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1 /* libFLAC - Free Lossless Audio Codec library
2  * Copyright (C) 2000-2009  Josh Coalson
3  * Copyright (C) 2011-2022  Xiph.Org Foundation
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * - Redistributions of source code must retain the above copyright
10  * notice, this list of conditions and the following disclaimer.
11  *
12  * - Redistributions in binary form must reproduce the above copyright
13  * notice, this list of conditions and the following disclaimer in the
14  * documentation and/or other materials provided with the distribution.
15  *
16  * - Neither the name of the Xiph.org Foundation nor the names of its
17  * contributors may be used to endorse or promote products derived from
18  * this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
24  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
27  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
29  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
30  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #ifdef HAVE_CONFIG_H
34 #  include <config.h>
35 #endif
36 
37 #include <stdlib.h>
38 #include <string.h>
39 #include "private/bitwriter.h"
40 #include "private/crc.h"
41 #include "private/format.h"
42 #include "private/macros.h"
43 #include "private/stream_encoder.h"
44 #include "FLAC/assert.h"
45 #include "share/alloc.h"
46 #include "share/compat.h"
47 #include "share/endswap.h"
48 
49 /* Things should be fastest when this matches the machine word size */
50 /* WATCHOUT: if you change this you must also change the following #defines down to SWAP_BE_WORD_TO_HOST below to match */
51 /* WATCHOUT: there are a few places where the code will not work unless bwword is >= 32 bits wide */
52 
53 #if (ENABLE_64_BIT_WORDS == 0)
54 
55 typedef FLAC__uint32 bwword;
56 typedef FLAC__uint64 FLAC__bwtemp;
57 #define FLAC__BYTES_PER_WORD 4		/* sizeof bwword */
58 #define FLAC__BITS_PER_WORD 32
59 #define FLAC__TEMP_BITS 64
60 #define FLAC__HALF_TEMP_BITS 32
61 /* SWAP_BE_WORD_TO_HOST swaps bytes in a bwword (which is always big-endian) if necessary to match host byte order */
62 #if WORDS_BIGENDIAN
63 #define SWAP_BE_WORD_TO_HOST(x) (x)
64 #else
65 #define SWAP_BE_WORD_TO_HOST(x) ENDSWAP_32(x)
66 #endif
67 
68 #else
69 
70 typedef FLAC__uint64 bwword;
71 typedef FLAC__uint64 FLAC__bwtemp;
72 #define FLAC__BYTES_PER_WORD 8		/* sizeof bwword */
73 #define FLAC__BITS_PER_WORD 64
74 #define FLAC__TEMP_BITS 64
75 #define FLAC__HALF_TEMP_BITS 32
76 /* SWAP_BE_WORD_TO_HOST swaps bytes in a bwword (which is always big-endian) if necessary to match host byte order */
77 #if WORDS_BIGENDIAN
78 #define SWAP_BE_WORD_TO_HOST(x) (x)
79 #else
80 #define SWAP_BE_WORD_TO_HOST(x) ENDSWAP_64(x)
81 #endif
82 
83 #endif
84 
85 /*
86  * The default capacity here doesn't matter too much.  The buffer always grows
87  * to hold whatever is written to it.  Usually the encoder will stop adding at
88  * a frame or metadata block, then write that out and clear the buffer for the
89  * next one.
90  */
91 static const uint32_t FLAC__BITWRITER_DEFAULT_CAPACITY = 32768u / sizeof(bwword); /* size in words */
92 /* When growing, increment 4K at a time */
93 static const uint32_t FLAC__BITWRITER_DEFAULT_INCREMENT = 4096u / sizeof(bwword); /* size in words */
94 
95 #define FLAC__WORDS_TO_BITS(words) ((words) * FLAC__BITS_PER_WORD)
96 #define FLAC__TOTAL_BITS(bw) (FLAC__WORDS_TO_BITS((bw)->words) + (bw)->bits)
97 
98 struct FLAC__BitWriter {
99 	bwword *buffer;
100 	bwword accum; /* accumulator; bits are right-justified; when full, accum is appended to buffer */
101 	uint32_t capacity; /* capacity of buffer in words */
102 	uint32_t words; /* # of complete words in buffer */
103 	uint32_t bits; /* # of used bits in accum */
104 };
105 
106 /* * WATCHOUT: The current implementation only grows the buffer. */
107 #ifndef __SUNPRO_C
108 static
109 #endif
bitwriter_grow_(FLAC__BitWriter * bw,uint32_t bits_to_add)110 FLAC__bool bitwriter_grow_(FLAC__BitWriter *bw, uint32_t bits_to_add)
111 {
112 	uint32_t new_capacity;
113 	bwword *new_buffer;
114 
115 	FLAC__ASSERT(0 != bw);
116 	FLAC__ASSERT(0 != bw->buffer);
117 
118 	/* calculate total words needed to store 'bits_to_add' additional bits */
119 	new_capacity = bw->words + ((bw->bits + bits_to_add + FLAC__BITS_PER_WORD - 1) / FLAC__BITS_PER_WORD);
120 
121 	/* it's possible (due to pessimism in the growth estimation that
122 	 * leads to this call) that we don't actually need to grow
123 	 */
124 	if(bw->capacity >= new_capacity)
125 		return true;
126 
127 	if(new_capacity * sizeof(bwword) > (1u << FLAC__STREAM_METADATA_LENGTH_LEN))
128 		/* Requested new capacity is larger than the largest possible metadata block,
129 		 * which is also larger than the largest sane framesize. That means something
130 		 * went very wrong somewhere and previous checks failed.
