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1 /* libFLAC - Free Lossless Audio Codec library
2 * Copyright (C) 2000,2001,2002,2003,2004,2005 Josh Coalson
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * - Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * - Neither the name of the Xiph.org Foundation nor the names of its
16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #ifndef FLAC__FORMAT_H
33 #define FLAC__FORMAT_H
34
35 #include "export.h"
36 #include "ordinals.h"
37
38 #ifdef __cplusplus
39 extern "C" {
40 #endif
41
42 /** \file include/FLAC/format.h
43 *
44 * \brief
45 * This module contains structure definitions for the representation
46 * of FLAC format components in memory. These are the basic
47 * structures used by the rest of the interfaces.
48 *
49 * See the detailed documentation in the
50 * \link flac_format format \endlink module.
51 */
52
53 /** \defgroup flac_format FLAC/format.h: format components
54 * \ingroup flac
55 *
56 * \brief
57 * This module contains structure definitions for the representation
58 * of FLAC format components in memory. These are the basic
59 * structures used by the rest of the interfaces.
60 *
61 * First, you should be familiar with the
62 * <A HREF="../format.html">FLAC format</A>. Many of the values here
63 * follow directly from the specification. As a user of libFLAC, the
64 * interesting parts really are the structures that describe the frame
65 * header and metadata blocks.
66 *
67 * The format structures here are very primitive, designed to store
68 * information in an efficient way. Reading information from the
69 * structures is easy but creating or modifying them directly is
70 * more complex. For the most part, as a user of a library, editing
71 * is not necessary; however, for metadata blocks it is, so there are
72 * convenience functions provided in the \link flac_metadata metadata
73 * module \endlink to simplify the manipulation of metadata blocks.
74 *
75 * \note
76 * It's not the best convention, but symbols ending in _LEN are in bits
77 * and _LENGTH are in bytes. _LENGTH symbols are \#defines instead of
78 * global variables because they are usually used when declaring byte
79 * arrays and some compilers require compile-time knowledge of array
80 * sizes when declared on the stack.
81 *
82 * \{
83 */
84
85
86 /*
87 Most of the values described in this file are defined by the FLAC
88 format specification. There is nothing to tune here.
89 */
90
91 /** The largest legal metadata type code. */
92 #define FLAC__MAX_METADATA_TYPE_CODE (126u)
93
94 /** The minimum block size, in samples, permitted by the format. */
95 #define FLAC__MIN_BLOCK_SIZE (16u)
96
97 /** The maximum block size, in samples, permitted by the format. */
98 #define FLAC__MAX_BLOCK_SIZE (65535u)
99
100 /** The maximum number of channels permitted by the format. */
101 #define FLAC__MAX_CHANNELS (8u)
102
103 /** The minimum sample resolution permitted by the format. */
104 #define FLAC__MIN_BITS_PER_SAMPLE (4u)
105
106 /** The maximum sample resolution permitted by the format. */
107 #define FLAC__MAX_BITS_PER_SAMPLE (32u)
108
109 /** The maximum sample resolution permitted by libFLAC.
110 *
111 * \warning
112 * FLAC__MAX_BITS_PER_SAMPLE is the limit of the FLAC format. However,
113 * the reference encoder/decoder is currently limited to 24 bits because
114 * of prevalent 32-bit math, so make sure and use this value when
115 * appropriate.
116 */
117 #define FLAC__REFERENCE_CODEC_MAX_BITS_PER_SAMPLE (24u)
118
119 /** The maximum sample rate permitted by the format. The value is
120 * ((2 ^ 16) - 1) * 10; see <A HREF="../format.html">FLAC format</A>
121 * as to why.
122 */
123 #define FLAC__MAX_SAMPLE_RATE (655350u)
124
125 /** The maximum LPC order permitted by the format. */
126 #define FLAC__MAX_LPC_ORDER (32u)
127
128 /** The minimum quantized linear predictor coefficient precision
129 * permitted by the format.
130 */
131 #define FLAC__MIN_QLP_COEFF_PRECISION (5u)
132
133 /** The maximum quantized linear predictor coefficient precision
134 * permitted by the format.
