• stream_encoder.h
  • /* libFLAC - Free Lossless Audio Codec library
     * Copyright (C) 2000-2009  Josh Coalson
     * Copyright (C) 2011-2025  Xiph.Org Foundation
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     *
     * - Redistributions of source code must retain the above copyright
     * notice, this list of conditions and the following disclaimer.
     *
     * - Redistributions in binary form must reproduce the above copyright
     * notice, this list of conditions and the following disclaimer in the
     * documentation and/or other materials provided with the distribution.
     *
     * - Neither the name of the Xiph.org Foundation nor the names of its
     * contributors may be used to endorse or promote products derived from
     * this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
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     * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     */
    
    #ifndef FLAC__STREAM_ENCODER_H
    #define FLAC__STREAM_ENCODER_H
    
    #include <stdio.h> /* for FILE */
    #include "export.h"
    #include "format.h"
    #include "stream_decoder.h"
    
    #ifdef __cplusplus
    extern "C" {
    #endif
    
    
    /** \file include/FLAC/stream_encoder.h
     *
     *  \brief
     *  This module contains the functions which implement the stream
     *  encoder.
     *
     *  See the detailed documentation in the
     *  \link flac_stream_encoder stream encoder \endlink module.
     */
    
    /** \defgroup flac_encoder FLAC/ \*_encoder.h: encoder interfaces
     *  \ingroup flac
     *
     *  \brief
     *  This module describes the encoder layers provided by libFLAC.
     *
     * The stream encoder can be used to encode complete streams either to the
     * client via callbacks, or directly to a file, depending on how it is
     * initialized.  When encoding via callbacks, the client provides a write
     * callback which will be called whenever FLAC data is ready to be written.
     * If the client also supplies a seek callback, the encoder will also
     * automatically handle the writing back of metadata discovered while
     * encoding, like stream info, seek points offsets, etc.  When encoding to
     * a file, the client needs only supply a filename or open \c FILE* and an
     * optional progress callback for periodic notification of progress; the
     * write and seek callbacks are supplied internally.  For more info see the
     * \link flac_stream_encoder stream encoder \endlink module.
     */
    
    /** \defgroup flac_stream_encoder FLAC/stream_encoder.h: stream encoder interface
     *  \ingroup flac_encoder
     *
     *  \brief
     *  This module contains the functions which implement the stream
     *  encoder.
     *
     * The stream encoder can encode to native FLAC, and optionally Ogg FLAC
     * (check FLAC_API_SUPPORTS_OGG_FLAC) streams and files.
     *
     * The basic usage of this encoder is as follows:
     * - The program creates an instance of an encoder using
     *   FLAC__stream_encoder_new().
     * - The program overrides the default settings using
     *   FLAC__stream_encoder_set_*() functions.  At a minimum, the following
     *   functions should be called:
     *   - FLAC__stream_encoder_set_channels()
     *   - FLAC__stream_encoder_set_bits_per_sample()
     *   - FLAC__stream_encoder_set_sample_rate()
     *   - FLAC__stream_encoder_set_ogg_serial_number() (if encoding to Ogg FLAC)
     *   - FLAC__stream_encoder_set_total_samples_estimate() (if known)
     * - If the application wants to control the compression level or set its own
     *   metadata, then the following should also be called:
     *   - FLAC__stream_encoder_set_compression_level()
     *   - FLAC__stream_encoder_set_verify()
     *   - FLAC__stream_encoder_set_metadata()
     * - The rest of the set functions should only be called if the client needs
     *   exact control over how the audio is compressed; thorough understanding
     *   of the FLAC format is necessary to achieve good results.
     * - The program initializes the instance to validate the settings and
     *   prepare for encoding using
     *   - FLAC__stream_encoder_init_stream() or FLAC__stream_encoder_init_FILE()
     *     or FLAC__stream_encoder_init_file() for native FLAC
     *   - FLAC__stream_encoder_init_ogg_stream() or FLAC__stream_encoder_init_ogg_FILE()
     *     or FLAC__stream_encoder_init_ogg_file() for Ogg FLAC
     * - The program calls FLAC__stream_encoder_process() or
     *   FLAC__stream_encoder_process_interleaved() to encode data, which
     *   subsequently calls the callbacks when there is encoder data ready
     *   to be written.
     * - The program finishes the encoding with FLAC__stream_encoder_finish(),
     *   which causes the encoder to encode any data still in its input pipe,
     *   update the metadata with the final encoding statistics if output
     *   seeking is possible, and finally reset the encoder to the
     *   uninitialized state.
     * - The instance may be used again or deleted with
     *   FLAC__stream_encoder_delete().
     *
     * In more detail, the stream encoder functions similarly to the
     * \link flac_stream_decoder stream decoder \endlink, but has fewer
     * callbacks and more options.  Typically the client will create a new
     * instance by calling FLAC__stream_encoder_new(), then set the necessary
     * parameters with FLAC__stream_encoder_set_*(), and initialize it by
     * calling one of the FLAC__stream_encoder_init_*() functions.
     *
     * Unlike the decoders, the stream encoder has many options that can
     * affect the speed and compression ratio.  When setting these parameters
     * you should have some basic knowledge of the format (see the
     * <A HREF="https://xiph.org/flac/documentation_format_overview.html">user-level documentation</A>
     * or the <A HREF="https://xiph.org/flac/format.html">formal description</A>).  The
     * FLAC__stream_encoder_set_*() functions themselves do not validate the
     * values as many are interdependent.  The FLAC__stream_encoder_init_*()
     * functions will do this, so make sure to pay attention to the state
     * returned by FLAC__stream_encoder_init_*() to make sure that it is
     * FLAC__STREAM_ENCODER_INIT_STATUS_OK.  Any parameters that are not set
     * before FLAC__stream_encoder_init_*() will take on the defaults from
     * the constructor.
     *
     * There are three initialization functions for native FLAC, one for
     * setting up the encoder to encode FLAC data to the client via
     * callbacks, and two for encoding directly to a file.
     *
     * For encoding via callbacks, use FLAC__stream_encoder_init_stream().
     * You must also supply a write callback which will be called anytime
     * there is raw encoded data to write.  If the client can seek the output
     * it is best to also supply seek and tell callbacks, as this allows the
     * encoder to go back after encoding is finished to write back
     * information that was collected while encoding, like seek point offsets,
     * frame sizes, etc.
     *
     * For encoding directly to a file, use FLAC__stream_encoder_init_FILE()
     * or FLAC__stream_encoder_init_file().  Then you must only supply a
     * filename or open \c FILE*; the encoder will handle all the callbacks
     * internally.  You may also supply a progress callback for periodic
     * notification of the encoding progress.
     *
     * There are three similarly-named init functions for encoding to Ogg
     * FLAC streams.  Check \c FLAC_API_SUPPORTS_OGG_FLAC to find out if the
     * library has been built with Ogg support.
     *
     * The call to FLAC__stream_encoder_init_*() currently will also immediately
     * call the write callback several times, once with the \c fLaC signature,
     * and once for each encoded metadata block.  Note that for Ogg FLAC
     * encoding you will usually get at least twice the number of callbacks than
     * with native FLAC, one for the Ogg page header and one for the page body.
     *
     * After initializing the instance, the client may feed audio data to the
     * encoder in one of two ways:
     *
     * - Channel separate, through FLAC__stream_encoder_process() - The client
     *   will pass an array of pointers to buffers, one for each channel, to
     *   the encoder, each of the same length.  The samples need not be
     *   block-aligned, but each channel should have the same number of samples.
     * - Channel interleaved, through
     *   FLAC__stream_encoder_process_interleaved() - The client will pass a single
     *   pointer to data that is channel-interleaved (i.e. channel0_sample0,
     *   channel1_sample0, ... , channelN_sample0, channel0_sample1, ...).
     *   Again, the samples need not be block-aligned but they must be
     *   sample-aligned, i.e. the first value should be channel0_sample0 and
     *   the last value channelN_sampleM.
     *
     * Note that for either process call, each sample in the buffers should be a
     * signed integer, right-justified to the resolution set by
     * FLAC__stream_encoder_set_bits_per_sample().  For example, if the resolution
     * is 16 bits per sample, the samples should all be in the range [-32768,32767].
     *
     * When the client is finished encoding data, it calls
     * FLAC__stream_encoder_finish(), which causes the encoder to encode any
     * data still in its input pipe, and call the metadata callback with the
     * final encoding statistics.  Then the instance may be deleted with
     * FLAC__stream_encoder_delete() or initialized again to encode another
     * stream.
     *
     * For programs that write their own metadata, but that do not know the
     * actual metadata until after encoding, it is advantageous to instruct
     * the encoder to write a PADDING block of the correct size, so that
     * instead of rewriting the whole stream after encoding, the program can
     * just overwrite the PADDING block.  If only the maximum size of the
     * metadata is known, the program can write a slightly larger padding
     * block, then split it after encoding.
     *
     * Make sure you understand how lengths are calculated.  All FLAC metadata
     * blocks have a 4 byte header which contains the type and length.  This
     * length does not include the 4 bytes of the header.  See the format page
     * for the specification of metadata blocks and their lengths.
     *
     * \note
     * If you are writing the FLAC data to a file via callbacks, make sure it
     * is open for update (e.g. mode "w+" for stdio streams).  This is because
     * after the first encoding pass, the encoder will try to seek back to the
     * beginning of the stream, to the STREAMINFO block, to write some data
     * there.  (If using FLAC__stream_encoder_init*_file() or
     * FLAC__stream_encoder_init*_FILE(), the file is managed internally.)
     *
     * \note
     * The "set" functions may only be called when the encoder is in the
     * state FLAC__STREAM_ENCODER_UNINITIALIZED, i.e. after
     * FLAC__stream_encoder_new() or FLAC__stream_encoder_finish(), but
     * before FLAC__stream_encoder_init_*().  If this is the case they will
     * return \c true, otherwise \c false.
     *
     * \note
     * FLAC__stream_encoder_finish() resets all settings to the constructor
     * defaults.
     *
     * \{
     */
    