131 		 * To prevent chrashing, give up */
132 		return false;
133 
134 	/* round up capacity increase to the nearest FLAC__BITWRITER_DEFAULT_INCREMENT */
135 	if((new_capacity - bw->capacity) % FLAC__BITWRITER_DEFAULT_INCREMENT)
136 		new_capacity += FLAC__BITWRITER_DEFAULT_INCREMENT - ((new_capacity - bw->capacity) % FLAC__BITWRITER_DEFAULT_INCREMENT);
137 	/* make sure we got everything right */
138 	FLAC__ASSERT(0 == (new_capacity - bw->capacity) % FLAC__BITWRITER_DEFAULT_INCREMENT);
139 	FLAC__ASSERT(new_capacity > bw->capacity);
140 	FLAC__ASSERT(new_capacity >= bw->words + ((bw->bits + bits_to_add + FLAC__BITS_PER_WORD - 1) / FLAC__BITS_PER_WORD));
141 
142 	new_buffer = safe_realloc_nofree_mul_2op_(bw->buffer, sizeof(bwword), /*times*/new_capacity);
143 	if(new_buffer == 0)
144 		return false;
145 	bw->buffer = new_buffer;
146 	bw->capacity = new_capacity;
147 	return true;
148 }
149 
150 
151 /***********************************************************************
152  *
153  * Class constructor/destructor
154  *
155  ***********************************************************************/
156 
FLAC__bitwriter_new(void)157 FLAC__BitWriter *FLAC__bitwriter_new(void)
158 {
159 	FLAC__BitWriter *bw = calloc(1, sizeof(FLAC__BitWriter));
160 	/* note that calloc() sets all members to 0 for us */
161 	return bw;
162 }
163 
FLAC__bitwriter_delete(FLAC__BitWriter * bw)164 void FLAC__bitwriter_delete(FLAC__BitWriter *bw)
165 {
166 	FLAC__ASSERT(0 != bw);
167 
168 	FLAC__bitwriter_free(bw);
169 	free(bw);
170 }
171 
172 /***********************************************************************
173  *
174  * Public class methods
175  *
176  ***********************************************************************/
177 
FLAC__bitwriter_init(FLAC__BitWriter * bw)178 FLAC__bool FLAC__bitwriter_init(FLAC__BitWriter *bw)
179 {
180 	FLAC__ASSERT(0 != bw);
181 
182 	bw->words = bw->bits = 0;
183 	bw->capacity = FLAC__BITWRITER_DEFAULT_CAPACITY;
184 	bw->buffer = malloc(sizeof(bwword) * bw->capacity);
185 	if(bw->buffer == 0)
186 		return false;
187 
188 	return true;
189 }
190 
FLAC__bitwriter_free(FLAC__BitWriter * bw)191 void FLAC__bitwriter_free(FLAC__BitWriter *bw)
192 {
193 	FLAC__ASSERT(0 != bw);
194 
195 	if(0 != bw->buffer)
196 		free(bw->buffer);
197 	bw->buffer = 0;
198 	bw->capacity = 0;
199 	bw->words = bw->bits = 0;
200 }
201 
FLAC__bitwriter_clear(FLAC__BitWriter * bw)202 void FLAC__bitwriter_clear(FLAC__BitWriter *bw)
203 {
204 	bw->words = bw->bits = 0;
205 }
206 
FLAC__bitwriter_get_write_crc16(FLAC__BitWriter * bw,FLAC__uint16 * crc)207 FLAC__bool FLAC__bitwriter_get_write_crc16(FLAC__BitWriter *bw, FLAC__uint16 *crc)
208 {
209 	const FLAC__byte *buffer;
210 	size_t bytes;
211 
212 	FLAC__ASSERT((bw->bits & 7) == 0); /* assert that we're byte-aligned */
213 
214 	if(!FLAC__bitwriter_get_buffer(bw, &buffer, &bytes))
215 		return false;
216 
217 	*crc = (FLAC__uint16)FLAC__crc16(buffer, bytes);
218 	FLAC__bitwriter_release_buffer(bw);
219 	return true;
220 }
221 
FLAC__bitwriter_get_write_crc8(FLAC__BitWriter * bw,FLAC__byte * crc)222 FLAC__bool FLAC__bitwriter_get_write_crc8(FLAC__BitWriter *bw, FLAC__byte *crc)
223 {
224 	const FLAC__byte *buffer;
225 	size_t bytes;
226 
227 	FLAC__ASSERT((bw->bits & 7) == 0); /* assert that we're byte-aligned */
228 
229 	if(!FLAC__bitwriter_get_buffer(bw, &buffer, &bytes))
230 		return false;
231 
232 	*crc = FLAC__crc8(buffer, bytes);
233 	FLAC__bitwriter_release_buffer(bw);
234 	return true;
235 }
236 
FLAC__bitwriter_is_byte_aligned(const FLAC__BitWriter * bw)237 FLAC__bool FLAC__bitwriter_is_byte_aligned(const FLAC__BitWriter *bw)
238 {
239 	return ((bw->bits & 7) == 0);
240 }
241 
FLAC__bitwriter_get_input_bits_unconsumed(const FLAC__BitWriter * bw)242 uint32_t FLAC__bitwriter_get_input_bits_unconsumed(const FLAC__BitWriter *bw)
243 {
244 	return FLAC__TOTAL_BITS(bw);
245 }
246 
FLAC__bitwriter_get_buffer(FLAC__BitWriter * bw,const FLAC__byte ** buffer,size_t * bytes)247 FLAC__bool FLAC__bitwriter_get_buffer(FLAC__BitWriter *bw, const FLAC__byte **buffer, size_t *bytes)
248 {
249 	FLAC__ASSERT((bw->bits & 7) == 0);
250 	/* double protection */
251 	if(bw->bits & 7)
252 		return false;
253 	/* if we have bits in the accumulator we have to flush those to the buffer first */
