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_ENCODER_H
21 #define FLAC__STREAM_ENCODER_H
24 #include "stream_decoder.h"
31 /** \file include/FLAC/stream_encoder.h
34 * This module contains the functions which implement the stream
37 * See the detailed documentation in the
38 * \link flac_stream_encoder stream encoder \endlink module.
41 /** \defgroup flac_encoder FLAC/ *_encoder.h: encoder interfaces
45 * This module describes the two encoder layers provided by libFLAC.
47 * For encoding FLAC streams, libFLAC provides two layers of access. The
48 * lowest layer is stream-level encoding, and the highest is file-level
49 * encoding. The interfaces are described in the \link flac_stream_encoder
50 * stream encoder \endlink and \link flac_file_encoder file encoder \endlink
51 * modules respectively. Typically you will choose the highest layer that
52 * your output source will support.
54 * The stream encoder relies on callbacks for writing the data and
55 * metadata. The file encoder provides these callbacks internally and you
56 * need only supply the filename.
59 /** \defgroup flac_stream_encoder FLAC/stream_encoder.h: stream encoder interface
60 * \ingroup flac_encoder
63 * This module contains the functions which implement the stream
66 * The basic usage of this encoder is as follows:
67 * - The program creates an instance of an encoder using
68 * FLAC__stream_encoder_new().
69 * - The program overrides the default settings and sets callbacks using
70 * FLAC__stream_encoder_set_*() functions.
71 * - The program initializes the instance to validate the settings and
72 * prepare for encoding using FLAC__stream_encoder_init().
73 * - The program calls FLAC__stream_encoder_process() or
74 * FLAC__stream_encoder_process_interleaved() to encode data, which
75 * subsequently calls the callbacks when there is encoder data ready
77 * - The program finishes the encoding with FLAC__stream_encoder_finish(),
78 * which causes the encoder to encode any data still in its input pipe,
79 * call the metadata callback with the final encoding statistics, and
80 * finally reset the encoder to the uninitialized state.
81 * - The instance may be used again or deleted with
82 * FLAC__stream_encoder_delete().
84 * In more detail, the stream encoder functions similarly to the
85 * \link flac_stream_decoder stream decoder \endlink, but has fewer
86 * callbacks and more options. Typically the user will create a new
87 * instance by calling FLAC__stream_encoder_new(), then set the necessary
88 * parameters and callbacks with FLAC__stream_encoder_set_*(), and
89 * initialize it by calling FLAC__stream_encoder_init().
91 * Unlike the decoders, the stream encoder has many options that can
92 * affect the speed and compression ratio. When setting these parameters
93 * you should have some basic knowledge of the format (see the
94 * <A HREF="../documentation.html#format">user-level documentation</A>
95 * or the <A HREF="../format.html">formal description</A>). The
96 * FLAC__stream_encoder_set_*() functions themselves do not validate the
97 * values as many are interdependent. The FLAC__stream_encoder_init()
98 * function will do this, so make sure to pay attention to the state
99 * returned by FLAC__stream_encoder_init() to make sure that it is
100 * FLAC__STREAM_ENCODER_OK. Any parameters that are not set before
101 * FLAC__stream_encoder_init() will take on the defaults from the
104 * The user must provide function pointers for the following callbacks:
106 * - Write callback - This function is called by the encoder anytime there
107 * is raw encoded data to write. It may include metadata mixed with
108 * encoded audio frames and the data is not guaranteed to be aligned on
109 * frame or metadata block boundaries.
110 * - Metadata callback - This function is called once at the end of
111 * encoding with the populated STREAMINFO structure. This is so file
112 * encoders can seek back to the beginning of the file and write the
113 * STREAMINFO block with the correct statistics after encoding (like
114 * minimum/maximum frame size).
116 * The call to FLAC__stream_encoder_init() currently will also immediately
117 * call the write callback several times, once with the \c fLaC signature,
118 * and once for each encoded metadata block.
120 * After initializing the instance, the user may feed audio data to the
121 * encoder in one of two ways:
123 * - Channel separate, through FLAC__stream_encoder_process() - The user
124 * will pass an array of pointers to buffers, one for each channel, to
125 * the encoder, each of the same length. The samples need not be
127 * - Channel interleaved, through
128 * FLAC__stream_encoder_process_interleaved() - The user will pass a single
129 * pointer to data that is channel-interleaved (i.e. channel0_sample0,
130 * channel1_sample0, ... , channelN_sample0, channel0_sample1, ...).
131 * Again, the samples need not be block-aligned but they must be
132 * sample-aligned, i.e. the first value should be channel0_sample0 and
133 * the last value channelN_sampleM.
