more doxygen docs

include/FLAC/all.h

@@ -31,7 +31,7 @@
 
 /** \mainpage
  *
- * \section intro Introduction.
+ * \section intro Introduction
  *
  * This is the documentation for the FLAC C and C++ APIs.  It is
  * highly interconnected; this introduction should give you a top
@@ -40,12 +40,29 @@
  * knowledge of the FLAC format, documented
  * <A HREF="../format.html">here</A>.
  *
+ * \section c_api FLAC C API
+ *
  * The FLAC C API is the interface to libFLAC, a set of structures
  * describing the components of FLAC streams, and functions for
  * encoding and decoding streams, as well as manipulating FLAC
  * metadata in files.  The public include files will be installed
  * in your include area as <include>/FLAC/...
  *
+ * By writing a little code and linking against libFLAC, it is
+ * relatively easy to add FLAC support to another program.  The
+ * library is licensed under the
+ * <A HREF="http://www.gnu.org/copyleft/lesser.html">LGPL</A>.
+ * Complete source code of libFLAC as well as the command-line
+ * encoder and plugins is available and is a useful source of
+ * examples.
+ *
+ * libFLAC usually only requires the standard C library and C math
+ * library. In particular, threading is not used so there is no
+ * dependency on a thread library. However, libFLAC does not use
+ * global variables and should be thread-safe.
+ *
+ * \section cpp_api FLAC C API
+ *
  * The FLAC C++ API is a set of classes that encapsulate the
  * structures and functions in libFLAC.  They provide slightly more
  * functionality with respect to metadata but are otherwise
@@ -55,6 +72,11 @@
  * for the C++ API will be installed in your include area as
  * <include>/FLAC++/...
  *
+ * libFLAC++ is also licensed under the
+ * <A HREF="http://www.gnu.org/copyleft/lesser.html">LGPL</A>.
+ *
+ * \section getting_started Getting Started
+ *
  * A good starting point for learning the API is to browse through
  * the <A HREF="modules.html">modules</A>.  Modules are logical 
  * groupings of related functions or classes, which correspond roughly

include/FLAC/format.h

@@ -552,13 +552,7 @@ typedef struct {
 extern const unsigned FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN; /**< == 32 (bits) */
 
 
-/*****************************************************************************
+/** FLAC metadata block structure.  (c.f. <A HREF="../format.html#metadata_block">format specification</A>)
- *
- *  1: =1 if this is the last meta-data block, else =0
- *  7: meta-data type (c.f. FLAC__MetadataType)
- * 24: length (in bytes) of the block-specific data to follow
- *---- -----------------
- *  4  bytes total
  */
 typedef struct {
 	FLAC__MetadataType type;

