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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 <stdio.h>
38 #include <stdlib.h> /* for qsort() */
39 #include <string.h> /* for memset() */
40 #include "FLAC/assert.h"
41 #include "FLAC/format.h"
42 #include "share/alloc.h"
43 #include "share/compat.h"
44 #include "private/format.h"
45 #include "private/macros.h"
46 
47 #if (defined GIT_COMMIT_HASH && defined GIT_COMMIT_DATE)
48 # ifdef GIT_COMMIT_TAG
49 FLAC_API const char *FLAC__VERSION_STRING = GIT_COMMIT_TAG;
50 FLAC_API const char *FLAC__VENDOR_STRING = "reference libFLAC " GIT_COMMIT_TAG " " GIT_COMMIT_DATE;
51 # else
52 FLAC_API const char *FLAC__VERSION_STRING = "git-" GIT_COMMIT_HASH " " GIT_COMMIT_DATE;
53 FLAC_API const char *FLAC__VENDOR_STRING = "reference libFLAC git-" GIT_COMMIT_HASH " " GIT_COMMIT_DATE;
54 # endif
55 #else
56 /* PACKAGE_VERSION should come from configure */
57 FLAC_API const char *FLAC__VERSION_STRING = PACKAGE_VERSION;
58 FLAC_API const char *FLAC__VENDOR_STRING = "reference libFLAC " PACKAGE_VERSION " 20221022";
59 #endif
60 
61 FLAC_API const FLAC__byte FLAC__STREAM_SYNC_STRING[4] = { 'f','L','a','C' };
62 FLAC_API const uint32_t FLAC__STREAM_SYNC = 0x664C6143;
63 FLAC_API const uint32_t FLAC__STREAM_SYNC_LEN = 32; /* bits */
64 
65 FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN = 16; /* bits */
66 FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN = 16; /* bits */
67 FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN = 24; /* bits */
68 FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN = 24; /* bits */
69 FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN = 20; /* bits */
70 FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN = 3; /* bits */
71 FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN = 5; /* bits */
72 FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_TOTAL_SAMPLES_LEN = 36; /* bits */
73 FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_MD5SUM_LEN = 128; /* bits */
74 
75 FLAC_API const uint32_t FLAC__STREAM_METADATA_APPLICATION_ID_LEN = 32; /* bits */
76 
77 FLAC_API const uint32_t FLAC__STREAM_METADATA_SEEKPOINT_SAMPLE_NUMBER_LEN = 64; /* bits */
78 FLAC_API const uint32_t FLAC__STREAM_METADATA_SEEKPOINT_STREAM_OFFSET_LEN = 64; /* bits */
79 FLAC_API const uint32_t FLAC__STREAM_METADATA_SEEKPOINT_FRAME_SAMPLES_LEN = 16; /* bits */
80 
81 FLAC_API const FLAC__uint64 FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER = FLAC__U64L(0xffffffffffffffff);
82 
83 FLAC_API const uint32_t FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN = 32; /* bits */
84 FLAC_API const uint32_t FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN = 32; /* bits */
85 
86 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN = 64; /* bits */
87 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN = 8; /* bits */
88 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN = 3*8; /* bits */
89 
90 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN = 64; /* bits */
91 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN = 8; /* bits */
92 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN = 12*8; /* bits */
93 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN = 1; /* bit */
94 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN = 1; /* bit */
95 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN = 6+13*8; /* bits */
