1 /* libFLAC - Free Lossless Audio Codec library
2 * Copyright (C) 2000,2001,2002,2003,2004,2005,2006 Josh Coalson
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
8 * - Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
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.
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.
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.
32 #ifndef FLAC__FORMAT_H
33 #define FLAC__FORMAT_H
42 /** \file include/FLAC/format.h
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.
49 * See the detailed documentation in the
50 * \link flac_format format \endlink module.
53 /** \defgroup flac_format FLAC/format.h: format components
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.
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.
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.
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.
87 Most of the values described in this file are defined by the FLAC
88 format specification. There is nothing to tune here.
91 /** The largest legal metadata type code. */
92 #define FLAC__MAX_METADATA_TYPE_CODE (126u)
94 /** The minimum block size, in samples, permitted by the format. */
95 #define FLAC__MIN_BLOCK_SIZE (16u)
97 /** The maximum block size, in samples, permitted by the format. */
98 #define FLAC__MAX_BLOCK_SIZE (65535u)
100 /** The maximum number of channels permitted by the format. */
101 #define FLAC__MAX_CHANNELS (8u)
103 /** The minimum sample resolution permitted by the format. */
104 #define FLAC__MIN_BITS_PER_SAMPLE (4u)
106 /** The maximum sample resolution permitted by the format. */
107 #define FLAC__MAX_BITS_PER_SAMPLE (32u)
109 /** The maximum sample resolution permitted by libFLAC.
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
117 #define FLAC__REFERENCE_CODEC_MAX_BITS_PER_SAMPLE (24u)
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>
123 #define FLAC__MAX_SAMPLE_RATE (655350u)
125 /** The maximum LPC order permitted by the format. */
126 #define FLAC__MAX_LPC_ORDER (32u)
128 /** The minimum quantized linear predictor coefficient precision
129 * permitted by the format.
131 #define FLAC__MIN_QLP_COEFF_PRECISION (5u)
133 /** The maximum quantized linear predictor coefficient precision
134 * permitted by the format.
136 #define FLAC__MAX_QLP_COEFF_PRECISION (15u)
138 /** The maximum order of the fixed predictors permitted by the format. */
139 #define FLAC__MAX_FIXED_ORDER (4u)
141 /** The maximum Rice partition order permitted by the format. */
142 #define FLAC__MAX_RICE_PARTITION_ORDER (15u)
144 /** The maximum Rice partition order permitted by the FLAC Subset. */
145 #define FLAC__SUBSET_MAX_RICE_PARTITION_ORDER (8u)
147 /** The version string of the release, stamped onto the libraries and binaries.
150 * This does not correspond to the shared library version number, which
151 * is used to determine binary compatibility.
153 extern FLAC_API const char *FLAC__VERSION_STRING;
155 /** The vendor string inserted by the encoder into the VORBIS_COMMENT block.
156 * This is a NUL-terminated ASCII string; when inserted into the
157 * VORBIS_COMMENT the trailing null is stripped.
159 extern FLAC_API const char *FLAC__VENDOR_STRING;
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" */
164 /** The 32-bit integer big-endian representation of the beginning of
167 extern FLAC_API const unsigned FLAC__STREAM_SYNC; /* = 0x664C6143 */
169 /** The length of the FLAC signature in bits. */
170 extern FLAC_API const unsigned FLAC__STREAM_SYNC_LEN; /* = 32 bits */
172 /** The length of the FLAC signature in bytes. */
173 #define FLAC__STREAM_SYNC_LENGTH (4u)
176 /*****************************************************************************
178 * Subframe structures
180 *****************************************************************************/
182 /*****************************************************************************/
184 /** An enumeration of the available entropy coding methods. */
186 FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE = 0
187 /**< Residual is coded by partitioning into contexts, each with it's own
189 } FLAC__EntropyCodingMethodType;
191 /** Maps a FLAC__EntropyCodingMethodType to a C string.
193 * Using a FLAC__EntropyCodingMethodType as the index to this array will
194 * give the string equivalent. The contents should not be modified.
196 extern FLAC_API const char * const FLAC__EntropyCodingMethodTypeString[];
199 /** Contents of a Rice partitioned residual
203 unsigned *parameters;
204 /**< The Rice parameters for each context. */
207 /**< Widths for escape-coded partitions. */
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.
