1/* libFLAC - Free Lossless Audio Codec library
2 * Copyright (C) 2000,2001,2002,2003,2004,2005,2006,2007  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
39extern "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 block size, in samples, permitted by the FLAC subset for
101 *  sample rates up to 48kHz. */
102#define FLAC__SUBSET_MAX_BLOCK_SIZE_48000HZ (4608u)
103
104/** The maximum number of channels permitted by the format. */
105#define FLAC__MAX_CHANNELS (8u)
106
107/** The minimum sample resolution permitted by the format. */
108#define FLAC__MIN_BITS_PER_SAMPLE (4u)
109
110/** The maximum sample resolution permitted by the format. */
111#define FLAC__MAX_BITS_PER_SAMPLE (32u)
112
113/** The maximum sample resolution permitted by libFLAC.
114 *
115 * \warning
116 * FLAC__MAX_BITS_PER_SAMPLE is the limit of the FLAC format.  However,
117 * the reference encoder/decoder is currently limited to 24 bits because
118 * of prevalent 32-bit math, so make sure and use this value when
119 * appropriate.
120 */
121#define FLAC__REFERENCE_CODEC_MAX_BITS_PER_SAMPLE (24u)
122
123/** The maximum sample rate permitted by the format.  The value is
124 *  ((2 ^ 16) - 1) * 10; see <A HREF="../format.html">FLAC format</A>
125 *  as to why.
126 */
127#define FLAC__MAX_SAMPLE_RATE (655350u)
128
129/** The maximum LPC order permitted by the format. */
130#define FLAC__MAX_LPC_ORDER (32u)
131
132/** The maximum LPC order permitted by the FLAC subset for sample rates
133 *  up to 48kHz. */
134#define FLAC__SUBSET_MAX_LPC_ORDER_48000HZ (12u)
135
136/** The minimum quantized linear predictor coefficient precision
137 *  permitted by the format.
138 */
139#define FLAC__MIN_QLP_COEFF_PRECISION (5u)
140
141/** The maximum quantized linear predictor coefficient precision
142 *  permitted by the format.
143 */
144#define FLAC__MAX_QLP_COEFF_PRECISION (15u)
145
146/** The maximum order of the fixed predictors permitted by the format. */
147#define FLAC__MAX_FIXED_ORDER (4u)
148
149/** The maximum Rice partition order permitted by the format. */
150#define FLAC__MAX_RICE_PARTITION_ORDER (15u)
151
152/** The maximum Rice partition order permitted by the FLAC Subset. */
153#define FLAC__SUBSET_MAX_RICE_PARTITION_ORDER (8u)
154
155/** The version string of the release, stamped onto the libraries and binaries.
156 *
157 * \note
158 * This does not correspond to the shared library version number, which
159 * is used to determine binary compatibility.
160 */
161extern FLAC_API const char *FLAC__VERSION_STRING;
162
163/** The vendor string inserted by the encoder into the VORBIS_COMMENT block.
164 *  This is a NUL-terminated ASCII string; when inserted into the
165 *  VORBIS_COMMENT the trailing null is stripped.
166 */
167extern FLAC_API const char *FLAC__VENDOR_STRING;
168
169/** The byte string representation of the beginning of a FLAC stream. */
170extern FLAC_API const FLAC__byte FLAC__STREAM_SYNC_STRING[4]; /* = "fLaC" */
171
172/** The 32-bit integer big-endian representation of the beginning of
173 *  a FLAC stream.
174 */
175extern FLAC_API const unsigned FLAC__STREAM_SYNC; /* = 0x664C6143 */
176
177/** The length of the FLAC signature in bits. */
178extern FLAC_API const unsigned FLAC__STREAM_SYNC_LEN; /* = 32 bits */
179
180/** The length of the FLAC signature in bytes. */
181#define FLAC__STREAM_SYNC_LENGTH (4u)
182
183
184/*****************************************************************************
185 *
186 * Subframe structures
187 *
188 *****************************************************************************/
189
190/*****************************************************************************/
191
192/** An enumeration of the available entropy coding methods. */
193typedef enum {
194	FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE = 0,
195	/**< Residual is coded by partitioning into contexts, each with it's own
196	 * 4-bit Rice parameter. */
197
198	FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2 = 1
199	/**< Residual is coded by partitioning into contexts, each with it's own
200	 * 5-bit Rice parameter. */
201} FLAC__EntropyCodingMethodType;
202
203/** Maps a FLAC__EntropyCodingMethodType to a C string.
204 *
205 *  Using a FLAC__EntropyCodingMethodType as the index to this array will
206 *  give the string equivalent.  The contents should not be modified.
207 */
208extern FLAC_API const char * const FLAC__EntropyCodingMethodTypeString[];
209
210
211/** Contents of a Rice partitioned residual
212 */
213typedef struct {
214
215	unsigned *parameters;
216	/**< The Rice parameters for each context. */
217
218	unsigned *raw_bits;
219	/**< Widths for escape-coded partitions.  Will be non-zero for escaped
220	 * partitions and zero for unescaped partitions.