    
    /** State values for a FLAC__StreamEncoder.
     *
     * The encoder's state can be obtained by calling FLAC__stream_encoder_get_state().
     *
     * If the encoder gets into any other state besides \c FLAC__STREAM_ENCODER_OK
     * or \c FLAC__STREAM_ENCODER_UNINITIALIZED, it becomes invalid for encoding and
     * must be deleted with FLAC__stream_encoder_delete().
     */
    typedef enum {
    
    	FLAC__STREAM_ENCODER_OK = 0,
    	/**< The encoder is in the normal OK state and samples can be processed. */
    
    	FLAC__STREAM_ENCODER_UNINITIALIZED,
    	/**< The encoder is in the uninitialized state; one of the
    	 * FLAC__stream_encoder_init_*() functions must be called before samples
    	 * can be processed.
    	 */
    
    	FLAC__STREAM_ENCODER_OGG_ERROR,
    	/**< An error occurred in the underlying Ogg layer.  */
    
    	FLAC__STREAM_ENCODER_VERIFY_DECODER_ERROR,
    	/**< An error occurred in the underlying verify stream decoder;
    	 * check FLAC__stream_encoder_get_verify_decoder_state().
    	 */
    
    	FLAC__STREAM_ENCODER_VERIFY_MISMATCH_IN_AUDIO_DATA,
    	/**< The verify decoder detected a mismatch between the original
    	 * audio signal and the decoded audio signal.
    	 */
    
    	FLAC__STREAM_ENCODER_CLIENT_ERROR,
    	/**< One of the callbacks returned a fatal error. */
    
    	FLAC__STREAM_ENCODER_IO_ERROR,
    	/**< An I/O error occurred while opening/reading/writing a file.
    	 * Check \c errno.
    	 */
    
    	FLAC__STREAM_ENCODER_FRAMING_ERROR,
    	/**< An error occurred while writing the stream; usually, the
    	 * write_callback returned an error.
    	 */
    
    	FLAC__STREAM_ENCODER_MEMORY_ALLOCATION_ERROR
    	/**< Memory allocation failed. */
    
    } FLAC__StreamEncoderState;
    
    /** Maps a FLAC__StreamEncoderState to a C string.
     *
     *  Using a FLAC__StreamEncoderState as the index to this array
     *  will give the string equivalent.  The contents should not be modified.
     */
    extern FLAC_API const char * const FLAC__StreamEncoderStateString[];
    
    
    #define FLAC__STREAM_ENCODER_SET_NUM_THREADS_OK 0
    #define FLAC__STREAM_ENCODER_SET_NUM_THREADS_NOT_COMPILED_WITH_MULTITHREADING_ENABLED 1
    #define FLAC__STREAM_ENCODER_SET_NUM_THREADS_ALREADY_INITIALIZED 2
    #define FLAC__STREAM_ENCODER_SET_NUM_THREADS_TOO_MANY_THREADS 3
    
    /** Possible return values for the FLAC__stream_encoder_init_*() functions.
     */
    typedef enum {
    
    	FLAC__STREAM_ENCODER_INIT_STATUS_OK = 0,
    	/**< Initialization was successful. */
    
    	FLAC__STREAM_ENCODER_INIT_STATUS_ENCODER_ERROR,
    	/**< General failure to set up encoder; call FLAC__stream_encoder_get_state() for cause. */
    
    	FLAC__STREAM_ENCODER_INIT_STATUS_UNSUPPORTED_CONTAINER,
    	/**< The library was not compiled with support for the given container
    	 * format.
    	 */
    
    	FLAC__STREAM_ENCODER_INIT_STATUS_INVALID_CALLBACKS,
    	/**< A required callback was not supplied. */
    
    	FLAC__STREAM_ENCODER_INIT_STATUS_INVALID_NUMBER_OF_CHANNELS,
    	/**< The encoder has an invalid setting for number of channels. */
    
    	FLAC__STREAM_ENCODER_INIT_STATUS_INVALID_BITS_PER_SAMPLE,
    	/**< The encoder has an invalid setting for bits-per-sample.
    	 * FLAC supports 4-32 bps.
    	 */
    
    	FLAC__STREAM_ENCODER_INIT_STATUS_INVALID_SAMPLE_RATE,
    	/**< The encoder has an invalid setting for the input sample rate. */
    
    	FLAC__STREAM_ENCODER_INIT_STATUS_INVALID_BLOCK_SIZE,
    	/**< The encoder has an invalid setting for the block size. */
    
    	FLAC__STREAM_ENCODER_INIT_STATUS_INVALID_MAX_LPC_ORDER,
    	/**< The encoder has an invalid setting for the maximum LPC order. */
    
    	FLAC__STREAM_ENCODER_INIT_STATUS_INVALID_QLP_COEFF_PRECISION,
    	/**< The encoder has an invalid setting for the precision of the quantized linear predictor coefficients. */
    
    	FLAC__STREAM_ENCODER_INIT_STATUS_BLOCK_SIZE_TOO_SMALL_FOR_LPC_ORDER,
    	/**< The specified block size is less than the maximum LPC order. */
    
    	FLAC__STREAM_ENCODER_INIT_STATUS_NOT_STREAMABLE,
    	/**< The encoder is bound to the <A HREF="https://xiph.org/flac/format.html#subset">Subset</A> but other settings violate it. */
    
    	FLAC__STREAM_ENCODER_INIT_STATUS_INVALID_METADATA,
    	/**< The metadata input to the encoder is invalid, in one of the following ways:
    	 * - FLAC__stream_encoder_set_metadata() was called with a null pointer but a block count > 0
    	 * - One of the metadata blocks contains an undefined type
    	 * - It contains an illegal CUESHEET as checked by FLAC__format_cuesheet_is_legal()
    	 * - It contains an illegal SEEKTABLE as checked by FLAC__format_seektable_is_legal()
    	 * - It contains more than one SEEKTABLE block or more than one VORBIS_COMMENT block
    	 */
    
    	FLAC__STREAM_ENCODER_INIT_STATUS_ALREADY_INITIALIZED
    	/**< FLAC__stream_encoder_init_*() was called when the encoder was
    	 * already initialized, usually because
    	 * FLAC__stream_encoder_finish() was not called.
    	 */
    
    } FLAC__StreamEncoderInitStatus;
    
    /** Maps a FLAC__StreamEncoderInitStatus to a C string.
     *
     *  Using a FLAC__StreamEncoderInitStatus as the index to this array
     *  will give the string equivalent.  The contents should not be modified.
     */
    extern FLAC_API const char * const FLAC__StreamEncoderInitStatusString[];
    
    
    /** Return values for the FLAC__StreamEncoder read callback.
     */
    typedef enum {
    
    	FLAC__STREAM_ENCODER_READ_STATUS_CONTINUE,
    	/**< The read was OK and decoding can continue. */
    
    	FLAC__STREAM_ENCODER_READ_STATUS_END_OF_STREAM,
    	/**< The read was attempted at the end of the stream. */
    
    	FLAC__STREAM_ENCODER_READ_STATUS_ABORT,
    	/**< An unrecoverable error occurred. */
    
    	FLAC__STREAM_ENCODER_READ_STATUS_UNSUPPORTED
    	/**< Client does not support reading back from the output. */
    
    } FLAC__StreamEncoderReadStatus;
    
    /** Maps a FLAC__StreamEncoderReadStatus to a C string.
     *
     *  Using a FLAC__StreamEncoderReadStatus as the index to this array
     *  will give the string equivalent.  The contents should not be modified.
     */
    extern FLAC_API const char * const FLAC__StreamEncoderReadStatusString[];
    
    
    /** Return values for the FLAC__StreamEncoder write callback.
     */
    typedef enum {
    
    	FLAC__STREAM_ENCODER_WRITE_STATUS_OK = 0,
    	/**< The write was OK and encoding can continue. */
    
    	FLAC__STREAM_ENCODER_WRITE_STATUS_FATAL_ERROR
    	/**< An unrecoverable error occurred.  The encoder will return from the process call. */
    
    } FLAC__StreamEncoderWriteStatus;
    
    /** Maps a FLAC__StreamEncoderWriteStatus to a C string.
     *
     *  Using a FLAC__StreamEncoderWriteStatus as the index to this array
     *  will give the string equivalent.  The contents should not be modified.
     */
    extern FLAC_API const char * const FLAC__StreamEncoderWriteStatusString[];
    
    
    /** Return values for the FLAC__StreamEncoder seek callback.
     */
    typedef enum {
    
    	FLAC__STREAM_ENCODER_SEEK_STATUS_OK,
    	/**< The seek was OK and encoding can continue. */
    
    	FLAC__STREAM_ENCODER_SEEK_STATUS_ERROR,
    	/**< An unrecoverable error occurred. */
    
    	FLAC__STREAM_ENCODER_SEEK_STATUS_UNSUPPORTED
    	/**< Client does not support seeking. */
    
    } FLAC__StreamEncoderSeekStatus;
    
    /** Maps a FLAC__StreamEncoderSeekStatus to a C string.
     *
     *  Using a FLAC__StreamEncoderSeekStatus as the index to this array
     *  will give the string equivalent.  The contents should not be modified.
     */
    extern FLAC_API const char * const FLAC__StreamEncoderSeekStatusString[];
    
    
    /** Return values for the FLAC__StreamEncoder tell callback.
     */
    typedef enum {
    
    	FLAC__STREAM_ENCODER_TELL_STATUS_OK,
    	/**< The tell was OK and encoding can continue. */
    
    	FLAC__STREAM_ENCODER_TELL_STATUS_ERROR,
    	/**< An unrecoverable error occurred. */
    
    	FLAC__STREAM_ENCODER_TELL_STATUS_UNSUPPORTED
    	/**< Client does not support seeking. */
    
    } FLAC__StreamEncoderTellStatus;
    
    /** Maps a FLAC__StreamEncoderTellStatus to a C string.
     *
     *  Using a FLAC__StreamEncoderTellStatus as the index to this array
     *  will give the string equivalent.  The contents should not be modified.
     */
    extern FLAC_API const char * const FLAC__StreamEncoderTellStatusString[];
    
