1 /* libFLAC - Free Lossless Audio Codec library
2 * Copyright (C) 2000,2001,2002 Josh Coalson
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
14 * You should have received a copy of the GNU Library General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
20 #ifndef FLAC__STREAM_DECODER_H
21 #define FLAC__STREAM_DECODER_H
31 /** \file include/FLAC/stream_decoder.h
34 * This module contains the functions which implement the stream
37 * See the detailed documentation in the
38 * \link flac_stream_decoder stream decoder \endlink module.
41 /** \defgroup flac_decoder FLAC/ *_decoder.h: decoder interfaces
45 * This module describes the three decoder layers provided by libFLAC.
47 * For decoding FLAC streams, libFLAC provides three layers of access. The
48 * lowest layer is non-seekable stream-level decoding, the next is seekable
49 * stream-level decoding, and the highest layer is file-level decoding. The
50 * interfaces are described in the \link flac_stream_decoder stream decoder
51 * \endlink, \link flac_seekable_stream_decoder seekable stream decoder
52 * \endlink, and \link flac_file_decoder file decoder \endlink modules
53 * respectively. Typically you will choose the highest layer that your input
54 * source will support.
56 * The stream decoder relies on callbacks for all input and output and has no
57 * provisions for seeking. The seekable stream decoder wraps the stream
58 * decoder and exposes functions for seeking. However, you must provide
59 * extra callbacks for seek-related operations on your stream, like seek and
60 * tell. The file decoder wraps the seekable stream decoder and supplies
61 * most of the callbacks internally, simplifying the processing of standard
65 /** \defgroup flac_stream_decoder FLAC/stream_decoder.h: stream decoder interface
66 * \ingroup flac_decoder
69 * This module contains the functions which implement the stream
72 * The basic usage of this decoder is as follows:
73 * - The program creates an instance of a decoder using
74 * FLAC__stream_decoder_new().
75 * - The program overrides the default settings and sets callbacks for
76 * reading, writing, error reporting, and metadata reporting using
77 * FLAC__stream_decoder_set_*() functions.
78 * - The program initializes the instance to validate the settings and
79 * prepare for decoding using FLAC__stream_decoder_init().
80 * - The program calls the FLAC__stream_decoder_process_*() functions
81 * to decode data, which subsequently calls the callbacks.
82 * - The program finishes the decoding with FLAC__stream_decoder_finish(),
83 * which flushes the input and output and resets the decoder to the
84 * uninitialized state.
85 * - The instance may be used again or deleted with
86 * FLAC__stream_decoder_delete().
88 * In more detail, the program will create a new instance by calling
89 * FLAC__stream_decoder_new(), then call FLAC__stream_decoder_set_*()
90 * functions to set the callbacks and client data, and call
91 * FLAC__stream_decoder_init(). The required callbacks are:
93 * - Read callback - This function will be called when the decoder needs
94 * more input data. The address of the buffer to be filled is supplied,
95 * along with the number of bytes the buffer can hold. The callback may
96 * choose to supply less data and modify the byte count but must be careful
97 * not to overflow the buffer. The callback then returns a status code
98 * chosen from FLAC__StreamDecoderReadStatus.
99 * - Write callback - This function will be called when the decoder has
100 * decoded a single frame of data. The decoder will pass the frame
101 * metadata as well as an array of pointers (one for each channel)
102 * pointing to the decoded audio.
103 * - Metadata callback - This function will be called when the decoder has
104 * decoded a metadata block. In a valid FLAC file there will always be
105 * one STREAMINFO block, followed by zero or more other metadata
106 * blocks. These will be supplied by the decoder in the same order as
107 * they appear in the stream and always before the first audio frame
108 * (i.e. write callback). The metadata block that is passed in must not
109 * be modified, and it doesn't live beyond the callback, so you should
110 * make a copy of it with FLAC__metadata_object_clone() if you will need
111 * it elsewhere. Since metadata blocks can potentially be large, by
112 * default the decoder only calls the metadata callback for the STREAMINFO
113 * block; you can instruct the decoder to pass or filter other blocks with
114 * FLAC__stream_decoder_set_metadata_*() calls.