135 * When the user is finished encoding data, it calls
136 * FLAC__stream_encoder_finish(), which causes the encoder to encode any
137 * data still in its input pipe, and call the metadata callback with the
138 * final encoding statistics. Then the instance may be deleted with
139 * FLAC__stream_encoder_delete() or initialized again to encode another
142 * For programs that write their own metadata, but that do not know the
143 * actual metadata until after encoding, it is advantageous to instruct
144 * the encoder to write a PADDING block of the correct size, so that
145 * instead of rewriting the whole stream after encoding, the program can
146 * just overwrite the PADDING block. If only the maximum size of the
147 * metadata is known, the program can write a slightly larger padding
148 * block, then split it after encoding.
150 * Make sure you understand how lengths are calculated. All FLAC metadata
151 * blocks have a 4 byte header which contains the type and length. This
152 * length does not include the 4 bytes of the header. See the format page
153 * for the specification of metadata blocks and their lengths.
156 * The "set" functions may only be called when the encoder is in the
157 * state FLAC__STREAM_ENCODER_UNINITIALIZED, i.e. after
158 * FLAC__stream_encoder_new() or FLAC__stream_encoder_finish(), but
159 * before FLAC__stream_encoder_init(). If this is the case they will
160 * return \c true, otherwise \c false.
163 * FLAC__stream_encoder_finish() resets all settings to the constructor
164 * defaults, including the callbacks.
170 /** State values for a FLAC__StreamEncoder
172 * The encoder's state can be obtained by calling FLAC__stream_encoder_get_state().
176 FLAC__STREAM_ENCODER_OK = 0,
177 /**< The encoder is in the normal OK state. */
179 FLAC__STREAM_ENCODER_VERIFY_DECODER_ERROR,
180 /**< An error occurred in the underlying verify stream decoder;
181 * check FLAC__stream_encoder_get_verify_decoder_state().
184 FLAC__STREAM_ENCODER_VERIFY_MISMATCH_IN_AUDIO_DATA,
185 /**< The verify decoder detected a mismatch between the original
186 * audio signal and the decoded audio signal.
189 FLAC__STREAM_ENCODER_INVALID_CALLBACK,
190 /**< The encoder was initialized before setting all the required callbacks. */
192 FLAC__STREAM_ENCODER_INVALID_NUMBER_OF_CHANNELS,
193 /**< The encoder has an invalid setting for number of channels. */
195 FLAC__STREAM_ENCODER_INVALID_BITS_PER_SAMPLE,
196 /**< The encoder has an invalid setting for bits-per-sample.
197 * FLAC supports 4-32 bps but the reference encoder currently supports
201 FLAC__STREAM_ENCODER_INVALID_SAMPLE_RATE,
202 /**< The encoder has an invalid setting for the input sample rate. */
204 FLAC__STREAM_ENCODER_INVALID_BLOCK_SIZE,
205 /**< The encoder has an invalid setting for the block size. */
207 FLAC__STREAM_ENCODER_INVALID_MAX_LPC_ORDER,
208 /**< The encoder has an invalid setting for the maximum LPC order. */
210 FLAC__STREAM_ENCODER_INVALID_QLP_COEFF_PRECISION,
211 /**< The encoder has an invalid setting for the precision of the quantized linear predictor coefficients. */
213 FLAC__STREAM_ENCODER_MID_SIDE_CHANNELS_MISMATCH,
214 /**< Mid/side coding was specified but the number of channels is not equal to 2. */
216 FLAC__STREAM_ENCODER_MID_SIDE_SAMPLE_SIZE_MISMATCH,
219 FLAC__STREAM_ENCODER_ILLEGAL_MID_SIDE_FORCE,
220 /**< Loose mid/side coding was specified but mid/side coding was not. */
222 FLAC__STREAM_ENCODER_BLOCK_SIZE_TOO_SMALL_FOR_LPC_ORDER,
223 /**< The specified block size is less than the maximum LPC order. */
225 FLAC__STREAM_ENCODER_NOT_STREAMABLE,
226 /**< The encoder is bound to the "streamable subset" but other settings violate it. */
228 FLAC__STREAM_ENCODER_FRAMING_ERROR,
229 /**< An error occurred while writing the stream; usually, the write_callback returned an error. */
231 FLAC__STREAM_ENCODER_INVALID_METADATA,
232 /**< The metadata input to the encoder is invalid, in one of the following ways:
233 * - FLAC__stream_encoder_set_metadata() was called with a null pointer but a block count > 0
234 * - It contains an illegal SEEKTABLE as checked by FLAC__format_seektable_is_legal()
235 * - It contains more than one SEEKTABLE block or more than one VORBIS_COMMENT block
238 FLAC__STREAM_ENCODER_FATAL_ERROR_WHILE_ENCODING,
239 /**< An error occurred while writing the stream; usually, the write_callback returned an error. */
241 FLAC__STREAM_ENCODER_FATAL_ERROR_WHILE_WRITING,
242 /**< The write_callback returned an error. */
244 FLAC__STREAM_ENCODER_MEMORY_ALLOCATION_ERROR,
245 /**< Memory allocation failed. */
247 FLAC__STREAM_ENCODER_ALREADY_INITIALIZED,
248 /**< FLAC__stream_encoder_init() was called when the encoder was
249 * already initialized, usually because
250 * FLAC__stream_encoder_finish() was not called.