    
    /***********************************************************************
     *
     * class FLAC__StreamEncoder
     *
     ***********************************************************************/
    
    struct FLAC__StreamEncoderProtected;
    struct FLAC__StreamEncoderPrivate;
    /** The opaque structure definition for the stream encoder type.
     *  See the \link flac_stream_encoder stream encoder module \endlink
     *  for a detailed description.
     */
    typedef struct {
    	struct FLAC__StreamEncoderProtected *protected_; /* avoid the C++ keyword 'protected' */
    	struct FLAC__StreamEncoderPrivate *private_; /* avoid the C++ keyword 'private' */
    } FLAC__StreamEncoder;
    
    /** Signature for the read callback.
     *
     *  A function pointer matching this signature must be passed to
     *  FLAC__stream_encoder_init_ogg_stream() if seeking is supported.
     *  The supplied function will be called when the encoder needs to read back
     *  encoded data.  This happens during the metadata callback, when the encoder
     *  has to read, modify, and rewrite the metadata (e.g. seekpoints) gathered
     *  while encoding.  The address of the buffer to be filled is supplied, along
     *  with the number of bytes the buffer can hold.  The callback may choose to
     *  supply less data and modify the byte count but must be careful not to
     *  overflow the buffer.  The callback then returns a status code chosen from
     *  FLAC__StreamEncoderReadStatus.
     *
     * Here is an example of a read callback for stdio streams:
     * \code
     * FLAC__StreamEncoderReadStatus read_cb(const FLAC__StreamEncoder *encoder, FLAC__byte buffer[], size_t *bytes, void *client_data)
     * {
     *   FILE *file = ((MyClientData*)client_data)->file;
     *   if(*bytes > 0) {
     *     *bytes = fread(buffer, sizeof(FLAC__byte), *bytes, file);
     *     if(ferror(file))
     *       return FLAC__STREAM_ENCODER_READ_STATUS_ABORT;
     *     else if(*bytes == 0)
     *       return FLAC__STREAM_ENCODER_READ_STATUS_END_OF_STREAM;
     *     else
     *       return FLAC__STREAM_ENCODER_READ_STATUS_CONTINUE;
     *   }
     *   else
     *     return FLAC__STREAM_ENCODER_READ_STATUS_ABORT;
     * }
     * \endcode
     *
     * \note In general, FLAC__StreamEncoder functions which change the
     * state should not be called on the \a encoder while in the callback.
     *
     * \param  encoder  The encoder instance calling the callback.
     * \param  buffer   A pointer to a location for the callee to store
     *                  data to be encoded.
     * \param  bytes    A pointer to the size of the buffer.  On entry
     *                  to the callback, it contains the maximum number
     *                  of bytes that may be stored in \a buffer.  The
     *                  callee must set it to the actual number of bytes
     *                  stored (0 in case of error or end-of-stream) before
     *                  returning.
     * \param  client_data  The callee's client data set through
     *                      FLAC__stream_encoder_set_client_data().
     * \retval FLAC__StreamEncoderReadStatus
     *    The callee's return status.
     */
    typedef FLAC__StreamEncoderReadStatus (*FLAC__StreamEncoderReadCallback)(const FLAC__StreamEncoder *encoder, FLAC__byte buffer[], size_t *bytes, void *client_data);
    
    /** Signature for the write callback.
     *
     *  A function pointer matching this signature must be passed to
     *  FLAC__stream_encoder_init*_stream().  The supplied function will be called
     *  by the encoder anytime there is raw encoded data ready to write.  It may
     *  include metadata mixed with encoded audio frames and the data is not
     *  guaranteed to be aligned on frame or metadata block boundaries.
     *
     *  The only duty of the callback is to write out the \a bytes worth of data
     *  in \a buffer to the current position in the output stream.  The arguments
     *  \a samples and \a current_frame are purely informational.  If \a samples
     *  is greater than \c 0, then \a current_frame will hold the current frame
     *  number that is being written; otherwise it indicates that the write
     *  callback is being called to write metadata.
     *
     * \note
     * Unlike when writing to native FLAC, when writing to Ogg FLAC the write
     * callback will be called at least twice when writing each audio frame; once
     * for the page header and once for the page body, possibly repeating this
     * pair of calls several times in a batch with the same value of
     * \a current_frame.  When writing the page header, as well as in all but the
     * first page body write of the batch, the \a samples argument to the write
     * callback will be \c 0. For the write callback call containing the first
     * page body, the \a samples argument is the number of samples contained in
     * all newly added complete packets (not pages). This means that in case a
     * packet is split over two pages, they are counted in the samples argument
     * of the page on which the packet is completed.
     *
     * \note In general, FLAC__StreamEncoder functions which change the
     * state should not be called on the \a encoder while in the callback.
     *
     * \param  encoder  The encoder instance calling the callback.
     * \param  buffer   An array of encoded data of length \a bytes.
     * \param  bytes    The byte length of \a buffer.
     * \param  samples  The number of samples encoded by \a buffer.
     *                  \c 0 has a special meaning; see above.
     * \param  current_frame  The number of the current frame being encoded.
     * \param  client_data  The callee's client data set through
     *                      FLAC__stream_encoder_init_*().
     * \retval FLAC__StreamEncoderWriteStatus
     *    The callee's return status.
     */
    typedef FLAC__StreamEncoderWriteStatus (*FLAC__StreamEncoderWriteCallback)(const FLAC__StreamEncoder *encoder, const FLAC__byte buffer[], size_t bytes, uint32_t samples, uint32_t current_frame, void *client_data);
    
    /** Signature for the seek callback.
     *
     *  A function pointer matching this signature may be passed to
     *  FLAC__stream_encoder_init*_stream().  The supplied function will be called
     *  when the encoder needs to seek the output stream.  The encoder will pass
     *  the absolute byte offset to seek to, 0 meaning the beginning of the stream.
     *
     * Here is an example of a seek callback for stdio streams:
     * \code
     * FLAC__StreamEncoderSeekStatus seek_cb(const FLAC__StreamEncoder *encoder, FLAC__uint64 absolute_byte_offset, void *client_data)
     * {
     *   FILE *file = ((MyClientData*)client_data)->file;
     *   if(file == stdin)
     *     return FLAC__STREAM_ENCODER_SEEK_STATUS_UNSUPPORTED;
     *   else if(fseeko(file, (off_t)absolute_byte_offset, SEEK_SET) < 0)
     *     return FLAC__STREAM_ENCODER_SEEK_STATUS_ERROR;
     *   else
     *     return FLAC__STREAM_ENCODER_SEEK_STATUS_OK;
     * }
     * \endcode
     *
     * \note In general, FLAC__StreamEncoder functions which change the
     * state should not be called on the \a encoder while in the callback.
     *
     * \param  encoder  The encoder instance calling the callback.
     * \param  absolute_byte_offset  The offset from the beginning of the stream
     *                               to seek to.
     * \param  client_data  The callee's client data set through
     *                      FLAC__stream_encoder_init_*().
     * \retval FLAC__StreamEncoderSeekStatus
     *    The callee's return status.
     */
    typedef FLAC__StreamEncoderSeekStatus (*FLAC__StreamEncoderSeekCallback)(const FLAC__StreamEncoder *encoder, FLAC__uint64 absolute_byte_offset, void *client_data);
    
    /** Signature for the tell callback.
     *
     *  A function pointer matching this signature may be passed to
     *  FLAC__stream_encoder_init*_stream().  The supplied function will be called
     *  when the encoder needs to know the current position of the output stream.
     *
     * \warning
     * The callback must return the true current byte offset of the output to
     * which the encoder is writing.  If you are buffering the output, make
     * sure and take this into account.  If you are writing directly to a
     * FILE* from your write callback, ftell() is sufficient.  If you are
     * writing directly to a file descriptor from your write callback, you
     * can use lseek(fd, SEEK_CUR, 0).  The encoder may later seek back to
     * these points to rewrite metadata after encoding.
     *
     * Here is an example of a tell callback for stdio streams:
     * \code
     * FLAC__StreamEncoderTellStatus tell_cb(const FLAC__StreamEncoder *encoder, FLAC__uint64 *absolute_byte_offset, void *client_data)
     * {
     *   FILE *file = ((MyClientData*)client_data)->file;
     *   off_t pos;
     *   if(file == stdin)
     *     return FLAC__STREAM_ENCODER_TELL_STATUS_UNSUPPORTED;
     *   else if((pos = ftello(file)) < 0)
     *     return FLAC__STREAM_ENCODER_TELL_STATUS_ERROR;
     *   else {
     *     *absolute_byte_offset = (FLAC__uint64)pos;
     *     return FLAC__STREAM_ENCODER_TELL_STATUS_OK;
     *   }
     * }
     * \endcode
     *
     * \note In general, FLAC__StreamEncoder functions which change the
     * state should not be called on the \a encoder while in the callback.
     *
     * \param  encoder  The encoder instance calling the callback.
     * \param  absolute_byte_offset  The address at which to store the current
     *                               position of the output.
     * \param  client_data  The callee's client data set through
     *                      FLAC__stream_encoder_init_*().
     * \retval FLAC__StreamEncoderTellStatus
     *    The callee's return status.
     */
    typedef FLAC__StreamEncoderTellStatus (*FLAC__StreamEncoderTellCallback)(const FLAC__StreamEncoder *encoder, FLAC__uint64 *absolute_byte_offset, void *client_data);
    
    /** Signature for the metadata callback.
     *
     *  A function pointer matching this signature may be passed to
     *  FLAC__stream_encoder_init*_stream().  The supplied function will be called
     *  once at the end of encoding with the populated STREAMINFO structure.  This
     *  is so the client can seek back to the beginning of the file and write the
     *  STREAMINFO block with the correct statistics after encoding (like
     *  minimum/maximum frame size and total samples).
     *
     * \note In general, FLAC__StreamEncoder functions which change the
     * state should not be called on the \a encoder while in the callback.
     *
     * \param  encoder      The encoder instance calling the callback.
     * \param  metadata     The final populated STREAMINFO block.
     * \param  client_data  The callee's client data set through
     *                      FLAC__stream_encoder_init_*().
     */
    typedef void (*FLAC__StreamEncoderMetadataCallback)(const FLAC__StreamEncoder *encoder, const FLAC__StreamMetadata *metadata, void *client_data);
    