96 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN = 8; /* bits */
97 
98 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN = 128*8; /* bits */
99 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN = 64; /* bits */
100 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN = 1; /* bit */
101 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN = 7+258*8; /* bits */
102 FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN = 8; /* bits */
103 
104 FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_TYPE_LEN = 32; /* bits */
105 FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN = 32; /* bits */
106 FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN = 32; /* bits */
107 FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN = 32; /* bits */
108 FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN = 32; /* bits */
109 FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN = 32; /* bits */
110 FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_COLORS_LEN = 32; /* bits */
111 FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN = 32; /* bits */
112 
113 FLAC_API const uint32_t FLAC__STREAM_METADATA_IS_LAST_LEN = 1; /* bits */
114 FLAC_API const uint32_t FLAC__STREAM_METADATA_TYPE_LEN = 7; /* bits */
115 FLAC_API const uint32_t FLAC__STREAM_METADATA_LENGTH_LEN = 24; /* bits */
116 
117 FLAC_API const uint32_t FLAC__FRAME_HEADER_SYNC = 0x3ffe;
118 FLAC_API const uint32_t FLAC__FRAME_HEADER_SYNC_LEN = 14; /* bits */
119 FLAC_API const uint32_t FLAC__FRAME_HEADER_RESERVED_LEN = 1; /* bits */
120 FLAC_API const uint32_t FLAC__FRAME_HEADER_BLOCKING_STRATEGY_LEN = 1; /* bits */
121 FLAC_API const uint32_t FLAC__FRAME_HEADER_BLOCK_SIZE_LEN = 4; /* bits */
122 FLAC_API const uint32_t FLAC__FRAME_HEADER_SAMPLE_RATE_LEN = 4; /* bits */
123 FLAC_API const uint32_t FLAC__FRAME_HEADER_CHANNEL_ASSIGNMENT_LEN = 4; /* bits */
124 FLAC_API const uint32_t FLAC__FRAME_HEADER_BITS_PER_SAMPLE_LEN = 3; /* bits */
125 FLAC_API const uint32_t FLAC__FRAME_HEADER_ZERO_PAD_LEN = 1; /* bits */
126 FLAC_API const uint32_t FLAC__FRAME_HEADER_CRC_LEN = 8; /* bits */
127 
128 FLAC_API const uint32_t FLAC__FRAME_FOOTER_CRC_LEN = 16; /* bits */
129 
130 FLAC_API const uint32_t FLAC__ENTROPY_CODING_METHOD_TYPE_LEN = 2; /* bits */
131 FLAC_API const uint32_t FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN = 4; /* bits */
132 FLAC_API const uint32_t FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN = 4; /* bits */
133 FLAC_API const uint32_t FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2_PARAMETER_LEN = 5; /* bits */
134 FLAC_API const uint32_t FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_RAW_LEN = 5; /* bits */
135 
136 FLAC_API const uint32_t FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ESCAPE_PARAMETER = 15; /* == (1<<FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN)-1 */
137 FLAC_API const uint32_t FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2_ESCAPE_PARAMETER = 31; /* == (1<<FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2_PARAMETER_LEN)-1 */
138 
139 FLAC_API const char * const FLAC__EntropyCodingMethodTypeString[] = {
140 	"PARTITIONED_RICE",
141 	"PARTITIONED_RICE2"
142 };
143 
144 FLAC_API const uint32_t FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN = 4; /* bits */
145 FLAC_API const uint32_t FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN = 5; /* bits */