221	 */
222
223	unsigned capacity_by_order;
224	/**< The capacity of the \a parameters and \a raw_bits arrays
225	 * specified as an order, i.e. the number of array elements
226	 * allocated is 2 ^ \a capacity_by_order.
227	 */
228} FLAC__EntropyCodingMethod_PartitionedRiceContents;
229
230/** Header for a Rice partitioned residual.  (c.f. <A HREF="../format.html#partitioned_rice">format specification</A>)
231 */
232typedef struct {
233
234	unsigned order;
235	/**< The partition order, i.e. # of contexts = 2 ^ \a order. */
236
237	const FLAC__EntropyCodingMethod_PartitionedRiceContents *contents;
238	/**< The context's Rice parameters and/or raw bits. */
239
240} FLAC__EntropyCodingMethod_PartitionedRice;
241
242extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN; /**< == 4 (bits) */
243extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN; /**< == 4 (bits) */
244extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2_PARAMETER_LEN; /**< == 5 (bits) */
245extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_RAW_LEN; /**< == 5 (bits) */
246
247extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ESCAPE_PARAMETER;
248/**< == (1<<FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN)-1 */
249extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2_ESCAPE_PARAMETER;
250/**< == (1<<FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2_PARAMETER_LEN)-1 */
251
252/** Header for the entropy coding method.  (c.f. <A HREF="../format.html#residual">format specification</A>)
253 */
254typedef struct {
255	FLAC__EntropyCodingMethodType type;
256	union {
257		FLAC__EntropyCodingMethod_PartitionedRice partitioned_rice;
258	} data;
259} FLAC__EntropyCodingMethod;
260
261extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_TYPE_LEN; /**< == 2 (bits) */
262
263/*****************************************************************************/
264
265/** An enumeration of the available subframe types. */
266typedef enum {
267	FLAC__SUBFRAME_TYPE_CONSTANT = 0, /**< constant signal */
268	FLAC__SUBFRAME_TYPE_VERBATIM = 1, /**< uncompressed signal */
269	FLAC__SUBFRAME_TYPE_FIXED = 2, /**< fixed polynomial prediction */
270	FLAC__SUBFRAME_TYPE_LPC = 3 /**< linear prediction */
271} FLAC__SubframeType;
272
273/** Maps a FLAC__SubframeType to a C string.
274 *
275 *  Using a FLAC__SubframeType as the index to this array will
276 *  give the string equivalent.  The contents should not be modified.
277 */
278extern FLAC_API const char * const FLAC__SubframeTypeString[];
279
280
281/** CONSTANT subframe.  (c.f. <A HREF="../format.html#subframe_constant">format specification</A>)
282 */
283typedef struct {
284	FLAC__int32 value; /**< The constant signal value. */
285} FLAC__Subframe_Constant;
286
287
288/** VERBATIM subframe.  (c.f. <A HREF="../format.html#subframe_verbatim">format specification</A>)
289 */
290typedef struct {
291	const FLAC__int32 *data; /**< A pointer to verbatim signal. */
292} FLAC__Subframe_Verbatim;
293
294
295/** FIXED subframe.  (c.f. <A HREF="../format.html#subframe_fixed">format specification</A>)
296 */
297typedef struct {
298	FLAC__EntropyCodingMethod entropy_coding_method;
299	/**< The residual coding method. */
300
301	unsigned order;
302	/**< The polynomial order. */
303
304	FLAC__int32 warmup[FLAC__MAX_FIXED_ORDER];
305	/**< Warmup samples to prime the predictor, length == order. */
306
307	const FLAC__int32 *residual;
308	/**< The residual signal, length == (blocksize minus order) samples. */
309} FLAC__Subframe_Fixed;
310
311
312/** LPC subframe.  (c.f. <A HREF="../format.html#subframe_lpc">format specification</A>)
313 */
314typedef struct {
315	FLAC__EntropyCodingMethod entropy_coding_method;
316	/**< The residual coding method. */
317
318	unsigned order;
319	/**< The FIR order. */
320
321	unsigned qlp_coeff_precision;
322	/**< Quantized FIR filter coefficient precision in bits. */
323
324	int quantization_level;
325	/**< The qlp coeff shift needed. */
326
327	FLAC__int32 qlp_coeff[FLAC__MAX_LPC_ORDER];
328	/**< FIR filter coefficients. */
329
330	FLAC__int32 warmup[FLAC__MAX_LPC_ORDER];
331	/**< Warmup samples to prime the predictor, length == order. */
332
333	const FLAC__int32 *residual;
334	/**< The residual signal, length == (blocksize minus order) samples. */
335} FLAC__Subframe_LPC;
336
337extern FLAC_API const unsigned FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN; /**< == 4 (bits) */
338extern FLAC_API const unsigned FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN; /**< == 5 (bits) */
339
340
341/** FLAC subframe structure.  (c.f. <A HREF="../format.html#subframe">format specification</A>)
342 */
343typedef struct {
344	FLAC__SubframeType type;
345	union {
346		FLAC__Subframe_Constant constant;
347		FLAC__Subframe_Fixed fixed;
348		FLAC__Subframe_LPC lpc;
349		FLAC__Subframe_Verbatim verbatim;
350	} data;
351	unsigned wasted_bits;
352} FLAC__Subframe;
353
354/** == 1 (bit)
355 *
356 * This used to be a zero-padding bit (hence the name
357 * FLAC__SUBFRAME_ZERO_PAD_LEN) but is now a reserved bit.  It still has a
358 * mandatory value of \c 0 but in the future may take on the value \c 0 or \c 1
359 * to mean something else.