include/FLAC/stream_encoder.h

@@ -27,35 +27,171 @@ 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_stream_encoder FLAC/stream_encoder.h: stream encoder interface
+ *  \ingroup flac
+ *
+ *  \brief
+ *  This module contains the functions which implement the stream
+ *  encoder.
+ *
+ * The basic usage of a libFLAC encoder is as follows: 
+ * - The program creates an instance of an encoder using
+ *   FLAC__stream_encoder_new().
+ * - The program overrides the default settings and sets callbacks for
+ *   reading, writing, error reporting, and metadata reporting using
+ *   FLAC__stream_encoder_set_*() functions.
+ * - The program initializes the instance to validate the settings and
+ *   prepare for encoding using FLAC__stream_encoder_init(). 
+ * - The program calls FLAC__stream_encoder_process() or
+ *   FLAC__stream_encoder_process_interleaved() to encode data, which
+ *   subsequently calls the callbacks. 
+ * - The program finishes the instance with FLAC__stream_encoder_finish(),
+ *   which flushes the input and output and resets the encoder to the
+ *   unitialized state. 
+ * - The instance may be used again or deleted with
+ *   FLAC__stream_encoder_delete(). 
+ *
+ * \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 true, otherwise false.
+ *
+ * \note
+ * The "set" functions do not validate the values as many are
+ * interdependent.  The FLAC__stream_encoder_init() function 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_OK.
+ *
+ * \note
+ * 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="../documentation.html#format">user-level documentation</A>
+ * or the <A HREF="../format.html">formal description</A>).
+ *
+ * \note
+ * Any parameters that are not set before FLAC__stream_encoder_init()
+ * will take on the defaults from the constructor.
+ *
+ * \note
+ * FLAC__stream_encoder_finish() resets all settings to the constructor
+ * defaults, including the callbacks.
+ * 
+ * \{
+ */
+
+
+/** State values for a FLAC__StreamEncoder
+ *
+ *  The encoder's state can be obtained by calling FLAC__stream_encoder_get_state().
+ */
 typedef enum {
+
 	FLAC__STREAM_ENCODER_OK = 0,
+	/**< The encoder is in the normal OK state. */
+
 	FLAC__STREAM_ENCODER_INVALID_CALLBACK,
+	/**< The encoder was initialized before setting all the required callbacks. */
+
 	FLAC__STREAM_ENCODER_INVALID_NUMBER_OF_CHANNELS,
+	/**< The encoder has an invalid setting for number of channels. */
+
 	FLAC__STREAM_ENCODER_INVALID_BITS_PER_SAMPLE,
+	/**< The encoder has an invalid setting for bits-per-sample.
+	 * FLAC supports 4-32 bps but the reference encoder currently supports
+	 * only up to 24 bps.
+	 */
+
 	FLAC__STREAM_ENCODER_INVALID_SAMPLE_RATE,
+	/**< The encoder has an invalid setting for the input sample rate. */
+
 	FLAC__STREAM_ENCODER_INVALID_BLOCK_SIZE,
+	/**< The encoder has an invalid setting for the block size. */
+
 	FLAC__STREAM_ENCODER_INVALID_QLP_COEFF_PRECISION,
+	/**< The encoder has an invalid setting for the precision of the quantized linear predictor coefficients. */
+
 	FLAC__STREAM_ENCODER_MID_SIDE_CHANNELS_MISMATCH,
+	/**< Mid/side coding was specified but the number of channels is not equal to 2. */
+
 	FLAC__STREAM_ENCODER_MID_SIDE_SAMPLE_SIZE_MISMATCH,
+	/**< Deprecated. */
+
 	FLAC__STREAM_ENCODER_ILLEGAL_MID_SIDE_FORCE,
+	/**< Loose mid/side coding was specified but mid/side coding was not. */
+
 	FLAC__STREAM_ENCODER_BLOCK_SIZE_TOO_SMALL_FOR_LPC_ORDER,
+	/**< The specified block size is less than the maximum LPC order. */
+
 	FLAC__STREAM_ENCODER_NOT_STREAMABLE,
+	/**< The encoder is bound to the "streamable subset" but other settings violate it. */
+
 	FLAC__STREAM_ENCODER_FRAMING_ERROR,
+	/**< An error occurred while writing the stream; usually, the write_callback returned an error. */
+
 	FLAC__STREAM_ENCODER_INVALID_METADATA,
+	/**< The metadata input to the encoder is invalid. */
+
 	FLAC__STREAM_ENCODER_FATAL_ERROR_WHILE_ENCODING,
-	FLAC__STREAM_ENCODER_FATAL_ERROR_WHILE_WRITING, /* that is, the write_callback returned an error */
+	/**< An error occurred while writing the stream; usually, the write_callback returned an error. */
+
+	FLAC__STREAM_ENCODER_FATAL_ERROR_WHILE_WRITING,
+	/**< The write_callback returned an error. */
+
 	FLAC__STREAM_ENCODER_MEMORY_ALLOCATION_ERROR,
+	/**< Memory allocation failed. */
+
 	FLAC__STREAM_ENCODER_ALREADY_INITIALIZED,
+	/**< FLAC__stream_encoder_init() was called when the encoder was
+	 * already initialized, usually because
+	 * FLAC__stream_encoder_finish() was not called.
+	 */
+
 	FLAC__STREAM_ENCODER_UNINITIALIZED
+	/**< The encoder is in the uninitialized state. */
+
 } 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 const char * const FLAC__StreamEncoderStateString[];
 
+/** Return values for the FLAC__StreamEncoder write callback.
+ */
 typedef enum {
+
 	FLAC__STREAM_ENCODER_WRITE_OK = 0,
+	/**< The write was OK and encoding can continue. */
+
 	FLAC__STREAM_ENCODER_WRITE_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 const char * const FLAC__StreamEncoderWriteStatusString[];
 