    /** Signature for the progress callback.
     *
     *  A function pointer matching this signature may be passed to
     *  FLAC__stream_encoder_init*_file() or FLAC__stream_encoder_init*_FILE().
     *  The supplied function will be called when the encoder has finished
     *  writing a frame.  The \c total_frames_estimate argument to the
     *  callback will be based on the value from
     *  FLAC__stream_encoder_set_total_samples_estimate().
     *
     * \note In general, FLAC__StreamEncoder functions which change the
     * state should not be called on the \a encoder while in the callback.
     *
     * \param  encoder          The encoder instance calling the callback.
     * \param  bytes_written    Bytes written so far.
     * \param  samples_written  Samples written so far.
     * \param  frames_written   Frames written so far.
     * \param  total_frames_estimate  The estimate of the total number of
     *                                frames to be written.
     * \param  client_data      The callee's client data set through
     *                          FLAC__stream_encoder_init_*().
     */
    typedef void (*FLAC__StreamEncoderProgressCallback)(const FLAC__StreamEncoder *encoder, FLAC__uint64 bytes_written, FLAC__uint64 samples_written, uint32_t frames_written, uint32_t total_frames_estimate, void *client_data);
    
    
    /***********************************************************************
     *
     * Class constructor/destructor
     *
     ***********************************************************************/
    
    /** Create a new stream encoder instance.  The instance is created with
     *  default settings; see the individual FLAC__stream_encoder_set_*()
     *  functions for each setting's default.
     *
     * \retval FLAC__StreamEncoder*
     *    \c NULL if there was an error allocating memory, else the new instance.
     */
    FLAC_API FLAC__StreamEncoder *FLAC__stream_encoder_new(void);
    
    /** Free an encoder instance.  Deletes the object pointed to by \a encoder.
     *
     * \param encoder  A pointer to an existing encoder.
     * \assert
     *    \code encoder != NULL \endcode
     */
    FLAC_API void FLAC__stream_encoder_delete(FLAC__StreamEncoder *encoder);
    
    
    /***********************************************************************
     *
     * Public class method prototypes
     *
     ***********************************************************************/
    
    /** Set the serial number for the FLAC stream to use in the Ogg container.
     *
     * \note
     * This does not need to be set for native FLAC encoding.
     *
     * \note
     * It is recommended to set a serial number explicitly as the default of '0'
     * may collide with other streams.
     *
     * \default \c 0
     * \param  encoder        An encoder instance to set.
     * \param  serial_number  See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_ogg_serial_number(FLAC__StreamEncoder *encoder, long serial_number);
    
    /** Set the "verify" flag.  If \c true, the encoder will verify it's own
     *  encoded output by feeding it through an internal decoder and comparing
     *  the original signal against the decoded signal.  If a mismatch occurs,
     *  the process call will return \c false.  Note that this will slow the
     *  encoding process by the extra time required for decoding and comparison.
     *
     * \default \c false
     * \param  encoder  An encoder instance to set.
     * \param  value    Flag value (see above).
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_verify(FLAC__StreamEncoder *encoder, FLAC__bool value);
    
    /** Set the <A HREF="https://xiph.org/flac/format.html#subset">Subset</A> flag.  If \c true,
     *  the encoder will comply with the Subset and will check the
     *  settings during FLAC__stream_encoder_init_*() to see if all settings
     *  comply.  If \c false, the settings may take advantage of the full
     *  range that the format allows.
     *
     *  Make sure you know what it entails before setting this to \c false.
     *
     * \default \c true
     * \param  encoder  An encoder instance to set.
     * \param  value    Flag value (see above).
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_streamable_subset(FLAC__StreamEncoder *encoder, FLAC__bool value);
    
    /** Set the number of channels to be encoded.
     *
     * \default \c 2
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_channels(FLAC__StreamEncoder *encoder, uint32_t value);
    
    /** Set the sample resolution of the input to be encoded.
     *
     * \warning
     * Do not feed the encoder data that is wider than the value you
     * set here or you will generate an invalid stream.
     *
     * \default \c 16
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_bits_per_sample(FLAC__StreamEncoder *encoder, uint32_t value);
    
    /** Set the sample rate (in Hz) of the input to be encoded.
     *
     * \default \c 44100
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_sample_rate(FLAC__StreamEncoder *encoder, uint32_t value);
    
    /** Set the compression level
     *
     * The compression level is roughly proportional to the amount of effort
     * the encoder expends to compress the file.  A higher level usually
     * means more computation but higher compression.  The default level is
     * suitable for most applications.
     *
     * Currently the levels range from \c 0 (fastest, least compression) to
     * \c 8 (slowest, most compression).  A value larger than \c 8 will be
     * treated as \c 8.
     *
     * This function automatically calls the following other \c _set_
     * functions with appropriate values, so the client does not need to
     * unless it specifically wants to override them:
     * - FLAC__stream_encoder_set_do_mid_side_stereo()
     * - FLAC__stream_encoder_set_loose_mid_side_stereo()
     * - FLAC__stream_encoder_set_apodization()
     * - FLAC__stream_encoder_set_max_lpc_order()
     * - FLAC__stream_encoder_set_qlp_coeff_precision()
     * - FLAC__stream_encoder_set_do_qlp_coeff_prec_search()
     * - FLAC__stream_encoder_set_do_escape_coding()
     * - FLAC__stream_encoder_set_do_exhaustive_model_search()
     * - FLAC__stream_encoder_set_min_residual_partition_order()
     * - FLAC__stream_encoder_set_max_residual_partition_order()
     * - FLAC__stream_encoder_set_rice_parameter_search_dist()
     *
     * The actual values set for each level are:
     * <table>
     * <tr>
     *  <td><b>level</b></td>
     *  <td>do mid-side stereo</td>
     *  <td>loose mid-side stereo</td>
     *  <td>apodization</td>
     *  <td>max lpc order</td>
     *  <td>qlp coeff precision</td>
     *  <td>qlp coeff prec search</td>
     *  <td>escape coding</td>
     *  <td>exhaustive model search</td>
     *  <td>min residual partition order</td>
     *  <td>max residual partition order</td>
     *  <td>rice parameter search dist</td>
     * </tr>
     * <tr>  <td><b>0</b></td> <td>false</td> <td>false</td> <td>tukey(0.5)</td>         <td>0</td>  <td>0</td> <td>false</td> <td>false</td> <td>false</td> <td>0</td> <td>3</td> <td>0</td> </tr>
     * <tr>  <td><b>1</b></td> <td>true</td>  <td>true</td>  <td>tukey(0.5)</td>         <td>0</td>  <td>0</td> <td>false</td> <td>false</td> <td>false</td> <td>0</td> <td>3</td> <td>0</td> </tr>
     * <tr>  <td><b>2</b></td> <td>true</td>  <td>false</td> <td>tukey(0.5)</td>         <td>0</td>  <td>0</td> <td>false</td> <td>false</td> <td>false</td> <td>0</td> <td>3</td> <td>0</td> </tr>
     * <tr>  <td><b>3</b></td> <td>false</td> <td>false</td> <td>tukey(0.5)</td>         <td>6</td>  <td>0</td> <td>false</td> <td>false</td> <td>false</td> <td>0</td> <td>4</td> <td>0</td> </tr>
     * <tr>  <td><b>4</b></td> <td>true</td>  <td>true</td>  <td>tukey(0.5)</td>         <td>8</td>  <td>0</td> <td>false</td> <td>false</td> <td>false</td> <td>0</td> <td>4</td> <td>0</td> </tr>
     * <tr>  <td><b>5</b></td> <td>true</td>  <td>false</td> <td>tukey(0.5)</td>         <td>8</td>  <td>0</td> <td>false</td> <td>false</td> <td>false</td> <td>0</td> <td>5</td> <td>0</td> </tr>
     * <tr>  <td><b>6</b></td> <td>true</td>  <td>false</td> <td>subdivide_tukey(2)</td> <td>8</td>  <td>0</td> <td>false</td> <td>false</td> <td>false</td> <td>0</td> <td>6</td> <td>0</td> </tr>
     * <tr>  <td><b>7</b></td> <td>true</td>  <td>false</td> <td>subdivide_tukey(2)</td> <td>12</td> <td>0</td> <td>false</td> <td>false</td> <td>false</td> <td>0</td> <td>6</td> <td>0</td> </tr>
     * <tr>  <td><b>8</b></td> <td>true</td>  <td>false</td> <td>subdivide_tukey(3)</td> <td>12</td> <td>0</td> <td>false</td> <td>false</td> <td>false</td> <td>0</td> <td>6</td> <td>0</td> </tr>
     * </table>
     *
     * \default \c 5
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_compression_level(FLAC__StreamEncoder *encoder, uint32_t value);
    
    /** Set the blocksize to use while encoding.
     *
     * The number of samples to use per frame.  Use \c 0 to let the encoder
     * estimate a blocksize; this is usually best.
     *
     * \default \c 0
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_blocksize(FLAC__StreamEncoder *encoder, uint32_t value);
    
    /** Set to \c true to enable mid-side encoding on stereo input.  The
     *  number of channels must be 2 for this to have any effect.  Set to
     *  \c false to use only independent channel coding.
     *
     * \default \c true
     * \param  encoder  An encoder instance to set.
     * \param  value    Flag value (see above).
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_do_mid_side_stereo(FLAC__StreamEncoder *encoder, FLAC__bool value);
    
    /** Set to \c true to enable adaptive switching between mid-side and
     *  left-right encoding on stereo input.  Set to \c false to use
     *  exhaustive searching.  Setting this to \c true requires
     *  FLAC__stream_encoder_set_do_mid_side_stereo() to also be set to
     *  \c true in order to have any effect.
     *
     * \default \c false
     * \param  encoder  An encoder instance to set.
     * \param  value    Flag value (see above).
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_loose_mid_side_stereo(FLAC__StreamEncoder *encoder, FLAC__bool value);
    