253 FLAC__STREAM_ENCODER_UNINITIALIZED
254 /**< The encoder is in the uninitialized state. */
256 } FLAC__StreamEncoderState;
258 /** Maps a FLAC__StreamEncoderState to a C string.
260 * Using a FLAC__StreamEncoderState as the index to this array
261 * will give the string equivalent. The contents should not be modified.
263 extern const char * const FLAC__StreamEncoderStateString[];
265 /** Return values for the FLAC__StreamEncoder write callback.
269 FLAC__STREAM_ENCODER_WRITE_STATUS_OK = 0,
270 /**< The write was OK and encoding can continue. */
272 FLAC__STREAM_ENCODER_WRITE_STATUS_FATAL_ERROR
273 /**< An unrecoverable error occurred. The encoder will return from the process call. */
275 } FLAC__StreamEncoderWriteStatus;
277 /** Maps a FLAC__StreamEncoderWriteStatus to a C string.
279 * Using a FLAC__StreamEncoderWriteStatus as the index to this array
280 * will give the string equivalent. The contents should not be modified.
282 extern const char * const FLAC__StreamEncoderWriteStatusString[];
285 /***********************************************************************
287 * class FLAC__StreamEncoder
289 ***********************************************************************/
291 struct FLAC__StreamEncoderProtected;
292 struct FLAC__StreamEncoderPrivate;
293 /** The opaque structure definition for the stream encoder type.
294 * See the \link flac_stream_encoder stream encoder module \endlink
295 * for a detailed description.
298 struct FLAC__StreamEncoderProtected *protected_; /* avoid the C++ keyword 'protected' */
299 struct FLAC__StreamEncoderPrivate *private_; /* avoid the C++ keyword 'private' */
300 } FLAC__StreamEncoder;
302 /** Signature for the write callback.
303 * See FLAC__stream_encoder_set_write_callback() for more info.
305 * \param encoder The encoder instance calling the callback.
306 * \param buffer An array of encoded data of length \a bytes.
307 * \param bytes The byte length of \a buffer.
308 * \param samples The number of samples encoded by \a buffer.
309 * \c 0 has a special meaning; see
310 * FLAC__stream_encoder_set_write_callback().
311 * \param current_frame The number of the current frame being encoded.
312 * \param client_data The callee's client data set through
313 * FLAC__stream_encoder_set_client_data().
314 * \retval FLAC__StreamDecoderWriteStatus
315 * The callee's return status.
317 typedef FLAC__StreamEncoderWriteStatus (*FLAC__StreamEncoderWriteCallback)(const FLAC__StreamEncoder *encoder, const FLAC__byte buffer[], unsigned bytes, unsigned samples, unsigned current_frame, void *client_data);
319 /** Signature for the metadata callback.
320 * See FLAC__stream_encoder_set_metadata_callback() for more info.
322 * \param encoder The encoder instance calling the callback.
323 * \param metadata The final populated STREAMINFO block.
324 * \param client_data The callee's client data set through
325 * FLAC__stream_encoder_set_client_data().
327 typedef void (*FLAC__StreamEncoderMetadataCallback)(const FLAC__StreamEncoder *encoder, const FLAC__StreamMetadata *metadata, void *client_data);
330 /***********************************************************************
332 * Class constructor/destructor
334 ***********************************************************************/
336 /** Create a new stream encoder instance. The instance is created with
337 * default settings; see the individual FLAC__stream_encoder_set_*()
338 * functions for each setting's default.
340 * \retval FLAC__StreamEncoder*
341 * \c NULL if there was an error allocating memory, else the new instance.
343 FLAC__StreamEncoder *FLAC__stream_encoder_new();
345 /** Free an encoder instance. Deletes the object pointed to by \a encoder.
347 * \param encoder A pointer to an existing encoder.
349 * \code encoder != NULL \endcode
351 void FLAC__stream_encoder_delete(FLAC__StreamEncoder *encoder);
353 /***********************************************************************
355 * Public class method prototypes
357 ***********************************************************************/
359 /** Set the "verify" flag. If \c true, the encoder will verify it's own
360 * encoded output by feeding it through an internal decoder and comparing
361 * the original signal against the decoded signal. If a mismatch occurs,
362 * the process call will return \c false. Note that this will slow the
363 * encoding process by the extra time required for decoding and comparison.
366 * \param encoder An encoder instance to set.
367 * \param value Flag value (see above).