214 } FLAC__EntropyCodingMethod_PartitionedRiceContents;
216 /** Header for a Rice partitioned residual. (c.f. <A HREF="../format.html#partitioned_rice">format specification</A>)
221 /**< The partition order, i.e. # of contexts = 2 ^ \a order. */
223 const FLAC__EntropyCodingMethod_PartitionedRiceContents *contents;
224 /**< The context's Rice parameters and/or raw bits. */
226 } FLAC__EntropyCodingMethod_PartitionedRice;
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) */
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 */
235 /** Header for the entropy coding method. (c.f. <A HREF="../format.html#residual">format specification</A>)
238 FLAC__EntropyCodingMethodType type;
240 FLAC__EntropyCodingMethod_PartitionedRice partitioned_rice;
242 } FLAC__EntropyCodingMethod;
244 extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_TYPE_LEN; /**< == 2 (bits) */
246 /*****************************************************************************/
248 /** An enumeration of the available subframe types. */
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;
256 /** Maps a FLAC__SubframeType to a C string.
258 * Using a FLAC__SubframeType as the index to this array will
259 * give the string equivalent. The contents should not be modified.
261 extern FLAC_API const char * const FLAC__SubframeTypeString[];
264 /** CONSTANT subframe. (c.f. <A HREF="../format.html#subframe_constant">format specification</A>)
267 FLAC__int32 value; /**< The constant signal value. */
268 } FLAC__Subframe_Constant;
271 /** VERBATIM subframe. (c.f. <A HREF="../format.html#subframe_verbatim">format specification</A>)
274 const FLAC__int32 *data; /**< A pointer to verbatim signal. */
275 } FLAC__Subframe_Verbatim;
278 /** FIXED subframe. (c.f. <A HREF="../format.html#subframe_fixed">format specification</A>)
281 FLAC__EntropyCodingMethod entropy_coding_method;
282 /**< The residual coding method. */
285 /**< The polynomial order. */
287 FLAC__int32 warmup[FLAC__MAX_FIXED_ORDER];
288 /**< Warmup samples to prime the predictor, length == order. */
290 const FLAC__int32 *residual;
291 /**< The residual signal, length == (blocksize minus order) samples. */
292 } FLAC__Subframe_Fixed;
295 /** LPC subframe. (c.f. <A HREF="../format.html#subframe_lpc">format specification</A>)
298 FLAC__EntropyCodingMethod entropy_coding_method;
299 /**< The residual coding method. */
302 /**< The FIR order. */
304 unsigned qlp_coeff_precision;
305 /**< Quantized FIR filter coefficient precision in bits. */
307 int quantization_level;
308 /**< The qlp coeff shift needed. */
310 FLAC__int32 qlp_coeff[FLAC__MAX_LPC_ORDER];
311 /**< FIR filter coefficients. */
313 FLAC__int32 warmup[FLAC__MAX_LPC_ORDER];
314 /**< Warmup samples to prime the predictor, length == order. */
316 const FLAC__int32 *residual;
317 /**< The residual signal, length == (blocksize minus order) samples. */
318 } FLAC__Subframe_LPC;
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) */
324 /** FLAC subframe structure. (c.f. <A HREF="../format.html#subframe">format specification</A>)
327 FLAC__SubframeType type;
329 FLAC__Subframe_Constant constant;
330 FLAC__Subframe_Fixed fixed;
331 FLAC__Subframe_LPC lpc;
332 FLAC__Subframe_Verbatim verbatim;
334 unsigned wasted_bits;
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) */
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 */
346 /*****************************************************************************/
349 /*****************************************************************************
353 *****************************************************************************/
355 /** An enumeration of the available channel assignments. */
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;
363 /** Maps a FLAC__ChannelAssignment to a C string.
365 * Using a FLAC__ChannelAssignment as the index to this array will
366 * give the string equivalent. The contents should not be modified.
368 extern FLAC_API const char * const FLAC__ChannelAssignmentString[];
370 /** An enumeration of the possible frame numbering methods. */
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;
376 /** Maps a FLAC__FrameNumberType to a C string.
378 * Using a FLAC__FrameNumberType as the index to this array will
379 * give the string equivalent. The contents should not be modified.