    /** Sets the apodization function(s) the encoder will use when windowing
     *  audio data for LPC analysis.
     *
     * The \a specification is a plain ASCII string which specifies exactly
     * which functions to use.  There may be more than one (up to 32),
     * separated by \c ';' characters.  Some functions take one or more
     * comma-separated arguments in parentheses.
     *
     * The available functions are \c bartlett, \c bartlett_hann,
     * \c blackman, \c blackman_harris_4term_92db, \c connes, \c flattop,
     * \c gauss(STDDEV), \c hamming, \c hann, \c kaiser_bessel, \c nuttall,
     * \c rectangle, \c triangle, \c tukey(P), \c partial_tukey(n[/ov[/P]]),
     * \c punchout_tukey(n[/ov[/P]]), \c subdivide_tukey(n[/P]), \c welch.
     *
     * For \c gauss(STDDEV), STDDEV specifies the standard deviation
     * (0<STDDEV<=0.5).
     *
     * For \c tukey(P), P specifies the fraction of the window that is
     * tapered (0<=P<=1).  P=0 corresponds to \c rectangle and P=1
     * corresponds to \c hann.
     *
     * Specifying \c partial_tukey or \c punchout_tukey works a little
     * different. These do not specify a single apodization function, but
     * a series of them with some overlap. partial_tukey specifies a series
     * of small windows (all treated separately) while punchout_tukey
     * specifies a series of windows that have a hole in them. In this way,
     * the predictor is constructed with only a part of the block, which
     * helps in case a block consists of dissimilar parts.
     *
     * The three parameters that can be specified for the functions are
     * n, ov and P. n is the number of functions to add, ov is the overlap
     * of the windows in case of partial_tukey and the overlap in the gaps
     * in case of punchout_tukey. P is the fraction of the window that is
     * tapered, like with a regular tukey window. The function can be
     * specified with only a number, a number and an overlap, or a number
     * an overlap and a P, for example, partial_tukey(3), partial_tukey(3/0.3)
     * and partial_tukey(3/0.3/0.5) are all valid. ov should be smaller than 1
     * and can be negative.
     *
     * subdivide_tukey(n) is a more efficient reimplementation of
     * partial_tukey and punchout_tukey taken together, recycling as much data
     * as possible. It combines all possible non-redundant partial_tukey(n)
     * and punchout_tukey(n) up to the n specified. Specifying
     * subdivide_tukey(3) is equivalent to specifying tukey, partial_tukey(2),
     * partial_tukey(3) and punchout_tukey(3), specifying subdivide_tukey(5)
     * equivalently adds partial_tukey(4), punchout_tukey(4), partial_tukey(5)
     * and punchout_tukey(5). To be able to reuse data as much as possible,
     * the tukey taper is taken equal for all windows, and the P specified is
     * applied for the smallest used window. In other words,
     * subdivide_tukey(2/0.5) results in a taper equal to that of tukey(0.25)
     * and subdivide_tukey(5) in a taper equal to that of tukey(0.1). The
     * default P for subdivide_tukey when none is specified is 0.5.
     *
     * Example specifications are \c "blackman" or
     * \c "hann;triangle;tukey(0.5);tukey(0.25);tukey(0.125)"
     *
     * Any function that is specified erroneously is silently dropped.  Up
     * to 32 functions are kept, the rest are dropped.  If the specification
     * is empty the encoder defaults to \c "tukey(0.5)".
     *
     * When more than one function is specified, then for every subframe the
     * encoder will try each of them separately and choose the window that
     * results in the smallest compressed subframe.
     *
     * Note that each function specified causes the encoder to occupy a
     * floating point array in which to store the window. Also note that the
     * values of P, STDDEV and ov are locale-specific, so if the comma
     * separator specified by the locale is a comma, a comma should be used.
     * A locale-independent way is to specify using scientific notation,
     * e.g. 5e-1 instad of 0.5 or 0,5.
     *
     * \default \c "tukey(0.5)"
     * \param  encoder        An encoder instance to set.
     * \param  specification  See above.
     * \assert
     *    \code encoder != NULL \endcode
     *    \code specification != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_apodization(FLAC__StreamEncoder *encoder, const char *specification);
    
    /** Set the maximum LPC order, or \c 0 to use only the fixed predictors.
     *
     * \default \c 8
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_max_lpc_order(FLAC__StreamEncoder *encoder, uint32_t value);
    
    /** Set the precision, in bits, of the quantized linear predictor
     *  coefficients, or \c 0 to let the encoder select it based on the
     *  blocksize.
     *
     * \default \c 0
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_qlp_coeff_precision(FLAC__StreamEncoder *encoder, uint32_t value);
    
    /** Set to \c false to use only the specified quantized linear predictor
     *  coefficient precision, or \c true to search neighboring precision
     *  values and use the best one.
     *
     * \default \c false
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_do_qlp_coeff_prec_search(FLAC__StreamEncoder *encoder, FLAC__bool value);
    
    /** Deprecated.  Setting this value has no effect.
     *
     * \default \c false
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_do_escape_coding(FLAC__StreamEncoder *encoder, FLAC__bool value);
    
    /** Set to \c false to let the encoder estimate the best model order
     *  based on the residual signal energy, or \c true to force the
     *  encoder to evaluate all order models and select the best.
     *
     * \default \c false
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_do_exhaustive_model_search(FLAC__StreamEncoder *encoder, FLAC__bool value);
    
    /** Set the minimum partition order to search when coding the residual.
     *  This is used in tandem with
     *  FLAC__stream_encoder_set_max_residual_partition_order().
     *
     *  The partition order determines the context size in the residual.
     *  The context size will be approximately <tt>blocksize / (2 ^ order)</tt>.
     *
     *  Set both min and max values to \c 0 to force a single context,
     *  whose Rice parameter is based on the residual signal variance.
     *  Otherwise, set a min and max order, and the encoder will search
     *  all orders, using the mean of each context for its Rice parameter,
     *  and use the best.
     *
     * \default \c 0
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_min_residual_partition_order(FLAC__StreamEncoder *encoder, uint32_t value);
    
    /** Set the maximum partition order to search when coding the residual.
     *  This is used in tandem with
     *  FLAC__stream_encoder_set_min_residual_partition_order().
     *
     *  The partition order determines the context size in the residual.
     *  The context size will be approximately <tt>blocksize / (2 ^ order)</tt>.
     *
     *  Set both min and max values to \c 0 to force a single context,
     *  whose Rice parameter is based on the residual signal variance.
     *  Otherwise, set a min and max order, and the encoder will search
     *  all orders, using the mean of each context for its Rice parameter,
     *  and use the best.
     *
     * \default \c 5
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_max_residual_partition_order(FLAC__StreamEncoder *encoder, uint32_t value);
    
    /** Set the maximum number of threads to use during encoding.
     *  Set to a value different than 1 to enable multithreaded encoding.
     *
     *  Note that enabling multithreading encoding (i.e., setting a value
     *  different than 1) results in the behaviour of
     *  FLAC__stream_encoder_finish(), FLAC__stream_encoder_process(),
     *  FLAC__stream_encoder_process_interleaved() subtly changing.
     *  For example, calling one of the process functions with enough
     *  samples to fill a block might not always result in a call to
     *  the write callback with a frame coding these samples. Instead,
     *  blocks with samples are distributed among worker threads,
     *  meaning that the first few calls to those functions will
     *  return very quickly, while later calls might block if all
     *  threads are occupied. Also, certain calls to the process
     *  functions will results in several calls to the write callback,
     *  while subsequent calls might again return very quickly with no
     *  calls to the write callback.
     *
     *  Also, a call to FLAC__stream_encoder_finish() blocks while
     *  waiting for all threads to finish, and therefore might take much
     *  longer than when not multithreading and result in multiple calls
     *  to the write callback.
     *
     *  Calls to the write callback are guaranteed to be in the correct
     *  order.
     *
     *  Currently, passing a value of 0 is synonymous with a value of 1,
     *  but this might change in the future.
     *
     * \default \c 1
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval uint32_t
     *    - \c FLAC__STREAM_ENCODER_SET_NUM_THREADS_OK if the number of threads was set correctly,
     *    - \c FLAC__STREAM_ENCODER_SET_NUM_THREADS_NOT_COMPILED_WITH_MULTITHREADING_ENABLED when
     *    multithreading was not enabled at compilation,
     *    - \c FLAC__STREAM_ENCODER_SET_NUM_THREADS_ALREADY_INITIALIZED when the encoder was
     *    already initialized,
     *    - \c FLAC__STREAM_ENCODER_SET_NUM_THREADS_TOO_MANY_THREADS when
     *    the number of threads was larger than the maximum allowed number of threads (currently
     *    128).
     */
    FLAC_API uint32_t FLAC__stream_encoder_set_num_threads(FLAC__StreamEncoder *encoder, uint32_t value);
    
    /** Deprecated.  Setting this value has no effect.
     *
     * \default \c 0
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_rice_parameter_search_dist(FLAC__StreamEncoder *encoder, uint32_t value);
    
    /** Set an estimate of the total samples that will be encoded.
     *  This is merely an estimate and may be set to \c 0 if unknown.
     *  This value will be written to the STREAMINFO block before encoding,
     *  and can remove the need for the caller to rewrite the value later
     *  if the value is known before encoding.
     *
     * \default \c 0
     * \param  encoder  An encoder instance to set.
     * \param  value    See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_total_samples_estimate(FLAC__StreamEncoder *encoder, FLAC__uint64 value);
    