360 */
361extern FLAC_API const unsigned FLAC__SUBFRAME_ZERO_PAD_LEN;
362extern FLAC_API const unsigned FLAC__SUBFRAME_TYPE_LEN; /**< == 6 (bits) */
363extern FLAC_API const unsigned FLAC__SUBFRAME_WASTED_BITS_FLAG_LEN; /**< == 1 (bit) */
364
365extern FLAC_API const unsigned FLAC__SUBFRAME_TYPE_CONSTANT_BYTE_ALIGNED_MASK; /**< = 0x00 */
366extern FLAC_API const unsigned FLAC__SUBFRAME_TYPE_VERBATIM_BYTE_ALIGNED_MASK; /**< = 0x02 */
367extern FLAC_API const unsigned FLAC__SUBFRAME_TYPE_FIXED_BYTE_ALIGNED_MASK; /**< = 0x10 */
368extern FLAC_API const unsigned FLAC__SUBFRAME_TYPE_LPC_BYTE_ALIGNED_MASK; /**< = 0x40 */
369
370/*****************************************************************************/
371
372
373/*****************************************************************************
374 *
375 * Frame structures
376 *
377 *****************************************************************************/
378
379/** An enumeration of the available channel assignments. */
380typedef enum {
381	FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT = 0, /**< independent channels */
382	FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE = 1, /**< left+side stereo */
383	FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE = 2, /**< right+side stereo */
384	FLAC__CHANNEL_ASSIGNMENT_MID_SIDE = 3 /**< mid+side stereo */
385} FLAC__ChannelAssignment;
386
387/** Maps a FLAC__ChannelAssignment to a C string.
388 *
389 *  Using a FLAC__ChannelAssignment as the index to this array will
390 *  give the string equivalent.  The contents should not be modified.
391 */
392extern FLAC_API const char * const FLAC__ChannelAssignmentString[];
393
394/** An enumeration of the possible frame numbering methods. */
395typedef enum {
396	FLAC__FRAME_NUMBER_TYPE_FRAME_NUMBER, /**< number contains the frame number */
397	FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER /**< number contains the sample number of first sample in frame */
398} FLAC__FrameNumberType;
399
400/** Maps a FLAC__FrameNumberType to a C string.
401 *
402 *  Using a FLAC__FrameNumberType as the index to this array will
403 *  give the string equivalent.  The contents should not be modified.
404 */
405extern FLAC_API const char * const FLAC__FrameNumberTypeString[];
406
407
408/** FLAC frame header structure.  (c.f. <A HREF="../format.html#frame_header">format specification</A>)
409 */
410typedef struct {
411	unsigned blocksize;
412	/**< The number of samples per subframe. */
413
414	unsigned sample_rate;
415	/**< The sample rate in Hz. */
416
417	unsigned channels;
418	/**< The number of channels (== number of subframes). */
419
420	FLAC__ChannelAssignment channel_assignment;
421	/**< The channel assignment for the frame. */
422
423	unsigned bits_per_sample;
424	/**< The sample resolution. */
425
426	FLAC__FrameNumberType number_type;
427	/**< The numbering scheme used for the frame.  As a convenience, the
428	 * decoder will always convert a frame number to a sample number because
429	 * the rules are complex. */
430
431	union {
432		FLAC__uint32 frame_number;
433		FLAC__uint64 sample_number;
434	} number;
435	/**< The frame number or sample number of first sample in frame;
436	 * use the \a number_type value to determine which to use. */
437
438	FLAC__uint8 crc;
439	/**< CRC-8 (polynomial = x^8 + x^2 + x^1 + x^0, initialized with 0)
440	 * of the raw frame header bytes, meaning everything before the CRC byte
441	 * including the sync code.
442	 */
443} FLAC__FrameHeader;
444
445extern FLAC_API const unsigned FLAC__FRAME_HEADER_SYNC; /**< == 0x3ffe; the frame header sync code */
446extern FLAC_API const unsigned FLAC__FRAME_HEADER_SYNC_LEN; /**< == 14 (bits) */
447extern FLAC_API const unsigned FLAC__FRAME_HEADER_RESERVED_LEN; /**< == 1 (bits) */
448extern FLAC_API const unsigned FLAC__FRAME_HEADER_BLOCKING_STRATEGY_LEN; /**< == 1 (bits) */
449extern FLAC_API const unsigned FLAC__FRAME_HEADER_BLOCK_SIZE_LEN; /**< == 4 (bits) */
450extern FLAC_API const unsigned FLAC__FRAME_HEADER_SAMPLE_RATE_LEN; /**< == 4 (bits) */
451extern FLAC_API const unsigned FLAC__FRAME_HEADER_CHANNEL_ASSIGNMENT_LEN; /**< == 4 (bits) */
452extern FLAC_API const unsigned FLAC__FRAME_HEADER_BITS_PER_SAMPLE_LEN; /**< == 3 (bits) */
453extern FLAC_API const unsigned FLAC__FRAME_HEADER_ZERO_PAD_LEN; /**< == 1 (bit) */
454extern FLAC_API const unsigned FLAC__FRAME_HEADER_CRC_LEN; /**< == 8 (bits) */
455
456
457/** FLAC frame footer structure.  (c.f. <A HREF="../format.html#frame_footer">format specification</A>)
458 */
459typedef struct {
460	FLAC__uint16 crc;
461	/**< CRC-16 (polynomial = x^16 + x^15 + x^2 + x^0, initialized with
462	 * 0) of the bytes before the crc, back to and including the frame header
463	 * sync code.