115 * - Error callback - This function will be called whenever an error occurs
118 * Once the decoder is initialized, your program will call one of several
119 * functions to start the decoding process:
121 * - FLAC__stream_decoder_process_single() - Tells the decoder to process at
122 * most one metadata block or audio frame and return, calling either the
123 * metadata callback or write callback, respectively, once. If the decoder
124 * loses sync it will return with only the error callback being called.
125 * - FLAC__stream_decoder_process_until_end_of_metadata() - Tells the decoder
126 * to process the stream from the current location and stop upon reaching
127 * the first audio frame. The user will get one metadata, write, or error
128 * callback per metadata block, audio frame, or sync error, respectively.
129 * - FLAC__stream_decoder_process_until_end_of_stream() - Tells the decoder
130 * to process the stream from the current location until the read callback
131 * returns FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM or
132 * FLAC__STREAM_DECODER_READ_STATUS_ABORT. The user will get one metadata,
133 * write, or error callback per metadata block, audio frame, or sync error,
136 * When the decoder has finished decoding (normally or through an abort),
137 * the instance is finished by calling FLAC__stream_decoder_finish(), which
138 * ensures the decoder is in the correct state and frees memory. Then the
139 * instance may be deleted with FLAC__stream_decoder_delete() or initialized
140 * again to decode another stream.
142 * Note that the stream decoder has no real concept of stream position, it
143 * just converts data. To seek within a stream the callbacks have only to
144 * flush the decoder using FLAC__stream_decoder_flush() and start feeding
145 * data from the new position through the read callback. The seekable
146 * stream decoder does just this.
148 * The FLAC__stream_decoder_set_metadata_*() functions deserve special
149 * attention. By default, the decoder only calls the metadata_callback for
150 * the STREAMINFO block. These functions allow you to tell the decoder
151 * explicitly which blocks to parse and return via the metadata_callback
152 * and/or which to skip. Use a FLAC__stream_decoder_respond_all(),
153 * FLAC__stream_decoder_ignore() ... or FLAC__stream_decoder_ignore_all(),
154 * FLAC__stream_decoder_respond() ... sequence to exactly specify which
155 * blocks to return. Remember that some metadata blocks can be big so
156 * filtering out the ones you don't use can reduce the memory requirements
157 * of the decoder. Also note the special forms
158 * FLAC__stream_decoder_respond_application(id) and
159 * FLAC__stream_decoder_ignore_application(id) for filtering APPLICATION
160 * blocks based on the application ID.
162 * STREAMINFO and SEEKTABLE blocks are always parsed and used internally, but
163 * they still can legally be filtered from the metadata_callback.
166 * The "set" functions may only be called when the decoder is in the
167 * state FLAC__STREAM_DECODER_UNINITIALIZED, i.e. after
168 * FLAC__stream_decoder_new() or FLAC__stream_decoder_finish(), but
169 * before FLAC__stream_decoder_init(). If this is the case they will
170 * return \c true, otherwise \c false.
173 * FLAC__stream_decoder_finish() resets all settings to the constructor
174 * defaults, including the callbacks.
180 /** State values for a FLAC__StreamDecoder
182 * The decoder's state can be obtained by calling FLAC__stream_decoder_get_state().
186 FLAC__STREAM_DECODER_SEARCH_FOR_METADATA = 0,
187 /**< The decoder is ready to search for metadata. */
189 FLAC__STREAM_DECODER_READ_METADATA,
190 /**< The decoder is ready to or is in the process of reading metadata. */
192 FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC,
193 /**< The decoder is ready to or is in the process of searching for the frame sync code. */
195 FLAC__STREAM_DECODER_READ_FRAME,
196 /**< The decoder is ready to or is in the process of reading a frame. */
198 FLAC__STREAM_DECODER_END_OF_STREAM,
199 /**< The decoder has reached the end of the stream. */
201 FLAC__STREAM_DECODER_ABORTED,
202 /**< The decoder was aborted by the read callback. */
204 FLAC__STREAM_DECODER_UNPARSEABLE_STREAM,
205 /**< The decoder encountered reserved fields in use in the stream. */
207 FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR,
208 /**< An error occurred allocating memory. */
210 FLAC__STREAM_DECODER_ALREADY_INITIALIZED,
211 /**< FLAC__stream_decoder_init() was called when the decoder was
212 * already initialized, usually because
213 * FLAC__stream_decoder_finish() was not called.