135 */
136 #define FLAC__MAX_QLP_COEFF_PRECISION (15u)
137
138 /** The maximum order of the fixed predictors permitted by the format. */
139 #define FLAC__MAX_FIXED_ORDER (4u)
140
141 /** The maximum Rice partition order permitted by the format. */
142 #define FLAC__MAX_RICE_PARTITION_ORDER (15u)
143
144 /** The maximum Rice partition order permitted by the FLAC Subset. */
145 #define FLAC__SUBSET_MAX_RICE_PARTITION_ORDER (8u)
146
147 /** The version string of the release, stamped onto the libraries and binaries.
148 *
149 * \note
150 * This does not correspond to the shared library version number, which
151 * is used to determine binary compatibility.
152 */
153 extern FLAC_API const char *FLAC__VERSION_STRING;
154
155 /** The vendor string inserted by the encoder into the VORBIS_COMMENT block.
156 * This is a nulL-terminated ASCII string; when inserted into the
157 * VORBIS_COMMENT the trailing null is stripped.
158 */
159 extern FLAC_API const char *FLAC__VENDOR_STRING;
160
161 /** The byte string representation of the beginning of a FLAC stream. */
162 extern FLAC_API const FLAC__byte FLAC__STREAM_SYNC_STRING[4]; /* = "fLaC" */
163
164 /** The 32-bit integer big-endian representation of the beginning of
165 * a FLAC stream.
166 */
167 extern FLAC_API const unsigned FLAC__STREAM_SYNC; /* = 0x664C6143 */
168
169 /** The length of the FLAC signature in bits. */
170 extern FLAC_API const unsigned FLAC__STREAM_SYNC_LEN; /* = 32 bits */
171
172 /** The length of the FLAC signature in bytes. */
173 #define FLAC__STREAM_SYNC_LENGTH (4u)
174
175
176 /*****************************************************************************
177 *
178 * Subframe structures
179 *
180 *****************************************************************************/
181
182 /*****************************************************************************/
183
184 /** An enumeration of the available entropy coding methods. */
185 typedef enum {
186 FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE = 0
187 /**< Residual is coded by partitioning into contexts, each with it's own
188 * Rice parameter. */
189 } FLAC__EntropyCodingMethodType;
190
191 /** Maps a FLAC__EntropyCodingMethodType to a C string.
192 *
193 * Using a FLAC__EntropyCodingMethodType as the index to this array will
194 * give the string equivalent. The contents should not be modified.
195 */
196 extern FLAC_API const char * const FLAC__EntropyCodingMethodTypeString[];
197
198
199 /** Contents of a Rice partitioned residual
200 */
201 typedef struct {
202
203 unsigned *parameters;
204 /**< The Rice parameters for each context. */
205
206 unsigned *raw_bits;
207 /**< Widths for escape-coded partitions. */
208
209 unsigned capacity_by_order;
210 /**< The capacity of the \a parameters and \a raw_bits arrays
211 * specified as an order, i.e. the number of array elements
212 * allocated is 2 ^ \a capacity_by_order.
213 */
214 } FLAC__EntropyCodingMethod_PartitionedRiceContents;
215
216 /** Header for a Rice partitioned residual. (c.f. <A HREF="../format.html#partitioned_rice">format specification</A>)
217 */
218 typedef struct {
219
220 unsigned order;
221 /**< The partition order, i.e. # of contexts = 2 ^ \a order. */
222
223 const FLAC__EntropyCodingMethod_PartitionedRiceContents *contents;
224 /**< The context's Rice parameters and/or raw bits. */
225
226 } FLAC__EntropyCodingMethod_PartitionedRice;
227
228 extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN; /**< == 4 (bits) */
229 extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN; /**< == 4 (bits) */
230 extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_RAW_LEN; /**< == 5 (bits) */
231
232 extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ESCAPE_PARAMETER;
233 /**< == (1<<FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN)-1 */
234
235 /** Header for the entropy coding method. (c.f. <A HREF="../format.html#residual">format specification</A>)
236 */
237 typedef struct {
238 FLAC__EntropyCodingMethodType type;
239 union {
240 FLAC__EntropyCodingMethod_PartitionedRice partitioned_rice;
241 } data;
242 } FLAC__EntropyCodingMethod;
243
244 extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_TYPE_LEN; /**< == 2 (bits) */
245
246 /*****************************************************************************/
247
248 /** An enumeration of the available subframe types. */
249 typedef enum {
250 FLAC__SUBFRAME_TYPE_CONSTANT = 0, /**< constant signal */
251 FLAC__SUBFRAME_TYPE_VERBATIM = 1, /**< uncompressed signal */
252 FLAC__SUBFRAME_TYPE_FIXED = 2, /**< fixed polynomial prediction */
253 FLAC__SUBFRAME_TYPE_LPC = 3 /**< linear prediction */
254 } FLAC__SubframeType;
255
256 /** Maps a FLAC__SubframeType to a C string.
