unsigned left;
523
524
525
526
527
528
529
530
531
532
533
	const unsigned lsbits = 1 + parameter;
	unsigned msbits;

	FLAC__ASSERT(0 != bw);
	FLAC__ASSERT(0 != bw->buffer);
	FLAC__ASSERT(parameter < 8*sizeof(bwword)-1);
	/* WATCHOUT: code does not work with <32bit words; we can make things much faster with this assertion */
	FLAC__ASSERT(FLAC__BITS_PER_WORD >= 32);

	while(nvals) {
		/* fold signed to unsigned; actual formula is: negative(v)? -2v-1 : 2v */
Josh Coalson's avatar
Josh Coalson committed
534
		uval = (*vals<<1) ^ (*vals>>31);
535
536
537

		msbits = uval >> parameter;

538
#if 0 /* OPT: can remove this special case if it doesn't make up for the extra compare (doesn't make a statistically significant difference with msvc or gcc/x86) */
539
540
		if(bw->bits && bw->bits + msbits + lsbits <= FLAC__BITS_PER_WORD) { /* i.e. if the whole thing fits in the current bwword */
			/* ^^^ if bw->bits is 0 then we may have filled the buffer and have no free bwword to work in */
541
542
543
544
545
546
547
548
549
550
551
552
553
554
			bw->bits = bw->bits + msbits + lsbits;
			uval |= mask1; /* set stop bit */
			uval &= mask2; /* mask off unused top bits */
			/* NOT: bw->accum <<= msbits + lsbits because msbits+lsbits could be 32, then the shift would be a NOP */
			bw->accum <<= msbits;
			bw->accum <<= lsbits;
			bw->accum |= uval;
			if(bw->bits == FLAC__BITS_PER_WORD) {
				bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum);
				bw->bits = 0;
				/* burying the capacity check down here means we have to grow the buffer a little if there are more vals to do */
				if(bw->capacity <= bw->words && nvals > 1 && !bitwriter_grow_(bw, 1)) {
					FLAC__ASSERT(bw->capacity == bw->words);
					return false;
555
556
557
				}
			}
		}
558
		else {
Josh Coalson's avatar
Josh Coalson committed
559
#elif 1 /*@@@@@@ OPT: try this version with MSVC6 to see if better, not much difference for gcc-4 */
560
561
		if(bw->bits && bw->bits + msbits + lsbits < FLAC__BITS_PER_WORD) { /* i.e. if the whole thing fits in the current bwword */
			/* ^^^ if bw->bits is 0 then we may have filled the buffer and have no free bwword to work in */
562
563
564
565
			bw->bits = bw->bits + msbits + lsbits;
			uval |= mask1; /* set stop bit */
			uval &= mask2; /* mask off unused top bits */
			bw->accum <<= msbits + lsbits;
566
567
568
			bw->accum |= uval;
		}
		else {
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
610
611
612
613
614
615
616
617
618
619
620
621
622
623
#endif
			/* slightly pessimistic size check but faster than "<= bw->words + (bw->bits+msbits+lsbits+FLAC__BITS_PER_WORD-1)/FLAC__BITS_PER_WORD" */
			/* OPT: pessimism may cause flurry of false calls to grow_ which eat up all savings before it */
			if(bw->capacity <= bw->words + bw->bits + msbits + 1/*lsbits always fit in 1 bwword*/ && !bitwriter_grow_(bw, msbits+lsbits))
				return false;

			if(msbits) {
				/* first part gets to word alignment */
				if(bw->bits) {
					left = FLAC__BITS_PER_WORD - bw->bits;
					if(msbits < left) {
						bw->accum <<= msbits;
						bw->bits += msbits;
						goto break1;
					}
					else {
						bw->accum <<= left;
						msbits -= left;
						bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum);
						bw->bits = 0;
					}
				}
				/* do whole words */
				while(msbits >= FLAC__BITS_PER_WORD) {
					bw->buffer[bw->words++] = 0;
					msbits -= FLAC__BITS_PER_WORD;
				}
				/* do any leftovers */
				if(msbits > 0) {
					bw->accum = 0;
					bw->bits = msbits;
				}
			}
break1:
			uval |= mask1; /* set stop bit */
			uval &= mask2; /* mask off unused top bits */

