/* libFLAC - Free Lossless Audio Codec library * Copyright (C) 2000,2001,2002,2003,2004,2005,2006,2007 Josh Coalson * * 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 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * 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 /* 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 * user-level documentation * or the formal description). 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[]; /** 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 but the reference encoder currently supports * only up to 24 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 Subset 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 twice when writing each audio * frame; once for the page header, and once for the page body. * When writing the page header, the \a samples argument to the * write callback will be \c 0. * * \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, unsigned samples, unsigned 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, unsigned frames_written, unsigned 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 Subset 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, 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 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: * * * * * * * * * * * * *
level * do mid-side stereo * loose mid-side stereo * apodization * max lpc order * qlp coeff precision * qlp coeff prec search * escape coding * exhaustive model search * min residual partition order * max residual partition order * rice parameter search dist *
0 false false tukey(0.5) 0 0 false false false 0 3 0
1 true true tukey(0.5) 0 0 false false false 0 3 0
2 true false tukey(0.5) 0 0 false false false 0 3 0
3 false false tukey(0.5) 6 0 false false false 0 4 0
4 true true tukey(0.5) 8 0 false false false 0 4 0
5 true false tukey(0.5) 8 0 false false false 0 5 0
6 true false tukey(0.5) 8 0 false false false 0 6 0
7 true false tukey(0.5) 8 0 false false true 0 6 0
8 true false tukey(0.5) 12 0 false false true 0 6 0
* * \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, unsigned 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, unsigned 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 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. 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 welch. * * For \c gauss(STDDEV), STDDEV specifies the standard deviation * (0blocksize / (2 ^ order). * * 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 blocksize / (2 ^ order). * * 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, 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, unsigned num_blocks); /** 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, unsigned *frame_number, unsigned *channel, unsigned *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 frame header. * * \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[], unsigned 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 * frame header. * * \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[], unsigned samples); /* \} */ #ifdef __cplusplus } #endif #endif