257 *
258 * Using a FLAC__SubframeType as the index to this array will
259 * give the string equivalent. The contents should not be modified.
260 */
261 extern FLAC_API const char * const FLAC__SubframeTypeString[];
262
263
264 /** CONSTANT subframe. (c.f. <A HREF="../format.html#subframe_constant">format specification</A>)
265 */
266 typedef struct {
267 FLAC__int32 value; /**< The constant signal value. */
268 } FLAC__Subframe_Constant;
269
270
271 /** VERBATIM subframe. (c.f. <A HREF="../format.html#subframe_verbatim">format specification</A>)
272 */
273 typedef struct {
274 const FLAC__int32 *data; /**< A pointer to verbatim signal. */
275 } FLAC__Subframe_Verbatim;
276
277
278 /** FIXED subframe. (c.f. <A HREF="../format.html#subframe_fixed">format specification</A>)
279 */
280 typedef struct {
281 FLAC__EntropyCodingMethod entropy_coding_method;
282 /**< The residual coding method. */
283
284 unsigned order;
285 /**< The polynomial order. */
286
287 FLAC__int32 warmup[FLAC__MAX_FIXED_ORDER];
288 /**< Warmup samples to prime the predictor, length == order. */
289
290 const FLAC__int32 *residual;
291 /**< The residual signal, length == (blocksize minus order) samples. */
292 } FLAC__Subframe_Fixed;
293
294
295 /** LPC subframe. (c.f. <A HREF="../format.html#subframe_lpc">format specification</A>)
296 */
297 typedef struct {
298 FLAC__EntropyCodingMethod entropy_coding_method;
299 /**< The residual coding method. */
300
301 unsigned order;
302 /**< The FIR order. */
303
304 unsigned qlp_coeff_precision;
305 /**< Quantized FIR filter coefficient precision in bits. */
306
307 int quantization_level;
308 /**< The qlp coeff shift needed. */
309
310 FLAC__int32 qlp_coeff[FLAC__MAX_LPC_ORDER];
311 /**< FIR filter coefficients. */
312
313 FLAC__int32 warmup[FLAC__MAX_LPC_ORDER];
314 /**< Warmup samples to prime the predictor, length == order. */
315
316 const FLAC__int32 *residual;
317 /**< The residual signal, length == (blocksize minus order) samples. */
318 } FLAC__Subframe_LPC;
319
320 extern FLAC_API const unsigned FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN; /**< == 4 (bits) */
321 extern FLAC_API const unsigned FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN; /**< == 5 (bits) */
322
323
324 /** FLAC subframe structure. (c.f. <A HREF="../format.html#subframe">format specification</A>)
325 */
326 typedef struct {
327 FLAC__SubframeType type;
328 union {
329 FLAC__Subframe_Constant constant;
330 FLAC__Subframe_Fixed fixed;
331 FLAC__Subframe_LPC lpc;
332 FLAC__Subframe_Verbatim verbatim;
333 } data;
334 unsigned wasted_bits;
335 } FLAC__Subframe;
336
337 extern FLAC_API const unsigned FLAC__SUBFRAME_ZERO_PAD_LEN; /**< == 1 (bit) */
338 extern FLAC_API const unsigned FLAC__SUBFRAME_TYPE_LEN; /**< == 6 (bits) */
339 extern FLAC_API const unsigned FLAC__SUBFRAME_WASTED_BITS_FLAG_LEN; /**< == 1 (bit) */
340
341 extern FLAC_API const unsigned FLAC__SUBFRAME_TYPE_CONSTANT_BYTE_ALIGNED_MASK; /* = 0x00 */
342 extern FLAC_API const unsigned FLAC__SUBFRAME_TYPE_VERBATIM_BYTE_ALIGNED_MASK; /* = 0x02 */
343 extern FLAC_API const unsigned FLAC__SUBFRAME_TYPE_FIXED_BYTE_ALIGNED_MASK; /* = 0x10 */
344 extern FLAC_API const unsigned FLAC__SUBFRAME_TYPE_LPC_BYTE_ALIGNED_MASK; /* = 0x40 */
345
346 /*****************************************************************************/
347
348
349 /*****************************************************************************
350 *
351 * Frame structures
352 *
353 *****************************************************************************/
354
355 /** An enumeration of the available channel assignments. */
356 typedef enum {
357 FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT = 0, /**< independent channels */
358 FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE = 1, /**< left+side stereo */
359 FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE = 2, /**< right+side stereo */
360 FLAC__CHANNEL_ASSIGNMENT_MID_SIDE = 3 /**< mid+side stereo */
361 } FLAC__ChannelAssignment;
362
363 /** Maps a FLAC__ChannelAssignment to a C string.
