flac/include/FLAC/seekable_stream_decoder.h
2002-07-25 05:35:16 +00:00

290 lines
15 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__SEEKABLE_STREAM_DECODER_H
#define FLAC__SEEKABLE_STREAM_DECODER_H
#include "stream_decoder.h"
#ifdef __cplusplus
extern "C" {
#endif
/** \file include/FLAC/seekable_stream_decoder.h
*
* \brief
* This module contains the functions which implement the seekable stream
* decoder.
*
* See the detailed documentation in the
* \link flac_seekable_stream_decoder seekable stream decoder \endlink module.
*/
/** \defgroup flac_seekable_stream_decoder FLAC/seekable_stream_decoder.h: seekable stream decoder interface
* \ingroup flac_decoder
*
* \brief
* This module contains the functions which implement the seekable stream
* decoder.
*
* The basic usage of this decoder is as follows:
* - The program creates an instance of a decoder using
* FLAC__seekable_stream_decoder_new().
* - The program overrides the default settings and sets callbacks for
* reading, writing, seeking, error reporting, and metadata reporting
* using FLAC__seekable_stream_decoder_set_*() functions.
* - The program initializes the instance to validate the settings and
* prepare for decoding using FLAC__seekable_stream_decoder_init().
* - The program calls the FLAC__seekable_stream_decoder_process_*()
* functions to decode data, which subsequently calls the callbacks.
* - The program finishes the decoding with
* FLAC__seekable_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__seekable_stream_decoder_delete().
*
* The seekable stream decoder is a wrapper around the
* \link flac_stream_decoder stream decoder \endlink which also provides
* seeking capability. In addition to the Read/Write/Metadata/Error
* callbacks of the stream decoder, the user must also provide the following:
*
* - Seek callback - This function will be called when the decoder wants to
* seek to an absolute position in the stream.
* - Tell callback - This function will be called when the decoder wants to
* know the current absolute position of the stream.
* - Length callback - This function will be called when the decoder wants
* to know length of the stream. The seeking algorithm currently requires
* that the overall stream length be known.
* - EOF callback - This function will be called when the decoder wants to
* know if it is at the end of the stream. This could be synthesized from
* the tell and length callbacks but it may be more expensive that way, so
* there is a separate callback for it.
*
* Seeking is exposed through the
* FLAC__seekable_stream_decoder_seek_absolute() method. At any point after
* the seekable stream decoder has been initialized, the user can call this
* function to seek to an exact sample within the stream. Subsequently, the
* first time the write callback is called it will be passed a (possibly
* partial) block starting at that sample.
*
* The seekable stream decoder also provides MD5 signature checking. If
* this is turned on before initialization,
* FLAC__seekable_stream_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 (until the next
* FLAC__seekable_stream_decoder_reset()) if there is no signature in the
* STREAMINFO block or when a seek is attempted.
*
* \note
* The "set" functions may only be called when the decoder is in the
* state FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED, i.e. after
* FLAC__seekable_stream_decoder_new() or
* FLAC__seekable_stream_decoder_finish(), but before
* FLAC__seekable_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__SeekableStreamDecoder
*
* The decoder's state can be obtained by calling FLAC__seekable_tream_decoder_get_state().
*/
typedef enum {
FLAC__SEEKABLE_STREAM_DECODER_OK = 0,
FLAC__SEEKABLE_STREAM_DECODER_SEEKING,
FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM,
FLAC__SEEKABLE_STREAM_DECODER_MEMORY_ALLOCATION_ERROR,
FLAC__SEEKABLE_STREAM_DECODER_STREAM_DECODER_ERROR,
FLAC__SEEKABLE_STREAM_DECODER_READ_ERROR,
FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR,
FLAC__SEEKABLE_STREAM_DECODER_ALREADY_INITIALIZED,
FLAC__SEEKABLE_STREAM_DECODER_INVALID_CALLBACK,
FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED
} FLAC__SeekableStreamDecoderState;
extern const char * const FLAC__SeekableStreamDecoderStateString[];
typedef enum {
FLAC__SEEKABLE_STREAM_DECODER_READ_STATUS_OK,
FLAC__SEEKABLE_STREAM_DECODER_READ_STATUS_ERROR
} FLAC__SeekableStreamDecoderReadStatus;
extern const char * const FLAC__SeekableStreamDecoderReadStatusString[];
typedef enum {
FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_OK,
FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_ERROR
} FLAC__SeekableStreamDecoderSeekStatus;
extern const char * const FLAC__SeekableStreamDecoderSeekStatusString[];
typedef enum {
FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_OK,
FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_ERROR
} FLAC__SeekableStreamDecoderTellStatus;
extern const char * const FLAC__SeekableStreamDecoderTellStatusString[];
typedef enum {
FLAC__SEEKABLE_STREAM_DECODER_LENGTH_STATUS_OK,
FLAC__SEEKABLE_STREAM_DECODER_LENGTH_STATUS_ERROR
} FLAC__SeekableStreamDecoderLengthStatus;
extern const char * const FLAC__SeekableStreamDecoderLengthStatusString[];
/***********************************************************************
*
* class FLAC__SeekableStreamDecoder : public FLAC__StreamDecoder
*
***********************************************************************/
struct FLAC__SeekableStreamDecoderProtected;
struct FLAC__SeekableStreamDecoderPrivate;
typedef struct {
struct FLAC__SeekableStreamDecoderProtected *protected_; /* avoid the C++ keyword 'protected' */
struct FLAC__SeekableStreamDecoderPrivate *private_; /* avoid the C++ keyword 'private' */
} FLAC__SeekableStreamDecoder;
/***********************************************************************
*
* Class constructor/destructor
*
***********************************************************************/
/*
* Any parameters that are not set before FLAC__seekable_stream_decoder_init()
* will take on the defaults from the constructor, shown below.