369 * \code encoder != NULL \endcode
371 * \c false if the encoder is already initialized, else \c true.
373 FLAC__bool FLAC__stream_encoder_set_verify(FLAC__StreamEncoder *encoder, FLAC__bool value);
375 /** Set the "streamable subset" flag. If \c true, the encoder will comply
376 * with the subset (see the format specification) and will check the
377 * settings during FLAC__stream_encoder_init() to see if all settings
378 * comply. If \c false, the settings may take advantage of the full
379 * range that the format allows.
381 * Make sure you know what it entails before setting this to \c false.
384 * \param encoder An encoder instance to set.
385 * \param value Flag value (see above).
387 * \code encoder != NULL \endcode
389 * \c false if the encoder is already initialized, else \c true.
391 FLAC__bool FLAC__stream_encoder_set_streamable_subset(FLAC__StreamEncoder *encoder, FLAC__bool value);
393 /** Set to \c true to enable mid-side encoding on stereo input. The
394 * number of channels must be 2. Set to \c false to use only
395 * independent channel coding.
398 * \param encoder An encoder instance to set.
399 * \param value Flag value (see above).
401 * \code encoder != NULL \endcode
403 * \c false if the encoder is already initialized, else \c true.
405 FLAC__bool FLAC__stream_encoder_set_do_mid_side_stereo(FLAC__StreamEncoder *encoder, FLAC__bool value);
407 /** Set to \c true to enable adaptive switching between mid-side and
408 * left-right encoding on stereo input. The number of channels must
409 * be 2. Set to \c false to use exhaustive searching. In either
410 * case, the mid/side stereo setting must be \c true.
413 * \param encoder An encoder instance to set.
414 * \param value Flag value (see above).
416 * \code encoder != NULL \endcode
418 * \c false if the encoder is already initialized, else \c true.
420 FLAC__bool FLAC__stream_encoder_set_loose_mid_side_stereo(FLAC__StreamEncoder *encoder, FLAC__bool value);
422 /** Set the number of channels to be encoded.
425 * \param encoder An encoder instance to set.
426 * \param value See above.
428 * \code encoder != NULL \endcode
430 * \c false if the encoder is already initialized, else \c true.
432 FLAC__bool FLAC__stream_encoder_set_channels(FLAC__StreamEncoder *encoder, unsigned value);
434 /** Set the sample resolution of the input to be encoded.
437 * Do not feed the encoder data that is wider than the value you
438 * set here or you will generate an invalid stream.
441 * \param encoder An encoder instance to set.
442 * \param value See above.
444 * \code encoder != NULL \endcode
446 * \c false if the encoder is already initialized, else \c true.
448 FLAC__bool FLAC__stream_encoder_set_bits_per_sample(FLAC__StreamEncoder *encoder, unsigned value);
450 /** Set the sample rate (in Hz) of the input to be encoded.
453 * \param encoder An encoder instance to set.
454 * \param value See above.
456 * \code encoder != NULL \endcode
458 * \c false if the encoder is already initialized, else \c true.
460 FLAC__bool FLAC__stream_encoder_set_sample_rate(FLAC__StreamEncoder *encoder, unsigned value);
462 /** Set the blocksize to use while encoding.
465 * \param encoder An encoder instance to set.
466 * \param value See above.
468 * \code encoder != NULL \endcode
470 * \c false if the encoder is already initialized, else \c true.
472 FLAC__bool FLAC__stream_encoder_set_blocksize(FLAC__StreamEncoder *encoder, unsigned value);
474 /** Set the maximum LPC order, or \c 0 to use only the fixed predictors.
477 * \param encoder An encoder instance to set.
478 * \param value See above.
480 * \code encoder != NULL \endcode
482 * \c false if the encoder is already initialized, else \c true.
484 FLAC__bool FLAC__stream_encoder_set_max_lpc_order(FLAC__StreamEncoder *encoder, unsigned value);
486 /** Set the precision, in bits, of the quantized linear predictor
487 * coefficients, or \c 0 to let the encoder select it based on the
491 * In the current implementation, qlp_coeff_precision + bits_per_sample must
495 * \param encoder An encoder instance to set.
496 * \param value See above.
498 * \code encoder != NULL \endcode
500 * \c false if the encoder is already initialized, else \c true.
502 FLAC__bool FLAC__stream_encoder_set_qlp_coeff_precision(FLAC__StreamEncoder *encoder, unsigned value);
504 /** Set to \c false to use only the specified quantized linear predictor
505 * coefficient precision, or \c true to search neighboring precision
506 * values and use the best one.
509 * \param encoder An encoder instance to set.
510 * \param value See above.
512 * \code encoder != NULL \endcode
514 * \c false if the encoder is already initialized, else \c true.