464	 */
465} FLAC__FrameFooter;
466
467extern FLAC_API const unsigned FLAC__FRAME_FOOTER_CRC_LEN; /**< == 16 (bits) */
468
469
470/** FLAC frame structure.  (c.f. <A HREF="../format.html#frame">format specification</A>)
471 */
472typedef struct {
473	FLAC__FrameHeader header;
474	FLAC__Subframe subframes[FLAC__MAX_CHANNELS];
475	FLAC__FrameFooter footer;
476} FLAC__Frame;
477
478/*****************************************************************************/
479
480
481/*****************************************************************************
482 *
483 * Meta-data structures
484 *
485 *****************************************************************************/
486
487/** An enumeration of the available metadata block types. */
488typedef enum {
489
490	FLAC__METADATA_TYPE_STREAMINFO = 0,
491	/**< <A HREF="../format.html#metadata_block_streaminfo">STREAMINFO</A> block */
492
493	FLAC__METADATA_TYPE_PADDING = 1,
494	/**< <A HREF="../format.html#metadata_block_padding">PADDING</A> block */
495
496	FLAC__METADATA_TYPE_APPLICATION = 2,
497	/**< <A HREF="../format.html#metadata_block_application">APPLICATION</A> block */
498
499	FLAC__METADATA_TYPE_SEEKTABLE = 3,
500	/**< <A HREF="../format.html#metadata_block_seektable">SEEKTABLE</A> block */
501
502	FLAC__METADATA_TYPE_VORBIS_COMMENT = 4,
503	/**< <A HREF="../format.html#metadata_block_vorbis_comment">VORBISCOMMENT</A> block (a.k.a. FLAC tags) */
504
505	FLAC__METADATA_TYPE_CUESHEET = 5,
506	/**< <A HREF="../format.html#metadata_block_cuesheet">CUESHEET</A> block */
507
508	FLAC__METADATA_TYPE_PICTURE = 6,
509	/**< <A HREF="../format.html#metadata_block_picture">PICTURE</A> block */
510
511	FLAC__METADATA_TYPE_UNDEFINED = 7
512	/**< marker to denote beginning of undefined type range; this number will increase as new metadata types are added */
513
514} FLAC__MetadataType;
515
516/** Maps a FLAC__MetadataType to a C string.
517 *
518 *  Using a FLAC__MetadataType as the index to this array will
519 *  give the string equivalent.  The contents should not be modified.
520 */
521extern FLAC_API const char * const FLAC__MetadataTypeString[];
522
523
524/** FLAC STREAMINFO structure.  (c.f. <A HREF="../format.html#metadata_block_streaminfo">format specification</A>)
525 */
526typedef struct {
527	unsigned min_blocksize, max_blocksize;
528	unsigned min_framesize, max_framesize;
529	unsigned sample_rate;
530	unsigned channels;
531	unsigned bits_per_sample;
532	FLAC__uint64 total_samples;
533	FLAC__byte md5sum[16];
534} FLAC__StreamMetadata_StreamInfo;
535
536extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN; /**< == 16 (bits) */
537extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN; /**< == 16 (bits) */
538extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN; /**< == 24 (bits) */
539extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN; /**< == 24 (bits) */
540extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN; /**< == 20 (bits) */
541extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN; /**< == 3 (bits) */
542extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN; /**< == 5 (bits) */
543extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_TOTAL_SAMPLES_LEN; /**< == 36 (bits) */
544extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MD5SUM_LEN; /**< == 128 (bits) */
545
546/** The total stream length of the STREAMINFO block in bytes. */
547#define FLAC__STREAM_METADATA_STREAMINFO_LENGTH (34u)
548
549/** FLAC PADDING structure.  (c.f. <A HREF="../format.html#metadata_block_padding">format specification</A>)
550 */
551typedef struct {
552	int dummy;
553	/**< Conceptually this is an empty struct since we don't store the
554	 * padding bytes.  Empty structs are not allowed by some C compilers,
555	 * hence the dummy.