146 
147 FLAC_API const uint32_t FLAC__SUBFRAME_ZERO_PAD_LEN = 1; /* bits */
148 FLAC_API const uint32_t FLAC__SUBFRAME_TYPE_LEN = 6; /* bits */
149 FLAC_API const uint32_t FLAC__SUBFRAME_WASTED_BITS_FLAG_LEN = 1; /* bits */
150 
151 FLAC_API const uint32_t FLAC__SUBFRAME_TYPE_CONSTANT_BYTE_ALIGNED_MASK = 0x00;
152 FLAC_API const uint32_t FLAC__SUBFRAME_TYPE_VERBATIM_BYTE_ALIGNED_MASK = 0x02;
153 FLAC_API const uint32_t FLAC__SUBFRAME_TYPE_FIXED_BYTE_ALIGNED_MASK = 0x10;
154 FLAC_API const uint32_t FLAC__SUBFRAME_TYPE_LPC_BYTE_ALIGNED_MASK = 0x40;
155 
156 FLAC_API const char * const FLAC__SubframeTypeString[] = {
157 	"CONSTANT",
158 	"VERBATIM",
159 	"FIXED",
160 	"LPC"
161 };
162 
163 FLAC_API const char * const FLAC__ChannelAssignmentString[] = {
164 	"INDEPENDENT",
165 	"LEFT_SIDE",
166 	"RIGHT_SIDE",
167 	"MID_SIDE"
168 };
169 
170 FLAC_API const char * const FLAC__FrameNumberTypeString[] = {
171 	"FRAME_NUMBER_TYPE_FRAME_NUMBER",
172 	"FRAME_NUMBER_TYPE_SAMPLE_NUMBER"
173 };
174 
175 FLAC_API const char * const FLAC__MetadataTypeString[] = {
176 	"STREAMINFO",
177 	"PADDING",
178 	"APPLICATION",
179 	"SEEKTABLE",
180 	"VORBIS_COMMENT",
181 	"CUESHEET",
182 	"PICTURE"
183 };
184 
185 FLAC_API const char * const FLAC__StreamMetadata_Picture_TypeString[] = {
186 	"Other",
187 	"32x32 pixels 'file icon' (PNG only)",
188 	"Other file icon",
189 	"Cover (front)",
190 	"Cover (back)",
191 	"Leaflet page",
192 	"Media (e.g. label side of CD)",
193 	"Lead artist/lead performer/soloist",
194 	"Artist/performer",
195 	"Conductor",
196 	"Band/Orchestra",
197 	"Composer",
198 	"Lyricist/text writer",
199 	"Recording Location",
200 	"During recording",
201 	"During performance",
202 	"Movie/video screen capture",
203 	"A bright coloured fish",
204 	"Illustration",
205 	"Band/artist logotype",
206 	"Publisher/Studio logotype"
207 };
208 
FLAC__format_sample_rate_is_valid(uint32_t sample_rate)209 FLAC_API FLAC__bool FLAC__format_sample_rate_is_valid(uint32_t sample_rate)
210 {
211 	if(sample_rate == 0 || sample_rate > FLAC__MAX_SAMPLE_RATE) {
212 		return false;
213 	}
214 	else
215 		return true;
216 }
217 
FLAC__format_blocksize_is_subset(uint32_t blocksize,uint32_t sample_rate)218 FLAC_API FLAC__bool FLAC__format_blocksize_is_subset(uint32_t blocksize, uint32_t sample_rate)
219 {
220 	if(blocksize > 16384)
221 		return false;
222 	else if(sample_rate <= 48000 && blocksize > 4608)
223 		return false;
224 	else
225 		return true;
226 }
227 
FLAC__format_sample_rate_is_subset(uint32_t sample_rate)228 FLAC_API FLAC__bool FLAC__format_sample_rate_is_subset(uint32_t sample_rate)
229 {
230 	if( // sample rate is not subset if
231 		!FLAC__format_sample_rate_is_valid(sample_rate) || // sample rate is invalid or
232 		sample_rate >= ((1u << 16) * 10) || // sample rate is larger then or equal to 655360 or
233 		(sample_rate >= (1u << 16) && sample_rate % 10 != 0) //sample rate is >= 65536 and not divisible by 10
234 	) {
235 		return false;
236 	}
237 	else
238 		return true;
239 }
240 
241 /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
FLAC__format_seektable_is_legal(const FLAC__StreamMetadata_SeekTable * seek_table)242 FLAC_API FLAC__bool FLAC__format_seektable_is_legal(const FLAC__StreamMetadata_SeekTable *seek_table)
243 {
244 	uint32_t i;
245 	FLAC__uint64 prev_sample_number = 0;
246 	FLAC__bool got_prev = false;
