/* libFLAC - Free Lossless Audio Codec library * Copyright (C) 2000,2001,2002,2003,2004 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_DECODER_H #define FLAC__STREAM_DECODER_H #include "export.h" #include "format.h" #ifdef __cplusplus extern "C" { #endif /** \file include/FLAC/stream_decoder.h * * \brief * This module contains the functions which implement the stream * decoder. * * See the detailed documentation in the * \link flac_stream_decoder stream decoder \endlink module. */ /** \defgroup flac_decoder FLAC/ *_decoder.h: decoder interfaces * \ingroup flac * * \brief * This module describes the three decoder layers provided by libFLAC. * * For decoding FLAC streams, libFLAC provides three layers of access. The * lowest layer is non-seekable stream-level decoding, the next is seekable * stream-level decoding, and the highest layer is file-level decoding. The * interfaces are described in the \link flac_stream_decoder stream decoder * \endlink, \link flac_seekable_stream_decoder seekable stream decoder * \endlink, and \link flac_file_decoder file decoder \endlink modules * respectively. Typically you will choose the highest layer that your input * source will support. * * The stream decoder relies on callbacks for all input and output and has no * provisions for seeking. The seekable stream decoder wraps the stream * decoder and exposes functions for seeking. However, you must provide * extra callbacks for seek-related operations on your stream, like seek and * tell. The file decoder wraps the seekable stream decoder and supplies * most of the callbacks internally, simplifying the processing of standard * files. */ /** \defgroup flac_stream_decoder FLAC/stream_decoder.h: stream decoder interface * \ingroup flac_decoder * * \brief * This module contains the functions which implement the stream * decoder. * * The basic usage of this decoder is as follows: * - The program creates an instance of a decoder using * FLAC__stream_decoder_new(). * - The program overrides the default settings and sets callbacks for * reading, writing, error reporting, and metadata reporting using * FLAC__stream_decoder_set_*() functions. * - The program initializes the instance to validate the settings and * prepare for decoding using FLAC__stream_decoder_init(). * - The program calls the FLAC__stream_decoder_process_*() functions * to decode data, which subsequently calls the callbacks. * - The program finishes the decoding with FLAC__stream_decoder_finish(), * which flushes the input and output and resets the decoder to the * uninitialized state. * - The instance may be used again or deleted with * FLAC__stream_decoder_delete(). * * In more detail, the program will create a new instance by calling * FLAC__stream_decoder_new(), then call FLAC__stream_decoder_set_*() * functions to set the callbacks and client data, and call * FLAC__stream_decoder_init(). The required callbacks are: * * - Read callback - This function will be called when the decoder needs * more input data. 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__StreamDecoderReadStatus. * - Write callback - This function will be called when the decoder has * decoded a single frame of data. The decoder will pass the frame * metadata as well as an array of pointers (one for each channel) * pointing to the decoded audio. * - Metadata callback - This function will be called when the decoder has * decoded a metadata block. In a valid FLAC file there will always be * one STREAMINFO block, followed by zero or more other metadata * blocks. These will be supplied by the decoder in the same order as * they appear in the stream and always before the first audio frame * (i.e. write callback). The metadata block that is passed in must not * be modified, and it doesn't live beyond the callback, so you should * make a copy of it with FLAC__metadata_object_clone() if you will need * it elsewhere. Since metadata blocks can potentially be large, by * default the decoder only calls the metadata callback for the STREAMINFO * block; you can instruct the decoder to pass or filter other blocks with * FLAC__stream_decoder_set_metadata_*() calls. * - Error callback - This function will be called whenever an error occurs * during decoding. * * Once the decoder is initialized, your program will call one of several * functions to start the decoding process: * * - FLAC__stream_decoder_process_single() - Tells the decoder to process at * most one metadata block or audio frame and return, calling either the * metadata callback or write callback, respectively, once. If the decoder * loses sync it will return with only the error callback being called. * - FLAC__stream_decoder_process_until_end_of_metadata() - Tells