556	 */
557} FLAC__StreamMetadata_Padding;
558
559
560/** FLAC APPLICATION structure.  (c.f. <A HREF="../format.html#metadata_block_application">format specification</A>)
561 */
562typedef struct {
563	FLAC__byte id[4];
564	FLAC__byte *data;
565} FLAC__StreamMetadata_Application;
566
567extern FLAC_API const unsigned FLAC__STREAM_METADATA_APPLICATION_ID_LEN; /**< == 32 (bits) */
568
569/** SeekPoint structure used in SEEKTABLE blocks.  (c.f. <A HREF="../format.html#seekpoint">format specification</A>)
570 */
571typedef struct {
572	FLAC__uint64 sample_number;
573	/**<  The sample number of the target frame. */
574
575	FLAC__uint64 stream_offset;
576	/**< The offset, in bytes, of the target frame with respect to
577	 * beginning of the first frame. */
578
579	unsigned frame_samples;
580	/**< The number of samples in the target frame. */
581} FLAC__StreamMetadata_SeekPoint;
582
583extern FLAC_API const unsigned FLAC__STREAM_METADATA_SEEKPOINT_SAMPLE_NUMBER_LEN; /**< == 64 (bits) */
584extern FLAC_API const unsigned FLAC__STREAM_METADATA_SEEKPOINT_STREAM_OFFSET_LEN; /**< == 64 (bits) */
585extern FLAC_API const unsigned FLAC__STREAM_METADATA_SEEKPOINT_FRAME_SAMPLES_LEN; /**< == 16 (bits) */
586
587/** The total stream length of a seek point in bytes. */
588#define FLAC__STREAM_METADATA_SEEKPOINT_LENGTH (18u)
589
590/** The value used in the \a sample_number field of
591 *  FLAC__StreamMetadataSeekPoint used to indicate a placeholder
592 *  point (== 0xffffffffffffffff).
593 */
594extern FLAC_API const FLAC__uint64 FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER;
595
596
597/** FLAC SEEKTABLE structure.  (c.f. <A HREF="../format.html#metadata_block_seektable">format specification</A>)
598 *
599 * \note From the format specification:
600 * - The seek points must be sorted by ascending sample number.
601 * - Each seek point's sample number must be the first sample of the
602 *   target frame.
603 * - Each seek point's sample number must be unique within the table.
604 * - Existence of a SEEKTABLE block implies a correct setting of
605 *   total_samples in the stream_info block.
606 * - Behavior is undefined when more than one SEEKTABLE block is
607 *   present in a stream.
608 */
609typedef struct {
610	unsigned num_points;
611	FLAC__StreamMetadata_SeekPoint *points;
612} FLAC__StreamMetadata_SeekTable;
613
614
615/** Vorbis comment entry structure used in VORBIS_COMMENT blocks.  (c.f. <A HREF="../format.html#metadata_block_vorbis_comment">format specification</A>)
616 *
617 *  For convenience, the APIs maintain a trailing NUL character at the end of
618 *  \a entry which is not counted toward \a length, i.e.
619 *  \code strlen(entry) == length \endcode
620 */
621typedef struct {
622	FLAC__uint32 length;
623	FLAC__byte *entry;
624} FLAC__StreamMetadata_VorbisComment_Entry;
625
626extern FLAC_API const unsigned FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN; /**< == 32 (bits) */
627
628
629/** FLAC VORBIS_COMMENT structure.  (c.f. <A HREF="../format.html#metadata_block_vorbis_comment">format specification</A>)
630 */
631typedef struct {
632	FLAC__StreamMetadata_VorbisComment_Entry vendor_string;
633	FLAC__uint32 num_comments;
634	FLAC__StreamMetadata_VorbisComment_Entry *comments;
635} FLAC__StreamMetadata_VorbisComment;
636
637extern FLAC_API const unsigned FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN; /**< == 32 (bits) */
638
639
640/** FLAC CUESHEET track index structure.  (See the
641 * <A HREF="../format.html#cuesheet_track_index">format specification</A> for
642 * the full description of each field.)
643 */
644typedef struct {
645	FLAC__uint64 offset;
646	/**< Offset in samples, relative to the track offset, of the index
647	 * point.
648	 */
649
650	FLAC__byte number;
651	/**< The index point number. */
652} FLAC__StreamMetadata_CueSheet_Index;
653
654extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN; /**< == 64 (bits) */
655extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN; /**< == 8 (bits) */
656extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN; /**< == 3*8 (bits) */
657
658
659/** FLAC CUESHEET track structure.  (See the
660 * <A HREF="../format.html#cuesheet_track">format specification</A> for
661 * the full description of each field.)
662 */
663typedef struct {
664	FLAC__uint64 offset;
665	/**< Track offset in samples, relative to the beginning of the FLAC audio stream. */
666
667	FLAC__byte number;
668	/**< The track number. */
669
670	char isrc[13];
671	/**< Track ISRC.  This is a 12-digit alphanumeric code plus a trailing \c NUL byte */
672
673	unsigned type:1;
674	/**< The track type: 0 for audio, 1 for non-audio. */
675
676	unsigned pre_emphasis:1;
677	/**< The pre-emphasis flag: 0 for no pre-emphasis, 1 for pre-emphasis. */
678
679	FLAC__byte num_indices;
680	/**< The number of track index points. */
681
682	FLAC__StreamMetadata_CueSheet_Index *indices;
683	/**< NULL if num_indices == 0, else pointer to array of index points. */
684
685} FLAC__StreamMetadata_CueSheet_Track;
686
687extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN; /**< == 64 (bits) */
688extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN; /**< == 8 (bits) */
689extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN; /**< == 12*8 (bits) */
690extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN; /**< == 1 (bit) */
691extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN; /**< == 1 (bit) */
692extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN; /**< == 6+13*8 (bits) */
693extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN; /**< == 8 (bits) */
694
695
696/** FLAC CUESHEET structure.  (See the
697 * <A HREF="../format.html#metadata_block_cuesheet">format specification</A>
698 * for the full description of each field.)