247 
248 	FLAC__ASSERT(0 != seek_table);
249 
250 	for(i = 0; i < seek_table->num_points; i++) {
251 		if(got_prev) {
252 			if(
253 				seek_table->points[i].sample_number != FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER &&
254 				seek_table->points[i].sample_number <= prev_sample_number
255 			)
256 				return false;
257 		}
258 		prev_sample_number = seek_table->points[i].sample_number;
259 		got_prev = true;
260 	}
261 
262 	return true;
263 }
264 
265 /* used as the sort predicate for qsort() */
seekpoint_compare_(const FLAC__StreamMetadata_SeekPoint * l,const FLAC__StreamMetadata_SeekPoint * r)266 static int seekpoint_compare_(const FLAC__StreamMetadata_SeekPoint *l, const FLAC__StreamMetadata_SeekPoint *r)
267 {
268 	/* we don't just 'return l->sample_number - r->sample_number' since the result (FLAC__int64) might overflow an 'int' */
269 	if(l->sample_number == r->sample_number)
270 		return 0;
271 	else if(l->sample_number < r->sample_number)
272 		return -1;
273 	else
274 		return 1;
275 }
276 
277 /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
FLAC__format_seektable_sort(FLAC__StreamMetadata_SeekTable * seek_table)278 FLAC_API uint32_t FLAC__format_seektable_sort(FLAC__StreamMetadata_SeekTable *seek_table)
279 {
280 	uint32_t i, j;
281 	FLAC__bool first;
282 
283 	FLAC__ASSERT(0 != seek_table);
284 
285 	if (seek_table->num_points == 0)
286 		return 0;
287 
288 	/* sort the seekpoints */
289 	qsort(seek_table->points, seek_table->num_points, sizeof(FLAC__StreamMetadata_SeekPoint), (int (*)(const void *, const void *))seekpoint_compare_);
290 
291 	/* uniquify the seekpoints */
292 	first = true;
293 	for(i = j = 0; i < seek_table->num_points; i++) {
294 		if(seek_table->points[i].sample_number != FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER) {
295 			if(!first) {
296 				if(seek_table->points[i].sample_number == seek_table->points[j-1].sample_number)
297 					continue;
298 			}
299 		}
300 		first = false;
301 		seek_table->points[j++] = seek_table->points[i];
302 	}
303 
304 	for(i = j; i < seek_table->num_points; i++) {
305 		seek_table->points[i].sample_number = FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER;
306 		seek_table->points[i].stream_offset = 0;
307 		seek_table->points[i].frame_samples = 0;
308 	}
309 
310 	return j;
311 }
312 
313 /*
314  * also disallows non-shortest-form encodings, c.f.
315  *   http://www.unicode.org/versions/corrigendum1.html
316  * and a more clear explanation at the end of this section:
317  *   http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
318  */
utf8len_(const FLAC__byte * utf8)319 static uint32_t utf8len_(const FLAC__byte *utf8)
320 {
321 	FLAC__ASSERT(0 != utf8);
322 	if ((utf8[0] & 0x80) == 0) {
323 		return 1;
324 	}
325 	else if ((utf8[0] & 0xE0) == 0xC0 && (utf8[1] & 0xC0) == 0x80) {
326 		if ((utf8[0] & 0xFE) == 0xC0) /* overlong sequence check */
327 			return 0;
328 		return 2;
329 	}
330 	else if ((utf8[0] & 0xF0) == 0xE0 && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80) {
331 		if (utf8[0] == 0xE0 && (utf8[1] & 0xE0) == 0x80) /* overlong sequence check */
332 			return 0;
333 		/* illegal surrogates check (U+D800...U+DFFF and U+FFFE...U+FFFF) */
334 		if (utf8[0] == 0xED && (utf8[1] & 0xE0) == 0xA0) /* D800-DFFF */
335 			return 0;
336 		if (utf8[0] == 0xEF && utf8[1] == 0xBF && (utf8[2] & 0xFE) == 0xBE) /* FFFE-FFFF */