381 extern FLAC_API const char * const FLAC__FrameNumberTypeString[];
384 /** FLAC frame header structure. (c.f. <A HREF="../format.html#frame_header">format specification</A>)
388 /**< The number of samples per subframe. */
390 unsigned sample_rate;
391 /**< The sample rate in Hz. */
394 /**< The number of channels (== number of subframes). */
396 FLAC__ChannelAssignment channel_assignment;
397 /**< The channel assignment for the frame. */
399 unsigned bits_per_sample;
400 /**< The sample resolution. */
402 FLAC__FrameNumberType number_type;
403 /**< The numbering scheme used for the frame. */
406 FLAC__uint32 frame_number;
407 FLAC__uint64 sample_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. */
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.
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) */
430 /** FLAC frame footer structure. (c.f. <A HREF="../format.html#frame_footer">format specification</A>)
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
440 extern FLAC_API const unsigned FLAC__FRAME_FOOTER_CRC_LEN; /**< == 16 (bits) */
443 /** FLAC frame structure. (c.f. <A HREF="../format.html#frame">format specification</A>)
446 FLAC__FrameHeader header;
447 FLAC__Subframe subframes[FLAC__MAX_CHANNELS];
448 FLAC__FrameFooter footer;
451 /*****************************************************************************/
454 /*****************************************************************************
456 * Meta-data structures
458 *****************************************************************************/
460 /** An enumeration of the available metadata block types. */
463 FLAC__METADATA_TYPE_STREAMINFO = 0,
464 /**< <A HREF="../format.html#metadata_block_streaminfo">STREAMINFO</A> block */
466 FLAC__METADATA_TYPE_PADDING = 1,
467 /**< <A HREF="../format.html#metadata_block_padding">PADDING</A> block */
469 FLAC__METADATA_TYPE_APPLICATION = 2,
470 /**< <A HREF="../format.html#metadata_block_application">APPLICATION</A> block */
472 FLAC__METADATA_TYPE_SEEKTABLE = 3,
473 /**< <A HREF="../format.html#metadata_block_seektable">SEEKTABLE</A> block */
475 FLAC__METADATA_TYPE_VORBIS_COMMENT = 4,
476 /**< <A HREF="../format.html#metadata_block_vorbis_comment">VORBISCOMMENT</A> block (a.k.a. FLAC tags) */
478 FLAC__METADATA_TYPE_CUESHEET = 5,
479 /**< <A HREF="../format.html#metadata_block_cuesheet">CUESHEET</A> block */
481 FLAC__METADATA_TYPE_PICTURE = 6,
482 /**< <A HREF="../format.html#metadata_block_picture">PICTURE</A> block */
484 FLAC__METADATA_TYPE_UNDEFINED = 7
485 /**< marker to denote beginning of undefined type range; this number will increase as new metadata types are added */
487 } FLAC__MetadataType;
489 /** Maps a FLAC__MetadataType to a C string.
491 * Using a FLAC__MetadataType as the index to this array will
492 * give the string equivalent. The contents should not be modified.
494 extern FLAC_API const char * const FLAC__MetadataTypeString[];
497 /** FLAC STREAMINFO structure. (c.f. <A HREF="../format.html#metadata_block_streaminfo">format specification</A>)
500 unsigned min_blocksize, max_blocksize;
501 unsigned min_framesize, max_framesize;
502 unsigned sample_rate;
504 unsigned bits_per_sample;
505 FLAC__uint64 total_samples;
506 FLAC__byte md5sum[16];
507 } FLAC__StreamMetadata_StreamInfo;
509 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN; /**< == 16 (bits) */
510 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN; /**< == 16 (bits) */
511 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN; /**< == 24 (bits) */
512 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN; /**< == 24 (bits) */
513 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN; /**< == 20 (bits) */
514 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN; /**< == 3 (bits) */
515 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN; /**< == 5 (bits) */
516 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_TOTAL_SAMPLES_LEN; /**< == 36 (bits) */
517 extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MD5SUM_LEN; /**< == 128 (bits) */
519 /** The total stream length of the STREAMINFO block in bytes. */
520 #define FLAC__STREAM_METADATA_STREAMINFO_LENGTH (34u)
522 /** FLAC PADDING structure. (c.f. <A HREF="../format.html#metadata_block_padding">format specification</A>)
526 /**< Conceptually this is an empty struct since we don't store the
527 * padding bytes. Empty structs are not allowed by some C compilers,
530 } FLAC__StreamMetadata_Padding;
533 /** FLAC APPLICATION structure. (c.f. <A HREF="../format.html#metadata_block_application">format specification</A>)
538 } FLAC__StreamMetadata_Application;
540 extern FLAC_API const unsigned FLAC__STREAM_METADATA_APPLICATION_ID_LEN; /**< == 32 (bits) */