the decoder * to process the stream from the current location and stop upon reaching * the first audio frame. The user will get one metadata, write, or error * callback per metadata block, audio frame, or sync error, respectively. * - FLAC__stream_decoder_process_until_end_of_stream() - Tells the decoder * to process the stream from the current location until the read callback * returns FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM or * FLAC__STREAM_DECODER_READ_STATUS_ABORT. The user will get one metadata, * write, or error callback per metadata block, audio frame, or sync error, * respectively. * * When the decoder has finished decoding (normally or through an abort), * the instance is finished by calling FLAC__stream_decoder_finish(), which * ensures the decoder is in the correct state and frees memory. Then the * instance may be deleted with FLAC__stream_decoder_delete() or initialized * again to decode another stream. * * Note that the stream decoder has no real concept of stream position, it * just converts data. To seek within a stream the callbacks have only to * flush the decoder using FLAC__stream_decoder_flush() and start feeding * data from the new position through the read callback. The seekable * stream decoder does just this. * * The FLAC__stream_decoder_set_metadata_*() functions deserve special * attention. By default, the decoder only calls the metadata_callback for * the STREAMINFO block. These functions allow you to tell the decoder * explicitly which blocks to parse and return via the metadata_callback * and/or which to skip. Use a FLAC__stream_decoder_set_metadata_respond_all(), * FLAC__stream_decoder_set_metadata_ignore() ... or FLAC__stream_decoder_set_metadata_ignore_all(), * FLAC__stream_decoder_set_metadata_respond() ... sequence to exactly specify which * blocks to return. Remember that some metadata blocks can be big so * filtering out the ones you don't use can reduce the memory requirements * of the decoder. Also note the special forms * FLAC__stream_decoder_set_metadata_respond_application(id) and * FLAC__stream_decoder_set_metadata_ignore_application(id) for filtering APPLICATION * blocks based on the application ID. * * STREAMINFO and SEEKTABLE blocks are always parsed and used internally, but * they still can legally be filtered from the metadata_callback. * * \note * The "set" functions may only be called when the decoder is in the * state FLAC__STREAM_DECODER_UNINITIALIZED, i.e. after * FLAC__stream_decoder_new() or FLAC__stream_decoder_finish(), but * before FLAC__stream_decoder_init(). If this is the case they will * return \c true, otherwise \c false. * * \note * FLAC__stream_decoder_finish() resets all settings to the constructor * defaults, including the callbacks. * * \{ */ /** State values for a FLAC__StreamDecoder * * The decoder's state can be obtained by calling FLAC__stream_decoder_get_state(). */ typedef enum { FLAC__STREAM_DECODER_SEARCH_FOR_METADATA = 0, /**< The decoder is ready to search for metadata. */ FLAC__STREAM_DECODER_READ_METADATA, /**< The decoder is ready to or is in the process of reading metadata. */ FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC, /**< The decoder is ready to or is in the process of searching for the frame sync code. */ FLAC__STREAM_DECODER_READ_FRAME, /**< The decoder is ready to or is in the process of reading a frame. */ FLAC__STREAM_DECODER_END_OF_STREAM, /**< The decoder has reached the end of the stream. */ FLAC__STREAM_DECODER_ABORTED, /**< The decoder was aborted by the read callback. */ FLAC__STREAM_DECODER_UNPARSEABLE_STREAM, /**< The decoder encountered reserved fields in use in the stream. */ FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR, /**< An error occurred allocating memory. */ FLAC__STREAM_DECODER_ALREADY_INITIALIZED, /**< FLAC__stream_decoder_init() was called when the decoder was * already initialized, usually because * FLAC__stream_decoder_finish() was not called. */ FLAC__STREAM_DECODER_INVALID_CALLBACK, /**< FLAC__stream_decoder_init() was called without all callbacks being set. */ FLAC__STREAM_DECODER_UNINITIALIZED /**< The decoder is in the uninitialized state. */ } FLAC__StreamDecoderState; /** Maps a FLAC__StreamDecoderState to a C string. * * Using a FLAC__StreamDecoderState as the index to this array * will give the string equivalent. The contents should not be modified. */ extern FLAC_API const char * const FLAC__StreamDecoderStateString[]; /** Return values for the FLAC__StreamDecoder read callback. */ typedef enum { FLAC__STREAM_DECODER_READ_STATUS_CONTINUE, /**< The read was OK and decoding can continue. */ FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM, /**< The read was attempted at the end of the stream. */ FLAC__STREAM_DECODER_READ_STATUS_ABORT /**< An unrecoverable error occurred. The decoder will return from the process call. */ } FLAC__StreamDecoderReadStatus; /** Maps a FLAC__StreamDecoderReadStatus to a C string. * * Using a FLAC__StreamDecoderReadStatus as the index to this array * will give the string equivalent. The contents should not be modified. */ extern FLAC_API const char * const FLAC__StreamDecoderReadStatusString[]; /** Return values for the FLAC__StreamDecoder write callback. */ typedef enum { FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE, /**< The write was OK and decoding can continue. */ FLAC__STREAM_DECODER_WRITE_STATUS_ABORT /**< An unrecoverable error occurred. The decoder will return from the process call. */ } FLAC__StreamDecoderWriteStatus; /** Maps a FLAC__StreamDecoderWriteStatus to a C string. * * Using a FLAC__StreamDecoderWriteStatus as the index to this array * will give the string equivalent. The contents should not be modified. */ extern FLAC_API const char * const FLAC__StreamDecoderWriteStatusString[]; /** Possible values passed in to the FLAC__StreamDecoder error callback. */ typedef enum { FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC, /**< An error in the stream caused the decoder to lose synchronization. */ FLAC__STREAM_DECODER_ERROR_STATUS_BAD_HEADER, /**< The decoder encountered a corrupted frame header. */ FLAC__STREAM_DECODER_ERROR_STATUS_FRAME_CRC_MISMATCH /**< The frame's data did not match the CRC in the footer. */ } FLAC__StreamDecoderErrorStatus; /** Maps a FLAC__StreamDecoderErrorStatus to a C string. * * Using a FLAC__StreamDecoderErrorStatus as the index to this array * will give the string equivalent. The contents should not be modified. */ extern FLAC_API const char * const FLAC__StreamDecoderErrorStatusString[]; /*********************************************************************** * * class FLAC__StreamDecoder * ***********************************************************************/ struct FLAC__StreamDecoderProtected; struct FLAC__StreamDecoderPrivate; /** The opaque structure definition for the stream decoder type. * See the \link flac_stream_decoder stream decoder module \endlink * for a detailed description. */ typedef struct { struct FLAC__StreamDecoderProtected *protected_; /* avoid the C++ keyword 'protected' */ struct FLAC__StreamDecoderPrivate *private_; /* avoid the C++ keyword 'private' */ } FLAC__StreamDecoder; /** Signature for the read callback. * See FLAC__stream_decoder_set_read_callback() for more info. * * \param decoder The decoder instance calling the callback. * \param buffer A pointer to a location for the callee to store * data to be decoded. * \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_decoder_set_client_data(). * \retval FLAC__StreamDecoderReadStatus * The callee's return status. */ typedef FLAC__StreamDecoderReadStatus (*FLAC__StreamDecoderReadCallback)(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], unsigned *bytes, void *client_data); /** Signature for the write callback. * See FLAC__stream_decoder_set_write_callback() for more info. * * \param decoder The decoder instance calling the callback. * \param frame The description of the decoded frame. See * FLAC__Frame. * \param buffer An array of pointers to decoded channels of data. * Each pointer will point to an array of signed * samples of length \a frame->header.blocksize. * Currently, the channel order has no meaning * except for stereo streams; in this case channel * 0 is left and 1 is right. * \param client_data The callee's client data set through * FLAC__stream_decoder_set_client_data(). * \retval FLAC__StreamDecoderWriteStatus * The callee's return status. */ typedef FLAC__StreamDecoderWriteStatus (*FLAC__StreamDecoderWriteCallback)(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data); /** Signature for the metadata callback. * See FLAC__stream_decoder_set_metadata_callback() for more info. * * \param decoder The decoder instance calling the callback. * \param metadata The decoded metadata block. * \param client_data The callee's client data set through * FLAC__stream_decoder_set_client_data(). */ typedef void (*FLAC__StreamDecoderMetadataCallback)(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data); /** Signature for the error callback. * See FLAC__stream_decoder_set_error_callback() for more info. * * \param decoder The decoder instance calling the callback. * \param status The error encountered by the decoder. * \param client_data The callee's client data set through * FLAC__stream_decoder_set_client_data(). */ typedef