254 	if(bw->bits) {
255 		FLAC__ASSERT(bw->words <= bw->capacity);
256 		if(bw->words == bw->capacity && !bitwriter_grow_(bw, FLAC__BITS_PER_WORD))
257 			return false;
258 		/* append bits as complete word to buffer, but don't change bw->accum or bw->bits */
259 		bw->buffer[bw->words] = SWAP_BE_WORD_TO_HOST(bw->accum << (FLAC__BITS_PER_WORD-bw->bits));
260 	}
261 	/* now we can just return what we have */
262 	*buffer = (FLAC__byte*)bw->buffer;
263 	*bytes = (FLAC__BYTES_PER_WORD * bw->words) + (bw->bits >> 3);
264 	return true;
265 }
266 
FLAC__bitwriter_release_buffer(FLAC__BitWriter * bw)267 void FLAC__bitwriter_release_buffer(FLAC__BitWriter *bw)
268 {
269 	/* nothing to do.  in the future, strict checking of a 'writer-is-in-
270 	 * get-mode' flag could be added everywhere and then cleared here
271 	 */
272 	(void)bw;
273 }
274 
FLAC__bitwriter_write_zeroes(FLAC__BitWriter * bw,uint32_t bits)275 inline FLAC__bool FLAC__bitwriter_write_zeroes(FLAC__BitWriter *bw, uint32_t bits)
276 {
277 	uint32_t n;
278 
279 	FLAC__ASSERT(0 != bw);
280 	FLAC__ASSERT(0 != bw->buffer);
281 
282 	if(bits == 0)
283 		return true;
284 	/* slightly pessimistic size check but faster than "<= bw->words + (bw->bits+bits+FLAC__BITS_PER_WORD-1)/FLAC__BITS_PER_WORD" */
285 	if(bw->capacity <= bw->words + bits && !bitwriter_grow_(bw, bits))
286 		return false;
287 	/* first part gets to word alignment */
288 	if(bw->bits) {
289 		n = flac_min(FLAC__BITS_PER_WORD - bw->bits, bits);
290 		bw->accum <<= n;
291 		bits -= n;
292 		bw->bits += n;
293 		if(bw->bits == FLAC__BITS_PER_WORD) {
294 			bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum);
295 			bw->bits = 0;
296 		}
297 		else
298 			return true;
299 	}
300 	/* do whole words */
301 	while(bits >= FLAC__BITS_PER_WORD) {
302 		bw->buffer[bw->words++] = 0;
303 		bits -= FLAC__BITS_PER_WORD;
304 	}
305 	/* do any leftovers */
306 	if(bits > 0) {
307 		bw->accum = 0;
308 		bw->bits = bits;
309 	}
310 	return true;
311 }
312 
FLAC__bitwriter_write_raw_uint32_nocheck(FLAC__BitWriter * bw,FLAC__uint32 val,uint32_t bits)313 static inline FLAC__bool FLAC__bitwriter_write_raw_uint32_nocheck(FLAC__BitWriter *bw, FLAC__uint32 val, uint32_t bits)
314 {
315 	register uint32_t left;
316 
317 	/* WATCHOUT: code does not work with <32bit words; we can make things much faster with this assertion */
318 	FLAC__ASSERT(FLAC__BITS_PER_WORD >= 32);
319 
320 	if(bw == 0 || bw->buffer == 0)
321 		return false;
322 
323 	if (bits > 32)
324 		return false;
325 
326 	if(bits == 0)
327 		return true;
328 
329 	FLAC__ASSERT((bits == 32) || (val>>bits == 0));
330 
331 	/* slightly pessimistic size check but faster than "<= bw->words + (bw->bits+bits+FLAC__BITS_PER_WORD-1)/FLAC__BITS_PER_WORD" */
332 	if(bw->capacity <= bw->words + bits && !bitwriter_grow_(bw, bits))
333 		return false;
334 
335 	left = FLAC__BITS_PER_WORD - bw->bits;
336 	if(bits < left) {
337 		bw->accum <<= bits;
338 		bw->accum |= val;
339 		bw->bits += bits;
340 	}
341 	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 */
342 		bw->accum <<= left;
343 		bw->accum |= val >> (bw->bits = bits - left);
344 		bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum);
345 		bw->accum = val; /* unused top bits can contain garbage */
346 	}
347 	else { /* at this point bits == FLAC__BITS_PER_WORD == 32  and  bw->bits == 0 */
348 		bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST((bwword)val);
349 	}
350 
351 	return true;
352 }
353 
FLAC__bitwriter_write_raw_uint32(FLAC__BitWriter * bw,FLAC__uint32 val,uint32_t bits)354 inline FLAC__bool FLAC__bitwriter_write_raw_uint32(FLAC__BitWriter *bw, FLAC__uint32 val, uint32_t bits)
355 {
356 	/* check that unused bits are unset */
357 	if((bits < 32) && (val>>bits != 0))
358 		return false;
359 
360 	return FLAC__bitwriter_write_raw_uint32_nocheck(bw, val, bits);
361 }
362 
FLAC__bitwriter_write_raw_int32(FLAC__BitWriter * bw,FLAC__int32 val,uint32_t bits)363 inline FLAC__bool FLAC__bitwriter_write_raw_int32(FLAC__BitWriter *bw, FLAC__int32 val, uint32_t bits)
364 {
365 	/* zero-out unused bits */
366 	if(bits < 32)
367 		val &= (~(0xffffffff << bits));
368 
369 	return FLAC__bitwriter_write_raw_uint32_nocheck(bw, (FLAC__uint32)val, bits);
370 }
371 