216 FLAC__STREAM_DECODER_INVALID_CALLBACK,
217 /**< FLAC__stream_decoder_init() was called without all callbacks being set. */
219 FLAC__STREAM_DECODER_UNINITIALIZED
220 /**< The decoder is in the uninitialized state. */
222 } FLAC__StreamDecoderState;
224 /** Maps a FLAC__StreamDecoderState to a C string.
226 * Using a FLAC__StreamDecoderState as the index to this array
227 * will give the string equivalent. The contents should not be modified.
229 extern FLAC_API const char * const FLAC__StreamDecoderStateString[];
232 /** Return values for the FLAC__StreamDecoder read callback.
236 FLAC__STREAM_DECODER_READ_STATUS_CONTINUE,
237 /**< The read was OK and decoding can continue. */
239 FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM,
240 /**< The read was attempted at the end of the stream. */
242 FLAC__STREAM_DECODER_READ_STATUS_ABORT
243 /**< An unrecoverable error occurred. The decoder will return from the process call. */
245 } FLAC__StreamDecoderReadStatus;
247 /** Maps a FLAC__StreamDecoderReadStatus to a C string.
249 * Using a FLAC__StreamDecoderReadStatus as the index to this array
250 * will give the string equivalent. The contents should not be modified.
252 extern FLAC_API const char * const FLAC__StreamDecoderReadStatusString[];
255 /** Return values for the FLAC__StreamDecoder write callback.
259 FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE,
260 /**< The write was OK and decoding can continue. */
262 FLAC__STREAM_DECODER_WRITE_STATUS_ABORT
263 /**< An unrecoverable error occurred. The decoder will return from the process call. */
265 } FLAC__StreamDecoderWriteStatus;
267 /** Maps a FLAC__StreamDecoderWriteStatus to a C string.
269 * Using a FLAC__StreamDecoderWriteStatus as the index to this array
270 * will give the string equivalent. The contents should not be modified.
272 extern FLAC_API const char * const FLAC__StreamDecoderWriteStatusString[];
275 /** Possible values passed in to the FLAC__StreamDecoder error callback.
279 FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC,
280 /**< An error in the stream caused the decoder to lose synchronization. */
282 FLAC__STREAM_DECODER_ERROR_STATUS_BAD_HEADER,
283 /**< The decoder encountered a corrupted frame header. */
285 FLAC__STREAM_DECODER_ERROR_STATUS_FRAME_CRC_MISMATCH
286 /**< The frame's data did not match the CRC in the footer. */
288 } FLAC__StreamDecoderErrorStatus;
290 /** Maps a FLAC__StreamDecoderErrorStatus to a C string.
292 * Using a FLAC__StreamDecoderErrorStatus as the index to this array
293 * will give the string equivalent. The contents should not be modified.
295 extern FLAC_API const char * const FLAC__StreamDecoderErrorStatusString[];
298 /***********************************************************************
300 * class FLAC__StreamDecoder
302 ***********************************************************************/
304 struct FLAC__StreamDecoderProtected;
305 struct FLAC__StreamDecoderPrivate;
306 /** The opaque structure definition for the stream decoder type.
307 * See the \link flac_stream_decoder stream decoder module \endlink
308 * for a detailed description.
311 struct FLAC__StreamDecoderProtected *protected_; /* avoid the C++ keyword 'protected' */
312 struct FLAC__StreamDecoderPrivate *private_; /* avoid the C++ keyword 'private' */
313 } FLAC__StreamDecoder;
315 /** Signature for the read callback.
316 * See FLAC__stream_decoder_set_read_callback() for more info.
318 * \param decoder The decoder instance calling the callback.
319 * \param buffer A pointer to a location for the callee to store
320 * data to be decoded.
321 * \param bytes A pointer to the size of the buffer. On entry
322 * to the callback, it contains the maximum number
323 * of bytes that may be stored in \a buffer. The
324 * callee must set it to the actual number of bytes
325 * stored before returning.
326 * \param client_data The callee's client data set through
327 * FLAC__stream_decoder_set_client_data().
328 * \retval FLAC__StreamDecoderReadStatus
329 * The callee's return status.