337 			return 0;
338 		return 3;
339 	}
340 	else if ((utf8[0] & 0xF8) == 0xF0 && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80 && (utf8[3] & 0xC0) == 0x80) {
341 		if (utf8[0] == 0xF0 && (utf8[1] & 0xF0) == 0x80) /* overlong sequence check */
342 			return 0;
343 		return 4;
344 	}
345 	else if ((utf8[0] & 0xFC) == 0xF8 && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80 && (utf8[3] & 0xC0) == 0x80 && (utf8[4] & 0xC0) == 0x80) {
346 		if (utf8[0] == 0xF8 && (utf8[1] & 0xF8) == 0x80) /* overlong sequence check */
347 			return 0;
348 		return 5;
349 	}
350 	else if ((utf8[0] & 0xFE) == 0xFC && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80 && (utf8[3] & 0xC0) == 0x80 && (utf8[4] & 0xC0) == 0x80 && (utf8[5] & 0xC0) == 0x80) {
351 		if (utf8[0] == 0xFC && (utf8[1] & 0xFC) == 0x80) /* overlong sequence check */
352 			return 0;
353 		return 6;
354 	}
355 	else {
356 		return 0;
357 	}
358 }
359 
FLAC__format_vorbiscomment_entry_name_is_legal(const char * name)360 FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_name_is_legal(const char *name)
361 {
362 	char c;
363 	for(c = *name; c; c = *(++name))
364 		if(c < 0x20 || c == 0x3d || c > 0x7d)
365 			return false;
366 	return true;
367 }
368 
FLAC__format_vorbiscomment_entry_value_is_legal(const FLAC__byte * value,uint32_t length)369 FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_value_is_legal(const FLAC__byte *value, uint32_t length)
370 {
371 	if(length == (uint32_t)(-1)) {
372 		while(*value) {
373 			uint32_t n = utf8len_(value);
374 			if(n == 0)
375 				return false;
376 			value += n;
377 		}
378 	}
379 	else {
380 		const FLAC__byte *end = value + length;
381 		while(value < end) {
382 			uint32_t n = utf8len_(value);
383 			if(n == 0)
384 				return false;
385 			value += n;
386 		}
387 		if(value != end)
388 			return false;
389 	}
390 	return true;
391 }
392 
FLAC__format_vorbiscomment_entry_is_legal(const FLAC__byte * entry,uint32_t length)393 FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_is_legal(const FLAC__byte *entry, uint32_t length)
394 {
395 	const FLAC__byte *s, *end;
396 
397 	for(s = entry, end = s + length; s < end && *s != '='; s++) {
398 		if(*s < 0x20 || *s > 0x7D)
399 			return false;
400 	}
401 	if(s == end)
402 		return false;
403 
404 	s++; /* skip '=' */
405 
406 	while(s < end) {
407 		uint32_t n = utf8len_(s);
408 		if(n == 0)
409 			return false;
410 		s += n;
411 	}
412 	if(s != end)
413 		return false;
414 
415 	return true;
416 }
417 
418 /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
FLAC__format_cuesheet_is_legal(const FLAC__StreamMetadata_CueSheet * cue_sheet,FLAC__bool check_cd_da_subset,const char ** violation)419 FLAC_API FLAC__bool FLAC__format_cuesheet_is_legal(const FLAC__StreamMetadata_CueSheet *cue_sheet, FLAC__bool check_cd_da_subset, const char **violation)
420 {
421 	uint32_t i, j;
422 
423 	if(check_cd_da_subset) {
424 		if(cue_sheet->lead_in < 2 * 44100) {
425 			if(violation) *violation = "CD-DA cue sheet must have a lead-in length of at least 2 seconds";
426 			return false;
427 		}
428 		if(cue_sheet->lead_in % 588 != 0) {
429 			if(violation) *violation = "CD-DA cue sheet lead-in length must be evenly divisible by 588 samples";
430 			return false;
431 		}
432 	}
433 
434 	if(cue_sheet->num_tracks == 0) {
435 		if(violation) *violation = "cue sheet must have at least one track (the lead-out)";