void (*FLAC__StreamDecoderErrorCallback)(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data); /*********************************************************************** * * Class constructor/destructor * ***********************************************************************/ /** Create a new stream decoder instance. The instance is created with * default settings; see the individual FLAC__stream_decoder_set_*() * functions for each setting's default. * * \retval FLAC__StreamDecoder* * \c NULL if there was an error allocating memory, else the new instance. */ FLAC_API FLAC__StreamDecoder *FLAC__stream_decoder_new(); /** Free a decoder instance. Deletes the object pointed to by \a decoder. * * \param decoder A pointer to an existing decoder. * \assert * \code decoder != NULL \endcode */ FLAC_API void FLAC__stream_decoder_delete(FLAC__StreamDecoder *decoder); /*********************************************************************** * * Public class method prototypes * ***********************************************************************/ /** Set the read callback. * The supplied function will be called when the decoder needs more input * data. 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__StreamDecoderReadStatus. * * \note * The callback is mandatory and must be set before initialization. * * \default \c NULL * \param decoder A decoder instance to set. * \param value See above. * \assert * \code decoder != NULL \endcode * \code value != NULL \endcode * \retval FLAC__bool * \c false if the decoder is already initialized, else \c true. */ FLAC_API FLAC__bool FLAC__stream_decoder_set_read_callback(FLAC__StreamDecoder *decoder, FLAC__StreamDecoderReadCallback value); /** Set the write callback. * The supplied function will be called when the decoder has decoded a * single frame of data. The decoder will pass the frame metadata as * well as an array of pointers (one for each channel) pointing to the * decoded audio. * * \note * The callback is mandatory and must be set before initialization. * * \default \c NULL * \param decoder A decoder instance to set. * \param value See above. * \assert * \code decoder != NULL \endcode * \code value != NULL \endcode * \retval FLAC__bool * \c false if the decoder is already initialized, else \c true. */ FLAC_API FLAC__bool FLAC__stream_decoder_set_write_callback(FLAC__StreamDecoder *decoder, FLAC__StreamDecoderWriteCallback value); /** Set the metadata callback. * The supplied function will be called when the decoder has decoded a metadata * block. In a valid FLAC file there will always be one STREAMINFO block, * followed by zero or more other metadata blocks. These will be supplied * by the decoder in the same order as they appear in the stream and always * before the first audio frame (i.e. write callback). The metadata block * that is passed in must not be modified, and it doesn't live beyond the * callback, so you should make a copy of it with * FLAC__metadata_object_clone() if you will need it elsewhere. Since * metadata blocks can potentially be large, by default the decoder only * calls the metadata callback for the STREAMINFO block; you can instruct * the decoder to pass or filter other blocks with * FLAC__stream_decoder_set_metadata_*() calls. * * \note * The callback is mandatory and must be set before initialization. * * \default \c NULL * \param decoder A decoder instance to set. * \param value See above. * \assert * \code decoder != NULL \endcode * \code value != NULL \endcode * \retval FLAC__bool * \c false if the decoder is already initialized, else \c true. */ FLAC_API FLAC__bool FLAC__stream_decoder_set_metadata_callback(FLAC__StreamDecoder *decoder, FLAC__StreamDecoderMetadataCallback value); /** Set the error callback. * The supplied function will be called whenever an error occurs during * decoding. * * \note * The callback is mandatory and must be set before initialization. * * \default \c NULL * \param decoder A decoder instance to set. * \param value See above. * \assert * \code decoder != NULL \endcode * \code value != NULL \endcode * \retval FLAC__bool * \c false if the decoder is already initialized, else \c true. */ FLAC_API FLAC__bool FLAC__stream_decoder_set_error_callback(FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorCallback value); /** Set the client data to be passed back to callbacks. * This value will be supplied to callbacks in their \a client_data * argument. * * \default \c NULL * \param decoder A decoder instance to set. * \param value See above. * \assert * \code decoder != NULL \endcode * \retval FLAC__bool * \c false if the decoder is already initialized, else \c true. */ FLAC_API FLAC__bool