331 typedef FLAC__StreamDecoderReadStatus (*FLAC__StreamDecoderReadCallback)(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], unsigned *bytes, void *client_data);
333 /** Signature for the write callback.
334 * See FLAC__stream_decoder_set_write_callback() for more info.
336 * \param decoder The decoder instance calling the callback.
337 * \param frame The description of the decoded frame. See
339 * \param buffer An array of pointers to decoded channels of data.
340 * Each pointer will point to an array of signed
341 * samples of length \a frame->header.blocksize.
342 * Currently, the channel order has no meaning
343 * except for stereo streams; in this case channel
344 * 0 is left and 1 is right.
345 * \param client_data The callee's client data set through
346 * FLAC__stream_decoder_set_client_data().
347 * \retval FLAC__StreamDecoderWriteStatus
348 * The callee's return status.
350 typedef FLAC__StreamDecoderWriteStatus (*FLAC__StreamDecoderWriteCallback)(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
352 /** Signature for the metadata callback.
353 * See FLAC__stream_decoder_set_metadata_callback() for more info.
355 * \param decoder The decoder instance calling the callback.
356 * \param metadata The decoded metadata block.
357 * \param client_data The callee's client data set through
358 * FLAC__stream_decoder_set_client_data().
360 typedef void (*FLAC__StreamDecoderMetadataCallback)(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
362 /** Signature for the error callback.
363 * See FLAC__stream_decoder_set_error_callback() for more info.
365 * \param decoder The decoder instance calling the callback.
366 * \param status The error encountered by the decoder.
367 * \param client_data The callee's client data set through
368 * FLAC__stream_decoder_set_client_data().
370 typedef void (*FLAC__StreamDecoderErrorCallback)(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
373 /***********************************************************************
375 * Class constructor/destructor
377 ***********************************************************************/
379 /** Create a new stream decoder instance. The instance is created with
380 * default settings; see the individual FLAC__stream_decoder_set_*()
381 * functions for each setting's default.
383 * \retval FLAC__StreamDecoder*
384 * \c NULL if there was an error allocating memory, else the new instance.
386 FLAC_API FLAC__StreamDecoder *FLAC__stream_decoder_new();
388 /** Free a decoder instance. Deletes the object pointed to by \a decoder.
390 * \param decoder A pointer to an existing decoder.
392 * \code decoder != NULL \endcode
394 FLAC_API void FLAC__stream_decoder_delete(FLAC__StreamDecoder *decoder);
397 /***********************************************************************
399 * Public class method prototypes
401 ***********************************************************************/
403 /** Set the read callback.
404 * The supplied function will be called when the decoder needs more input
405 * data. The address of the buffer to be filled is supplied, along with
406 * the number of bytes the buffer can hold. The callback may choose to
407 * supply less data and modify the byte count but must be careful not to
408 * overflow the buffer. The callback then returns a status code chosen
409 * from FLAC__StreamDecoderReadStatus.
412 * The callback is mandatory and must be set before initialization.
415 * \param decoder A decoder instance to set.
416 * \param value See above.
418 * \code decoder != NULL \endcode
419 * \code value != NULL \endcode
421 * \c false if the decoder is already initialized, else \c true.
423 FLAC_API FLAC__bool FLAC__stream_decoder_set_read_callback(FLAC__StreamDecoder *decoder, FLAC__StreamDecoderReadCallback value);
425 /** Set the write callback.
426 * The supplied function will be called when the decoder has decoded a
427 * single frame of data. The decoder will pass the frame metadata as
428 * well as an array of pointers (one for each channel) pointing to the
432 * The callback is mandatory and must be set before initialization.
435 * \param decoder A decoder instance to set.
436 * \param value See above.
438 * \code decoder != NULL \endcode
439 * \code value != NULL \endcode
441 * \c false if the decoder is already initialized, else \c true.
443 FLAC_API FLAC__bool FLAC__stream_decoder_set_write_callback(FLAC__StreamDecoder *decoder, FLAC__StreamDecoderWriteCallback value);
445 /** Set the metadata callback.