FLAC__bitwriter_write_raw_uint64(FLAC__BitWriter * bw,FLAC__uint64 val,uint32_t bits)372 inline FLAC__bool FLAC__bitwriter_write_raw_uint64(FLAC__BitWriter *bw, FLAC__uint64 val, uint32_t bits)
373 {
374 	/* this could be a little faster but it's not used for much */
375 	if(bits > 32) {
376 		return
377 			FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)(val>>32), bits-32) &&
378 			FLAC__bitwriter_write_raw_uint32_nocheck(bw, (FLAC__uint32)val, 32);
379 	}
380 	else
381 		return FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)val, bits);
382 }
383 
FLAC__bitwriter_write_raw_int64(FLAC__BitWriter * bw,FLAC__int64 val,uint32_t bits)384 inline FLAC__bool FLAC__bitwriter_write_raw_int64(FLAC__BitWriter *bw, FLAC__int64 val, uint32_t bits)
385 {
386 	FLAC__uint64 uval = val;
387 	/* zero-out unused bits */
388 	if(bits < 64)
389 		uval &= (~(UINT64_MAX << bits));
390 	return FLAC__bitwriter_write_raw_uint64(bw, uval, bits);
391 }
392 
FLAC__bitwriter_write_raw_uint32_little_endian(FLAC__BitWriter * bw,FLAC__uint32 val)393 inline FLAC__bool FLAC__bitwriter_write_raw_uint32_little_endian(FLAC__BitWriter *bw, FLAC__uint32 val)
394 {
395 	/* this doesn't need to be that fast as currently it is only used for vorbis comments */
396 
397 	if(!FLAC__bitwriter_write_raw_uint32_nocheck(bw, val & 0xff, 8))
398 		return false;
399 	if(!FLAC__bitwriter_write_raw_uint32_nocheck(bw, (val>>8) & 0xff, 8))
400 		return false;
401 	if(!FLAC__bitwriter_write_raw_uint32_nocheck(bw, (val>>16) & 0xff, 8))
402 		return false;
403 	if(!FLAC__bitwriter_write_raw_uint32_nocheck(bw, val>>24, 8))
404 		return false;
405 
406 	return true;
407 }
408 
FLAC__bitwriter_write_byte_block(FLAC__BitWriter * bw,const FLAC__byte vals[],uint32_t nvals)409 inline FLAC__bool FLAC__bitwriter_write_byte_block(FLAC__BitWriter *bw, const FLAC__byte vals[], uint32_t nvals)
410 {
411 	uint32_t i;
412 
413 	/* grow capacity upfront to prevent constant reallocation during writes */
414 	if(bw->capacity <= bw->words + nvals / (FLAC__BITS_PER_WORD / 8) + 1 && !bitwriter_grow_(bw, nvals * 8))
415 		return false;
416 
417 	/* this could be faster but currently we don't need it to be since it's only used for writing metadata */
418 	for(i = 0; i < nvals; i++) {
419 		if(!FLAC__bitwriter_write_raw_uint32_nocheck(bw, (FLAC__uint32)(vals[i]), 8))
420 			return false;
421 	}
422 
423 	return true;
424 }
425 
FLAC__bitwriter_write_unary_unsigned(FLAC__BitWriter * bw,uint32_t val)426 FLAC__bool FLAC__bitwriter_write_unary_unsigned(FLAC__BitWriter *bw, uint32_t val)
427 {
428 	if(val < 32)
429 		return FLAC__bitwriter_write_raw_uint32_nocheck(bw, 1, ++val);
430 	else
431 		return
432 			FLAC__bitwriter_write_zeroes(bw, val) &&
433 			FLAC__bitwriter_write_raw_uint32_nocheck(bw, 1, 1);
434 }
435 
436 #if 0 /* UNUSED */
437 uint32_t FLAC__bitwriter_rice_bits(FLAC__int32 val, uint32_t parameter)
438 {
439 	FLAC__uint32 uval;
440 
441 	FLAC__ASSERT(parameter < 32);
442 
443 	/* fold signed to uint32_t; actual formula is: negative(v)? -2v-1 : 2v */
444 	uval = val;
445 	uval <<= 1;
446 	uval ^= (val>>31);
447 
448 	return 1 + parameter + (uval >> parameter);
449 }
450 
451 uint32_t FLAC__bitwriter_golomb_bits_signed(int val, uint32_t parameter)
452 {
453 	uint32_t bits, msbs, uval;
454 	uint32_t k;
455 
456 	FLAC__ASSERT(parameter > 0);
457 
458 	/* fold signed to uint32_t */
459 	if(val < 0)
460 		uval = (uint32_t)(((-(++val)) << 1) + 1);
461 	else
462 		uval = (uint32_t)(val << 1);
463 
464 	k = FLAC__bitmath_ilog2(parameter);
465 	if(parameter == 1u<<k) {
466 		FLAC__ASSERT(k <= 30);
467 
468 		msbs = uval >> k;
469 		bits = 1 + k + msbs;
470 	}
471 	else {
472 		uint32_t q, r, d;
473 
474 		d = (1 << (k+1)) - parameter;
475 		q = uval / parameter;
476 		r = uval - (q * parameter);
477 
478 		bits = 1 + q + k;
479 		if(r >= d)
480 			bits++;
481 	}
482 	return bits;
483 }
484 
485 uint32_t FLAC__bitwriter_golomb_bits_unsigned(uint32_t uval, uint32_t parameter)
486 {
487 	uint32_t bits, msbs;
488 	uint32_t k;
489 
490 	FLAC__ASSERT(parameter > 0);
491 
492 	k = FLAC__bitmath_ilog2(parameter);
493 	if(parameter == 1u<<k) {
494 		FLAC__ASSERT(k <= 30);
495 
496 		msbs = uval >> k;
497 		bits = 1 + k + msbs;
498 	}
499 	else {
500 		uint32_t q, r, d;
501 
502 		d = (1 << (k+1)) - parameter;
503 		q = uval / parameter;