FLAC__stream_decoder_set_client_data(FLAC__StreamDecoder *decoder, void *value); /** Direct the decoder to pass on all metadata blocks of type \a type. * * \default By default, only the \c STREAMINFO block is returned via the * metadata callback. * \param decoder A decoder instance to set. * \param type See above. * \assert * \code decoder != NULL \endcode * \a type is valid * \retval FLAC__bool * \c false if the decoder is already initialized, else \c true. */ FLAC_API FLAC__bool FLAC__stream_decoder_set_metadata_respond(FLAC__StreamDecoder *decoder, FLAC__MetadataType type); /** Direct the decoder to pass on all APPLICATION metadata blocks of the * given \a id. * * \default By default, only the \c STREAMINFO block is returned via the * metadata callback. * \param decoder A decoder instance to set. * \param id See above. * \assert * \code decoder != NULL \endcode * \code id != NULL \endcode * \retval FLAC__bool * \c false if the decoder is already initialized, else \c true. */ FLAC_API FLAC__bool FLAC__stream_decoder_set_metadata_respond_application(FLAC__StreamDecoder *decoder, const FLAC__byte id[4]); /** Direct the decoder to pass on all metadata blocks of any type. * * \default By default, only the \c STREAMINFO block is returned via the * metadata callback. * \param decoder A decoder instance to set. * \assert * \code decoder != NULL \endcode * \retval FLAC__bool * \c false if the decoder is already initialized, else \c true. */ FLAC_API FLAC__bool FLAC__stream_decoder_set_metadata_respond_all(FLAC__StreamDecoder *decoder); /** Direct the decoder to filter out all metadata blocks of type \a type. * * \default By default, only the \c STREAMINFO block is returned via the * metadata callback. * \param decoder A decoder instance to set. * \param type See above. * \assert * \code decoder != NULL \endcode * \a type is valid * \retval FLAC__bool * \c false if the decoder is already initialized, else \c true. */ FLAC_API FLAC__bool FLAC__stream_decoder_set_metadata_ignore(FLAC__StreamDecoder *decoder, FLAC__MetadataType type); /** Direct the decoder to filter out all APPLICATION metadata blocks of * the given \a id. * * \default By default, only the \c STREAMINFO block is returned via the * metadata callback. * \param decoder A decoder instance to set. * \param id See above. * \assert * \code decoder != NULL \endcode * \code id != NULL \endcode * \retval FLAC__bool * \c false if the decoder is already initialized, else \c true. */ FLAC_API FLAC__bool FLAC__stream_decoder_set_metadata_ignore_application(FLAC__StreamDecoder *decoder, const FLAC__byte id[4]); /** Direct the decoder to filter out all metadata blocks of any type. * * \default By default, only the \c STREAMINFO block is returned via the * metadata callback. * \param decoder A decoder instance to set. * \assert * \code decoder != NULL \endcode * \retval FLAC__bool * \c false if the decoder is already initialized, else \c true. */ FLAC_API FLAC__bool FLAC__stream_decoder_set_metadata_ignore_all(FLAC__StreamDecoder *decoder); /** Get the current decoder state. * * \param decoder A decoder instance to query. * \assert * \code decoder != NULL \endcode * \retval FLAC__StreamDecoderState * The current decoder state. */ FLAC_API FLAC__StreamDecoderState FLAC__stream_decoder_get_state(const FLAC__StreamDecoder *decoder); /** Get the current decoder state as a C string. * * \param decoder A decoder instance to query. * \assert * \code decoder != NULL \endcode * \retval const char * * The decoder state as a C string. Do not modify the contents. */ FLAC_API const char *FLAC__stream_decoder_get_resolved_state_string(const FLAC__StreamDecoder *decoder); /** Get the current number of channels in the stream being decoded. * Will only be valid after decoding has started and will contain the * value from the most recently decoded frame header. * * \param decoder A decoder instance to query. * \assert * \code decoder != NULL \endcode * \retval unsigned * See above. */ FLAC_API unsigned FLAC__stream_decoder_get_channels(const FLAC__StreamDecoder *decoder); /** Get the current channel assignment in the stream being decoded. * Will only be valid after decoding has started and will contain the * value from the most recently decoded frame header. * * \param decoder A decoder instance to query. * \assert * \code decoder != NULL \endcode * \retval FLAC__ChannelAssignment * See above. */ FLAC_API FLAC__ChannelAssignment FLAC__stream_decoder_get_channel_assignment(const FLAC__StreamDecoder *decoder); /** Get the current sample resolution in the stream being decoded. * Will only be valid after decoding has started and will contain the * value from the most recently decoded frame