516 FLAC__bool FLAC__stream_encoder_set_do_qlp_coeff_prec_search(FLAC__StreamEncoder *encoder, FLAC__bool value);
518 /** Deprecated. Setting this value has no effect.
521 * \param encoder An encoder instance to set.
522 * \param value See above.
524 * \code encoder != NULL \endcode
526 * \c false if the encoder is already initialized, else \c true.
528 FLAC__bool FLAC__stream_encoder_set_do_escape_coding(FLAC__StreamEncoder *encoder, FLAC__bool value);
530 /** Set to \c false to let the encoder estimate the best model order
531 * based on the residual signal energy, or \c true to force the
532 * encoder to evaluate all order models and select the best.
535 * \param encoder An encoder instance to set.
536 * \param value See above.
538 * \code encoder != NULL \endcode
540 * \c false if the encoder is already initialized, else \c true.
542 FLAC__bool FLAC__stream_encoder_set_do_exhaustive_model_search(FLAC__StreamEncoder *encoder, FLAC__bool value);
544 /** Set the minimum partition order to search when coding the residual.
545 * This is used in tandem with
546 * FLAC__stream_encoder_set_max_residual_partition_order().
548 * The partition order determines the context size in the residual.
549 * The context size will be approximately <tt>blocksize / (2 ^ order)</tt>.
551 * Set both min and max values to \c 0 to force a single context,
552 * whose Rice parameter is based on the residual signal variance.
553 * Otherwise, set a min and max order, and the encoder will search
554 * all orders, using the mean of each context for its Rice parameter,
558 * \param encoder An encoder instance to set.
559 * \param value See above.
561 * \code encoder != NULL \endcode
563 * \c false if the encoder is already initialized, else \c true.
565 FLAC__bool FLAC__stream_encoder_set_min_residual_partition_order(FLAC__StreamEncoder *encoder, unsigned value);
567 /** Set the maximum partition order to search when coding the residual.
568 * This is used in tandem with
569 * FLAC__stream_encoder_set_min_residual_partition_order().
571 * The partition order determines the context size in the residual.
572 * The context size will be approximately <tt>blocksize / (2 ^ order)</tt>.
574 * Set both min and max values to \c 0 to force a single context,
575 * whose Rice parameter is based on the residual signal variance.
576 * Otherwise, set a min and max order, and the encoder will search
577 * all orders, using the mean of each context for its Rice parameter,
581 * \param encoder An encoder instance to set.
582 * \param value See above.
584 * \code encoder != NULL \endcode
586 * \c false if the encoder is already initialized, else \c true.
588 FLAC__bool FLAC__stream_encoder_set_max_residual_partition_order(FLAC__StreamEncoder *encoder, unsigned value);
590 /** Deprecated. Setting this value has no effect.
593 * \param encoder An encoder instance to set.
594 * \param value See above.
596 * \code encoder != NULL \endcode
598 * \c false if the encoder is already initialized, else \c true.
600 FLAC__bool FLAC__stream_encoder_set_rice_parameter_search_dist(FLAC__StreamEncoder *encoder, unsigned value);
602 /** Set an estimate of the total samples that will be encoded.
603 * This is merely an estimate and may be set to \c 0 if unknown.
604 * This value will be written to the STREAMINFO block before encoding,
605 * and can remove the need for the caller to rewrite the value later
606 * if the value is known before encoding.
609 * \param encoder An encoder instance to set.
610 * \param value See above.
612 * \code encoder != NULL \endcode
614 * \c false if the encoder is already initialized, else \c true.
616 FLAC__bool FLAC__stream_encoder_set_total_samples_estimate(FLAC__StreamEncoder *encoder, FLAC__uint64 value);
618 /** Set the metadata blocks to be emitted to the stream before encoding.
619 * A value of \c NULL, \c 0 implies no metadata; otherwise, supply an
620 * array of pointers to metadata blocks. The array is non-const since
621 * the encoder may need to change the \a is_last flag inside them.
622 * Otherwise, the encoder will not modify or free the blocks. It is up
623 * to the caller to free the metadata blocks after encoding.
626 * The encoder stores only the \a metadata pointer; the passed-in array
627 * must survive at least until after FLAC__stream_encoder_init() returns.
628 * Do not modify the array or free the blocks until then.
631 * The STREAMINFO block is always written and no STREAMINFO block may
632 * occur in the supplied array.
635 * By default the encoder does not create a SEEKTABLE. If one is supplied
636 * in the \a metadata array it will be written verbatim. However by itself
637 * this is not very useful as the user will not know the stream offsets for
638 * the seekpoints ahead of time. You must use the seekable stream encoder
639 * to generate a legal seektable
640 * (see FLAC__seekable_stream_encoder_set_metadata())
643 * A VORBIS_COMMENT block may be supplied. The vendor string in it
644 * will be ignored. libFLAC will use it's own vendor string. libFLAC
645 * will not modify the passed-in VORBIS_COMMENT's vendor string, it
646 * will simply write it's own into the stream. If no VORBIS_COMMENT
647 * block is present in the \a metadata array, libFLAC will write an
648 * empty one, containing only the vendor string.