    /** Set the metadata blocks to be emitted to the stream before encoding.
     *  A value of \c NULL, \c 0 implies no metadata; otherwise, supply an
     *  array of pointers to metadata blocks.  The array is non-const since
     *  the encoder may need to change the \a is_last flag inside them, and
     *  in some cases update seek point offsets.  Otherwise, the encoder will
     *  not modify or free the blocks.  It is up to the caller to free the
     *  metadata blocks after encoding finishes.
     *
     * \note
     * The encoder stores only copies of the pointers in the \a metadata array;
     * the metadata blocks themselves must survive at least until after
     * FLAC__stream_encoder_finish() returns.  Do not free the blocks until then.
     *
     * \note
     * The STREAMINFO block is always written and no STREAMINFO block may
     * occur in the supplied array.
     *
     * \note
     * By default the encoder does not create a SEEKTABLE.  If one is supplied
     * in the \a metadata array, but the client has specified that it does not
     * support seeking, then the SEEKTABLE will be written verbatim.  However
     * by itself this is not very useful as the client will not know the stream
     * offsets for the seekpoints ahead of time.  In order to get a proper
     * seektable the client must support seeking.  See next note.
     *
     * \note
     * SEEKTABLE blocks are handled specially.  Since you will not know
     * the values for the seek point stream offsets, you should pass in
     * a SEEKTABLE 'template', that is, a SEEKTABLE object with the
     * required sample numbers (or placeholder points), with \c 0 for the
     * \a frame_samples and \a stream_offset fields for each point.  If the
     * client has specified that it supports seeking by providing a seek
     * callback to FLAC__stream_encoder_init_stream() or both seek AND read
     * callback to FLAC__stream_encoder_init_ogg_stream() (or by using
     * FLAC__stream_encoder_init*_file() or FLAC__stream_encoder_init*_FILE()),
     * then while it is encoding the encoder will fill the stream offsets in
     * for you and when encoding is finished, it will seek back and write the
     * real values into the SEEKTABLE block in the stream.  There are helper
     * routines for manipulating seektable template blocks; see metadata.h:
     * FLAC__metadata_object_seektable_template_*().  If the client does
     * not support seeking, the SEEKTABLE will have inaccurate offsets which
     * will slow down or remove the ability to seek in the FLAC stream.
     *
     * \note
     * The encoder instance \b will modify the first \c SEEKTABLE block
     * as it transforms the template to a valid seektable while encoding,
     * but it is still up to the caller to free all metadata blocks after
     * encoding.
     *
     * \note
     * A VORBIS_COMMENT block may be supplied.  The vendor string in it
     * will be ignored.  libFLAC will use it's own vendor string. libFLAC
     * will not modify the passed-in VORBIS_COMMENT's vendor string, it
     * will simply write it's own into the stream.  If no VORBIS_COMMENT
     * block is present in the \a metadata array, libFLAC will write an
     * empty one, containing only the vendor string.
     *
     * \note The Ogg FLAC mapping requires that the VORBIS_COMMENT block be
     * the second metadata block of the stream.  The encoder already supplies
     * the STREAMINFO block automatically.  If \a metadata does not contain a
     * VORBIS_COMMENT block, the encoder will supply that too.  Otherwise, if
     * \a metadata does contain a VORBIS_COMMENT block and it is not the
     * first, the init function will reorder \a metadata by moving the
     * VORBIS_COMMENT block to the front; the relative ordering of the other
     * blocks will remain as they were.
     *
     * \note The Ogg FLAC mapping limits the number of metadata blocks per
     * stream to \c 65535.  If \a num_blocks exceeds this the function will
     * return \c false.
     *
     * \default \c NULL, 0
     * \param  encoder     An encoder instance to set.
     * \param  metadata    See above.
     * \param  num_blocks  See above.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     *    \c false if the encoder is already initialized, or if
     *    \a num_blocks > 65535 if encoding to Ogg FLAC, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_metadata(FLAC__StreamEncoder *encoder, FLAC__StreamMetadata **metadata, uint32_t num_blocks);
    
    /** Set to \c true to make the encoder not output frames which contain
     *  only constant subframes. This is beneficial for streaming
     *  applications: very small frames can cause problems with buffering
     *  as bitrates can drop as low 1kbit/s for CDDA audio encoded within
     *  subset. The minimum bitrate for a FLAC file encoded with this
     *  function used is raised to 1bit/sample (i.e. 48kbit/s for 48kHz
     *  material).
     *
     * \default \c false
     * \param  encoder  An encoder instance to set.
     * \param  value    Flag value (see above).
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if the encoder is already initialized, else \c true.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_set_limit_min_bitrate(FLAC__StreamEncoder *encoder, FLAC__bool value);
    
    /** Get the current encoder state.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__StreamEncoderState
     *    The current encoder state.
     */
    FLAC_API FLAC__StreamEncoderState FLAC__stream_encoder_get_state(const FLAC__StreamEncoder *encoder);
    
    /** Get the state of the verify stream decoder.
     *  Useful when the stream encoder state is
     *  \c FLAC__STREAM_ENCODER_VERIFY_DECODER_ERROR.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__StreamDecoderState
     *    The verify stream decoder state.
     */
    FLAC_API FLAC__StreamDecoderState FLAC__stream_encoder_get_verify_decoder_state(const FLAC__StreamEncoder *encoder);
    
    /** Get the current encoder state as a C string.
     *  This version automatically resolves
     *  \c FLAC__STREAM_ENCODER_VERIFY_DECODER_ERROR by getting the
     *  verify decoder's state.
     *
     * \param  encoder  A encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval const char *
     *    The encoder state as a C string.  Do not modify the contents.
     */
    FLAC_API const char *FLAC__stream_encoder_get_resolved_state_string(const FLAC__StreamEncoder *encoder);
    
    /** Get relevant values about the nature of a verify decoder error.
     *  Useful when the stream encoder state is
     *  \c FLAC__STREAM_ENCODER_VERIFY_DECODER_ERROR.  The arguments should
     *  be addresses in which the stats will be returned, or NULL if value
     *  is not desired.
     *
     * \param  encoder  An encoder instance to query.
     * \param  absolute_sample  The absolute sample number of the mismatch.
     * \param  frame_number  The number of the frame in which the mismatch occurred.
     * \param  channel       The channel in which the mismatch occurred.
     * \param  sample        The number of the sample (relative to the frame) in
     *                       which the mismatch occurred.
     * \param  expected      The expected value for the sample in question.
     * \param  got           The actual value returned by the decoder.
     * \assert
     *    \code encoder != NULL \endcode
     */
    FLAC_API void FLAC__stream_encoder_get_verify_decoder_error_stats(const FLAC__StreamEncoder *encoder, FLAC__uint64 *absolute_sample, uint32_t *frame_number, uint32_t *channel, uint32_t *sample, FLAC__int32 *expected, FLAC__int32 *got);
    
    /** Get the "verify" flag.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    See FLAC__stream_encoder_set_verify().
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_get_verify(const FLAC__StreamEncoder *encoder);
    
    /** Get the <A HREF="https://xiph.org/flac/format.html#subset">Subset</A> flag.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    See FLAC__stream_encoder_set_streamable_subset().
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_get_streamable_subset(const FLAC__StreamEncoder *encoder);
    
    /** Get the number of input channels being processed.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval uint32_t
     *    See FLAC__stream_encoder_set_channels().
     */
    FLAC_API uint32_t FLAC__stream_encoder_get_channels(const FLAC__StreamEncoder *encoder);
    
    /** Get the input sample resolution setting.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval uint32_t
     *    See FLAC__stream_encoder_set_bits_per_sample().
     */
    FLAC_API uint32_t FLAC__stream_encoder_get_bits_per_sample(const FLAC__StreamEncoder *encoder);
    
    /** Get the input sample rate setting.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval uint32_t
     *    See FLAC__stream_encoder_set_sample_rate().
     */
    FLAC_API uint32_t FLAC__stream_encoder_get_sample_rate(const FLAC__StreamEncoder *encoder);
    
    /** Get the blocksize setting.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval uint32_t
     *    See FLAC__stream_encoder_set_blocksize().
     */
    FLAC_API uint32_t FLAC__stream_encoder_get_blocksize(const FLAC__StreamEncoder *encoder);
    
    /** Get the "mid/side stereo coding" flag.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    See FLAC__stream_encoder_get_do_mid_side_stereo().
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_get_do_mid_side_stereo(const FLAC__StreamEncoder *encoder);
    
    /** Get the "adaptive mid/side switching" flag.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    See FLAC__stream_encoder_set_loose_mid_side_stereo().
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_get_loose_mid_side_stereo(const FLAC__StreamEncoder *encoder);
    
    /** Get the maximum LPC order setting.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval uint32_t
     *    See FLAC__stream_encoder_set_max_lpc_order().
     */
    FLAC_API uint32_t FLAC__stream_encoder_get_max_lpc_order(const FLAC__StreamEncoder *encoder);
    
    /** Get the quantized linear predictor coefficient precision setting.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval uint32_t
     *    See FLAC__stream_encoder_set_qlp_coeff_precision().
     */
    FLAC_API uint32_t FLAC__stream_encoder_get_qlp_coeff_precision(const FLAC__StreamEncoder *encoder);
    
    /** Get the qlp coefficient precision search flag.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    See FLAC__stream_encoder_set_do_qlp_coeff_prec_search().
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_get_do_qlp_coeff_prec_search(const FLAC__StreamEncoder *encoder);
    
    /** Get the "escape coding" flag.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    See FLAC__stream_encoder_set_do_escape_coding().
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_get_do_escape_coding(const FLAC__StreamEncoder *encoder);
    
    /** Get the exhaustive model search flag.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    See FLAC__stream_encoder_set_do_exhaustive_model_search().
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_get_do_exhaustive_model_search(const FLAC__StreamEncoder *encoder);
    
    /** Get the minimum residual partition order setting.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval uint32_t
     *    See FLAC__stream_encoder_set_min_residual_partition_order().
     */
    FLAC_API uint32_t FLAC__stream_encoder_get_min_residual_partition_order(const FLAC__StreamEncoder *encoder);
    
    /** Get maximum residual partition order setting.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval uint32_t
     *    See FLAC__stream_encoder_set_max_residual_partition_order().
     */
    FLAC_API uint32_t FLAC__stream_encoder_get_max_residual_partition_order(const FLAC__StreamEncoder *encoder);
    
    /** Get maximum number of threads setting.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval uint32_t
     *    See FLAC__stream_encoder_set_num_threads().
     */
    FLAC_API uint32_t FLAC__stream_encoder_get_num_threads(const FLAC__StreamEncoder *encoder);
    