header. * * \param decoder A decoder instance to query. * \assert * \code decoder != NULL \endcode * \retval unsigned * See above. */ FLAC_API unsigned FLAC__stream_decoder_get_bits_per_sample(const FLAC__StreamDecoder *decoder); /** Get the current sample rate in Hz of the stream being decoded. * Will only be valid after decoding has started and will contain the * value from the most recently decoded frame header. * * \param decoder A decoder instance to query. * \assert * \code decoder != NULL \endcode * \retval unsigned * See above. */ FLAC_API unsigned FLAC__stream_decoder_get_sample_rate(const FLAC__StreamDecoder *decoder); /** Get the current blocksize of the stream being decoded. * Will only be valid after decoding has started and will contain the * value from the most recently decoded frame header. * * \param decoder A decoder instance to query. * \assert * \code decoder != NULL \endcode * \retval unsigned * See above. */ FLAC_API unsigned FLAC__stream_decoder_get_blocksize(const FLAC__StreamDecoder *decoder); /** Initialize the decoder instance. * Should be called after FLAC__stream_decoder_new() and * FLAC__stream_decoder_set_*() but before any of the * FLAC__stream_decoder_process_*() functions. Will set and return the * decoder state, which will be FLAC__STREAM_DECODER_SEARCH_FOR_METADATA * if initialization succeeded. * * \param decoder An uninitialized decoder instance. * \assert * \code decoder != NULL \endcode * \retval FLAC__StreamDecoderState * \c FLAC__STREAM_DECODER_SEARCH_FOR_METADATA if initialization was * successful; see FLAC__StreamDecoderState for the meanings of other * return values. */ FLAC_API FLAC__StreamDecoderState FLAC__stream_decoder_init(FLAC__StreamDecoder *decoder); /** Finish the decoding process. * Flushes the decoding buffer, releases resources, resets the decoder * settings to their defaults, and returns the decoder state to * FLAC__STREAM_DECODER_UNINITIALIZED. * * In the event of a prematurely-terminated decode, it is not strictly * necessary to call this immediately before FLAC__stream_decoder_delete() * but it is good practice to match every FLAC__stream_decoder_init() * with a FLAC__stream_decoder_finish(). * * \param decoder An uninitialized decoder instance. * \assert * \code decoder != NULL \endcode */ FLAC_API void FLAC__stream_decoder_finish(FLAC__StreamDecoder *decoder); /** Flush the stream input. * The decoder's input buffer will be cleared and the state set to * \c FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC. * * \param decoder A decoder instance. * \assert * \code decoder != NULL \endcode * \retval FLAC__bool * \c true if successful, else \c false if a memory allocation * error occurs. */ FLAC_API FLAC__bool FLAC__stream_decoder_flush(FLAC__StreamDecoder *decoder); /** Reset the decoding process. * The decoder's input buffer will be cleared and the state set to * \c FLAC__STREAM_DECODER_SEARCH_FOR_METADATA. This is similar to * FLAC__stream_decoder_finish() except that the settings are * preserved; there is no need to call FLAC__stream_decoder_init() * before decoding again. * * \param decoder A decoder instance. * \assert * \code decoder != NULL \endcode * \retval FLAC__bool * \c true if successful, else \c false if a memory allocation * error occurs. */ FLAC_API FLAC__bool FLAC__stream_decoder_reset(FLAC__StreamDecoder *decoder); /** Decode one metadata block or audio frame. * This version instructs the decoder to decode a either a single metadata * block or a single frame and stop, unless the callbacks return a fatal * error or the read callback returns * \c FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM. * * As the decoder needs more input it will call the read callback. * Depending on what was decoded, the metadata or write callback will be * called with the decoded metadata block or audio frame, unless an error * occurred. If the decoder loses sync it will call the error callback * instead. * * Unless there is a fatal read error or end of stream, this function * will return once one whole frame is decoded. In other words, if the * stream is not syncronized or points to a corrupt frame header, the * decoder will continue to try and resync until it gets to a valid * frame, then decode one frame, then return. If the decoder points to * frame whose frame CRC in the frame footer does not match the * computed frame CRC, this function will issue a * FLAC__STREAM_DECODER_ERROR_STATUS_FRAME_CRC_MISMATCH error to the * error callback, and return, having decoded one complete, although * corrupt, frame. (Such corrupted frames are sent as silence of the * correct length to the write callback.) * * \param decoder An initialized decoder