650 * \default \c NULL, 0
651 * \param encoder An encoder instance to set.
652 * \param metadata See above.
653 * \param num_blocks See above.
655 * \code encoder != NULL \endcode
657 * \c false if the encoder is already initialized, else \c true.
659 FLAC__bool FLAC__stream_encoder_set_metadata(FLAC__StreamEncoder *encoder, FLAC__StreamMetadata **metadata, unsigned num_blocks);
661 /** Set the write callback.
662 * The supplied function will be called by the encoder anytime there is raw
663 * encoded data ready to write. It may include metadata mixed with encoded
664 * audio frames and the data is not guaranteed to be aligned on frame or
665 * metadata block boundaries.
667 * The only duty of the callback is to write out the \a bytes worth of data
668 * in \a buffer to the current position in the output stream. The arguments
669 * \a samples and \a current_frame are purely informational. If \a samples
670 * is greater than \c 0, then \a current_frame will hold the current frame
671 * number that is being written; otherwise, the write callback is being called
675 * The callback is mandatory and must be set before initialization.
678 * \param encoder An encoder instance to set.
679 * \param value See above.
681 * \code encoder != NULL \endcode
682 * \code value != NULL \endcode
684 * \c false if the encoder is already initialized, else \c true.
686 FLAC__bool FLAC__stream_encoder_set_write_callback(FLAC__StreamEncoder *encoder, FLAC__StreamEncoderWriteCallback value);
688 /** Set the metadata callback.
689 * The supplied function will be called once at the end of encoding with
690 * the populated STREAMINFO structure. This is so file encoders can seek
691 * back to the beginning of the file and write the STREAMINFO block with
692 * the correct statistics after encoding (like minimum/maximum frame size
693 * and total samples).
696 * The callback is mandatory and must be set before initialization.
699 * \param encoder An encoder instance to set.
700 * \param value See above.
702 * \code encoder != NULL \endcode
703 * \code value != NULL \endcode
705 * \c false if the encoder is already initialized, else \c true.
707 FLAC__bool FLAC__stream_encoder_set_metadata_callback(FLAC__StreamEncoder *encoder, FLAC__StreamEncoderMetadataCallback value);
709 /** Set the client data to be passed back to callbacks.
710 * This value will be supplied to callbacks in their \a client_data
714 * \param encoder An encoder instance to set.
715 * \param value See above.
717 * \code encoder != NULL \endcode
719 * \c false if the encoder is already initialized, else \c true.
721 FLAC__bool FLAC__stream_encoder_set_client_data(FLAC__StreamEncoder *encoder, void *value);
723 /** Get the current encoder state.
725 * \param encoder An encoder instance to query.
727 * \code encoder != NULL \endcode
728 * \retval FLAC__StreamEncoderState
729 * The current encoder state.
731 FLAC__StreamEncoderState FLAC__stream_encoder_get_state(const FLAC__StreamEncoder *encoder);
733 /** Get the state of the verify stream decoder.
734 * Useful when the stream encoder state is
735 * \c FLAC__STREAM_ENCODER_VERIFY_DECODER_ERROR.
737 * \param encoder An encoder instance to query.
739 * \code encoder != NULL \endcode
740 * \retval FLAC__StreamDecoderState
741 * The verify stream decoder state.
743 FLAC__StreamDecoderState FLAC__stream_encoder_get_verify_decoder_state(const FLAC__StreamEncoder *encoder);
745 /** Get relevant values about the nature of a verify decoder error.
746 * Useful when the stream encoder state is
747 * \c FLAC__STREAM_ENCODER_VERIFY_DECODER_ERROR. The arguments should
748 * be addresses in which the stats will be returned, or NULL if value
751 * \param encoder An encoder instance to query.
752 * \param absolute_sample The absolute sample number of the mismatch.
753 * \param frame_number The number of the frame in which the mismatch occurred.
754 * \param channel The channel in which the mismatch occurred.
755 * \param sample The number of the sample (relative to the frame) in
756 * which the mismatch occurred.
757 * \param expected The expected value for the sample in question.
758 * \param got The actual value returned by the decoder.
760 * \code encoder != NULL \endcode
762 void FLAC__stream_encoder_get_verify_decoder_error_stats(const FLAC__StreamEncoder *encoder, FLAC__uint64 *absolute_sample, unsigned *frame_number, unsigned *channel, unsigned *sample, FLAC__int32 *expected, FLAC__int32 *got);
764 /** Get the "verify" flag.
766 * \param encoder An encoder instance to query.
