stream_encoder.h

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/***********************************************************************
 *
 * 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();

/** 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 "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 "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.
 *
 *  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 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_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.  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_API 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_API 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_API 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_API 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_API 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_API 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_API FLAC__bool FLAC__stream_encoder_set_qlp_coeff_precision(FLAC__StreamEncoder *encoder, unsigned 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, unsigned 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 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_max_residual_partition_order(FLAC__StreamEncoder *encoder, unsigned 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, unsigned 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.
 *  Otherwise, the encoder will not modify or free the blocks.  It is up
 *  to the caller to free the metadata blocks after encoding.
 *
 * \note
 * The encoder stores only the \a metadata pointer; the passed-in array
 * must survive at least until after FLAC__stream_encoder_init() returns.
 * Do not modify the array or 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 it will be written verbatim.  However by itself
 * this is not very useful as the user will not know the stream offsets for
 * the seekpoints ahead of time.  You must use the seekable stream encoder
 * to generate a legal seektable
 * (see FLAC__seekable_stream_encoder_set_metadata())
 *
 * \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.
 *
 * \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.
 */
FLAC_API FLAC__bool FLAC__stream_encoder_set_metadata(FLAC__StreamEncoder *encoder, FLAC__StreamMetadata **metadata, unsigned num_blocks);

/** Set the write callback.
 *  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, the write callback is being called
 *  to write metadata.
 *
 * \note
 * The callback is mandatory and must be set before initialization.
 *
 * \default \c NULL
 * \param  encoder  An encoder instance to set.
 * \param  value    See above.
 * \assert
 *    \code encoder != NULL \endcode
 *    \code value != NULL \endcode
 * \retval FLAC__bool