436 		return false;
437 	}
438 
439 	if(check_cd_da_subset && cue_sheet->tracks[cue_sheet->num_tracks-1].number != 170) {
440 		if(violation) *violation = "CD-DA cue sheet must have a lead-out track number 170 (0xAA)";
441 		return false;
442 	}
443 
444 	for(i = 0; i < cue_sheet->num_tracks; i++) {
445 		if(cue_sheet->tracks[i].number == 0) {
446 			if(violation) *violation = "cue sheet may not have a track number 0";
447 			return false;
448 		}
449 
450 		if(check_cd_da_subset) {
451 			if(!((cue_sheet->tracks[i].number >= 1 && cue_sheet->tracks[i].number <= 99) || cue_sheet->tracks[i].number == 170)) {
452 				if(violation) *violation = "CD-DA cue sheet track number must be 1-99 or 170";
453 				return false;
454 			}
455 		}
456 
457 		if(check_cd_da_subset && cue_sheet->tracks[i].offset % 588 != 0) {
458 			if(violation) {
459 				if(i == cue_sheet->num_tracks-1) /* the lead-out track... */
460 					*violation = "CD-DA cue sheet lead-out offset must be evenly divisible by 588 samples";
461 				else
462 					*violation = "CD-DA cue sheet track offset must be evenly divisible by 588 samples";
463 			}
464 			return false;
465 		}
466 
467 		if(i < cue_sheet->num_tracks - 1) {
468 			if(cue_sheet->tracks[i].num_indices == 0) {
469 				if(violation) *violation = "cue sheet track must have at least one index point";
470 				return false;
471 			}
472 
473 			if(cue_sheet->tracks[i].indices[0].number > 1) {
474 				if(violation) *violation = "cue sheet track's first index number must be 0 or 1";
475 				return false;
476 			}
477 		}
478 
479 		for(j = 0; j < cue_sheet->tracks[i].num_indices; j++) {
480 			if(check_cd_da_subset && cue_sheet->tracks[i].indices[j].offset % 588 != 0) {
481 				if(violation) *violation = "CD-DA cue sheet track index offset must be evenly divisible by 588 samples";
482 				return false;
483 			}
484 
485 			if(j > 0) {
486 				if(cue_sheet->tracks[i].indices[j].number != cue_sheet->tracks[i].indices[j-1].number + 1) {
487 					if(violation) *violation = "cue sheet track index numbers must increase by 1";
488 					return false;
489 				}
490 			}
491 		}
492 	}
493 
494 	return true;
495 }
496 
497 /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
FLAC__format_picture_is_legal(const FLAC__StreamMetadata_Picture * picture,const char ** violation)498 FLAC_API FLAC__bool FLAC__format_picture_is_legal(const FLAC__StreamMetadata_Picture *picture, const char **violation)
499 {
500 	char *p;
501 	FLAC__byte *b;
502 
503 	for(p = picture->mime_type; *p; p++) {
504 		if(*p < 0x20 || *p > 0x7e) {
505 			if(violation) *violation = "MIME type string must contain only printable ASCII characters (0x20-0x7e)";
506 			return false;
507 		}
508 	}
509 
510 	for(b = picture->description; *b; ) {
511 		uint32_t n = utf8len_(b);
512 		if(n == 0) {
513 			if(violation) *violation = "description string must be valid UTF-8";
514 			return false;
515 		}
516 		b += n;
517 	}
518 
519 	return true;
520 }
521 
522 /*
523  * These routines are private to libFLAC
524  */
525 #if 0 /* UNUSED */
526 uint32_t FLAC__format_get_max_rice_partition_order(uint32_t blocksize, uint32_t predictor_order)
527 {
528 	return
529 		FLAC__format_get_max_rice_partition_order_from_blocksize_limited_max_and_predictor_order(
530 			FLAC__format_get_max_rice_partition_order_from_blocksize(blocksize),