768 * \code encoder != NULL \endcode
770 * See FLAC__stream_encoder_set_verify().
772 FLAC__bool FLAC__stream_encoder_get_verify(const FLAC__StreamEncoder *encoder);
774 /** Get the "streamable subset" flag.
776 * \param encoder An encoder instance to query.
778 * \code encoder != NULL \endcode
780 * See FLAC__stream_encoder_set_streamable_subset().
782 FLAC__bool FLAC__stream_encoder_get_streamable_subset(const FLAC__StreamEncoder *encoder);
784 /** Get the "mid/side stereo coding" flag.
786 * \param encoder An encoder instance to query.
788 * \code encoder != NULL \endcode
790 * See FLAC__stream_encoder_get_do_mid_side_stereo().
792 FLAC__bool FLAC__stream_encoder_get_do_mid_side_stereo(const FLAC__StreamEncoder *encoder);
794 /** Get the "adaptive mid/side switching" flag.
796 * \param encoder An encoder instance to query.
798 * \code encoder != NULL \endcode
800 * See FLAC__stream_encoder_set_loose_mid_side_stereo().
802 FLAC__bool FLAC__stream_encoder_get_loose_mid_side_stereo(const FLAC__StreamEncoder *encoder);
804 /** Get the number of input channels being processed.
806 * \param encoder An encoder instance to query.
808 * \code encoder != NULL \endcode
810 * See FLAC__stream_encoder_set_channels().
812 unsigned FLAC__stream_encoder_get_channels(const FLAC__StreamEncoder *encoder);
814 /** Get the input sample resolution setting.
816 * \param encoder An encoder instance to query.
818 * \code encoder != NULL \endcode
820 * See FLAC__stream_encoder_set_bits_per_sample().
822 unsigned FLAC__stream_encoder_get_bits_per_sample(const FLAC__StreamEncoder *encoder);
824 /** Get the input sample rate setting.
826 * \param encoder An encoder instance to query.
828 * \code encoder != NULL \endcode
830 * See FLAC__stream_encoder_set_sample_rate().
832 unsigned FLAC__stream_encoder_get_sample_rate(const FLAC__StreamEncoder *encoder);
834 /** Get the blocksize setting.
836 * \param encoder An encoder instance to query.
838 * \code encoder != NULL \endcode
840 * See FLAC__stream_encoder_set_blocksize().
842 unsigned FLAC__stream_encoder_get_blocksize(const FLAC__StreamEncoder *encoder);
844 /** Get the maximum LPC order setting.
846 * \param encoder An encoder instance to query.
848 * \code encoder != NULL \endcode
850 * See FLAC__stream_encoder_set_max_lpc_order().
852 unsigned FLAC__stream_encoder_get_max_lpc_order(const FLAC__StreamEncoder *encoder);
854 /** Get the quantized linear predictor coefficient precision setting.
856 * \param encoder An encoder instance to query.
858 * \code encoder != NULL \endcode
860 * See FLAC__stream_encoder_set_qlp_coeff_precision().
862 unsigned FLAC__stream_encoder_get_qlp_coeff_precision(const FLAC__StreamEncoder *encoder);
864 /** Get the qlp coefficient precision search flag.
866 * \param encoder An encoder instance to query.
868 * \code encoder != NULL \endcode
870 * See FLAC__stream_encoder_set_do_qlp_coeff_prec_search().
872 FLAC__bool FLAC__stream_encoder_get_do_qlp_coeff_prec_search(const FLAC__StreamEncoder *encoder);
874 /** Get the "escape coding" flag.
876 * \param encoder An encoder instance to query.
878 * \code encoder != NULL \endcode
880 * See FLAC__stream_encoder_set_do_escape_coding().
882 FLAC__bool FLAC__stream_encoder_get_do_escape_coding(const FLAC__StreamEncoder *encoder);
884 /** Get the exhaustive model search flag.
886 * \param encoder An encoder instance to query.
888 * \code encoder != NULL \endcode
890 * See FLAC__stream_encoder_set_do_exhaustive_model_search().
892 FLAC__bool FLAC__stream_encoder_get_do_exhaustive_model_search(const FLAC__StreamEncoder *encoder);
894 /** Get the minimum residual partition order setting.
896 * \param encoder An encoder instance to query.
898 * \code encoder != NULL \endcode
900 * See FLAC__stream_encoder_set_min_residual_partition_order().
902 unsigned FLAC__stream_encoder_get_min_residual_partition_order(const FLAC__StreamEncoder *encoder);
904 /** Get maximum residual partition order setting.
906 * \param encoder An encoder instance to query.
908 * \code encoder != NULL \endcode
910 * See FLAC__stream_encoder_set_max_residual_partition_order().
912 unsigned FLAC__stream_encoder_get_max_residual_partition_order(const FLAC__StreamEncoder *encoder);
914 /** Get the Rice parameter search distance setting.