699 */
700typedef struct {
701	char media_catalog_number[129];
702	/**< Media catalog number, in ASCII printable characters 0x20-0x7e.  In
703	 * general, the media catalog number may be 0 to 128 bytes long; any
704	 * unused characters should be right-padded with NUL characters.
705	 */
706
707	FLAC__uint64 lead_in;
708	/**< The number of lead-in samples. */
709
710	FLAC__bool is_cd;
711	/**< \c true if CUESHEET corresponds to a Compact Disc, else \c false. */
712
713	unsigned num_tracks;
714	/**< The number of tracks. */
715
716	FLAC__StreamMetadata_CueSheet_Track *tracks;
717	/**< NULL if num_tracks == 0, else pointer to array of tracks. */
718
719} FLAC__StreamMetadata_CueSheet;
720
721extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN; /**< == 128*8 (bits) */
722extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN; /**< == 64 (bits) */
723extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN; /**< == 1 (bit) */
724extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN; /**< == 7+258*8 (bits) */
725extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN; /**< == 8 (bits) */
726
727
728/** An enumeration of the PICTURE types (see FLAC__StreamMetadataPicture and id3 v2.4 APIC tag). */
729typedef enum {
730	FLAC__STREAM_METADATA_PICTURE_TYPE_OTHER = 0, /**< Other */
731	FLAC__STREAM_METADATA_PICTURE_TYPE_FILE_ICON_STANDARD = 1, /**< 32x32 pixels 'file icon' (PNG only) */
732	FLAC__STREAM_METADATA_PICTURE_TYPE_FILE_ICON = 2, /**< Other file icon */
733	FLAC__STREAM_METADATA_PICTURE_TYPE_FRONT_COVER = 3, /**< Cover (front) */
734	FLAC__STREAM_METADATA_PICTURE_TYPE_BACK_COVER = 4, /**< Cover (back) */
735	FLAC__STREAM_METADATA_PICTURE_TYPE_LEAFLET_PAGE = 5, /**< Leaflet page */
736	FLAC__STREAM_METADATA_PICTURE_TYPE_MEDIA = 6, /**< Media (e.g. label side of CD) */
737	FLAC__STREAM_METADATA_PICTURE_TYPE_LEAD_ARTIST = 7, /**< Lead artist/lead performer/soloist */
738	FLAC__STREAM_METADATA_PICTURE_TYPE_ARTIST = 8, /**< Artist/performer */
739	FLAC__STREAM_METADATA_PICTURE_TYPE_CONDUCTOR = 9, /**< Conductor */
740	FLAC__STREAM_METADATA_PICTURE_TYPE_BAND = 10, /**< Band/Orchestra */
741	FLAC__STREAM_METADATA_PICTURE_TYPE_COMPOSER = 11, /**< Composer */
742	FLAC__STREAM_METADATA_PICTURE_TYPE_LYRICIST = 12, /**< Lyricist/text writer */
743	FLAC__STREAM_METADATA_PICTURE_TYPE_RECORDING_LOCATION = 13, /**< Recording Location */
744	FLAC__STREAM_METADATA_PICTURE_TYPE_DURING_RECORDING = 14, /**< During recording */
745	FLAC__STREAM_METADATA_PICTURE_TYPE_DURING_PERFORMANCE = 15, /**< During performance */
746	FLAC__STREAM_METADATA_PICTURE_TYPE_VIDEO_SCREEN_CAPTURE = 16, /**< Movie/video screen capture */
747	FLAC__STREAM_METADATA_PICTURE_TYPE_FISH = 17, /**< A bright coloured fish */
748	FLAC__STREAM_METADATA_PICTURE_TYPE_ILLUSTRATION = 18, /**< Illustration */
749	FLAC__STREAM_METADATA_PICTURE_TYPE_BAND_LOGOTYPE = 19, /**< Band/artist logotype */
750	FLAC__STREAM_METADATA_PICTURE_TYPE_PUBLISHER_LOGOTYPE = 20, /**< Publisher/Studio logotype */
751	FLAC__STREAM_METADATA_PICTURE_TYPE_UNDEFINED
752} FLAC__StreamMetadata_Picture_Type;
753
754/** Maps a FLAC__StreamMetadata_Picture_Type to a C string.
755 *
756 *  Using a FLAC__StreamMetadata_Picture_Type as the index to this array
757 *  will give the string equivalent.  The contents should not be
758 *  modified.
759 */
760extern FLAC_API const char * const FLAC__StreamMetadata_Picture_TypeString[];
761
762/** FLAC PICTURE structure.  (See the
763 * <A HREF="../format.html#metadata_block_picture">format specification</A>
764 * for the full description of each field.)