364 *
365 * Using a FLAC__ChannelAssignment as the index to this array will
366 * give the string equivalent. The contents should not be modified.
367 */
368 extern FLAC_API const char * const FLAC__ChannelAssignmentString[];
369
370 /** An enumeration of the possible frame numbering methods. */
371 typedef enum {
372 FLAC__FRAME_NUMBER_TYPE_FRAME_NUMBER, /**< number contains the frame number */
373 FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER /**< number contains the sample number of first sample in frame */
374 } FLAC__FrameNumberType;
375
376 /** Maps a FLAC__FrameNumberType to a C string.
377 *
378 * Using a FLAC__FrameNumberType as the index to this array will
379 * give the string equivalent. The contents should not be modified.
380 */
381 extern FLAC_API const char * const FLAC__FrameNumberTypeString[];
382
383
384 /** FLAC frame header structure. (c.f. <A HREF="../format.html#frame_header">format specification</A>)
385 */
386 typedef struct {
387 unsigned blocksize;
388 /**< The number of samples per subframe. */
389
390 unsigned sample_rate;
391 /**< The sample rate in Hz. */
392
393 unsigned channels;
394 /**< The number of channels (== number of subframes). */
395
396 FLAC__ChannelAssignment channel_assignment;
397 /**< The channel assignment for the frame. */
398
399 unsigned bits_per_sample;
400 /**< The sample resolution. */
401
402 FLAC__FrameNumberType number_type;
403 /**< The numbering scheme used for the frame. */
404
405 union {
406 FLAC__uint32 frame_number;
407 FLAC__uint64 sample_number;
408 } number;
409 /**< The frame number or sample number of first sample in frame;
410 * use the \a number_type value to determine which to use. */
411
412 FLAC__uint8 crc;
413 /**< CRC-8 (polynomial = x^8 + x^2 + x^1 + x^0, initialized with 0)
414 * of the raw frame header bytes, meaning everything before the CRC byte
415 * including the sync code.
416 */
417 } FLAC__FrameHeader;
418
419 extern FLAC_API const unsigned FLAC__FRAME_HEADER_SYNC; /**< == 0x3ffe; the frame header sync code */
420 extern FLAC_API const unsigned FLAC__FRAME_HEADER_SYNC_LEN; /**< == 14 (bits) */
421 extern FLAC_API const unsigned FLAC__FRAME_HEADER_RESERVED_LEN; /**< == 2 (bits) */
422 extern FLAC_API const unsigned FLAC__FRAME_HEADER_BLOCK_SIZE_LEN; /**< == 4 (bits) */
423 extern FLAC_API const unsigned FLAC__FRAME_HEADER_SAMPLE_RATE_LEN; /**< == 4 (bits) */
424 extern FLAC_API const unsigned FLAC__FRAME_HEADER_CHANNEL_ASSIGNMENT_LEN; /**< == 4 (bits) */
425 extern FLAC_API const unsigned FLAC__FRAME_HEADER_BITS_PER_SAMPLE_LEN; /**< == 3 (bits) */
426 extern FLAC_API const unsigned FLAC__FRAME_HEADER_ZERO_PAD_LEN; /**< == 1 (bit) */
427 extern FLAC_API const unsigned FLAC__FRAME_HEADER_CRC_LEN; /**< == 8 (bits) */
428
429
430 /** FLAC frame footer structure. (c.f. <A HREF="../format.html#frame_footer">format specification</A>)
431 */
432 typedef struct {
433 FLAC__uint16 crc;
434 /**< CRC-16 (polynomial = x^16 + x^15 + x^2 + x^0, initialized with
435 * 0) of the bytes before the crc, back to and including the frame header
436 * sync code.