446 * The supplied function will be called when the decoder has decoded a metadata
447 * block. In a valid FLAC file there will always be one STREAMINFO block,
448 * followed by zero or more other metadata blocks. These will be supplied
449 * by the decoder in the same order as they appear in the stream and always
450 * before the first audio frame (i.e. write callback). The metadata block
451 * that is passed in must not be modified, and it doesn't live beyond the
452 * callback, so you should make a copy of it with
453 * FLAC__metadata_object_clone() if you will need it elsewhere. Since
454 * metadata blocks can potentially be large, by default the decoder only
455 * calls the metadata callback for the STREAMINFO block; you can instruct
456 * the decoder to pass or filter other blocks with
457 * FLAC__stream_decoder_set_metadata_*() calls.
460 * The callback is mandatory and must be set before initialization.
463 * \param decoder A decoder instance to set.
464 * \param value See above.
466 * \code decoder != NULL \endcode
467 * \code value != NULL \endcode
469 * \c false if the decoder is already initialized, else \c true.
471 FLAC_API FLAC__bool FLAC__stream_decoder_set_metadata_callback(FLAC__StreamDecoder *decoder, FLAC__StreamDecoderMetadataCallback value);
473 /** Set the error callback.
474 * The supplied function will be called whenever an error occurs during
478 * The callback is mandatory and must be set before initialization.
481 * \param decoder A decoder instance to set.
482 * \param value See above.
484 * \code decoder != NULL \endcode
485 * \code value != NULL \endcode
487 * \c false if the decoder is already initialized, else \c true.
489 FLAC_API FLAC__bool FLAC__stream_decoder_set_error_callback(FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorCallback value);
491 /** Set the client data to be passed back to callbacks.
492 * This value will be supplied to callbacks in their \a client_data
496 * \param decoder A decoder instance to set.
497 * \param value See above.
499 * \code decoder != NULL \endcode
501 * \c false if the decoder is already initialized, else \c true.
503 FLAC_API FLAC__bool FLAC__stream_decoder_set_client_data(FLAC__StreamDecoder *decoder, void *value);
505 /** Direct the decoder to pass on all metadata blocks of type \a type.
507 * \default By default, only the \c STREAMINFO block is returned via the
509 * \param decoder A decoder instance to set.
510 * \param type See above.
512 * \code decoder != NULL \endcode
515 * \c false if the decoder is already initialized, else \c true.
517 FLAC_API FLAC__bool FLAC__stream_decoder_set_metadata_respond(FLAC__StreamDecoder *decoder, FLAC__MetadataType type);
519 /** Direct the decoder to pass on all APPLICATION metadata blocks of the
522 * \default By default, only the \c STREAMINFO block is returned via the
524 * \param decoder A decoder instance to set.
525 * \param id See above.
527 * \code decoder != NULL \endcode
528 * \code id != NULL \endcode
530 * \c false if the decoder is already initialized, else \c true.
532 FLAC_API FLAC__bool FLAC__stream_decoder_set_metadata_respond_application(FLAC__StreamDecoder *decoder, const FLAC__byte id[4]);
534 /** Direct the decoder to pass on all metadata blocks of any type.
536 * \default By default, only the \c STREAMINFO block is returned via the
538 * \param decoder A decoder instance to set.
540 * \code decoder != NULL \endcode
542 * \c false if the decoder is already initialized, else \c true.
544 FLAC_API FLAC__bool FLAC__stream_decoder_set_metadata_respond_all(FLAC__StreamDecoder *decoder);
546 /** Direct the decoder to filter out all metadata blocks of type \a type.
548 * \default By default, only the \c STREAMINFO block is returned via the
550 * \param decoder A decoder instance to set.
551 * \param type See above.
553 * \code decoder != NULL \endcode
556 * \c false if the decoder is already initialized, else \c true.
558 FLAC_API FLAC__bool FLAC__stream_decoder_set_metadata_ignore(FLAC__StreamDecoder *decoder, FLAC__MetadataType type);
560 /** Direct the decoder to filter out all APPLICATION metadata blocks of
563 * \default By default, only the \c STREAMINFO block is returned via the
565 * \param decoder A decoder instance to set.
566 * \param id See above.
568 * \code decoder != NULL \endcode
569 * \code id != NULL \endcode
571 * \c false if the decoder is already initialized, else \c true.
573 FLAC_API FLAC__bool FLAC__stream_decoder_set_metadata_ignore_application(FLAC__StreamDecoder *decoder, const FLAC__byte id[4]);
575 /** Direct the decoder to filter out all metadata blocks of any type.