504 		r = uval - (q * parameter);
505 
506 		bits = 1 + q + k;
507 		if(r >= d)
508 			bits++;
509 	}
510 	return bits;
511 }
512 
513 FLAC__bool FLAC__bitwriter_write_rice_signed(FLAC__BitWriter *bw, FLAC__int32 val, uint32_t parameter)
514 {
515 	uint32_t total_bits, interesting_bits, msbs;
516 	FLAC__uint32 uval, pattern;
517 
518 	FLAC__ASSERT(0 != bw);
519 	FLAC__ASSERT(0 != bw->buffer);
520 	FLAC__ASSERT(parameter < 32);
521 
522 	/* fold signed to uint32_t; actual formula is: negative(v)? -2v-1 : 2v */
523 	uval = val;
524 	uval <<= 1;
525 	uval ^= (val>>31);
526 
527 	msbs = uval >> parameter;
528 	interesting_bits = 1 + parameter;
529 	total_bits = interesting_bits + msbs;
530 	pattern = 1 << parameter; /* the unary end bit */
531 	pattern |= (uval & ((1<<parameter)-1)); /* the binary LSBs */
532 
533 	if(total_bits <= 32)
534 		return FLAC__bitwriter_write_raw_uint32(bw, pattern, total_bits);
535 	else
536 		return
537 			FLAC__bitwriter_write_zeroes(bw, msbs) && /* write the unary MSBs */
538 			FLAC__bitwriter_write_raw_uint32(bw, pattern, interesting_bits); /* write the unary end bit and binary LSBs */
539 }
540 #endif /* UNUSED */
541 
542 #if (ENABLE_64_BIT_WORDS == 0)
543 
544 #define WIDE_ACCUM_TO_BW {  \
545 	bw->accum = wide_accum >> FLAC__HALF_TEMP_BITS;  \
546 	bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum); \
547 	wide_accum <<= FLAC__HALF_TEMP_BITS;  \
548 	bitpointer += FLAC__HALF_TEMP_BITS;  \
549 }
550 
551 #else
552 
553 #define WIDE_ACCUM_TO_BW {  \
554 	FLAC__ASSERT(bw->bits % FLAC__HALF_TEMP_BITS == 0);  \
555 	if(bw->bits == 0) {  \
556 		bw->accum = wide_accum >> FLAC__HALF_TEMP_BITS;  \
557 		wide_accum <<= FLAC__HALF_TEMP_BITS;  \
558 		bw->bits = FLAC__HALF_TEMP_BITS;  \
559 	}  \
560 	else {  \
561 		bw->accum <<= FLAC__HALF_TEMP_BITS;  \
562 		bw->accum += wide_accum >> FLAC__HALF_TEMP_BITS;  \
563 		bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum);  \
564 		wide_accum <<= FLAC__HALF_TEMP_BITS;  \
565 		bw->bits = 0;  \
566 	}  \
567 	bitpointer += FLAC__HALF_TEMP_BITS;  \
568 }
569 
570 #endif
571 
FLAC__bitwriter_write_rice_signed_block(FLAC__BitWriter * bw,const FLAC__int32 * vals,uint32_t nvals,uint32_t parameter)572 FLAC__bool FLAC__bitwriter_write_rice_signed_block(FLAC__BitWriter *bw, const FLAC__int32 *vals, uint32_t nvals, uint32_t parameter)
573 {
574 	const FLAC__uint32 mask1 = (FLAC__uint32)0xffffffff << parameter; /* we val|=mask1 to set the stop bit above it... */
575 	const FLAC__uint32 mask2 = (FLAC__uint32)0xffffffff >> (31-parameter); /* ...then mask off the bits above the stop bit with val&=mask2 */
576 	FLAC__uint32 uval;
577 	const uint32_t lsbits = 1 + parameter;
578 	uint32_t msbits, total_bits;
579 	FLAC__bwtemp wide_accum = 0;
580 	FLAC__uint32 bitpointer = FLAC__TEMP_BITS;
581 
582 	FLAC__ASSERT(0 != bw);
583 	FLAC__ASSERT(0 != bw->buffer);
584 	FLAC__ASSERT(parameter < 31);
585 	/* WATCHOUT: code does not work with <32bit words; we can make things much faster with this assertion */
586 	FLAC__ASSERT(FLAC__BITS_PER_WORD >= 32);
587 #if (ENABLE_64_BIT_WORDS == 0)
588 	if(bw->bits > 0) {
589 		bitpointer -= bw->bits;
590 		wide_accum = (FLAC__bwtemp)(bw->accum) << bitpointer;
591 		bw->bits = 0;
592 	}
593 #else
594 	if(bw->bits > 0 && bw->bits < FLAC__HALF_TEMP_BITS) {
595 		bitpointer -= bw->bits;
596 		wide_accum = bw->accum << bitpointer;
597 		bw->bits = 0;
598 	}
599 	else if(bw->bits > FLAC__HALF_TEMP_BITS) {
600 		bitpointer -= (bw->bits - FLAC__HALF_TEMP_BITS);
601 		wide_accum = bw->accum << bitpointer;
602 		bw->accum >>= (bw->bits - FLAC__HALF_TEMP_BITS);
603 		bw->bits = FLAC__HALF_TEMP_BITS;
604 	}
605 #endif
606 
607 	/* Reserve one FLAC__TEMP_BITS per symbol, so checks for space are only necessary when very large symbols are encountered
608 	 * this might be considered wasteful, but is only at most 8kB more than necessary for a blocksize of 4096 */
609 	if(bw->capacity * FLAC__BITS_PER_WORD <= bw->words * FLAC__BITS_PER_WORD + nvals * FLAC__TEMP_BITS + bw->bits && !bitwriter_grow_(bw, nvals * FLAC__TEMP_BITS))
610 		return false;
611 
612 	while(nvals) {
613 		/* fold signed to uint32_t; actual formula is: negative(v)? -2v-1 : 2v */
614 		uval = *vals;
615 		uval <<= 1;
616 		uval ^= (*vals>>31);
617 
618 		msbits = uval >> parameter;