* For more on what the parameters mean, see the documentation.
*
* FLAC__bool md5_checking (DEFAULT: false) MD5 checking will be turned off if a seek is requested
* (*read_callback)() (DEFAULT: NULL ) The callbacks are the only values that MUST be set before FLAC__seekable_stream_decoder_init()
* (*seek_callback)() (DEFAULT: NULL )
* (*tell_callback)() (DEFAULT: NULL )
* (*length_callback)() (DEFAULT: NULL )
* (*eof_callback)() (DEFAULT: NULL )
* (*write_callback)() (DEFAULT: NULL )
* (*metadata_callback)() (DEFAULT: NULL )
* (*error_callback)() (DEFAULT: NULL )
* void* client_data (DEFAULT: NULL ) passed back through the callbacks
* metadata_respond/ignore By default, only the STREAMINFO block is returned via metadata_callback()
*/
FLAC__SeekableStreamDecoder *FLAC__seekable_stream_decoder_new();
void FLAC__seekable_stream_decoder_delete(FLAC__SeekableStreamDecoder *);
/***********************************************************************
*
* Public class method prototypes
*
***********************************************************************/
/*
* Various "set" methods. These may only be called when the decoder
* is in the state FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED, i.e. after
* FLAC__seekable_stream_decoder_new() or FLAC__seekable_stream_decoder_finish(),
* but before FLAC__seekable_stream_decoder_init(). If this is the case they
* will return true, otherwise false.
*
* NOTE that these functions do not validate the values as many are
* interdependent. The FLAC__seekable_stream_decoder_init() function will
* do this, so make sure to pay attention to the state returned by
* FLAC__seekable_stream_decoder_init().
*
* Any parameters that are not set before FLAC__seekable_stream_decoder_init()
* will take on the defaults from the constructor. NOTE that
* FLAC__seekable_stream_decoder_flush() or FLAC__seekable_stream_decoder_reset()
* do NOT reset the values to the constructor defaults.