542 /** SeekPoint structure used in SEEKTABLE blocks. (c.f. <A HREF="../format.html#seekpoint">format specification</A>)
545 FLAC__uint64 sample_number;
546 /**< The sample number of the target frame. */
548 FLAC__uint64 stream_offset;
549 /**< The offset, in bytes, of the target frame with respect to
550 * beginning of the first frame. */
552 unsigned frame_samples;
553 /**< The number of samples in the target frame. */
554 } FLAC__StreamMetadata_SeekPoint;
556 extern FLAC_API const unsigned FLAC__STREAM_METADATA_SEEKPOINT_SAMPLE_NUMBER_LEN; /**< == 64 (bits) */
557 extern FLAC_API const unsigned FLAC__STREAM_METADATA_SEEKPOINT_STREAM_OFFSET_LEN; /**< == 64 (bits) */
558 extern FLAC_API const unsigned FLAC__STREAM_METADATA_SEEKPOINT_FRAME_SAMPLES_LEN; /**< == 16 (bits) */
560 /** The total stream length of a seek point in bytes. */
561 #define FLAC__STREAM_METADATA_SEEKPOINT_LENGTH (18u)
563 /** The value used in the \a sample_number field of
564 * FLAC__StreamMetadataSeekPoint used to indicate a placeholder
565 * point (== 0xffffffffffffffff).
567 extern FLAC_API const FLAC__uint64 FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER;
570 /** FLAC SEEKTABLE structure. (c.f. <A HREF="../format.html#metadata_block_seektable">format specification</A>)
572 * \note From the format specification:
573 * - The seek points must be sorted by ascending sample number.
574 * - Each seek point's sample number must be the first sample of the
576 * - Each seek point's sample number must be unique within the table.
577 * - Existence of a SEEKTABLE block implies a correct setting of
578 * total_samples in the stream_info block.
579 * - Behavior is undefined when more than one SEEKTABLE block is
580 * present in a stream.
584 FLAC__StreamMetadata_SeekPoint *points;
585 } FLAC__StreamMetadata_SeekTable;
588 /** Vorbis comment entry structure used in VORBIS_COMMENT blocks. (c.f. <A HREF="../format.html#metadata_block_vorbis_comment">format specification</A>)
590 * For convenience, the APIs maintain a trailing NUL character at the end of
591 * \a entry which is not counted toward \a length, i.e.
592 * \code strlen(entry) == length \endcode
597 } FLAC__StreamMetadata_VorbisComment_Entry;
599 extern FLAC_API const unsigned FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN; /**< == 32 (bits) */
602 /** FLAC VORBIS_COMMENT structure. (c.f. <A HREF="../format.html#metadata_block_vorbis_comment">format specification</A>)
605 FLAC__StreamMetadata_VorbisComment_Entry vendor_string;
606 FLAC__uint32 num_comments;
607 FLAC__StreamMetadata_VorbisComment_Entry *comments;
608 } FLAC__StreamMetadata_VorbisComment;
610 extern FLAC_API const unsigned FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN; /**< == 32 (bits) */
613 /** FLAC CUESHEET track index structure. (See the
614 * <A HREF="../format.html#cuesheet_track_index">format specification</A> for
615 * the full description of each field.)
619 /**< Offset in samples, relative to the track offset, of the index
624 /**< The index point number. */
625 } FLAC__StreamMetadata_CueSheet_Index;
627 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN; /**< == 64 (bits) */
628 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN; /**< == 8 (bits) */
629 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN; /**< == 3*8 (bits) */
632 /** FLAC CUESHEET track structure. (See the
633 * <A HREF="../format.html#cuesheet_track">format specification</A> for
634 * the full description of each field.)
638 /**< Track offset in samples, relative to the beginning of the FLAC audio stream. */
641 /**< The track number. */
644 /**< Track ISRC. This is a 12-digit alphanumeric code plus a trailing '\0' */
647 /**< The track type: 0 for audio, 1 for non-audio. */
649 unsigned pre_emphasis:1;
650 /**< The pre-emphasis flag: 0 for no pre-emphasis, 1 for pre-emphasis. */
652 FLAC__byte num_indices;
653 /**< The number of track index points. */
655 FLAC__StreamMetadata_CueSheet_Index *indices;
656 /**< NULL if num_indices == 0, else pointer to array of index points. */
658 } FLAC__StreamMetadata_CueSheet_Track;
660 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN; /**< == 64 (bits) */
661 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN; /**< == 8 (bits) */
662 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN; /**< == 12*8 (bits) */
663 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN; /**< == 1 (bit) */
664 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN; /**< == 1 (bit) */
665 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN; /**< == 6+13*8 (bits) */
666 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN; /**< == 8 (bits) */
669 /** FLAC CUESHEET structure. (See the
670 * <A HREF="../format.html#metadata_block_cuesheet">format specification</A>
671 * for the full description of each field.)