    /** Get the Rice parameter search distance setting.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval uint32_t
     *    See FLAC__stream_encoder_set_rice_parameter_search_dist().
     */
    FLAC_API uint32_t FLAC__stream_encoder_get_rice_parameter_search_dist(const FLAC__StreamEncoder *encoder);
    
    /** Get the previously set estimate of the total samples to be encoded.
     *  The encoder merely mimics back the value given to
     *  FLAC__stream_encoder_set_total_samples_estimate() since it has no
     *  other way of knowing how many samples the client will encode.
     *
     * \param  encoder  An encoder instance to set.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__uint64
     *    See FLAC__stream_encoder_get_total_samples_estimate().
     */
    FLAC_API FLAC__uint64 FLAC__stream_encoder_get_total_samples_estimate(const FLAC__StreamEncoder *encoder);
    
    /** Get the "limit_min_bitrate" flag.
     *
     * \param  encoder  An encoder instance to query.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    See FLAC__stream_encoder_set_limit_min_bitrate().
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_get_limit_min_bitrate(const FLAC__StreamEncoder *encoder);
    
    /** Initialize the encoder instance to encode native FLAC streams.
     *
     *  This flavor of initialization sets up the encoder to encode to a
     *  native FLAC stream. I/O is performed via callbacks to the client.
     *  For encoding to a plain file via filename or open \c FILE*,
     *  FLAC__stream_encoder_init_file() and FLAC__stream_encoder_init_FILE()
     *  provide a simpler interface.
     *
     *  This function should be called after FLAC__stream_encoder_new() and
     *  FLAC__stream_encoder_set_*() but before FLAC__stream_encoder_process()
     *  or FLAC__stream_encoder_process_interleaved().
     *  initialization succeeded.
     *
     *  The call to FLAC__stream_encoder_init_stream() currently will also
     *  immediately call the write callback several times, once with the \c fLaC
     *  signature, and once for each encoded metadata block.
     *
     * \param  encoder            An uninitialized encoder instance.
     * \param  write_callback     See FLAC__StreamEncoderWriteCallback.  This
     *                            pointer must not be \c NULL.
     * \param  seek_callback      See FLAC__StreamEncoderSeekCallback.  This
     *                            pointer may be \c NULL if seeking is not
     *                            supported.  The encoder uses seeking to go back
     *                            and write some some stream statistics to the
     *                            STREAMINFO block; this is recommended but not
     *                            necessary to create a valid FLAC stream.  If
     *                            \a seek_callback is not \c NULL then a
     *                            \a tell_callback must also be supplied.
     *                            Alternatively, a dummy seek callback that just
     *                            returns \c FLAC__STREAM_ENCODER_SEEK_STATUS_UNSUPPORTED
     *                            may also be supplied, all though this is slightly
     *                            less efficient for the encoder.
     * \param  tell_callback      See FLAC__StreamEncoderTellCallback.  This
     *                            pointer may be \c NULL if seeking is not
     *                            supported.  If \a seek_callback is \c NULL then
     *                            this argument will be ignored.  If
     *                            \a seek_callback is not \c NULL then a
     *                            \a tell_callback must also be supplied.
     *                            Alternatively, a dummy tell callback that just
     *                            returns \c FLAC__STREAM_ENCODER_TELL_STATUS_UNSUPPORTED
     *                            may also be supplied, all though this is slightly
     *                            less efficient for the encoder.
     * \param  metadata_callback  See FLAC__StreamEncoderMetadataCallback.  This
     *                            pointer may be \c NULL if the callback is not
     *                            desired.  If the client provides a seek callback,
     *                            this function is not necessary as the encoder
     *                            will automatically seek back and update the
     *                            STREAMINFO block.  It may also be \c NULL if the
     *                            client does not support seeking, since it will
     *                            have no way of going back to update the
     *                            STREAMINFO.  However the client can still supply
     *                            a callback if it would like to know the details
     *                            from the STREAMINFO.
     * \param  client_data        This value will be supplied to callbacks in their
     *                            \a client_data argument.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__StreamEncoderInitStatus
     *    \c FLAC__STREAM_ENCODER_INIT_STATUS_OK if initialization was successful;
     *    see FLAC__StreamEncoderInitStatus for the meanings of other return values.
     */
    FLAC_API FLAC__StreamEncoderInitStatus FLAC__stream_encoder_init_stream(FLAC__StreamEncoder *encoder, FLAC__StreamEncoderWriteCallback write_callback, FLAC__StreamEncoderSeekCallback seek_callback, FLAC__StreamEncoderTellCallback tell_callback, FLAC__StreamEncoderMetadataCallback metadata_callback, void *client_data);
    
    /** Initialize the encoder instance to encode Ogg FLAC streams.
     *
     *  This flavor of initialization sets up the encoder to encode to a FLAC
     *  stream in an Ogg container.  I/O is performed via callbacks to the
     *  client.  For encoding to a plain file via filename or open \c FILE*,
     *  FLAC__stream_encoder_init_ogg_file() and FLAC__stream_encoder_init_ogg_FILE()
     *  provide a simpler interface.
     *
     *  This function should be called after FLAC__stream_encoder_new() and
     *  FLAC__stream_encoder_set_*() but before FLAC__stream_encoder_process()
     *  or FLAC__stream_encoder_process_interleaved().
     *  initialization succeeded.
     *
     *  The call to FLAC__stream_encoder_init_ogg_stream() currently will also
     *  immediately call the write callback several times to write the metadata
     *  packets.
     *
     * \param  encoder            An uninitialized encoder instance.
     * \param  read_callback      See FLAC__StreamEncoderReadCallback.  This
     *                            pointer must not be \c NULL if \a seek_callback
     *                            is non-NULL since they are both needed to be
     *                            able to write data back to the Ogg FLAC stream
     *                            in the post-encode phase.
     * \param  write_callback     See FLAC__StreamEncoderWriteCallback.  This
     *                            pointer must not be \c NULL.
     * \param  seek_callback      See FLAC__StreamEncoderSeekCallback.  This
     *                            pointer may be \c NULL if seeking is not
     *                            supported.  The encoder uses seeking to go back
     *                            and write some some stream statistics to the
     *                            STREAMINFO block; this is recommended but not
     *                            necessary to create a valid FLAC stream.  If
     *                            \a seek_callback is not \c NULL then a
     *                            \a tell_callback must also be supplied.
     *                            Alternatively, a dummy seek callback that just
     *                            returns \c FLAC__STREAM_ENCODER_SEEK_STATUS_UNSUPPORTED
     *                            may also be supplied, all though this is slightly
     *                            less efficient for the encoder.
     * \param  tell_callback      See FLAC__StreamEncoderTellCallback.  This
     *                            pointer may be \c NULL if seeking is not
     *                            supported.  If \a seek_callback is \c NULL then
     *                            this argument will be ignored.  If
     *                            \a seek_callback is not \c NULL then a
     *                            \a tell_callback must also be supplied.
     *                            Alternatively, a dummy tell callback that just
     *                            returns \c FLAC__STREAM_ENCODER_TELL_STATUS_UNSUPPORTED
     *                            may also be supplied, all though this is slightly
     *                            less efficient for the encoder.
     * \param  metadata_callback  See FLAC__StreamEncoderMetadataCallback.  This
     *                            pointer may be \c NULL if the callback is not
     *                            desired.  If the client provides a seek callback,
     *                            this function is not necessary as the encoder
     *                            will automatically seek back and update the
     *                            STREAMINFO block.  It may also be \c NULL if the
     *                            client does not support seeking, since it will
     *                            have no way of going back to update the
     *                            STREAMINFO.  However the client can still supply
     *                            a callback if it would like to know the details
     *                            from the STREAMINFO.
     * \param  client_data        This value will be supplied to callbacks in their
     *                            \a client_data argument.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__StreamEncoderInitStatus
     *    \c FLAC__STREAM_ENCODER_INIT_STATUS_OK if initialization was successful;
     *    see FLAC__StreamEncoderInitStatus for the meanings of other return values.
     */
    FLAC_API FLAC__StreamEncoderInitStatus FLAC__stream_encoder_init_ogg_stream(FLAC__StreamEncoder *encoder, FLAC__StreamEncoderReadCallback read_callback, FLAC__StreamEncoderWriteCallback write_callback, FLAC__StreamEncoderSeekCallback seek_callback, FLAC__StreamEncoderTellCallback tell_callback, FLAC__StreamEncoderMetadataCallback metadata_callback, void *client_data);
    
    /** Initialize the encoder instance to encode native FLAC files.
     *
     *  This flavor of initialization sets up the encoder to encode to a
     *  plain native FLAC file.  For non-stdio streams, you must use
     *  FLAC__stream_encoder_init_stream() and provide callbacks for the I/O.
     *
     *  This function should be called after FLAC__stream_encoder_new() and
     *  FLAC__stream_encoder_set_*() but before FLAC__stream_encoder_process()
     *  or FLAC__stream_encoder_process_interleaved().
     *  initialization succeeded.
     *
     * \param  encoder            An uninitialized encoder instance.
     * \param  file               An open file.  The file should have been opened
     *                            with mode \c "w+b" and rewound.  The file
     *                            becomes owned by the encoder and should not be
     *                            manipulated by the client while encoding.
     *                            Unless \a file is \c stdout, it will be closed
     *                            when FLAC__stream_encoder_finish() is called.
     *                            Note however that a proper SEEKTABLE cannot be
     *                            created when encoding to \c stdout since it is
     *                            not seekable.
     * \param  progress_callback  See FLAC__StreamEncoderProgressCallback.  This
     *                            pointer may be \c NULL if the callback is not
     *                            desired.
     * \param  client_data        This value will be supplied to callbacks in their
     *                            \a client_data argument.
     * \assert
     *    \code encoder != NULL \endcode
     *    \code file != NULL \endcode
     * \retval FLAC__StreamEncoderInitStatus
     *    \c FLAC__STREAM_ENCODER_INIT_STATUS_OK if initialization was successful;
     *    see FLAC__StreamEncoderInitStatus for the meanings of other return values.
     */
    FLAC_API FLAC__StreamEncoderInitStatus FLAC__stream_encoder_init_FILE(FLAC__StreamEncoder *encoder, FILE *file, FLAC__StreamEncoderProgressCallback progress_callback, void *client_data);
    