			left = FLAC__BITS_PER_WORD - bw->bits;
			if(lsbits < left) {
				bw->accum <<= lsbits;
				bw->accum |= uval;
				bw->bits += lsbits;
			}
			else {
				/* if bw->bits == 0, left==FLAC__BITS_PER_WORD which will always
				 * be > lsbits (because of previous assertions) so it would have
				 * triggered the (lsbits<left) case above.
				 */
				FLAC__ASSERT(bw->bits);
				FLAC__ASSERT(left < FLAC__BITS_PER_WORD);
				bw->accum <<= left;
				bw->accum |= uval >> (bw->bits = lsbits - left);
				bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum);
				bw->accum = uval;
			}
Josh Coalson's avatar
Josh Coalson committed
624
#if 1
625
		}
626
#endif
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
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
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
		vals++;
		nvals--;
	}
	return true;
}

#if 0 /* UNUSED */
FLAC__bool FLAC__bitwriter_write_golomb_signed(FLAC__BitWriter *bw, int val, unsigned parameter)
{
	unsigned total_bits, msbs, uval;
	unsigned k;

	FLAC__ASSERT(0 != bw);
	FLAC__ASSERT(0 != bw->buffer);
	FLAC__ASSERT(parameter > 0);

	/* fold signed to unsigned */
	if(val < 0)
		uval = (unsigned)(((-(++val)) << 1) + 1);
	else
		uval = (unsigned)(val << 1);

	k = FLAC__bitmath_ilog2(parameter);
	if(parameter == 1u<<k) {
		unsigned pattern;

		FLAC__ASSERT(k <= 30);

		msbs = uval >> k;
		total_bits = 1 + k + msbs;
		pattern = 1 << k; /* the unary end bit */
		pattern |= (uval & ((1u<<k)-1)); /* the binary LSBs */

		if(total_bits <= 32) {
			if(!FLAC__bitwriter_write_raw_uint32(bw, pattern, total_bits))
				return false;
		}
		else {
			/* write the unary MSBs */
			if(!FLAC__bitwriter_write_zeroes(bw, msbs))
				return false;
			/* write the unary end bit and binary LSBs */
			if(!FLAC__bitwriter_write_raw_uint32(bw, pattern, k+1))
				return false;
		}
	}
	else {
		unsigned q, r, d;

		d = (1 << (k+1)) - parameter;
		q = uval / parameter;
		r = uval - (q * parameter);
		/* write the unary MSBs */
		if(!FLAC__bitwriter_write_zeroes(bw, q))
			return false;
		/* write the unary end bit */
		if(!FLAC__bitwriter_write_raw_uint32(bw, 1, 1))
			return false;
		/* write the binary LSBs */
		if(r >= d) {
			if(!FLAC__bitwriter_write_raw_uint32(bw, r+d, k+1))
				return false;
		}
		else {
			if(!FLAC__bitwriter_write_raw_uint32(bw, r, k))
				return false;
		}
	}
	return true;
}

FLAC__bool FLAC__bitwriter_write_golomb_unsigned(FLAC__BitWriter *bw, unsigned uval, unsigned parameter)
{
	unsigned total_bits, msbs;
	unsigned k;

	FLAC__ASSERT(0 != bw);
	FLAC__ASSERT(0 != bw->buffer);
	FLAC__ASSERT(parameter > 0);

	k = FLAC__bitmath_ilog2(parameter);
	if(parameter == 1u<<k) {
		unsigned pattern;