577 * \default By default, only the \c STREAMINFO block is returned via the
579 * \param decoder A decoder instance to set.
581 * \code decoder != NULL \endcode
583 * \c false if the decoder is already initialized, else \c true.
585 FLAC_API FLAC__bool FLAC__stream_decoder_set_metadata_ignore_all(FLAC__StreamDecoder *decoder);
587 /** Get the current decoder state.
589 * \param decoder A decoder instance to query.
591 * \code decoder != NULL \endcode
592 * \retval FLAC__StreamDecoderState
593 * The current decoder state.
595 FLAC_API FLAC__StreamDecoderState FLAC__stream_decoder_get_state(const FLAC__StreamDecoder *decoder);
597 /** Get the current number of channels in the stream being decoded.
598 * Will only be valid after decoding has started and will contain the
599 * value from the most recently decoded frame header.
601 * \param decoder A decoder instance to query.
603 * \code decoder != NULL \endcode
607 FLAC_API unsigned FLAC__stream_decoder_get_channels(const FLAC__StreamDecoder *decoder);
609 /** Get the current channel assignment in the stream being decoded.
610 * Will only be valid after decoding has started and will contain the
611 * value from the most recently decoded frame header.
613 * \param decoder A decoder instance to query.
615 * \code decoder != NULL \endcode
616 * \retval FLAC__ChannelAssignment
619 FLAC_API FLAC__ChannelAssignment FLAC__stream_decoder_get_channel_assignment(const FLAC__StreamDecoder *decoder);
621 /** Get the current sample resolution in the stream being decoded.
622 * Will only be valid after decoding has started and will contain the
623 * value from the most recently decoded frame header.
625 * \param decoder A decoder instance to query.
627 * \code decoder != NULL \endcode
631 FLAC_API unsigned FLAC__stream_decoder_get_bits_per_sample(const FLAC__StreamDecoder *decoder);
633 /** Get the current sample rate in Hz of the stream being decoded.
634 * Will only be valid after decoding has started and will contain the
635 * value from the most recently decoded frame header.
637 * \param decoder A decoder instance to query.
639 * \code decoder != NULL \endcode
643 FLAC_API unsigned FLAC__stream_decoder_get_sample_rate(const FLAC__StreamDecoder *decoder);
645 /** Get the current blocksize of the stream being decoded.
646 * Will only be valid after decoding has started and will contain the
647 * value from the most recently decoded frame header.
649 * \param decoder A decoder instance to query.
651 * \code decoder != NULL \endcode
655 FLAC_API unsigned FLAC__stream_decoder_get_blocksize(const FLAC__StreamDecoder *decoder);
657 /** Initialize the decoder instance.
658 * Should be called after FLAC__stream_decoder_new() and
659 * FLAC__stream_decoder_set_*() but before any of the
660 * FLAC__stream_decoder_process_*() functions. Will set and return the
661 * decoder state, which will be FLAC__STREAM_DECODER_SEARCH_FOR_METADATA
662 * if initialization succeeded.
664 * \param decoder An uninitialized decoder instance.
666 * \code decoder != NULL \endcode
667 * \retval FLAC__StreamDecoderState
668 * \c FLAC__STREAM_DECODER_SEARCH_FOR_MEATADATA if initialization was
669 * successful; see FLAC__StreamDecoderState for the meanings of other
672 FLAC_API FLAC__StreamDecoderState FLAC__stream_decoder_init(FLAC__StreamDecoder *decoder);
674 /** Finish the decoding process.
675 * Flushes the decoding buffer, releases resources, resets the decoder
676 * settings to their defaults, and returns the decoder state to
677 * FLAC__STREAM_DECODER_UNINITIALIZED.
679 * In the event of a prematurely-terminated decode, it is not strictly
680 * necessary to call this immediately before FLAC__stream_decoder_delete()
681 * but it is good practice to match every FLAC__stream_decoder_init()
682 * with a FLAC__stream_decoder_finish().
684 * \param decoder An uninitialized decoder instance.
686 * \code decoder != NULL \endcode
688 FLAC_API void FLAC__stream_decoder_finish(FLAC__StreamDecoder *decoder);
690 /** Flush the stream input.