+
 /***********************************************************************
  *
  * class FLAC__StreamEncoder
@@ -64,46 +200,35 @@ extern const char * const FLAC__StreamEncoderWriteStatusString[];
 
 struct FLAC__StreamEncoderProtected;
 struct FLAC__StreamEncoderPrivate;
+/** The opaque structure definition for the stream encoder type.
+ */
 typedef struct {
 	struct FLAC__StreamEncoderProtected *protected_; /* avoid the C++ keyword 'protected' */
 	struct FLAC__StreamEncoderPrivate *private_; /* avoid the C++ keyword 'private' */
 } FLAC__StreamEncoder;
 
+
 /***********************************************************************
  *
  * Class constructor/destructor
  *
  ***********************************************************************/
 
-/*
+/** Create a new stream encoder instance.  The instance is created with
- * Any parameters that are not set before FLAC__stream_encoder_init()
+ *  default settings; see the individual FLAC__stream_encoder_set_*()
- * will take on the defaults from the constructor, shown below.
+ *  functions for each setting's default.
- * For more on what the parameters mean, see the documentation.
  *
- * FLAC__bool   streamable_subset             (DEFAULT: true  ) true to limit encoder to generating a Subset stream, else false
+ * \retval FLAC__StreamEncoder*
- * FLAC__bool   do_mid_side_stereo            (DEFAULT: false ) if true then channels must be 2
+ *    \c NULL if there was an error allocating memory, else the new instance.
- * FLAC__bool   loose_mid_side_stereo         (DEFAULT: false ) if true then do_mid_side_stereo must be true
- * unsigned     channels                      (DEFAULT: 2     ) must be <= FLAC__MAX_CHANNELS
- * unsigned     bits_per_sample               (DEFAULT: 16    ) do not give the encoder wider data than what you specify here or bad things will happen!
- * unsigned     sample_rate                   (DEFAULT: 44100 )
- * unsigned     blocksize                     (DEFAULT: 1152  )
- * unsigned     max_lpc_order                 (DEFAULT: 0     ) 0 => encoder will not try general LPC, only fixed predictors; must be <= FLAC__MAX_LPC_ORDER
- * unsigned     qlp_coeff_precision           (DEFAULT: 0     ) >= FLAC__MIN_QLP_COEFF_PRECISION, or 0 to let encoder select based on blocksize;
- *                                                              qlp_coeff_precision+bits_per_sample must be < 32
- * FLAC__bool   do_qlp_coeff_prec_search      (DEFAULT: false ) false => use qlp_coeff_precision, true => search around qlp_coeff_precision, take best
- * FLAC__bool   do_escape_coding              (DEFAULT: false ) true => search for escape codes in the entropy coding stage for slightly better compression
- * FLAC__bool   do_exhaustive_model_search    (DEFAULT: false ) false => use estimated bits per residual for scoring, true => generate all, take shortest
- * unsigned     min_residual_partition_order  (DEFAULT: 0     ) 0 => estimate Rice parameter based on residual variance; >0 => partition residual, use parameter
- * unsigned     max_residual_partition_order  (DEFAULT: 0     )      for each based on mean; min_ and max_ specify the min and max Rice partition order
- * unsigned     rice_parameter_search_dist    (DEFAULT: 0     ) 0 => try only calc'd parameter k; else try all [k-dist..k+dist] parameters, use best
- * FLAC__uint64 total_samples_estimate        (DEFAULT: 0     ) may be 0 if unknown.  acts as a placeholder in the STREAMINFO until the actual total is calculated
- * FLAC__StreamMetadata **metadata            (DEFAULT: NULL,0) optional metadata blocks to prepend.  STREAMINFO is not allowed since it is done internally.
- * + unsigned num_blocks
- *            (*write_callback)()             (DEFAULT: NULL  ) The callbacks are the only values that MUST be set before FLAC__stream_encoder_init()
- *            (*metadata_callback)()          (DEFAULT: NULL  )
- * void*        client_data                   (DEFAULT: NULL  ) passed back through the callbacks
  */
 FLAC__StreamEncoder *FLAC__stream_encoder_new();
+
+/** 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
+ */
 void FLAC__stream_encoder_delete(FLAC__StreamEncoder *encoder);
 
