flac/include/FLAC/file_decoder.h
2002-07-31 06:57:31 +00:00

560 lines
19 KiB
C

/* libFLAC - Free Lossless Audio Codec library
* Copyright (C) 2000,2001,2002 Josh Coalson
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef FLAC__FILE_DECODER_H
#define FLAC__FILE_DECODER_H
#include "stream_decoder.h"
#ifdef __cplusplus
extern "C" {
#endif
/** \file include/FLAC/file_decoder.h
*
* \brief
* This module contains the functions which implement the file
* decoder.
*
* See the detailed documentation in the
* \link flac_file_decoder file decoder \endlink module.
*/
/** \defgroup flac_file_decoder FLAC/file_decoder.h: file decoder interface
* \ingroup flac_decoder
*
* \brief
* This module contains the functions which implement the file
* decoder.
*
* The basic usage of this decoder is as follows:
* - The program creates an instance of a decoder using
* FLAC__file_decoder_new().
* - The program overrides the default settings and sets callbacks for
* writing, error reporting, and metadata reporting using
* FLAC__file_decoder_set_*() functions.
* - The program initializes the instance to validate the settings and
* prepare for decoding using FLAC__file_decoder_init().
* - The program calls the FLAC__file_decoder_process_*() functions
* to decode data, which subsequently calls the callbacks.
* - The program finishes the decoding with FLAC__file_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__file_decoder_delete().
*
* The file decoder is a trivial wrapper around the
* \link flac_seekable_stream_decoder seekable stream decoder \endlink
* meant to simplfy the process of decoding from a standard file. The
* file decoder supplies all but the Write/Metadata/Error callbacks.
* The user needs only to provide the path to the file and the file
* decoder handles the rest.
*
* Like the seekable stream decoder, seeking is exposed through the
* FLAC__file_decoder_seek_absolute() method. At any point after the file
* decoder has been initialized, the user can call this function to seek to
* an exact sample within the file. Subsequently, the first time the write
* callback is called it will be passed a (possibly partial) block starting
* at that sample.
*
* The file decoder also inherits MD5 signature checking from the seekable
* stream decoder. If this is turned on before initialization,
* FLAC__file_decoder_finish() will report when the decoded MD5 signature
* does not match the one stored in the STREAMINFO block. MD5 checking is
* automatically turned off if there is no signature in the STREAMINFO
* block or when a seek is attempted.
*
* Make sure to read the detailed descriptions of the
* \link flac_seekable_stream_decoder seekable stream decoder module \endlink
* and \link flac_stream_decoder stream decoder module \endlink
* since the file decoder inherits much of its behavior from them.
*
* \note
* The "set" functions may only be called when the decoder is in the
* state FLAC__FILE_DECODER_UNINITIALIZED, i.e. after
* FLAC__file_decoder_new() or FLAC__file_decoder_finish(), but
* before FLAC__file_decoder_init(). If this is the case they will
* return \c true, otherwise \c false.
*
* \note
* FLAC__file_decoder_finish() resets all settings to the constructor
* defaults, including the callbacks.
*
* \{
*/
/** State values for a FLAC__FileDecoder
*
* The decoder's state can be obtained by calling FLAC__file_decoder_get_state().
*/
typedef enum {
FLAC__FILE_DECODER_OK = 0,
/**< The decoder is in the normal OK state. */
FLAC__FILE_DECODER_END_OF_FILE,
/**< The decoder has reached the end of the file. */
FLAC__FILE_DECODER_ERROR_OPENING_FILE,
/**< An error occurred opening the input file. */
FLAC__FILE_DECODER_MEMORY_ALLOCATION_ERROR,
/**< An error occurred allocating memory. */
FLAC__FILE_DECODER_SEEK_ERROR,
/**< An error occurred while seeking. */
FLAC__FILE_DECODER_SEEKABLE_STREAM_DECODER_ERROR,
/**< An error occurred in the underlying seekable stream decoder. */
FLAC__FILE_DECODER_ALREADY_INITIALIZED,
/**< FLAC__file_decoder_init() was called when the decoder was already
* initialized, usually because FLAC__file_decoder_finish() was not
* called.
*/
FLAC__FILE_DECODER_INVALID_CALLBACK,
/**< FLAC__file_decoder_init() was called without all callbacks
* being set.
*/
FLAC__FILE_DECODER_UNINITIALIZED
/**< The decoder is in the uninitialized state. */
} FLAC__FileDecoderState;
/** Maps a FLAC__FileDecoderState to a C string.