765 */
766typedef struct {
767	FLAC__StreamMetadata_Picture_Type type;
768	/**< The kind of picture stored. */
769
770	char *mime_type;
771	/**< Picture data's MIME type, in ASCII printable characters
772	 * 0x20-0x7e, NUL terminated.  For best compatibility with players,
773	 * use picture data of MIME type \c image/jpeg or \c image/png.  A
774	 * MIME type of '-->' is also allowed, in which case the picture
775	 * data should be a complete URL.  In file storage, the MIME type is
776	 * stored as a 32-bit length followed by the ASCII string with no NUL
777	 * terminator, but is converted to a plain C string in this structure
778	 * for convenience.
779	 */
780
781	FLAC__byte *description;
782	/**< Picture's description in UTF-8, NUL terminated.  In file storage,
783	 * the description is stored as a 32-bit length followed by the UTF-8
784	 * string with no NUL terminator, but is converted to a plain C string
785	 * in this structure for convenience.
786	 */
787
788	FLAC__uint32 width;
789	/**< Picture's width in pixels. */
790
791	FLAC__uint32 height;
792	/**< Picture's height in pixels. */
793
794	FLAC__uint32 depth;
795	/**< Picture's color depth in bits-per-pixel. */
796
797	FLAC__uint32 colors;
798	/**< For indexed palettes (like GIF), picture's number of colors (the
799	 * number of palette entries), or \c 0 for non-indexed (i.e. 2^depth).
800	 */
801
802	FLAC__uint32 data_length;
803	/**< Length of binary picture data in bytes. */
804
805	FLAC__byte *data;
806	/**< Binary picture data. */
807
808} FLAC__StreamMetadata_Picture;
809
810extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_TYPE_LEN; /**< == 32 (bits) */
811extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN; /**< == 32 (bits) */
812extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN; /**< == 32 (bits) */
813extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN; /**< == 32 (bits) */
814extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN; /**< == 32 (bits) */
815extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN; /**< == 32 (bits) */
816extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_COLORS_LEN; /**< == 32 (bits) */
817extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN; /**< == 32 (bits) */
818
819
820/** Structure that is used when a metadata block of unknown type is loaded.
821 *  The contents are opaque.  The structure is used only internally to
822 *  correctly handle unknown metadata.
823 */
824typedef struct {
825	FLAC__byte *data;
826} FLAC__StreamMetadata_Unknown;
827
828
829/** FLAC metadata block structure.  (c.f. <A HREF="../format.html#metadata_block">format specification</A>)
830 */
831typedef struct {
832	FLAC__MetadataType type;
833	/**< The type of the metadata block; used determine which member of the
834	 * \a data union to dereference.  If type >= FLAC__METADATA_TYPE_UNDEFINED
835	 * then \a data.unknown must be used. */
836
837	FLAC__bool is_last;
838	/**< \c true if this metadata block is the last, else \a false */
839
840	unsigned length;
841	/**< Length, in bytes, of the block data as it appears in the stream. */
842
843	union {
844		FLAC__StreamMetadata_StreamInfo stream_info;
845		FLAC__StreamMetadata_Padding padding;
846		FLAC__StreamMetadata_Application application;
847		FLAC__StreamMetadata_SeekTable seek_table;
848		FLAC__StreamMetadata_VorbisComment vorbis_comment;
849		FLAC__StreamMetadata_CueSheet cue_sheet;
850		FLAC__StreamMetadata_Picture picture;
851		FLAC__StreamMetadata_Unknown unknown;
852	} data;
853	/**< Polymorphic block data; use the \a type value to determine which
854	 * to use. */
855} FLAC__StreamMetadata;
856
857extern FLAC_API const unsigned FLAC__STREAM_METADATA_IS_LAST_LEN; /**< == 1 (bit) */
858extern FLAC_API const unsigned FLAC__STREAM_METADATA_TYPE_LEN; /**< == 7 (bits) */
859extern FLAC_API const unsigned FLAC__STREAM_METADATA_LENGTH_LEN; /**< == 24 (bits) */
860
861/** The total stream length of a metadata block header in bytes. */
862#define FLAC__STREAM_METADATA_HEADER_LENGTH (4u)
863
864/*****************************************************************************/
865
866
867/*****************************************************************************
868 *
869 * Utility functions
870 *
871 *****************************************************************************/
872
873/** Tests that a sample rate is valid for FLAC.
874 *
875 * \param sample_rate  The sample rate to test for compliance.
876 * \retval FLAC__bool
877 *    \c true if the given sample rate conforms to the specification, else
878 *    \c false.
879 */
880FLAC_API FLAC__bool FLAC__format_sample_rate_is_valid(unsigned sample_rate);
881
882/** Tests that a sample rate is valid for the FLAC subset.  The subset rules
883 *  for valid sample rates are slightly more complex since the rate has to
884 *  be expressible completely in the frame header.
885 *
886 * \param sample_rate  The sample rate to test for compliance.
887 * \retval FLAC__bool
888 *    \c true if the given sample rate conforms to the specification for the
889 *    subset, else \c false.
