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GLAST/LAT > DAQ and FSW > FSW > Doxygen Index > LDT / V0-0-0

Constituent: encdec     Tag: rad750

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APD.h File Reference

Arithmetic Word Decoder interface file. More...

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Data Structures
struct	_APD_dtx
	Decoding context. More...
Typedefs
typedef _APD_dtx	APD_dtx
	Typedef for struct _APD_dtx.
Functions
void	APD_start (APD_dtx *dtx, const unsigned char *in, unsigned int boff)
	Begins a decoding session.
unsigned int	APD_decode (APD_dtx *dtx, const unsigned int *table)
	Decodes the next symbol.
int	APD_bdecompress (unsigned char *out, int cnt, const unsigned char *in, unsigned int boff, const unsigned int *table)
	Convenience routine to decode a bit stream using the specified table.
int	APD_finish (APD_dtx *dtx)
	Finishes the decoding, cleaning up any inprogress context.

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Detailed Description

Arithmetic Word Decoder interface file.

Author:

JJRussell - russell@slac.stanford.edu

  CVS $Id: APD.h,v 1.1.1.1 2005/09/23 06:41:07 russell Exp $ 

Interface specification for routines to decode streams using an arithmetic word (32-bit) encoding technique. It is based on a 32-bit table (hence the word notation) giving the relative probabilities of the encoded symbols.

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Typedef Documentation

APD_dtx

Typedef for struct _APD_dtx. While this is defined in the public interface, this structure should be treated like a C++ private member. All manipulation of this structure should be through the APD routines.

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Function Documentation

int APD_bdecompress (  unsigned char *  out, int  cnt, const unsigned char *  in, unsigned int  boff, const unsigned int *  table )

Convenience routine to decode a bit stream using the specified table. Returns: The number of decoded bits Parameters: out  The output buffer cnt  The number of bytes in the output buffer in  The input buffer boff  The bit offset to start at in the input buffer table  The decoding table This is a convenience routine, combining APD_start, APD_decode and APD_finish. This routine can only be used if the decoding table is the same for all symbols in the input stream.

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unsigned int APD_decode (  APD_dtx *  dtx, const unsigned int *  table )

Decodes the next symbol. Returns: The decoded symbol Parameters: dtx  The decoding context table  The table to use in the decoding

int APD_finish (  APD_dtx *  dtx  )

Finishes the decoding, cleaning up any inprogress context. Returns: The number of bits decoded

void APD_start (  APD_dtx *  dtx, const unsigned char *  in, unsigned int  boff )

Begins a decoding session. Parameters: dtx  The decoding context to be initialized in  The input bit stream boff  The bit offset into the input bit stream

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