ref: f347dd3b3d9c1ffef4f707d39208ffa4750370ab
dir: /libentcode/entenc.h/
#if !defined(_entenc_H)
# define _entenc_H (1)
# include <stddef.h>
# include "entcode.h"
typedef struct ec_enc ec_enc;
/*The entropy encoder.*/
struct ec_enc{
/*Buffered output.*/
ec_byte_buffer *buf;
/*A buffered output symbol, awaiting carry propagation.*/
int rem;
/*Number of extra carry propagating symbols.*/
size_t ext;
/*The number of values in the current range.*/
ec_uint32 rng;
/*The low end of the current range (inclusive).*/
ec_uint32 low;
};
/*Initializes the encoder.
_buf: The buffer to store output bytes in.
This must have already been initialized for writing and reset.*/
void ec_enc_init(ec_enc *_this,ec_byte_buffer *_buf);
/*Encodes a symbol given its frequency information.
The frequency information must be discernable by the decoder, assuming it
has read only the previous symbols from the stream.
It is allowable to change the frequency information, or even the entire
source alphabet, so long as the decoder can tell from the context of the
previously encoded information that it is supposed to do so as well.
_fl: The cumulative frequency of all symbols that come before the one to be
encoded.
_fh: The cumulative frequency of all symbols up to and including the one to
be encoded.
Together with _fl, this defines the range [_fl,_fh) in which the
decoded value will fall.
_ft: The sum of the frequencies of all the symbols*/
void ec_encode(ec_enc *_this,unsigned _fl,unsigned _fh,unsigned _ft);
/*Encodes a sequence of raw bits in the stream.
_fl: The bits to encode.
_ftb: The number of bits to encode.
This must be at least one, and no more than 32.*/
void ec_enc_bits(ec_enc *_this,ec_uint32 _fl,int _ftb);
/*Encodes a sequence of raw bits in the stream.
_fl: The bits to encode.
_ftb: The number of bits to encode.
This must be at least one, and no more than 64.*/
void ec_enc_bits64(ec_enc *_this,ec_uint64 _fl,int _ftb);
/*Encodes a raw unsigned integer in the stream.
_fl: The integer to encode.
_ft: The number of integers that can be encoded (one more than the max).
This must be at least one, and no more than 2**32-1.*/
void ec_enc_uint(ec_enc *_this,ec_uint32 _fl,ec_uint32 _ft);
/*Encodes a raw unsigned integer in the stream.
_fl: The integer to encode.
_ft: The number of integers that can be encoded (one more than the max).
This must be at least one, and no more than 2**64-1.*/
void ec_enc_uint64(ec_enc *_this,ec_uint64 _fl,ec_uint64 _ft);
/*Indicates that there are no more symbols to encode.
All reamining output bytes are flushed to the output buffer.
ec_enc_init() must be called before the encoder can be used again.*/
void ec_enc_done(ec_enc *_this);
#endif