    /** Initialize the encoder instance to encode Ogg FLAC files.
     *
     *  This flavor of initialization sets up the encoder to encode to a
     *  plain Ogg FLAC file.  For non-stdio streams, you must use
     *  FLAC__stream_encoder_init_ogg_stream() and provide callbacks for the I/O.
     *
     *  This function should be called after FLAC__stream_encoder_new() and
     *  FLAC__stream_encoder_set_*() but before FLAC__stream_encoder_process()
     *  or FLAC__stream_encoder_process_interleaved().
     *  initialization succeeded.
     *
     * \param  encoder            An uninitialized encoder instance.
     * \param  file               An open file.  The file should have been opened
     *                            with mode \c "w+b" and rewound.  The file
     *                            becomes owned by the encoder and should not be
     *                            manipulated by the client while encoding.
     *                            Unless \a file is \c stdout, it will be closed
     *                            when FLAC__stream_encoder_finish() is called.
     *                            Note however that a proper SEEKTABLE cannot be
     *                            created when encoding to \c stdout since it is
     *                            not seekable.
     * \param  progress_callback  See FLAC__StreamEncoderProgressCallback.  This
     *                            pointer may be \c NULL if the callback is not
     *                            desired.
     * \param  client_data        This value will be supplied to callbacks in their
     *                            \a client_data argument.
     * \assert
     *    \code encoder != NULL \endcode
     *    \code file != NULL \endcode
     * \retval FLAC__StreamEncoderInitStatus
     *    \c FLAC__STREAM_ENCODER_INIT_STATUS_OK if initialization was successful;
     *    see FLAC__StreamEncoderInitStatus for the meanings of other return values.
     */
    FLAC_API FLAC__StreamEncoderInitStatus FLAC__stream_encoder_init_ogg_FILE(FLAC__StreamEncoder *encoder, FILE *file, FLAC__StreamEncoderProgressCallback progress_callback, void *client_data);
    
    /** Initialize the encoder instance to encode native FLAC files.
     *
     *  This flavor of initialization sets up the encoder to encode to a plain
     *  FLAC file.  If POSIX fopen() semantics are not sufficient you must use
     *  FLAC__stream_encoder_init_FILE(), or FLAC__stream_encoder_init_stream()
     *  and provide callbacks for the I/O.
     *
     *  On Windows, filename must be a UTF-8 encoded filename, which libFLAC
     *  internally translates to an appropriate representation to use with
     *  _wfopen. On all other systems, filename is passed to fopen without
     *  any translation.
     *
     *  This function should be called after FLAC__stream_encoder_new() and
     *  FLAC__stream_encoder_set_*() but before FLAC__stream_encoder_process()
     *  or FLAC__stream_encoder_process_interleaved().
     *  initialization succeeded.
     *
     * \param  encoder            An uninitialized encoder instance.
     * \param  filename           The name of the file to encode to.  The file will
     *                            be opened with fopen().  Use \c NULL to encode to
     *                            \c stdout.  Note however that a proper SEEKTABLE
     *                            cannot be created when encoding to \c stdout since
     *                            it is not seekable.
     * \param  progress_callback  See FLAC__StreamEncoderProgressCallback.  This
     *                            pointer may be \c NULL if the callback is not
     *                            desired.
     * \param  client_data        This value will be supplied to callbacks in their
     *                            \a client_data argument.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__StreamEncoderInitStatus
     *    \c FLAC__STREAM_ENCODER_INIT_STATUS_OK if initialization was successful;
     *    see FLAC__StreamEncoderInitStatus for the meanings of other return values.
     */
    FLAC_API FLAC__StreamEncoderInitStatus FLAC__stream_encoder_init_file(FLAC__StreamEncoder *encoder, const char *filename, FLAC__StreamEncoderProgressCallback progress_callback, void *client_data);
    
    /** Initialize the encoder instance to encode Ogg FLAC files.
     *
     *  This flavor of initialization sets up the encoder to encode to a plain
     *  Ogg FLAC file.  If POSIX fopen() semantics are not sufficient, you must use
     *  FLAC__stream_encoder_init_ogg_FILE(), or FLAC__stream_encoder_init_ogg_stream()
     *  and provide callbacks for the I/O.
     *
     *  On Windows, filename must be a UTF-8 encoded filename, which libFLAC
     *  internally translates to an appropriate representation to use with
     *  _wfopen. On all other systems, filename is passed to fopen without
     *  any translation.
     *
     *  This function should be called after FLAC__stream_encoder_new() and
     *  FLAC__stream_encoder_set_*() but before FLAC__stream_encoder_process()
     *  or FLAC__stream_encoder_process_interleaved().
     *  initialization succeeded.
     *
     * \param  encoder            An uninitialized encoder instance.
     * \param  filename           The name of the file to encode to.  The file will
     *                            be opened with fopen().  Use \c NULL to encode to
     *                            \c stdout.  Note however that a proper SEEKTABLE
     *                            cannot be created when encoding to \c stdout since
     *                            it is not seekable.
     * \param  progress_callback  See FLAC__StreamEncoderProgressCallback.  This
     *                            pointer may be \c NULL if the callback is not
     *                            desired.
     * \param  client_data        This value will be supplied to callbacks in their
     *                            \a client_data argument.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__StreamEncoderInitStatus
     *    \c FLAC__STREAM_ENCODER_INIT_STATUS_OK if initialization was successful;
     *    see FLAC__StreamEncoderInitStatus for the meanings of other return values.
     */
    FLAC_API FLAC__StreamEncoderInitStatus FLAC__stream_encoder_init_ogg_file(FLAC__StreamEncoder *encoder, const char *filename, FLAC__StreamEncoderProgressCallback progress_callback, void *client_data);
    
    /** Finish the encoding process.
     *  Flushes the encoding buffer, releases resources, resets the encoder
     *  settings to their defaults, and returns the encoder state to
     *  FLAC__STREAM_ENCODER_UNINITIALIZED.  Note that this can generate
     *  one or more write callbacks before returning, and will generate
     *  a metadata callback.
     *
     *  Note that in the course of processing the last frame, errors can
     *  occur, so the caller should be sure to check the return value to
     *  ensure the file was encoded properly.
     *
     *  In the event of a prematurely-terminated encode, it is not strictly
     *  necessary to call this immediately before FLAC__stream_encoder_delete()
     *  but it is good practice to match every FLAC__stream_encoder_init_*()
     *  with a FLAC__stream_encoder_finish().
     *
     * \param  encoder  An uninitialized encoder instance.
     * \assert
     *    \code encoder != NULL \endcode
     * \retval FLAC__bool
     *    \c false if an error occurred processing the last frame; or if verify
     *    mode is set (see FLAC__stream_encoder_set_verify()), there was a
     *    verify mismatch; else \c true.  If \c false, caller should check the
     *    state with FLAC__stream_encoder_get_state() for more information
     *    about the error.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_finish(FLAC__StreamEncoder *encoder);
    
    /** Submit data for encoding.
     *  This version allows you to supply the input data via an array of
     *  pointers, each pointer pointing to an array of \a samples samples
     *  representing one channel.  The samples need not be block-aligned,
     *  but each channel should have the same number of samples.  Each sample
     *  should be a signed integer, right-justified to the resolution set by
     *  FLAC__stream_encoder_set_bits_per_sample().  For example, if the
     *  resolution is 16 bits per sample, the samples should all be in the
     *  range [-32768,32767].
     *
     *  For applications where channel order is important, channels must
     *  follow the order as described in the
     *  <A HREF="https://xiph.org/flac/format.html#frame_header">frame header</A>.
     *
     * \param  encoder  An initialized encoder instance in the OK state.
     * \param  buffer   An array of pointers to each channel's signal.
     * \param  samples  The number of samples in one channel.
     * \assert
     *    \code encoder != NULL \endcode
     *    \code FLAC__stream_encoder_get_state(encoder) == FLAC__STREAM_ENCODER_OK \endcode
     * \retval FLAC__bool
     *    \c true if successful, else \c false; in this case, check the
     *    encoder state with FLAC__stream_encoder_get_state() to see what
     *    went wrong.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_process(FLAC__StreamEncoder *encoder, const FLAC__int32 * const buffer[], uint32_t samples);
    
    /** Submit data for encoding.
     *  This version allows you to supply the input data where the channels
     *  are interleaved into a single array (i.e. channel0_sample0,
     *  channel1_sample0, ... , channelN_sample0, channel0_sample1, ...).
     *  The samples need not be block-aligned but they must be
     *  sample-aligned, i.e. the first value should be channel0_sample0
     *  and the last value channelN_sampleM.  Each sample should be a signed
     *  integer, right-justified to the resolution set by
     *  FLAC__stream_encoder_set_bits_per_sample().  For example, if the
     *  resolution is 16 bits per sample, the samples should all be in the
     *  range [-32768,32767].
     *
     *  For applications where channel order is important, channels must
     *  follow the order as described in the
     *  <A HREF="https://xiph.org/flac/format.html#frame_header">frame header</A>.
     *
     * \param  encoder  An initialized encoder instance in the OK state.
     * \param  buffer   An array of channel-interleaved data (see above).
     * \param  samples  The number of samples in one channel, the same as for
     *                  FLAC__stream_encoder_process().  For example, if
     *                  encoding two channels, \c 1000 \a samples corresponds
     *                  to a \a buffer of 2000 values.
     * \assert
     *    \code encoder != NULL \endcode
     *    \code FLAC__stream_encoder_get_state(encoder) == FLAC__STREAM_ENCODER_OK \endcode
     * \retval FLAC__bool
     *    \c true if successful, else \c false; in this case, check the
     *    encoder state with FLAC__stream_encoder_get_state() to see what
     *    went wrong.
     */
    FLAC_API FLAC__bool FLAC__stream_encoder_process_interleaved(FLAC__StreamEncoder *encoder, const FLAC__int32 buffer[], uint32_t samples);
    
    /* \} */
    
    #ifdef __cplusplus
    }
    #endif
    
    #endif