674 char media_catalog_number[129];
675 /**< Media catalog number, in ASCII printable characters 0x20-0x7e. In
676 * general, the media catalog number may be 0 to 128 bytes long; any
677 * unused characters should be right-padded with NUL characters.
680 FLAC__uint64 lead_in;
681 /**< The number of lead-in samples. */
684 /**< \c true if CUESHEET corresponds to a Compact Disc, else \c false. */
687 /**< The number of tracks. */
689 FLAC__StreamMetadata_CueSheet_Track *tracks;
690 /**< NULL if num_tracks == 0, else pointer to array of tracks. */
692 } FLAC__StreamMetadata_CueSheet;
694 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN; /**< == 128*8 (bits) */
695 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN; /**< == 64 (bits) */
696 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN; /**< == 1 (bit) */
697 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN; /**< == 7+258*8 (bits) */
698 extern FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN; /**< == 8 (bits) */
701 /** An enumeration of the PICTURE types (see FLAC__StreamMetadataPicture and id3 v2.4 APIC tag). */
703 FLAC__STREAM_METADATA_PICTURE_TYPE_OTHER = 0, /**< Other */
704 FLAC__STREAM_METADATA_PICTURE_TYPE_FILE_ICON_STANDARD = 1, /**< 32x32 pixels 'file icon' (PNG only) */
705 FLAC__STREAM_METADATA_PICTURE_TYPE_FILE_ICON = 2, /**< Other file icon */
706 FLAC__STREAM_METADATA_PICTURE_TYPE_FRONT_COVER = 3, /**< Cover (front) */
707 FLAC__STREAM_METADATA_PICTURE_TYPE_BACK_COVER = 4, /**< Cover (back) */
708 FLAC__STREAM_METADATA_PICTURE_TYPE_LEAFLET_PAGE = 5, /**< Leaflet page */
709 FLAC__STREAM_METADATA_PICTURE_TYPE_MEDIA = 6, /**< Media (e.g. label side of CD) */
710 FLAC__STREAM_METADATA_PICTURE_TYPE_LEAD_ARTIST = 7, /**< Lead artist/lead performer/soloist */
711 FLAC__STREAM_METADATA_PICTURE_TYPE_ARTIST = 8, /**< Artist/performer */
712 FLAC__STREAM_METADATA_PICTURE_TYPE_CONDUCTOR = 9, /**< Conductor */
713 FLAC__STREAM_METADATA_PICTURE_TYPE_BAND = 10, /**< Band/Orchestra */
714 FLAC__STREAM_METADATA_PICTURE_TYPE_COMPOSER = 11, /**< Composer */
715 FLAC__STREAM_METADATA_PICTURE_TYPE_LYRICIST = 12, /**< Lyricist/text writer */
716 FLAC__STREAM_METADATA_PICTURE_TYPE_RECORDING_LOCATION = 13, /**< Recording Location */
717 FLAC__STREAM_METADATA_PICTURE_TYPE_DURING_RECORDING = 14, /**< During recording */
718 FLAC__STREAM_METADATA_PICTURE_TYPE_DURING_PERFORMANCE = 15, /**< During performance */
719 FLAC__STREAM_METADATA_PICTURE_TYPE_VIDEO_SCREEN_CAPTURE = 16, /**< Movie/video screen capture */
720 FLAC__STREAM_METADATA_PICTURE_TYPE_FISH = 17, /**< A bright coloured fish */
721 FLAC__STREAM_METADATA_PICTURE_TYPE_ILLUSTRATION = 18, /**< Illustration */
722 FLAC__STREAM_METADATA_PICTURE_TYPE_BAND_LOGOTYPE = 19, /**< Band/artist logotype */
723 FLAC__STREAM_METADATA_PICTURE_TYPE_PUBLISHER_LOGOTYPE = 20, /**< Publisher/Studio logotype */
724 FLAC__STREAM_METADATA_PICTURE_TYPE_UNDEFINED
725 } FLAC__StreamMetadata_Picture_Type;
727 /** Maps a FLAC__StreamMetadata_Picture_Type to a C string.