instance. * \assert * \code decoder != NULL \endcode * \retval FLAC__bool * \c false if any read or write error occurred (except * \c FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC), else \c true; * in any case, check the decoder state with * FLAC__stream_decoder_get_state() to see what went wrong or to * check for lost synchronization (a sign of stream corruption). */ FLAC_API FLAC__bool FLAC__stream_decoder_process_single(FLAC__StreamDecoder *decoder); /** Decode until the end of the metadata. * This version instructs the decoder to decode from the current position * and continue until all the metadata has been read, or until the * callbacks return a fatal error or the read callback returns * \c FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM. * * As the decoder needs more input it will call the read callback. * As each metadata block is decoded, the metadata callback will be called * with the decoded metadata. If the decoder loses sync it will call the * error callback. * * \param decoder An initialized decoder instance. * \assert * \code decoder != NULL \endcode * \retval FLAC__bool * \c false if any read or write error occurred (except * \c FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC), else \c true; * in any case, check the decoder state with * FLAC__stream_decoder_get_state() to see what went wrong or to * check for lost synchronization (a sign of stream corruption). */ FLAC_API FLAC__bool FLAC__stream_decoder_process_until_end_of_metadata(FLAC__StreamDecoder *decoder); /** Decode until the end of the stream. * This version instructs the decoder to decode from the current position * and continue until the end of stream (the read callback returns * \c FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM), or until the * callbacks return a fatal error. * * As the decoder needs more input it will call the read callback. * As each metadata block and frame is decoded, the metadata or write * callback will be called with the decoded metadata or frame. If the * decoder loses sync it will call the error callback. * * \param decoder An initialized decoder instance. * \assert * \code decoder != NULL \endcode * \retval FLAC__bool * \c false if any read or write error occurred (except * \c FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC), else \c true; * in any case, check the decoder state with * FLAC__stream_decoder_get_state() to see what went wrong or to * check for lost synchronization (a sign of stream corruption). */ FLAC_API FLAC__bool FLAC__stream_decoder_process_until_end_of_stream(FLAC__StreamDecoder *decoder); /** Skip one audio frame. * This version instructs the decoder to 'skip' a single frame and stop, * unless the callbacks return a fatal error or the read callback returns * \c FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM. * * The decoding flow is the same as what occurs when * FLAC__stream_decoder_process_single() is called to process an audio * frame, except that this function does not decode the parsed data into * PCM or call the write callback. The integrity of the frame is still * checked the same way as in the other process functions. * * This function will return once one whole frame is skipped, in the * same way that FLAC__stream_decoder_process_single() will return once * one whole frame is decoded. * * This function, when used from the higher FLAC__SeekableStreamDecoder * layer, can be used in more quickly determining FLAC frame boundaries * when decoding of the actual data is not needed, for example when a * application is separating a FLAC stream into frames for editing or * storing in a container. To do this, the application can use * FLAC__seekable_stream_decoder_skip_single_frame() to quickly advance * to the next frame, then use * FLAC__seekable_stream_decoder_get_decode_position() to find the new * frame boundary. * * This function should only be called when the stream has advanced * past all the metadata, otherwise it will return \c false. * * \param decoder An initialized decoder instance not in a metadata * state. * \assert * \code decoder != NULL \endcode * \retval FLAC__bool * \c false if any read or write error occurred (except * \c FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC), or if the decoder * is in the FLAC__STREAM_DECODER_SEARCH_FOR_METADATA or * FLAC__STREAM_DECODER_READ_METADATA state, else \c true; * in any case, check the decoder state with * FLAC__stream_decoder_get_state() to see what went wrong or to * check for lost synchronization (a sign of stream corruption). */ FLAC_API FLAC__bool FLAC__stream_decoder_skip_single_frame(FLAC__StreamDecoder *decoder); /* \} */ #ifdef __cplusplus } #endif #endif