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#ifndef _FORMAT_BITSTREAM_H
#define _FORMAT_BITSTREAM_H
/*********************************************************************
Copyright (c) 1995 ISO/IEC JTC1 SC29 WG1, All Rights Reserved
formatBitstream.h
**********************************************************************/
/*
Revision History:
Date Programmer Comment
========== ========================= ===============================
1995/09/06 mc@fivebats.com created
*/
#ifndef MAX_CHANNELS
#define MAX_CHANNELS 2
#endif
#ifndef MAX_GRANULES
#define MAX_GRANULES 2
#endif
/* Find the ANSI header for these! */
typedef unsigned int uint32;
typedef unsigned short uint16;
/*
This is the prototype for the function pointer you must
provide to write bits to the bitstream. It should write
'length' bits from 'value,' msb first. Bits in value are
assumed to be right-justified.
*/
typedef void (*BitsFcnPtr)( uint32 value, uint16 length );
/*
A BitstreamElement contains encoded data
to be written to the bitstream.
'length' bits of 'value' will be written to
the bitstream msb-first.
*/
typedef struct
{
uint32 value;
uint16 length;
} BF_BitstreamElement;
/*
A BitstreamPart contains a group
of 'nrEntries' of BitstreamElements.
Each BitstreamElement will be written
to the bitstream in the order it appears
in the 'element' array.
*/
typedef struct
{
uint32 nrEntries;
BF_BitstreamElement *element;
} BF_BitstreamPart;
/*
This structure contains all the information needed by the
bitstream formatter to encode one frame of data. You must
fill this out and provide a pointer to it when you call
the formatter.
Maintainers: If you add or remove part of the side
information, you will have to update the routines that
make local copies of that information (in formatBitstream.c)
*/
typedef struct BF_FrameData
{
BitsFcnPtr putbits; /* your low-level bitstream function */
int frameLength;
int nGranules;
int nChannels;
BF_BitstreamPart *header;
BF_BitstreamPart *frameSI;
BF_BitstreamPart *channelSI[MAX_CHANNELS];
BF_BitstreamPart *spectrumSI[MAX_GRANULES][MAX_CHANNELS];
BF_BitstreamPart *scaleFactors[MAX_GRANULES][MAX_CHANNELS];
BF_BitstreamPart *codedData[MAX_GRANULES][MAX_CHANNELS];
BF_BitstreamPart *userSpectrum[MAX_GRANULES][MAX_CHANNELS];
BF_BitstreamPart *userFrameData;
} BF_FrameData;
/*
This structure contains information provided by
the bitstream formatter. You can use this to
check to see if your code agrees with the results
of the call to the formatter.
*/
typedef struct BF_FrameResults
{
int SILength;
int mainDataLength;
int nextBackPtr;
} BF_FrameResults;
/*
The following is a shorthand bitstream syntax for
the type of bitstream this package will create.
The bitstream has headers and side information that
are placed at appropriate sections to allow framing.
The main data is placed where it fits in a manner
similar to layer3, which means that main data for a
frame may be written to the bitstream before the
frame's header and side information is written.
BitstreamFrame()
{
Header();
FrameSI();
for ( ch )
ChannelSI();
for ( gr )
for ( ch )
SpectrumSI();
MainData();
}
MainData()
{
for ( gr )
for ( ch )
{
Scalefactors();
CodedData();
UserSpectrum();
}
UserFrameData();
}
*/
/*
public functions in formatBitstream.c
*/
/* count the bits in a BitstreamPart */
int BF_PartLength( BF_BitstreamPart *part );
/* encode a frame of audio and write it to your bitstream */
void BF_BitstreamFrame( BF_FrameData *frameInfo, BF_FrameResults *results );
/* write any remaining frames to the bitstream, padding with zeros */
void BF_FlushBitstream( BF_FrameData *frameInfo, BF_FrameResults *results );
typedef struct BF_PartHolder
{
int max_elements;
BF_BitstreamPart *part;
} BF_PartHolder;
BF_PartHolder *BF_newPartHolder( int max_elements );
BF_PartHolder *BF_resizePartHolder( BF_PartHolder *oldPH, int max_elements );
BF_PartHolder *BF_addElement( BF_PartHolder *thePH, BF_BitstreamElement *theElement );
BF_PartHolder *BF_addEntry( BF_PartHolder *thePH, uint32 value, uint16 length );
BF_PartHolder *BF_NewHolderFromBitstreamPart( BF_BitstreamPart *thePart );
BF_PartHolder *BF_LoadHolderFromBitstreamPart( BF_PartHolder *theHolder, BF_BitstreamPart *thePart );
BF_PartHolder *BF_freePartHolder( BF_PartHolder *thePH );
#endif
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