531 			blocksize,
532 			predictor_order
533 		);
534 }
535 #endif
536 
FLAC__format_get_max_rice_partition_order_from_blocksize(uint32_t blocksize)537 uint32_t FLAC__format_get_max_rice_partition_order_from_blocksize(uint32_t blocksize)
538 {
539 	uint32_t max_rice_partition_order = 0;
540 	while(!(blocksize & 1)) {
541 		max_rice_partition_order++;
542 		blocksize >>= 1;
543 	}
544 	return flac_min(FLAC__MAX_RICE_PARTITION_ORDER, max_rice_partition_order);
545 }
546 
FLAC__format_get_max_rice_partition_order_from_blocksize_limited_max_and_predictor_order(uint32_t limit,uint32_t blocksize,uint32_t predictor_order)547 uint32_t FLAC__format_get_max_rice_partition_order_from_blocksize_limited_max_and_predictor_order(uint32_t limit, uint32_t blocksize, uint32_t predictor_order)
548 {
549 	uint32_t max_rice_partition_order = limit;
550 
551 	while(max_rice_partition_order > 0 && (blocksize >> max_rice_partition_order) <= predictor_order)
552 		max_rice_partition_order--;
553 
554 	FLAC__ASSERT(
555 		(max_rice_partition_order == 0 && blocksize >= predictor_order) ||
556 		(max_rice_partition_order > 0 && blocksize >> max_rice_partition_order > predictor_order)
557 	);
558 
559 	return max_rice_partition_order;
560 }
561 
FLAC__format_entropy_coding_method_partitioned_rice_contents_init(FLAC__EntropyCodingMethod_PartitionedRiceContents * object)562 void FLAC__format_entropy_coding_method_partitioned_rice_contents_init(FLAC__EntropyCodingMethod_PartitionedRiceContents *object)
563 {
564 	FLAC__ASSERT(0 != object);
565 
566 	object->parameters = 0;
567 	object->raw_bits = 0;
568 	object->capacity_by_order = 0;
569 }
570 
FLAC__format_entropy_coding_method_partitioned_rice_contents_clear(FLAC__EntropyCodingMethod_PartitionedRiceContents * object)571 void FLAC__format_entropy_coding_method_partitioned_rice_contents_clear(FLAC__EntropyCodingMethod_PartitionedRiceContents *object)
572 {
573 	FLAC__ASSERT(0 != object);
574 
575 	if(0 != object->parameters)
576 		free(object->parameters);
577 	if(0 != object->raw_bits)
578 		free(object->raw_bits);
579 	FLAC__format_entropy_coding_method_partitioned_rice_contents_init(object);
580 }
581 
582 #if defined(_MSC_VER)
583 // silence three MSVC warnings 'result of 32-bit shift implicitly converted to 64 bits (was 64-bit shift intended?)'
584 #pragma warning ( disable : 4334 )
585 #endif
586 
FLAC__format_entropy_coding_method_partitioned_rice_contents_ensure_size(FLAC__EntropyCodingMethod_PartitionedRiceContents * object,uint32_t max_partition_order)587 FLAC__bool FLAC__format_entropy_coding_method_partitioned_rice_contents_ensure_size(FLAC__EntropyCodingMethod_PartitionedRiceContents *object, uint32_t max_partition_order)
588 {
589 	FLAC__ASSERT(0 != object);
590 
591 	if(object->capacity_by_order < max_partition_order || object->parameters == NULL || object->raw_bits == NULL) {
592 		if(0 == (object->parameters = safe_realloc_(object->parameters, sizeof(uint32_t)*(1 << max_partition_order))))
593 			return false;
594 		if(0 == (object->raw_bits = safe_realloc_(object->raw_bits, sizeof(uint32_t)*(1 << max_partition_order))))
595 			return false;
596 		memset(object->raw_bits, 0, sizeof(uint32_t)*(1 << max_partition_order));
597 		object->capacity_by_order = max_partition_order;
598 	}
599 
600 	return true;
601 }
602 
603 #if defined(_MSC_VER)
604 #pragma warning ( default : 4334 )
605 #endif
606