916 * \param encoder An encoder instance to query.
918 * \code encoder != NULL \endcode
920 * See FLAC__stream_encoder_set_rice_parameter_search_dist().
922 unsigned FLAC__stream_encoder_get_rice_parameter_search_dist(const FLAC__StreamEncoder *encoder);
924 /** Get the previously set estimate of the total samples to be encoded.
925 * The encoder merely mimics back the value given to
926 * FLAC__stream_encoder_set_total_samples_estimate() since it has no
927 * other way of knowing how many samples the user will encode.
929 * \param encoder An encoder instance to set.
931 * \code encoder != NULL \endcode
932 * \retval FLAC__uint64
933 * See FLAC__stream_encoder_get_total_samples_estimate().
935 FLAC__uint64 FLAC__stream_encoder_get_total_samples_estimate(const FLAC__StreamEncoder *encoder);
937 /** Initialize the encoder instance.
938 * Should be called after FLAC__stream_encoder_new() and
939 * FLAC__stream_encoder_set_*() but before FLAC__stream_encoder_process()
940 * or FLAC__stream_encoder_process_interleaved(). Will set and return
941 * the encoder state, which will be FLAC__STREAM_ENCODER_OK if
942 * initialization succeeded.
944 * The call to FLAC__stream_encoder_init() currently will also immediately
945 * call the write callback several times, once with the \c fLaC signature,
946 * and once for each encoded metadata block.
948 * \param encoder An uninitialized encoder instance.
950 * \code encoder != NULL \endcode
951 * \retval FLAC__StreamEncoderState
952 * \c FLAC__STREAM_ENCODER_OK if initialization was successful; see
953 * FLAC__StreamEncoderState for the meanings of other return values.
955 FLAC__StreamEncoderState FLAC__stream_encoder_init(FLAC__StreamEncoder *encoder);
957 /** Finish the encoding process.
958 * Flushes the encoding buffer, releases resources, resets the encoder
959 * settings to their defaults, and returns the encoder state to
960 * FLAC__STREAM_ENCODER_UNINITIALIZED. Note that this can generate
961 * one or more write callbacks before returning, and will generate
962 * a metadata callback.
964 * In the event of a prematurely-terminated encode, it is not strictly
965 * necessary to call this immediately before FLAC__stream_encoder_delete()
966 * but it is good practice to match every FLAC__stream_encoder_init()
967 * with a FLAC__stream_encoder_finish().
969 * \param encoder An uninitialized encoder instance.
971 * \code encoder != NULL \endcode
973 void FLAC__stream_encoder_finish(FLAC__StreamEncoder *encoder);
975 /** Submit data for encoding.
976 * This version allows you to supply the input data via an array of
977 * pointers, each pointer pointing to an array of \a samples samples
978 * representing one channel. The samples need not be block-aligned,
979 * but each channel should have the same number of samples.
981 * \param encoder An initialized encoder instance in the OK state.
982 * \param buffer An array of pointers to each channel's signal.
983 * \param samples The number of samples in one channel.
985 * \code encoder != NULL \endcode
986 * \code FLAC__stream_encoder_get_state(encoder) == FLAC__STREAM_ENCODER_OK \endcode
988 * \c true if successful, else \c false; in this case, check the
989 * encoder state with FLAC__stream_encoder_get_state() to see what
992 FLAC__bool FLAC__stream_encoder_process(FLAC__StreamEncoder *encoder, const FLAC__int32 * const buffer[], unsigned samples);
994 /** Submit data for encoding.
995 * This version allows you to supply the input data where the channels
996 * are interleaved into a single array (i.e. channel0_sample0,
997 * channel1_sample0, ... , channelN_sample0, channel0_sample1, ...).
998 * The samples need not be block-aligned but they must be
999 * sample-aligned, i.e. the first value should be channel0_sample0
1000 * and the last value channelN_sampleM.
1002 * \param encoder An initialized encoder instance in the OK state.
1003 * \param buffer An array of channel-interleaved data (see above).
1004 * \param samples The number of samples in one channel, the same as for
1005 * FLAC__stream_encoder_process(). For example, if
1006 * encoding two channels, \c 1000 \a samples corresponds
1007 * to a \a buffer of 2000 values.
1009 * \code encoder != NULL \endcode
1010 * \code FLAC__stream_encoder_get_state(encoder) == FLAC__STREAM_ENCODER_OK \endcode
1011 * \retval FLAC__bool
1012 * \c true if successful, else \c false; in this case, check the
1013 * encoder state with FLAC__stream_encoder_get_state() to see what
1016 FLAC__bool FLAC__stream_encoder_process_interleaved(FLAC__StreamEncoder *encoder, const FLAC__int32 buffer[], unsigned samples);