437 */
438 } FLAC__FrameFooter;
439
440 extern FLAC_API const unsigned FLAC__FRAME_FOOTER_CRC_LEN; /**< == 16 (bits) */
441
442
443 /** FLAC frame structure. (c.f. <A HREF="../format.html#frame">format specification</A>)
444 */
445 typedef struct {
446 FLAC__FrameHeader header;
447 FLAC__Subframe subframes[FLAC__MAX_CHANNELS];
448 FLAC__FrameFooter footer;
449 } FLAC__Frame;
450
451 /*****************************************************************************/
452
453
454 /*****************************************************************************
455 *
456 * Meta-data structures
457 *
458 *****************************************************************************/
459
460 /** An enumeration of the available metadata block types. */
461 typedef enum {
462
463 FLAC__METADATA_TYPE_STREAMINFO = 0,
464 /**< <A HREF="../format.html#metadata_block_streaminfo">STREAMINFO</A> block */
465
466 FLAC__METADATA_TYPE_PADDING = 1,
467 /**< <A HREF="../format.html#metadata_block_padding">PADDING</A> block */
468
469 FLAC__METADATA_TYPE_APPLICATION = 2,
470 /**< <A HREF="../format.html#metadata_block_application">APPLICATION</A> block */
471
472 FLAC__METADATA_TYPE_SEEKTABLE = 3,
473 /**< <A HREF="../format.html#metadata_block_seektable">SEEKTABLE</A> block */
474
475 FLAC__METADATA_TYPE_VORBIS_COMMENT = 4,
476 /**< <A HREF="../format.html#metadata_block_vorbis_comment">VORBISCOMMENT</A> block */
477
478 FLAC__METADATA_TYPE_CUESHEET = 5,
479 /**< <A HREF="../format.html#metadata_block_cuesheet">CUESHEET</A> block */
480
481 FLAC__METADATA_TYPE_UNDEFINED = 6
482 /**< marker to denote beginning of undefined type range; this number will increase as new metadata types are added */
483
484 } FLAC__MetadataType;
485
486 /** Maps a FLAC__MetadataType to a C string.
487 *
488 * Using a FLAC__MetadataType as the index to this array will
489 * give the string equivalent. The contents should not be modified.
490 */
491 extern FLAC_API const char * const FLAC__MetadataTypeString[];
492
493
494 /** FLAC STREAMINFO structure. (c.f. <A HREF="../format.html#metadata_block_streaminfo">format specification</A>)
495 */
496 typedef struct {
497 unsigned min_blocksize, max_blocksize;
498 unsigned min_framesize, max_framesize;
499 unsigned sample_rate;
500 unsigned channels;
501 unsigned bits_per_sample;
502 FLAC__uint64 total_samples;
503 FLAC__byte md5sum[16];
504 } FLAC__StreamMetadata_StreamInfo;
505
506 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN; /**< == 16 (bits) */
507 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN; /**< == 16 (bits) */
508 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN; /**< == 24 (bits) */
509 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN; /**< == 24 (bits) */
510 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN; /**< == 20 (bits) */
511 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN; /**< == 3 (bits) */
512 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN; /**< == 5 (bits) */
513 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_TOTAL_SAMPLES_LEN; /**< == 36 (bits) */
514 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MD5SUM_LEN; /**< == 128 (bits) */
515
516 /** The total stream length of the STREAMINFO block in bytes. */
517 #define FLAC__STREAM_METADATA_STREAMINFO_LENGTH (34u)
518
519 /** FLAC PADDING structure. (c.f. <A HREF="../format.html#metadata_block_padding">format specification</A>)
520 */
521 typedef struct {
522 int dummy;
523 /**< Conceptually this is an empty struct since we don't store the
524 * padding bytes. Empty structs are not allowed by some C compilers,
525 * hence the dummy.