729 * Using a FLAC__StreamMetadata_Picture_Type as the index to this array
730 * will give the string equivalent. The contents should not be
733 extern FLAC_API const char * const FLAC__StreamMetadata_Picture_TypeString[];
735 /** FLAC PICTURE structure. (See the
736 * <A HREF="../format.html#metadata_block_picture">format specification</A>
737 * for the full description of each field.)
740 FLAC__StreamMetadata_Picture_Type type;
741 /**< The kind of picture stored. */
744 /**< Picture data's MIME type, in ASCII printable characters
745 * 0x20-0x7e, NUL terminated. For best compatibility with players,
746 * use picture data of MIME type \c image/jpeg or \c image/png. A
747 * MIME type of '-->' is also allowed, in which case the picture
748 * data should be a complete URL. In file storage, the MIME type is
749 * stored as a 32-bit length followed by the ASCII string with no NUL
750 * terminator, but is converted to a plain C string in this structure
754 FLAC__byte *description;
755 /**< Picture's description in UTF-8, NUL terminated. In file storage,
756 * the description is stored as a 32-bit length followed by the UTF-8
757 * string with no NUL terminator, but is converted to a plain C string
758 * in this structure for convenience.
762 /**< Picture's width in pixels. */
765 /**< Picture's height in pixels. */
768 /**< Picture's color depth in bits-per-pixel. */
771 /**< For indexed palettes (like GIF), picture's number of colors (the
772 * number of palette entries), or \c 0 for non-indexed (i.e. 2^depth).
775 FLAC__uint32 data_length;
776 /**< Length of binary picture data in bytes. */
779 /**< Binary picture data. */
781 } FLAC__StreamMetadata_Picture;
783 extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_TYPE_LEN; /**< == 32 (bits) */
784 extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN; /**< == 32 (bits) */
785 extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN; /**< == 32 (bits) */
786 extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN; /**< == 32 (bits) */
787 extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN; /**< == 32 (bits) */
788 extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN; /**< == 32 (bits) */
789 extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_COLORS_LEN; /**< == 32 (bits) */
790 extern FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN; /**< == 32 (bits) */
793 /** Structure that is used when a metadata block of unknown type is loaded.
794 * The contents are opaque. The structure is used only internally to
795 * correctly handle unknown metadata.
799 } FLAC__StreamMetadata_Unknown;
802 /** FLAC metadata block structure. (c.f. <A HREF="../format.html#metadata_block">format specification</A>)
805 FLAC__MetadataType type;
806 /**< The type of the metadata block; used determine which member of the
807 * \a data union to dereference. If type >= FLAC__METADATA_TYPE_UNDEFINED
808 * then \a data.unknown must be used. */
811 /**< \c true if this metadata block is the last, else \a false */
814 /**< Length, in bytes, of the block data as it appears in the stream. */
817 FLAC__StreamMetadata_StreamInfo stream_info;
818 FLAC__StreamMetadata_Padding padding;
819 FLAC__StreamMetadata_Application application;
820 FLAC__StreamMetadata_SeekTable seek_table;
821 FLAC__StreamMetadata_VorbisComment vorbis_comment;
822 FLAC__StreamMetadata_CueSheet cue_sheet;
823 FLAC__StreamMetadata_Picture picture;
824 FLAC__StreamMetadata_Unknown unknown;
826 /**< Polymorphic block data; use the \a type value to determine which
828 } FLAC__StreamMetadata;
830 extern FLAC_API const unsigned FLAC__STREAM_METADATA_IS_LAST_LEN; /**< == 1 (bit) */
831 extern FLAC_API const unsigned FLAC__STREAM_METADATA_TYPE_LEN; /**< == 7 (bits) */
832 extern FLAC_API const unsigned FLAC__STREAM_METADATA_LENGTH_LEN; /**< == 24 (bits) */
834 /** The total stream length of a metadata block header in bytes. */
835 #define FLAC__STREAM_METADATA_HEADER_LENGTH (4u)
837 /*****************************************************************************/
840 /*****************************************************************************
844 *****************************************************************************/
846 /** Tests that a sample rate is valid for FLAC. Since the rules for valid
847 * sample rates are slightly complex, they are encapsulated in this function.