*/
FLAC__bool FLAC__seekable_stream_decoder_set_md5_checking(FLAC__SeekableStreamDecoder *decoder, FLAC__bool value);
FLAC__bool FLAC__seekable_stream_decoder_set_read_callback(FLAC__SeekableStreamDecoder *decoder, FLAC__SeekableStreamDecoderReadStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__byte buffer[], unsigned *bytes, void *client_data));
FLAC__bool FLAC__seekable_stream_decoder_set_seek_callback(FLAC__SeekableStreamDecoder *decoder, FLAC__SeekableStreamDecoderSeekStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 absolute_byte_offset, void *client_data));
FLAC__bool FLAC__seekable_stream_decoder_set_tell_callback(FLAC__SeekableStreamDecoder *decoder, FLAC__SeekableStreamDecoderTellStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 *absolute_byte_offset, void *client_data));
FLAC__bool FLAC__seekable_stream_decoder_set_length_callback(FLAC__SeekableStreamDecoder *decoder, FLAC__SeekableStreamDecoderLengthStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 *stream_length, void *client_data));
FLAC__bool FLAC__seekable_stream_decoder_set_eof_callback(FLAC__SeekableStreamDecoder *decoder, FLAC__bool (*value)(const FLAC__SeekableStreamDecoder *decoder, void *client_data));
FLAC__bool FLAC__seekable_stream_decoder_set_write_callback(FLAC__SeekableStreamDecoder *decoder, FLAC__StreamDecoderWriteStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data));
FLAC__bool FLAC__seekable_stream_decoder_set_metadata_callback(FLAC__SeekableStreamDecoder *decoder, void (*value)(const FLAC__SeekableStreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data));
FLAC__bool FLAC__seekable_stream_decoder_set_error_callback(FLAC__SeekableStreamDecoder *decoder, void (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data));
FLAC__bool FLAC__seekable_stream_decoder_set_client_data(FLAC__SeekableStreamDecoder *decoder, void *value);
/*
* See the comments for the equivalent functions in stream_decoder.h
*/
FLAC__bool FLAC__seekable_stream_decoder_set_metadata_respond(FLAC__SeekableStreamDecoder *decoder, FLAC__MetadataType type);
FLAC__bool FLAC__seekable_stream_decoder_set_metadata_respond_application(FLAC__SeekableStreamDecoder *decoder, const FLAC__byte id[4]);
FLAC__bool FLAC__seekable_stream_decoder_set_metadata_respond_all(FLAC__SeekableStreamDecoder *decoder);
FLAC__bool FLAC__seekable_stream_decoder_set_metadata_ignore(FLAC__SeekableStreamDecoder *decoder, FLAC__MetadataType type);
FLAC__bool FLAC__seekable_stream_decoder_set_metadata_ignore_application(FLAC__SeekableStreamDecoder *decoder, const FLAC__byte id[4]);
FLAC__bool FLAC__seekable_stream_decoder_set_metadata_ignore_all(FLAC__SeekableStreamDecoder *decoder);
/*
* Various "get" methods
*/
FLAC__SeekableStreamDecoderState FLAC__seekable_stream_decoder_get_state(const FLAC__SeekableStreamDecoder *decoder);
FLAC__bool FLAC__seekable_stream_decoder_get_md5_checking(const FLAC__SeekableStreamDecoder *decoder);
/*
* Methods to return the current number of channels, channel assignment
* bits-per-sample, sample rate in Hz, and blocksize in samples. These
* will only be valid after decoding has started.
*/
unsigned FLAC__seekable_stream_decoder_get_channels(const FLAC__SeekableStreamDecoder *decoder);
FLAC__ChannelAssignment FLAC__seekable_stream_decoder_get_channel_assignment(const FLAC__SeekableStreamDecoder *decoder);
unsigned FLAC__seekable_stream_decoder_get_bits_per_sample(const FLAC__SeekableStreamDecoder *decoder);
unsigned FLAC__seekable_stream_decoder_get_sample_rate(const FLAC__SeekableStreamDecoder *decoder);
unsigned FLAC__seekable_stream_decoder_get_blocksize(const FLAC__SeekableStreamDecoder *decoder);
/*
* Initialize the instance; should be called after construction and
* 'set' calls but before any of the 'process' or 'seek' calls. Will
* set and return the decoder state, which will be
* FLAC__SEEKABLE_STREAM_DECODER_OK if initialization succeeded.
*/
FLAC__SeekableStreamDecoderState FLAC__seekable_stream_decoder_init(FLAC__SeekableStreamDecoder *decoder);
/*
* Flush the decoding buffer, release resources, and return the decoder
* state to FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED. Only returns false if
* md5_checking is set AND the stored MD5 sum is non-zero AND the stored
* MD5 sum and computed MD5 sum do not match.
*/
FLAC__bool FLAC__seekable_stream_decoder_finish(FLAC__SeekableStreamDecoder *decoder);
/*
* state control methods
*/
FLAC__bool FLAC__seekable_stream_decoder_flush(FLAC__SeekableStreamDecoder *decoder);
FLAC__bool FLAC__seekable_stream_decoder_reset(FLAC__SeekableStreamDecoder *decoder);
/*
* Methods for decoding the data
*/
FLAC__bool FLAC__seekable_stream_decoder_process_whole_stream(FLAC__SeekableStreamDecoder *decoder);
FLAC__bool FLAC__seekable_stream_decoder_process_metadata(FLAC__SeekableStreamDecoder *decoder);
FLAC__bool FLAC__seekable_stream_decoder_process_one_frame(FLAC__SeekableStreamDecoder *decoder);
FLAC__bool FLAC__seekable_stream_decoder_process_remaining_frames(FLAC__SeekableStreamDecoder *decoder);
FLAC__bool FLAC__seekable_stream_decoder_seek_absolute(FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 sample);
/* \} */
#ifdef __cplusplus
}
#endif
#endif