 /***********************************************************************
@@ -113,41 +238,279 @@ void FLAC__stream_encoder_delete(FLAC__StreamEncoder *encoder);
  ***********************************************************************/
 
 /*
- * Various "set" methods.  These may only be called when the encoder
+ * FLAC__bool   do_qlp_coeff_prec_search      (DEFAULT: false ) false => use qlp_coeff_precision, true => search around qlp_coeff_precision, take best
- * is in the state FLAC__STREAM_ENCODER_UNINITIALIZED, i.e. after
+ * FLAC__bool   do_escape_coding              (DEFAULT: false ) true => search for escape codes in the entropy coding stage for slightly better compression
- * FLAC__stream_encoder_new() or FLAC__stream_encoder_finish(), but
+ * FLAC__bool   do_exhaustive_model_search    (DEFAULT: false ) false => use estimated bits per residual for scoring, true => generate all, take shortest
- * before FLAC__stream_encoder_init().  If this is the case they will
+ * unsigned     min_residual_partition_order  (DEFAULT: 0     ) 0 => estimate Rice parameter based on residual variance; >0 => partition residual, use parameter
- * return true, otherwise false.
+ * unsigned     max_residual_partition_order  (DEFAULT: 0     )      for each based on mean; min_ and max_ specify the min and max Rice partition order
+ * unsigned     rice_parameter_search_dist    (DEFAULT: 0     ) 0 => try only calc'd parameter k; else try all [k-dist..k+dist] parameters, use best
+ * FLAC__uint64 total_samples_estimate        (DEFAULT: 0     ) may be 0 if unknown.  acts as a placeholder in the STREAMINFO until the actual total is calculated
+ * FLAC__StreamMetadata **metadata            (DEFAULT: NULL,0) optional metadata blocks to prepend.  STREAMINFO is not allowed since it is done internally.
+ * + unsigned num_blocks
+ * void*        client_data                   (DEFAULT: NULL  ) passed back through the callbacks
+ */
+
+/** Set the "streamable subset" flag.  If \c true, the encoder will comply
+ *  with the subset (see the format specification) 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.
  *
- * NOTE that these functions do not validate the values as many are
+ *  Make sure you know what it entails before setting this to \c false.
- * interdependent.  The FLAC__stream_encoder_init() function will do
- * this, so make sure to pay attention to the state returned by
- * FLAC__stream_encoder_init().
  *
- * Any parameters that are not set before FLAC__stream_encoder_init()
+ * \default \c true
- * will take on the defaults from the constructor.  NOTE that
+ * \param  encoder  An encoder instance to set.
- * FLAC__stream_encoder_finish() does NOT reset the values to the
+ * \param  value    Flag value (see above).
- * constructor defaults.
+ * \assert
+ *    \code encoder != NULL \endcode
+ * \retval FLAC__bool
+ *    \c false if the encoder is already initialized, else \c true.
  */
 FLAC__bool FLAC__stream_encoder_set_streamable_subset(FLAC__StreamEncoder *encoder, FLAC__bool value);
+
+/** Set to \c true to enable mid-side encoding on stereo input.  The
+ *  number of channels must be 2.  Set to \c false to use only
+ *  independent channel coding.
+ *
+ * \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__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.  The number of channels must
+ *  be 2.  Set to \c false to use exhaustive searching.  In either
+ *  case, the mid/side stereo setting must be \c true.
+ *
+ * \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__bool FLAC__stream_encoder_set_loose_mid_side_stereo(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__bool FLAC__stream_encoder_set_channels(FLAC__StreamEncoder *encoder, unsigned 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__bool FLAC__stream_encoder_set_bits_per_sample(FLAC__StreamEncoder *encoder, unsigned 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__bool FLAC__stream_encoder_set_sample_rate(FLAC__StreamEncoder *encoder, unsigned value);
+
+/** Set the blocksize to use while encoding.
+ *
+ * \default \c 1152
+ * \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__bool FLAC__stream_encoder_set_blocksize(FLAC__StreamEncoder *encoder, unsigned value);