		FLAC__ASSERT(k <= 30);

		msbs = uval >> k;
		total_bits = 1 + k + msbs;
		pattern = 1 << k; /* the unary end bit */
		pattern |= (uval & ((1u<<k)-1)); /* the binary LSBs */

		if(total_bits <= 32) {
			if(!FLAC__bitwriter_write_raw_uint32(bw, pattern, total_bits))
				return false;
		}
		else {
			/* write the unary MSBs */
			if(!FLAC__bitwriter_write_zeroes(bw, msbs))
				return false;
			/* write the unary end bit and binary LSBs */
			if(!FLAC__bitwriter_write_raw_uint32(bw, pattern, k+1))
				return false;
		}
	}
	else {
		unsigned q, r, d;

		d = (1 << (k+1)) - parameter;
		q = uval / parameter;
		r = uval - (q * parameter);
		/* write the unary MSBs */
		if(!FLAC__bitwriter_write_zeroes(bw, q))
			return false;
		/* write the unary end bit */
		if(!FLAC__bitwriter_write_raw_uint32(bw, 1, 1))
			return false;
		/* write the binary LSBs */
		if(r >= d) {
			if(!FLAC__bitwriter_write_raw_uint32(bw, r+d, k+1))
				return false;
		}
		else {
			if(!FLAC__bitwriter_write_raw_uint32(bw, r, k))
				return false;
		}
	}
	return true;
}
#endif /* UNUSED */

FLAC__bool FLAC__bitwriter_write_utf8_uint32(FLAC__BitWriter *bw, FLAC__uint32 val)
{
	FLAC__bool ok = 1;

	FLAC__ASSERT(0 != bw);
	FLAC__ASSERT(0 != bw->buffer);

	FLAC__ASSERT(!(val & 0x80000000)); /* this version only handles 31 bits */

	if(val < 0x80) {
		return FLAC__bitwriter_write_raw_uint32(bw, val, 8);
	}
	else if(val < 0x800) {
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xC0 | (val>>6), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val&0x3F), 8);
	}
	else if(val < 0x10000) {
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xE0 | (val>>12), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>6)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val&0x3F), 8);
	}
	else if(val < 0x200000) {
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xF0 | (val>>18), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>12)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>6)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val&0x3F), 8);
	}
	else if(val < 0x4000000) {
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xF8 | (val>>24), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>18)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>12)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>6)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val&0x3F), 8);
	}
	else {
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xFC | (val>>30), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>24)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>18)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>12)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>6)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val&0x3F), 8);
	}

	return ok;
}

FLAC__bool FLAC__bitwriter_write_utf8_uint64(FLAC__BitWriter *bw, FLAC__uint64 val)
{
	FLAC__bool ok = 1;

	FLAC__ASSERT(0 != bw);
	FLAC__ASSERT(0 != bw->buffer);

	FLAC__ASSERT(!(val & FLAC__U64L(0xFFFFFFF000000000))); /* this version only handles 36 bits */

	if(val < 0x80) {
		return FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)val, 8);
	}
	else if(val < 0x800) {
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xC0 | (FLAC__uint32)(val>>6), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
	}
	else if(val < 0x10000) {
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xE0 | (FLAC__uint32)(val>>12), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
	}
	else if(val < 0x200000) {
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xF0 | (FLAC__uint32)(val>>18), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
	}
	else if(val < 0x4000000) {
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xF8 | (FLAC__uint32)(val>>24), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>18)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
	}
	else if(val < 0x80000000) {
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xFC | (FLAC__uint32)(val>>30), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>24)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>18)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
	}
	else {
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xFE, 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>30)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>24)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>18)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
		ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
	}

	return ok;
}

FLAC__bool FLAC__bitwriter_zero_pad_to_byte_boundary(FLAC__BitWriter *bw)
{
	/* 0-pad to byte boundary */
	if(bw->bits & 7u)
		return FLAC__bitwriter_write_zeroes(bw, 8 - (bw->bits & 7u));
	else
		return true;
}