691 * The decoder's input buffer will be cleared and the state set to
692 * \c FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC.
694 * \param decoder A decoder instance.
696 * \code decoder != NULL \endcode
698 * \c true if successful, else \c false if a memory allocation
701 FLAC_API FLAC__bool FLAC__stream_decoder_flush(FLAC__StreamDecoder *decoder);
703 /** Reset the decoding process.
704 * The decoder's input buffer will be cleared and the state set to
705 * \c FLAC__STREAM_DECODER_SEARCH_FOR_METADATA. This is similar to
706 * FLAC__stream_decoder_finish() except that the settings are
707 * preserved; there is no need to call FLAC__stream_decoder_init()
708 * before decoding again.
710 * \param decoder A decoder instance.
712 * \code decoder != NULL \endcode
714 * \c true if successful, else \c false if a memory allocation
717 FLAC_API FLAC__bool FLAC__stream_decoder_reset(FLAC__StreamDecoder *decoder);
719 /** Decode one metadata block or audio frame.
720 * This version instructs the decoder to decode a either a single metadata
721 * block or a single frame and stop, unless the callbacks return a fatal
722 * error or the read callback returns
723 * \c FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM.
725 * As the decoder needs more input it will call the read callback.
726 * Depending on what was decoded, the metadata or write callback will be
727 * called with the decoded metadata block or audio frame, unless an error
728 * occurred. If the decoder loses sync it will call the error callback
731 * \param decoder An initialized decoder instance in the state
732 * \c FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC.
734 * \code decoder != NULL \endcode
735 * \code FLAC__stream_decoder_get_state(decoder) == FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC \endcode
737 * \c false if any read or write error occurred (except
738 * \c FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC), else \c true;
739 * in any case, check the decoder state with
740 * FLAC__stream_decoder_get_state() to see what went wrong or to
741 * check for lost synchronization (a sign of stream corruption).
743 FLAC_API FLAC__bool FLAC__stream_decoder_process_single(FLAC__StreamDecoder *decoder);
745 /** Decode until the end of the metadata.
746 * This version instructs the decoder to decode from the current position
747 * and continue until all the metadata has been read, or until the
748 * callbacks return a fatal error or the read callback returns
749 * \c FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM.
751 * As the decoder needs more input it will call the read callback.
752 * As each metadata block is decoded, the metadata callback will be called
753 * with the decoded metadata. If the decoder loses sync it will call the
756 * \param decoder An initialized decoder instance in the state
757 * \c FLAC__STREAM_DECODER_SEARCH_FOR_METADATA.
759 * \code decoder != NULL \endcode
760 * \code FLAC__stream_decoder_get_state(decoder) == FLAC__STREAM_DECODER_SEARCH_FOR_METADATA \endcode
762 * \c false if any read or write error occurred (except
763 * \c FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC), else \c true;
764 * in any case, check the decoder state with
765 * FLAC__stream_decoder_get_state() to see what went wrong or to
766 * check for lost synchronization (a sign of stream corruption).
768 FLAC_API FLAC__bool FLAC__stream_decoder_process_until_end_of_metadata(FLAC__StreamDecoder *decoder);
770 /** Decode until the end of the stream.
771 * This version instructs the decoder to decode from the current position
772 * and continue until the end of stream (the read callback returns
773 * \c FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM), or until the
774 * callbacks return a fatal error.
776 * As the decoder needs more input it will call the read callback.
777 * As each metadata block and frame is decoded, the metadata or write
778 * callback will be called with the decoded metadata or frame. If the
779 * decoder loses sync it will call the error callback.
781 * \param decoder An initialized decoder instance in the state
782 * \c FLAC__STREAM_DECODER_SEARCH_FOR_METADATA.
784 * \code decoder != NULL \endcode
785 * \code FLAC__stream_decoder_get_state(decoder) == FLAC__STREAM_DECODER_SEARCH_FOR_METADATA \endcode
787 * \c false if any read or write error occurred (except
788 * \c FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC), else \c true;
789 * in any case, check the decoder state with
790 * FLAC__stream_decoder_get_state() to see what went wrong or to
791 * check for lost synchronization (a sign of stream corruption).
793 FLAC_API FLAC__bool FLAC__stream_decoder_process_until_end_of_stream(FLAC__StreamDecoder *decoder);