+
+/** Set the maximum LPC order, or \c 0 to use only the fixed predictors.
+ *
+ * \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__bool FLAC__stream_encoder_set_max_lpc_order(FLAC__StreamEncoder *encoder, unsigned 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.
+ *
+ * \note
+ * In the current implementation, qlp_coeff_precision + bits_per_sample must
+ * be less than 32.
+ *
+ * \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__bool FLAC__stream_encoder_set_qlp_coeff_precision(FLAC__StreamEncoder *encoder, unsigned value);
+
+/** Set the number of channels to be encoded.
+ *
+ * \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__bool FLAC__stream_encoder_set_do_qlp_coeff_prec_search(FLAC__StreamEncoder *encoder, FLAC__bool value);
+
+/** Set the number of channels to be encoded.
+ *
+ * \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__bool FLAC__stream_encoder_set_do_escape_coding(FLAC__StreamEncoder *encoder, FLAC__bool value);
+
+/** Set the number of channels to be encoded.
+ *
+ * \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__bool FLAC__stream_encoder_set_do_exhaustive_model_search(FLAC__StreamEncoder *encoder, FLAC__bool value);
+
+/** Set the number of channels to be encoded.
+ *
+ * \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__bool FLAC__stream_encoder_set_min_residual_partition_order(FLAC__StreamEncoder *encoder, unsigned value);
+
+/** Set the number of channels to be encoded.
+ *
+ * \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__bool FLAC__stream_encoder_set_max_residual_partition_order(FLAC__StreamEncoder *encoder, unsigned value);
+
+/** Set the number of channels to be encoded.
+ *
+ * \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__bool FLAC__stream_encoder_set_rice_parameter_search_dist(FLAC__StreamEncoder *encoder, unsigned value);
+
+/** Set the number of channels to be encoded.
+ *
+ * \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__bool FLAC__stream_encoder_set_total_samples_estimate(FLAC__StreamEncoder *encoder, FLAC__uint64 value);
+
+/** Set the number of channels to be encoded.
+ *
+ * \default \c NULL, 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__bool FLAC__stream_encoder_set_metadata(FLAC__StreamEncoder *encoder, FLAC__StreamMetadata **metadata, unsigned num_blocks);
+
+/** Set the number of channels to be encoded.
+ *
+ * \default \c NULL; the callback is mandatory and must be set before initialization
+ * \param  encoder  An encoder instance to set.
+ * \param  value    See above.
+ * \assert
+ *    \code encoder != NULL \endcode
+ *    \code value != NULL \endcode
+ * \retval FLAC__bool
+ *    \c false if the encoder is already initialized, else \c true.
+ */
 FLAC__bool FLAC__stream_encoder_set_write_callback(FLAC__StreamEncoder *encoder, FLAC__StreamEncoderWriteStatus (*value)(const FLAC__StreamEncoder *encoder, const FLAC__byte buffer[], unsigned bytes, unsigned samples, unsigned current_frame, void *client_data));
+
+/** Set the number of channels to be encoded.
+ *
+ * \default \c NULL; the callback is mandatory and must be set before initialization
+ * \param  encoder  An encoder instance to set.
+ * \param  value    See above.
+ * \assert
+ *    \code encoder != NULL \endcode
+ *    \code value != NULL \endcode
+ * \retval FLAC__bool
+ *    \c false if the encoder is already initialized, else \c true.
+ */
 FLAC__bool FLAC__stream_encoder_set_metadata_callback(FLAC__StreamEncoder *encoder, void (*value)(const FLAC__StreamEncoder *encoder, const FLAC__StreamMetadata *metadata, void *client_data));
+
+/** Set the number of channels to be encoded.
+ *
+ * \default \c NULL
+ * \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__bool FLAC__stream_encoder_set_client_data(FLAC__StreamEncoder *encoder, void *value);
 
 /*
@@ -191,6 +554,8 @@ void FLAC__stream_encoder_finish(FLAC__StreamEncoder *encoder);
 FLAC__bool FLAC__stream_encoder_process(FLAC__StreamEncoder *encoder, const FLAC__int32 * const buffer[], unsigned samples);
 FLAC__bool FLAC__stream_encoder_process_interleaved(FLAC__StreamEncoder *encoder, const FLAC__int32 buffer[], unsigned samples);
 
+/* \} */
+
 #ifdef __cplusplus
 }
 #endif