619 		total_bits = lsbits + msbits;
620 
621 		uval |= mask1; /* set stop bit */
622 		uval &= mask2; /* mask off unused top bits */
623 
624 
625 		if(total_bits <= bitpointer) {
626 			/* There is room enough to store the symbol whole at once */
627 			wide_accum |= (FLAC__bwtemp)(uval) << (bitpointer - total_bits);
628 			bitpointer -= total_bits;
629 			if(bitpointer <= FLAC__HALF_TEMP_BITS) {
630 				/* A word is finished, copy the upper 32 bits of the wide_accum */
631 				WIDE_ACCUM_TO_BW
632 			}
633 		}
634 		else {
635 			/* The symbol needs to be split. This code isn't used often */
636 			/* First check for space in the bitwriter */
637 			if(total_bits > FLAC__TEMP_BITS) {
638 				FLAC__uint32 oversize_in_bits = total_bits - FLAC__TEMP_BITS;
639 				FLAC__uint32 capacity_needed = bw->words * FLAC__BITS_PER_WORD + bw->bits + nvals * FLAC__TEMP_BITS + oversize_in_bits;
640 				if(bw->capacity * FLAC__BITS_PER_WORD <= capacity_needed && !bitwriter_grow_(bw, nvals * FLAC__TEMP_BITS + oversize_in_bits))
641 					return false;
642 			}
643 			if(msbits > bitpointer) {
644 				/* We have a lot of 0 bits to write, first align with bitwriter word */
645 				msbits -= bitpointer - FLAC__HALF_TEMP_BITS;
646 				bitpointer = FLAC__HALF_TEMP_BITS;
647 				WIDE_ACCUM_TO_BW
648 				while(msbits > bitpointer) {
649 					/* As the accumulator is already zero, we only need to
650 					 * assign zeroes to the bitbuffer */
651 					WIDE_ACCUM_TO_BW
652 					bitpointer -= FLAC__HALF_TEMP_BITS;
653 					msbits -= FLAC__HALF_TEMP_BITS;
654 				}
655 				/* The remaining bits are zero, and the accumulator already is zero,
656 				 * so just subtract the number of bits from bitpointer. When storing,
657 				 * we can also just store 0 */
658 				bitpointer -= msbits;
659 				if(bitpointer <= FLAC__HALF_TEMP_BITS)
660 					WIDE_ACCUM_TO_BW
661 			}
662 			else {
663 				bitpointer -= msbits;
664 				if(bitpointer <= FLAC__HALF_TEMP_BITS)
665 					WIDE_ACCUM_TO_BW
666 			}
667 			/* The lsbs + stop bit always fit 32 bit, so this code mirrors the code above */
668                         wide_accum |= (FLAC__bwtemp)(uval) << (bitpointer - lsbits);
669                         bitpointer -= lsbits;
670                         if(bitpointer <= FLAC__HALF_TEMP_BITS) {
671                                 /* A word is finished, copy the upper 32 bits of the wide_accum */
672                                 WIDE_ACCUM_TO_BW
673                         }
674 		}
675 		vals++;
676 		nvals--;
677 	}
678 	/* Now fixup remainder of wide_accum */
679 #if (ENABLE_64_BIT_WORDS == 0)
680 	if(bitpointer < FLAC__TEMP_BITS) {
681 		bw->accum = wide_accum >> bitpointer;
682 		bw->bits = FLAC__TEMP_BITS - bitpointer;
683 	}
684 #else
685 	if(bitpointer < FLAC__TEMP_BITS) {
686 		if(bw->bits == 0) {
687 			bw->accum = wide_accum >> bitpointer;
688 			bw->bits = FLAC__TEMP_BITS - bitpointer;
689 		}
690 		else if (bw->bits == FLAC__HALF_TEMP_BITS) {
691 			bw->accum <<= FLAC__TEMP_BITS - bitpointer;
692 			bw->accum |= (wide_accum >> bitpointer);
693 			bw->bits = FLAC__HALF_TEMP_BITS + FLAC__TEMP_BITS - bitpointer;
694 		}
695 		else {
696 			FLAC__ASSERT(0);
697 		}
698 	}
699 #endif
700 
701 
702 	return true;
703 }
704 
705 #if 0 /* UNUSED */
706 FLAC__bool FLAC__bitwriter_write_golomb_signed(FLAC__BitWriter *bw, int val, uint32_t parameter)
707 {
708 	uint32_t total_bits, msbs, uval;
709 	uint32_t k;
710 
711 	FLAC__ASSERT(0 != bw);
712 	FLAC__ASSERT(0 != bw->buffer);
713 	FLAC__ASSERT(parameter > 0);
714 
715 	/* fold signed to uint32_t */
716 	if(val < 0)
717 		uval = (uint32_t)(((-(++val)) << 1) + 1);
718 	else
719 		uval = (uint32_t)(val << 1);
720 
721 	k = FLAC__bitmath_ilog2(parameter);
722 	if(parameter == 1u<<k) {
723 		uint32_t pattern;
724 
725 		FLAC__ASSERT(k <= 30);
726 
727 		msbs = uval >> k;
728 		total_bits = 1 + k + msbs;
729 		pattern = 1 << k; /* the unary end bit */
730 		pattern |= (uval & ((1u<<k)-1)); /* the binary LSBs */
731 
732 		if(total_bits <= 32) {
733 			if(!FLAC__bitwriter_write_raw_uint32(bw, pattern, total_bits))
734 				return false;
735 		}
736 		else {
737 			/* write the unary MSBs */
738 			if(!FLAC__bitwriter_write_zeroes(bw, msbs))
739 				return false;
740 			/* write the unary end bit and binary LSBs */