*
* Using a FLAC__FileDecoderState as the index to this array
* will give the string equivalent. The contents should not be modified.
*/
extern const char * const FLAC__FileDecoderStateString[];
/***********************************************************************
*
* class FLAC__FileDecoder : public FLAC__StreamDecoder
*
***********************************************************************/
struct FLAC__FileDecoderProtected;
struct FLAC__FileDecoderPrivate;
/** The opaque structure definition for the file decoder type. See the
* \link flac_file_decoder file decoder module \endlink for a detailed
* description.
*/
typedef struct {
struct FLAC__FileDecoderProtected *protected_; /* avoid the C++ keyword 'protected' */
struct FLAC__FileDecoderPrivate *private_; /* avoid the C++ keyword 'private' */
} FLAC__FileDecoder;
/***********************************************************************
*
* Class constructor/destructor
*
***********************************************************************/
/** Create a new file decoder instance. The instance is created with
* default settings; see the individual FLAC__file_decoder_set_*()
* functions for each setting's default.
*
* \retval FLAC__FileDecoder*
* \c NULL if there was an error allocating memory, else the new instance.
*/
FLAC__FileDecoder *FLAC__file_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
*/
void FLAC__file_decoder_delete(FLAC__FileDecoder *decoder);
/***********************************************************************
*
* Public class method prototypes
*
***********************************************************************/
/** Set the "MD5 signature checking" flag.
* This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_set_md5_checking().
*
* \default \c false
* \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__bool FLAC__file_decoder_set_md5_checking(FLAC__FileDecoder *decoder, FLAC__bool value);
/** Set the input file name to decode.
*
* \default \c "-"
* \param decoder A decoder instance to set.
* \param value The input file name, or "-" for \c stdin.
* \assert
* \code decoder != NULL \endcode
* \code value != NULL \endcode
* \retval FLAC__bool
* \c false if the decoder is already initialized, or there was a memory
* allocation error, else \c true.
*/
FLAC__bool FLAC__file_decoder_set_filename(FLAC__FileDecoder *decoder, const char *value);
/** Set the write callback.
* This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_set_write_callback().
*
* \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__bool FLAC__file_decoder_set_write_callback(FLAC__FileDecoder *decoder, FLAC__StreamDecoderWriteStatus (*value)(const FLAC__FileDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data));
/** Set the metadata callback.
* This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_set_metadata_callback().
*
* \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__bool FLAC__file_decoder_set_metadata_callback(FLAC__FileDecoder *decoder, void (*value)(const FLAC__FileDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data));
/** Set the error callback.
* This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_set_error_callback().
*
* \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__bool FLAC__file_decoder_set_error_callback(FLAC__FileDecoder *decoder, void (*value)(const FLAC__FileDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data));
/** 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 An 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__bool FLAC__file_decoder_set_client_data(FLAC__FileDecoder *decoder, void *value);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_set_metadata_respond().
*
* \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__bool FLAC__file_decoder_set_metadata_respond(FLAC__FileDecoder *decoder, FLAC__MetadataType type);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_set_metadata_respond_application().
*
* \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__bool FLAC__file_decoder_set_metadata_respond_application(FLAC__FileDecoder *decoder, const FLAC__byte id[4]);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_set_metadata_respond_all().
*
* \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__bool FLAC__file_decoder_set_metadata_respond_all(FLAC__FileDecoder *decoder);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_set_metadata_ignore().
*
* \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__bool FLAC__file_decoder_set_metadata_ignore(FLAC__FileDecoder *decoder, FLAC__MetadataType type);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_set_metadata_ignore_application().
*
* \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__bool FLAC__file_decoder_set_metadata_ignore_application(FLAC__FileDecoder *decoder, const FLAC__byte id[4]);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_set_metadata_ignore_all().
*
* \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__bool FLAC__file_decoder_set_metadata_ignore_all(FLAC__FileDecoder *decoder);
/** Get the current decoder state.
*
* \param decoder A decoder instance to query.
* \assert
* \code decoder != NULL \endcode
* \retval FLAC__FileDecoderState
* The current decoder state.
*/
FLAC__FileDecoderState FLAC__file_decoder_get_state(const FLAC__FileDecoder *decoder);
/** Get the "MD5 signature checking" flag.
* This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_get_md5_checking().
*
* \param decoder A decoder instance to query.
* \assert
* \code decoder != NULL \endcode
* \retval FLAC__bool
* See above.
*/
FLAC__bool FLAC__file_decoder_get_md5_checking(const FLAC__FileDecoder *decoder);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_get_channels().