849 * \param sample_rate The sample rate to test for compliance.
851 * \c true if the given sample rate conforms to the specification, else
854 FLAC_API FLAC__bool FLAC__format_sample_rate_is_valid(unsigned sample_rate);
856 /** Check a Vorbis comment entry name to see if it conforms to the Vorbis
857 * comment specification.
859 * Vorbis comment names must be composed only of characters from
860 * [0x20-0x3C,0x3E-0x7D].
862 * \param name A NUL-terminated string to be checked.
864 * \code name != NULL \endcode
866 * \c false if entry name is illegal, else \c true.
868 FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_name_is_legal(const char *name);
870 /** Check a Vorbis comment entry value to see if it conforms to the Vorbis
871 * comment specification.
873 * Vorbis comment values must be valid UTF-8 sequences.
875 * \param value A string to be checked.
876 * \param length A the length of \a value in bytes. May be
877 * \c (unsigned)(-1) to indicate that \a value is a plain
878 * UTF-8 NUL-terminated string.
880 * \code value != NULL \endcode
882 * \c false if entry name is illegal, else \c true.
884 FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_value_is_legal(const FLAC__byte *value, unsigned length);
886 /** Check a Vorbis comment entry to see if it conforms to the Vorbis
887 * comment specification.
889 * Vorbis comment entries must be of the form 'name=value', and 'name' and
890 * 'value' must be legal according to
891 * FLAC__format_vorbiscomment_entry_name_is_legal() and
892 * FLAC__format_vorbiscomment_entry_value_is_legal() respectively.
894 * \param value A string to be checked.
896 * \code value != NULL \endcode
898 * \c false if entry name is illegal, else \c true.
900 FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_is_legal(const FLAC__byte *entry, unsigned length);
902 /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
903 /** Check a seek table to see if it conforms to the FLAC specification.
904 * See the format specification for limits on the contents of the
907 * \param seek_table A pointer to a seek table to be checked.
909 * \code seek_table != NULL \endcode
911 * \c false if seek table is illegal, else \c true.
913 FLAC_API FLAC__bool FLAC__format_seektable_is_legal(const FLAC__StreamMetadata_SeekTable *seek_table);
915 /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
916 /** Sort a seek table's seek points according to the format specification.
917 * This includes a "unique-ification" step to remove duplicates, i.e.
918 * seek points with identical \a sample_number values. Duplicate seek
919 * points are converted into placeholder points and sorted to the end of
922 * \param seek_table A pointer to a seek table to be sorted.
924 * \code seek_table != NULL \endcode
926 * The number of duplicate seek points converted into placeholders.
928 FLAC_API unsigned FLAC__format_seektable_sort(FLAC__StreamMetadata_SeekTable *seek_table);
930 /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
931 /** Check a cue sheet to see if it conforms to the FLAC specification.
932 * See the format specification for limits on the contents of the
935 * \param cue_sheet A pointer to an existing cue sheet to be checked.
936 * \param check_cd_da_subset If \c true, check CUESHEET against more
937 * stringent requirements for a CD-DA (audio) disc.
938 * \param violation Address of a pointer to a string. If there is a
939 * violation, a pointer to a string explanation of the
940 * violation will be returned here. \a violation may be
941 * \c NULL if you don't need the returned string. Do not
942 * free the returned string; it will always point to static
945 * \code cue_sheet != NULL \endcode
947 * \c false if cue sheet is illegal, else \c true.
949 FLAC_API FLAC__bool FLAC__format_cuesheet_is_legal(const FLAC__StreamMetadata_CueSheet *cue_sheet, FLAC__bool check_cd_da_subset, const char **violation);
951 /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
952 /** Check picture data to see if it conforms to the FLAC specification.
953 * See the format specification for limits on the contents of the
956 * \param picture A pointer to existing picture data to be checked.
957 * \param violation Address of a pointer to a string. If there is a
958 * violation, a pointer to a string explanation of the
959 * violation will be returned here. \a violation may be
960 * \c NULL if you don't need the returned string. Do not
961 * free the returned string; it will always point to static
964 * \code picture != NULL \endcode
966 * \c false if picture data is illegal, else \c true.
968 FLAC_API FLAC__bool FLAC__format_picture_is_legal(const FLAC__StreamMetadata_Picture *picture, const char **violation);