format.h (32680B)
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