526 */
527 } FLAC__StreamMetadata_Padding;
528
529
530 /** FLAC APPLICATION structure. (c.f. <A HREF="../format.html#metadata_block_application">format specification</A>)
531 */
532 typedef struct {
533 FLAC__byte id[4];
534 FLAC__byte *data;
535 } FLAC__StreamMetadata_Application;
536
537 extern FLAC_API const unsigned FLAC__STREAM_METADATA_APPLICATION_ID_LEN; /**< == 32 (bits) */
538
539 /** SeekPoint structure used in SEEKTABLE blocks. (c.f. <A HREF="../format.html#seekpoint">format specification</A>)
540 */
541 typedef struct {
542 FLAC__uint64 sample_number;
543 /**< The sample number of the target frame. */
544
545 FLAC__uint64 stream_offset;
546 /**< The offset, in bytes, of the target frame with respect to
547 * beginning of the first frame. */
548
549 unsigned frame_samples;
550 /**< The number of samples in the target frame. */
551 } FLAC__StreamMetadata_SeekPoint;
552
553 extern FLAC_API const unsigned FLAC__STREAM_METADATA_SEEKPOINT_SAMPLE_NUMBER_LEN; /**< == 64 (bits) */
554 extern FLAC_API const unsigned FLAC__STREAM_METADATA_SEEKPOINT_STREAM_OFFSET_LEN; /**< == 64 (bits) */
555 extern FLAC_API const unsigned FLAC__STREAM_METADATA_SEEKPOINT_FRAME_SAMPLES_LEN; /**< == 16 (bits) */
556
557 /** The total stream length of a seek point in bytes. */
558 #define FLAC__STREAM_METADATA_SEEKPOINT_LENGTH (18u)
559
560 /** The value used in the \a sample_number field of
561 * FLAC__StreamMetadataSeekPoint used to indicate a placeholder
562 * point (== 0xffffffffffffffff).
563 */
564 extern FLAC_API const FLAC__uint64 FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER;
565
566
567 /** FLAC SEEKTABLE structure. (c.f. <A HREF="../format.html#metadata_block_seektable">format specification</A>)
568 *
569 * \note From the format specification:
570 * - The seek points must be sorted by ascending sample number.
571 * - Each seek point's sample number must be the first sample of the
572 * target frame.
573 * - Each seek point's sample number must be unique within the table.
574 * - Existence of a SEEKTABLE block implies a correct setting of
575 * total_samples in the stream_info block.
576 * - Behavior is undefined when more than one SEEKTABLE block is
577 * present in a stream.
578 */
579 typedef struct {
580 unsigned num_points;
581 FLAC__StreamMetadata_SeekPoint *points;
582 } FLAC__StreamMetadata_SeekTable;
583
584
585 /** Vorbis comment entry structure used in VORBIS_COMMENT blocks. (c.f. <A HREF="../format.html#metadata_block_vorbis_comment">format specification</A>)
586 *
587 * For convenience, the APIs maintain a trailing NUL character at the end of
588 * \a entry which is not counted toward \a length, i.e.
589 * \code strlen(entry) == length \endcode
590 */
591 typedef struct {
592 FLAC__uint32 length;
593 FLAC__byte *entry;
594 } FLAC__StreamMetadata_VorbisComment_Entry;
595
596 extern FLAC_API const unsigned FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN; /**< == 32 (bits) */
597
598
599 /** FLAC VORBIS_COMMENT structure. (c.f. <A HREF="../format.html#metadata_block_vorbis_comment">format specification</A>)
600 */
601 typedef struct {
602 FLAC__StreamMetadata_VorbisComment_Entry vendor_string;
603 FLAC__uint32 num_comments;
604 FLAC__StreamMetadata_VorbisComment_Entry *comments;
605 } FLAC__StreamMetadata_VorbisComment;
606
607 extern FLAC_API const unsigned FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN; /**< == 32 (bits) */
608
609
610 /** FLAC CUESHEET track index structure. (See the
611 * <A HREF="../format.html#cuesheet_track_index">format specification</A> for
612 * the full description of each field.)
613 */
614 typedef struct {
615 FLAC__uint64 offset;
616 /**< Offset in samples, relative to the track offset, of the index
617 * point.
618 */
619
620 FLAC__byte number;
621 /**< The index point number. */
622 } FLAC__StreamMetadata_CueSheet_Index;
623
624 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN; /**< == 64 (bits) */
625 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN; /**< == 8 (bits) */
626 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN; /**< == 3*8 (bits) */
627
628
629 /** FLAC CUESHEET track structure. (See the
630 * <A HREF="../format.html#cuesheet_track">format specification</A> for
631 * the full description of each field.)