741 			if(!FLAC__bitwriter_write_raw_uint32(bw, pattern, k+1))
742 				return false;
743 		}
744 	}
745 	else {
746 		uint32_t q, r, d;
747 
748 		d = (1 << (k+1)) - parameter;
749 		q = uval / parameter;
750 		r = uval - (q * parameter);
751 		/* write the unary MSBs */
752 		if(!FLAC__bitwriter_write_zeroes(bw, q))
753 			return false;
754 		/* write the unary end bit */
755 		if(!FLAC__bitwriter_write_raw_uint32(bw, 1, 1))
756 			return false;
757 		/* write the binary LSBs */
758 		if(r >= d) {
759 			if(!FLAC__bitwriter_write_raw_uint32(bw, r+d, k+1))
760 				return false;
761 		}
762 		else {
763 			if(!FLAC__bitwriter_write_raw_uint32(bw, r, k))
764 				return false;
765 		}
766 	}
767 	return true;
768 }
769 
770 FLAC__bool FLAC__bitwriter_write_golomb_unsigned(FLAC__BitWriter *bw, uint32_t uval, uint32_t parameter)
771 {
772 	uint32_t total_bits, msbs;
773 	uint32_t k;
774 
775 	FLAC__ASSERT(0 != bw);
776 	FLAC__ASSERT(0 != bw->buffer);
777 	FLAC__ASSERT(parameter > 0);
778 
779 	k = FLAC__bitmath_ilog2(parameter);
780 	if(parameter == 1u<<k) {
781 		uint32_t pattern;
782 
783 		FLAC__ASSERT(k <= 30);
784 
785 		msbs = uval >> k;
786 		total_bits = 1 + k + msbs;
787 		pattern = 1 << k; /* the unary end bit */
788 		pattern |= (uval & ((1u<<k)-1)); /* the binary LSBs */
789 
790 		if(total_bits <= 32) {
791 			if(!FLAC__bitwriter_write_raw_uint32(bw, pattern, total_bits))
792 				return false;
793 		}
794 		else {
795 			/* write the unary MSBs */
796 			if(!FLAC__bitwriter_write_zeroes(bw, msbs))
797 				return false;
798 			/* write the unary end bit and binary LSBs */
799 			if(!FLAC__bitwriter_write_raw_uint32(bw, pattern, k+1))
800 				return false;
801 		}
802 	}
803 	else {
804 		uint32_t q, r, d;
805 
806 		d = (1 << (k+1)) - parameter;
807 		q = uval / parameter;
808 		r = uval - (q * parameter);
809 		/* write the unary MSBs */
810 		if(!FLAC__bitwriter_write_zeroes(bw, q))
811 			return false;
812 		/* write the unary end bit */
813 		if(!FLAC__bitwriter_write_raw_uint32(bw, 1, 1))
814 			return false;
815 		/* write the binary LSBs */
816 		if(r >= d) {
817 			if(!FLAC__bitwriter_write_raw_uint32(bw, r+d, k+1))
818 				return false;
819 		}
820 		else {
821 			if(!FLAC__bitwriter_write_raw_uint32(bw, r, k))
822 				return false;
823 		}
824 	}
825 	return true;
826 }
827 #endif /* UNUSED */
828 
FLAC__bitwriter_write_utf8_uint32(FLAC__BitWriter * bw,FLAC__uint32 val)829 FLAC__bool FLAC__bitwriter_write_utf8_uint32(FLAC__BitWriter *bw, FLAC__uint32 val)
830 {
831 	FLAC__bool ok = 1;
832 
833 	FLAC__ASSERT(0 != bw);
834 	FLAC__ASSERT(0 != bw->buffer);
835 
836 	if((val & 0x80000000) != 0) /* this version only handles 31 bits */
837 		return false;
838 
839 	if(val < 0x80) {
840 		return FLAC__bitwriter_write_raw_uint32_nocheck(bw, val, 8);
841 	}
842 	else if(val < 0x800) {
843 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xC0 | (val>>6), 8);
844 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (val&0x3F), 8);
845 	}
846 	else if(val < 0x10000) {
847 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xE0 | (val>>12), 8);
848 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>6)&0x3F), 8);
849 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (val&0x3F), 8);
850 	}
851 	else if(val < 0x200000) {
852 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xF0 | (val>>18), 8);
853 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>12)&0x3F), 8);
854 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>6)&0x3F), 8);
855 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (val&0x3F), 8);
856 	}
857 	else if(val < 0x4000000) {
858 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xF8 | (val>>24), 8);
859 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>18)&0x3F), 8);
860 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>12)&0x3F), 8);
861 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>6)&0x3F), 8);
862 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (val&0x3F), 8);
863 	}
864 	else {
865 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xFC | (val>>30), 8);
866 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>24)&0x3F), 8);
867 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>18)&0x3F), 8);
868 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>12)&0x3F), 8);
