gstreamer/gst-libs/ext/mplex/bits.hh

83 lines
1.7 KiB
C++
Raw Normal View History

#ifndef __BITS_H__
#define __BITS_H__
#include <config.h>
#include <stdio.h>
typedef uint64_t bitcount_t;
class BitStreamUndo
{
//protected:
public:
uint8_t outbyte;
unsigned int byteidx;
int bitidx;
unsigned int bufcount;
fpos_t actpos;
bitcount_t totbits;
bitcount_t buffer_start;
bitcount_t readpos;
uint8_t *bfr;
unsigned int bfr_size;
public:
bool eobs;
};
typedef class BitStream _BitStream;
typedef size_t (*ReadCallback) (_BitStream *bs, uint8_t *dest, size_t size, void *user_data);
class BitStream : public BitStreamUndo
{
public:
void *user_data;
static const unsigned int BUFFER_SIZE = 4 * 1024;
public:
BitStream ();
~BitStream ();
inline bitcount_t bitcount ()
{
return totbits;
}
inline bool eos ()
{
return eobs;
}
};
//
// Input bit stream class. Supports the "scanning" of a stream
// into a large buffer which is flushed once it has been read.
// N.b. if you scan ahead a long way and don't read its your
// responsibility to flush manually...
//
class IBitStream:public BitStream
{
public:
void open (ReadCallback read_callback, void *user_data, unsigned int buf_size = BUFFER_SIZE);
void SetBufSize (unsigned int buf_size);
void close ();
uint32_t get1bit ();
uint32_t getbits (int N);
void prepareundo (BitStreamUndo & undobuf);
void undochanges (BitStreamUndo & undobuf);
bool seek_sync (unsigned int sync, int N, int lim);
void flush (bitcount_t bitposition);
inline unsigned int buffered_bytes ()
{
return (buffer_start + bufcount - readpos);
}
unsigned int read_buffered_bytes (uint8_t * dst, unsigned int length_bytes);
private:
bool refill_buffer ();
static uint8_t masks[8];
ReadCallback read_callback;
};
#endif // __BITS_H__