632 */
633 typedef struct {
634 FLAC__uint64 offset;
635 /**< Track offset in samples, relative to the beginning of the FLAC audio stream. */
636
637 FLAC__byte number;
638 /**< The track number. */
639
640 char isrc[13];
641 /**< Track ISRC. This is a 12-digit alphanumeric code plus a trailing '\0' */
642
643 unsigned type:1;
644 /**< The track type: 0 for audio, 1 for non-audio. */
645
646 unsigned pre_emphasis:1;
647 /**< The pre-emphasis flag: 0 for no pre-emphasis, 1 for pre-emphasis. */
648
649 FLAC__byte num_indices;
650 /**< The number of track index points. */
651
652 FLAC__StreamMetadata_CueSheet_Index *indices;
653 /**< NULL if num_indices == 0, else pointer to array of index points. */
654
655 } FLAC__StreamMetadata_CueSheet_Track;
656
657 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN; /**< == 64 (bits) */
658 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN; /**< == 8 (bits) */
659 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN; /**< == 12*8 (bits) */
660 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN; /**< == 1 (bit) */
661 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN; /**< == 1 (bit) */
662 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN; /**< == 6+13*8 (bits) */
663 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN; /**< == 8 (bits) */
664
665
666 /** FLAC CUESHEET structure. (See the
667 * <A HREF="../format.html#metadata_block_cuesheet">format specification</A>
668 * for the full description of each field.)
669 */
670 typedef struct {
671 char media_catalog_number[129];
672 /**< Media catalog number, in ASCII printable characters 0x20-0x7e. In
673 * general, the media catalog number may be 0 to 128 bytes long; any
674 * unused characters should be right-padded with NUL characters.
675 */
676
677 FLAC__uint64 lead_in;
678 /**< The number of lead-in samples. */
679
680 FLAC__bool is_cd;
681 /**< \c true if CUESHEET corresponds to a Compact Disc, else \c false */
682
683 unsigned num_tracks;
684 /**< The number of tracks. */
685
686 FLAC__StreamMetadata_CueSheet_Track *tracks;
687 /**< NULL if num_tracks == 0, else pointer to array of tracks. */
688
689 } FLAC__StreamMetadata_CueSheet;
690
691 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN; /**< == 128*8 (bits) */
692 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN; /**< == 64 (bits) */
693 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN; /**< == 1 (bit) */
694 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN; /**< == 7+258*8 (bits) */
695 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN; /**< == 8 (bits) */
696
697
698 /** Structure that is used when a metadata block of unknown type is loaded.
699 * The contents are opaque. The structure is used only internally to
700 * correctly handle unknown metadata.
701 */
702 typedef struct {
703 FLAC__byte *data;
704 } FLAC__StreamMetadata_Unknown;
705
706
707 /** FLAC metadata block structure. (c.f. <A HREF="../format.html#metadata_block">format specification</A>)
708 */
709 typedef struct {
710 FLAC__MetadataType type;
711 /**< The type of the metadata block; used determine which member of the
712 * \a data union to dereference. If type >= FLAC__METADATA_TYPE_UNDEFINED
713 * then \a data.unknown must be used. */
714
715 FLAC__bool is_last;
716 /**< \c true if this metadata block is the last, else \a false */
717
718 unsigned length;
719 /**< Length, in bytes, of the block data as it appears in the stream. */
720
721 union {
722 FLAC__StreamMetadata_StreamInfo stream_info;
723 FLAC__StreamMetadata_Padding padding;
724 FLAC__StreamMetadata_Application application;
725 FLAC__StreamMetadata_SeekTable seek_table;
726 FLAC__StreamMetadata_VorbisComment vorbis_comment;
727 FLAC__StreamMetadata_CueSheet cue_sheet;
728 FLAC__StreamMetadata_Unknown unknown;
729 } data;
730 /**< Polymorphic block data; use the \a type value to determine which
731 * to use. */
732 } FLAC__StreamMetadata;
733
734 extern FLAC_API const unsigned FLAC__STREAM_METADATA_IS_LAST_LEN; /**< == 1 (bit) */
735 extern FLAC_API const unsigned FLAC__STREAM_METADATA_TYPE_LEN; /**< == 7 (bits) */
736 extern FLAC_API const unsigned FLAC__STREAM_METADATA_LENGTH_LEN; /**< == 24 (bits) */
737
738 /** The total stream length of a metadata block header in bytes. */
739 #define FLAC__STREAM_METADATA_HEADER_LENGTH (4u)
740
741 /*****************************************************************************/
742
743
744 /*****************************************************************************
745 *
746 * Utility functions
747 *
748 *****************************************************************************/
749
750 /** Tests that a sample rate is valid for FLAC. Since the rules for valid
751 * sample rates are slightly complex, they are encapsulated in this function.