869 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>6)&0x3F), 8);
870 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (val&0x3F), 8);
871 	}
872 
873 	return ok;
874 }
875 
FLAC__bitwriter_write_utf8_uint64(FLAC__BitWriter * bw,FLAC__uint64 val)876 FLAC__bool FLAC__bitwriter_write_utf8_uint64(FLAC__BitWriter *bw, FLAC__uint64 val)
877 {
878 	FLAC__bool ok = 1;
879 
880 	FLAC__ASSERT(0 != bw);
881 	FLAC__ASSERT(0 != bw->buffer);
882 
883 	if((val & FLAC__U64L(0xFFFFFFF000000000)) != 0) /* this version only handles 36 bits */
884 		return false;
885 
886 	if(val < 0x80) {
887 		return FLAC__bitwriter_write_raw_uint32_nocheck(bw, (FLAC__uint32)val, 8);
888 	}
889 	else if(val < 0x800) {
890 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xC0 | (FLAC__uint32)(val>>6), 8);
891 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
892 	}
893 	else if(val < 0x10000) {
894 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xE0 | (FLAC__uint32)(val>>12), 8);
895 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
896 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
897 	}
898 	else if(val < 0x200000) {
899 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xF0 | (FLAC__uint32)(val>>18), 8);
900 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
901 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
902 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
903 	}
904 	else if(val < 0x4000000) {
905 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xF8 | (FLAC__uint32)(val>>24), 8);
906 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>18)&0x3F), 8);
907 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
908 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
909 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
910 	}
911 	else if(val < 0x80000000) {
912 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xFC | (FLAC__uint32)(val>>30), 8);
913 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>24)&0x3F), 8);
914 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>18)&0x3F), 8);
915 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
916 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
917 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
918 	}
919 	else {
920 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xFE, 8);
921 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>30)&0x3F), 8);
922 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>24)&0x3F), 8);
923 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>18)&0x3F), 8);
924 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
925 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
926 		ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
927 	}
928 
929 	return ok;
930 }
931 
FLAC__bitwriter_zero_pad_to_byte_boundary(FLAC__BitWriter * bw)932 FLAC__bool FLAC__bitwriter_zero_pad_to_byte_boundary(FLAC__BitWriter *bw)
933 {
934 	/* 0-pad to byte boundary */
935 	if(bw->bits & 7u)
936 		return FLAC__bitwriter_write_zeroes(bw, 8 - (bw->bits & 7u));
937 	else
938 		return true;
939 }
940 
941 /* These functions are declared inline in this file but are also callable as
942  * externs from elsewhere.
943  * According to the C99 spec, section 6.7.4, simply providing a function
944  * prototype in a header file without 'inline' and making the function inline
945  * in this file should be sufficient.
946  * Unfortunately, the Microsoft VS compiler doesn't pick them up externally. To
947  * fix that we add extern declarations here.
948  */
949 extern FLAC__bool FLAC__bitwriter_write_zeroes(FLAC__BitWriter *bw, uint32_t bits);
950 extern FLAC__bool FLAC__bitwriter_write_raw_uint32(FLAC__BitWriter *bw, FLAC__uint32 val, uint32_t bits);
951 extern FLAC__bool FLAC__bitwriter_write_raw_int32(FLAC__BitWriter *bw, FLAC__int32 val, uint32_t bits);
952 extern FLAC__bool FLAC__bitwriter_write_raw_uint64(FLAC__BitWriter *bw, FLAC__uint64 val, uint32_t bits);
953 extern FLAC__bool FLAC__bitwriter_write_raw_int64(FLAC__BitWriter *bw, FLAC__int64 val, uint32_t bits);
954 extern FLAC__bool FLAC__bitwriter_write_raw_uint32_little_endian(FLAC__BitWriter *bw, FLAC__uint32 val);
955 extern FLAC__bool FLAC__bitwriter_write_byte_block(FLAC__BitWriter *bw, const FLAC__byte vals[], uint32_t nvals);
956