890 */
891FLAC_API FLAC__bool FLAC__format_sample_rate_is_subset(unsigned sample_rate);
892
893/** Check a Vorbis comment entry name to see if it conforms to the Vorbis
894 *  comment specification.
895 *
896 *  Vorbis comment names must be composed only of characters from
897 *  [0x20-0x3C,0x3E-0x7D].
898 *
899 * \param name       A NUL-terminated string to be checked.
900 * \assert
901 *    \code name != NULL \endcode
902 * \retval FLAC__bool
903 *    \c false if entry name is illegal, else \c true.
904 */
905FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_name_is_legal(const char *name);
906
907/** Check a Vorbis comment entry value to see if it conforms to the Vorbis
908 *  comment specification.
909 *
910 *  Vorbis comment values must be valid UTF-8 sequences.
911 *
912 * \param value      A string to be checked.
913 * \param length     A the length of \a value in bytes.  May be
914 *                   \c (unsigned)(-1) to indicate that \a value is a plain
915 *                   UTF-8 NUL-terminated string.
916 * \assert
917 *    \code value != NULL \endcode
918 * \retval FLAC__bool
919 *    \c false if entry name is illegal, else \c true.
920 */
921FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_value_is_legal(const FLAC__byte *value, unsigned length);
922
923/** Check a Vorbis comment entry to see if it conforms to the Vorbis
924 *  comment specification.
925 *
926 *  Vorbis comment entries must be of the form 'name=value', and 'name' and
927 *  'value' must be legal according to
928 *  FLAC__format_vorbiscomment_entry_name_is_legal() and
929 *  FLAC__format_vorbiscomment_entry_value_is_legal() respectively.
930 *
931 * \param entry      An entry to be checked.
932 * \param length     The length of \a entry in bytes.
933 * \assert
934 *    \code value != NULL \endcode
935 * \retval FLAC__bool
936 *    \c false if entry name is illegal, else \c true.
937 */
938FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_is_legal(const FLAC__byte *entry, unsigned length);
939
940/** Check a seek table to see if it conforms to the FLAC specification.
941 *  See the format specification for limits on the contents of the
942 *  seek table.
943 *
944 * \param seek_table  A pointer to a seek table to be checked.
945 * \assert
946 *    \code seek_table != NULL \endcode
947 * \retval FLAC__bool
948 *    \c false if seek table is illegal, else \c true.
949 */
950FLAC_API FLAC__bool FLAC__format_seektable_is_legal(const FLAC__StreamMetadata_SeekTable *seek_table);
951
952/** Sort a seek table's seek points according to the format specification.
953 *  This includes a "unique-ification" step to remove duplicates, i.e.
954 *  seek points with identical \a sample_number values.  Duplicate seek
955 *  points are converted into placeholder points and sorted to the end of
956 *  the table.
957 *
958 * \param seek_table  A pointer to a seek table to be sorted.
959 * \assert
960 *    \code seek_table != NULL \endcode
961 * \retval unsigned
962 *    The number of duplicate seek points converted into placeholders.
963 */
964FLAC_API unsigned FLAC__format_seektable_sort(FLAC__StreamMetadata_SeekTable *seek_table);
965
966/** Check a cue sheet to see if it conforms to the FLAC specification.
967 *  See the format specification for limits on the contents of the
968 *  cue sheet.
969 *
970 * \param cue_sheet  A pointer to an existing cue sheet to be checked.
971 * \param check_cd_da_subset  If \c true, check CUESHEET against more
972 *                   stringent requirements for a CD-DA (audio) disc.
973 * \param violation  Address of a pointer to a string.  If there is a
974 *                   violation, a pointer to a string explanation of the
975 *                   violation will be returned here. \a violation may be
976 *                   \c NULL if you don't need the returned string.  Do not
977 *                   free the returned string; it will always point to static
978 *                   data.
979 * \assert
980 *    \code cue_sheet != NULL \endcode
981 * \retval FLAC__bool
982 *    \c false if cue sheet is illegal, else \c true.
983 */
984FLAC_API FLAC__bool FLAC__format_cuesheet_is_legal(const FLAC__StreamMetadata_CueSheet *cue_sheet, FLAC__bool check_cd_da_subset, const char **violation);
985
986/** Check picture data to see if it conforms to the FLAC specification.
987 *  See the format specification for limits on the contents of the
988 *  PICTURE block.
989 *
990 * \param picture    A pointer to existing picture data to be checked.
991 * \param violation  Address of a pointer to a string.  If there is a
992 *                   violation, a pointer to a string explanation of the
993 *                   violation will be returned here. \a violation may be
994 *                   \c NULL if you don't need the returned string.  Do not
995 *                   free the returned string; it will always point to static
996 *                   data.
997 * \assert
998 *    \code picture != NULL \endcode
999 * \retval FLAC__bool
1000 *    \c false if picture data is illegal, else \c true.
1001 */
1002FLAC_API FLAC__bool FLAC__format_picture_is_legal(const FLAC__StreamMetadata_Picture *picture, const char **violation);
1003
1004/* \} */
1005
1006#ifdef __cplusplus
1007}
1008#endif
1009
1010#endif
1011