752 *
753 * \param sample_rate The sample rate to test for compliance.
754 * \retval FLAC__bool
755 * \c true if the given sample rate conforms to the specification, else
756 * \c false.
757 */
758 FLAC_API FLAC__bool FLAC__format_sample_rate_is_valid(unsigned sample_rate);
759
760 /** Check a Vorbis comment entry name to see if it conforms to the Vorbis
761 * comment specification.
762 *
763 * Vorbis comment names must be composed only of characters from
764 * [0x20-0x3C,0x3E-0x7D].
765 *
766 * \param name A NUL-terminated string to be checked.
767 * \assert
768 * \code name != NULL \endcode
769 * \retval FLAC__bool
770 * \c false if entry name is illegal, else \c true.
771 */
772 FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_name_is_legal(const char *name);
773
774 /** Check a Vorbis comment entry value to see if it conforms to the Vorbis
775 * comment specification.
776 *
777 * Vorbis comment values must be valid UTF-8 sequences.
778 *
779 * \param value A string to be checked.
780 * \param length A the length of \a value in bytes. May be
781 * \c (unsigned)(-1) to indicate that \a value is a plain
782 * UTF-8 NUL-terminated string.
783 * \assert
784 * \code value != NULL \endcode
785 * \retval FLAC__bool
786 * \c false if entry name is illegal, else \c true.
787 */
788 FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_value_is_legal(const FLAC__byte *value, unsigned length);
789
790 /** Check a Vorbis comment entry to see if it conforms to the Vorbis
791 * comment specification.
792 *
793 * Vorbis comment entries must be of the form 'name=value', and 'name' and
794 * 'value' must be legal according to
795 * FLAC__format_vorbiscomment_entry_name_is_legal() and
796 * FLAC__format_vorbiscomment_entry_value_is_legal() respectively.
797 *
798 * \param value A string to be checked.
799 * \assert
800 * \code value != NULL \endcode
801 * \retval FLAC__bool
802 * \c false if entry name is illegal, else \c true.
803 */
804 FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_is_legal(const FLAC__byte *entry, unsigned length);
805
806 /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
807 /** Check a seek table to see if it conforms to the FLAC specification.
808 * See the format specification for limits on the contents of the
809 * seek table.
810 *
811 * \param seek_table A pointer to a seek table to be checked.
812 * \assert
813 * \code seek_table != NULL \endcode
814 * \retval FLAC__bool
815 * \c false if seek table is illegal, else \c true.
816 */
817 FLAC_API FLAC__bool FLAC__format_seektable_is_legal(const FLAC__StreamMetadata_SeekTable *seek_table);
818
819 /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
820 /** Sort a seek table's seek points according to the format specification.
821 * This includes a "unique-ification" step to remove duplicates, i.e.
822 * seek points with identical \a sample_number values. Duplicate seek
823 * points are converted into placeholder points and sorted to the end of
824 * the table.
825 *
826 * \param seek_table A pointer to a seek table to be sorted.
827 * \assert
828 * \code seek_table != NULL \endcode
829 * \retval unsigned
830 * The number of duplicate seek points converted into placeholders.
831 */
832 FLAC_API unsigned FLAC__format_seektable_sort(FLAC__StreamMetadata_SeekTable *seek_table);
833
834 /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
835 /** Check a cue sheet to see if it conforms to the FLAC specification.
836 * See the format specification for limits on the contents of the
837 * cue sheet.
838 *
839 * \param cue_sheet A pointer to an existing cue sheet to be checked.
840 * \param check_cd_da_subset If \c true, check CUESHEET against more
841 * stringent requirements for a CD-DA (audio) disc.
842 * \param violation Address of a pointer to a string. If there is a
843 * violation, a pointer to a string explanation of the
844 * violation will be returned here. \a violation may be
845 * \c NULL if you don't need the returned string. Do not
846 * free the returned string; it will always point to static
847 * data.
848 * \assert
849 * \code cue_sheet != NULL \endcode
850 * \retval FLAC__bool
851 * \c false if cue sheet is illegal, else \c true.
852 */
853 FLAC_API FLAC__bool FLAC__format_cuesheet_is_legal(const FLAC__StreamMetadata_CueSheet *cue_sheet, FLAC__bool check_cd_da_subset, const char **violation);
854
855 /* \} */
856
857 #ifdef __cplusplus
858 }
859 #endif
860
861 #endif