*
* \param decoder A decoder instance to query.
* \assert
* \code decoder != NULL \endcode
* \retval unsigned
* See above.
*/
unsigned FLAC__file_decoder_get_channels(const FLAC__FileDecoder *decoder);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_get_channel_assignment().
*
* \param decoder A decoder instance to query.
* \assert
* \code decoder != NULL \endcode
* \retval FLAC__ChannelAssignment
* See above.
*/
FLAC__ChannelAssignment FLAC__file_decoder_get_channel_assignment(const FLAC__FileDecoder *decoder);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_get_bits_per_sample().
*
* \param decoder A decoder instance to query.
* \assert
* \code decoder != NULL \endcode
* \retval unsigned
* See above.
*/
unsigned FLAC__file_decoder_get_bits_per_sample(const FLAC__FileDecoder *decoder);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_get_sample_rate().
*
* \param decoder A decoder instance to query.
* \assert
* \code decoder != NULL \endcode
* \retval unsigned
* See above.
*/
unsigned FLAC__file_decoder_get_sample_rate(const FLAC__FileDecoder *decoder);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_get_blocksize().
*
* \param decoder A decoder instance to query.
* \assert
* \code decoder != NULL \endcode
* \retval unsigned
* See above.
*/
unsigned FLAC__file_decoder_get_blocksize(const FLAC__FileDecoder *decoder);
/** Initialize the decoder instance.
* Should be called after FLAC__file_decoder_new() and
* FLAC__file_decoder_set_*() but before any of the
* FLAC__file_decoder_process_*() functions. Will set and return
* the decoder state, which will be FLAC__FILE_DECODER_OK if
* initialization succeeded.
*
* \param decoder An uninitialized decoder instance.
* \assert
* \code decoder != NULL \endcode
* \retval FLAC__FileDecoderState
* \c FLAC__FILE_DECODER_OK if initialization was successful; see
* FLAC__FileDecoderState for the meanings of other return values.
*/
FLAC__FileDecoderState FLAC__file_decoder_init(FLAC__FileDecoder *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__FILE_DECODER_UNINITIALIZED.
*
* In the event of a prematurely-terminated decode, it is not strictly
* necessary to call this immediately before FLAC__file_decoder_delete()
* but it is good practice to match every FLAC__file_decoder_init() with
* a FLAC__file_decoder_finish().
*
* \param decoder An uninitialized decoder instance.
* \assert
* \code decoder != NULL \endcode
* \retval FLAC__bool
* \c false if MD5 checking is on AND a STREAMINFO block was available
* AND the MD5 signature in the STREAMINFO block was non-zero AND the
* signature does not match the one computed by the decoder; else
* \c true.
*/
FLAC__bool FLAC__file_decoder_finish(FLAC__FileDecoder *decoder);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_process_whole_stream().
*
* \param decoder A decoder instance.
* \assert
* \code decoder != NULL \endcode
* \retval FLAC__bool
* See above.
*/
FLAC__bool FLAC__file_decoder_process_whole_file(FLAC__FileDecoder *decoder);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_process_metadata().
*
* \param decoder A decoder instance.
* \assert
* \code decoder != NULL \endcode
* \retval FLAC__bool
* See above.
*/
FLAC__bool FLAC__file_decoder_process_metadata(FLAC__FileDecoder *decoder);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_process_one_frame().
*
* \param decoder A decoder instance.
* \assert
* \code decoder != NULL \endcode
* \retval FLAC__bool
* See above.
*/
FLAC__bool FLAC__file_decoder_process_one_frame(FLAC__FileDecoder *decoder);
/** This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_process_remaining_frames().
*
* \param decoder A decoder instance.
* \assert
* \code decoder != NULL \endcode
* \retval FLAC__bool
* See above.
*/
FLAC__bool FLAC__file_decoder_process_remaining_frames(FLAC__FileDecoder *decoder);
/** Flush the input and seek to an absolute sample.
* This is inherited from FLAC__SeekableStreamDecoder; see
* FLAC__seekable_stream_decoder_seek_absolute().
*
* \param decoder A decoder instance.
* \param sample The target sample number to seek to.
* \assert
* \code decoder != NULL \endcode
* \retval FLAC__bool
* \c true if successful, else \c false.
*/
FLAC__bool FLAC__file_decoder_seek_absolute(FLAC__FileDecoder *decoder, FLAC__uint64 sample);
/* \} */
#ifdef __cplusplus
}
#endif
#endif