bitstream.h

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#ifndef _BITSTREAM_H
#define _BITSTREAM_H

typedef enum _bitstream_error
{
        BITSTREAM_ERROR_OKAY = 0,               
        BITSTREAM_ERROR_UNDERFLOW,              
        BITSTREAM_ERROR_OVERFLOW,               
        BITSTREAM_ERROR_BADTAG,                 

        //TODO: Add more bitstream errors

} BITSTREAM_ERROR;

typedef uint32_t BITWORD;                       
typedef uint_fast8_t BITCOUNT;          

static const BITCOUNT bit_word_count = 32;

#define BIT_WORD_MAX 0xFFFFFFFF

#define MAX_SAMPLE_OFFSET_COUNT         8

typedef struct _bitstream
{
        BITSTREAM_ERROR error;          
        struct _stream *stream;         
        BITWORD buffer;                         
        BITCOUNT count;                         

        uint32_t sample_offset_stack[MAX_SAMPLE_OFFSET_COUNT];

        uint_fast8_t sample_offset_count;

        FILE *logfile;

        bool putbits_flag;

} BITSTREAM;

// Initialize a bitstream data structure
CODEC_ERROR InitBitstream(BITSTREAM *bitstream);

// Bind the bitstream to a byte stream
CODEC_ERROR AttachBitstream(struct _bitstream *bitstream, struct _stream *stream);

CODEC_ERROR ReleaseBitstream(BITSTREAM *stream);

BITWORD GetBits(BITSTREAM *stream, BITCOUNT count);

BITWORD GetBuffer(BITSTREAM *stream);

CODEC_ERROR PutBits(BITSTREAM *stream, BITWORD bits, BITCOUNT count);

CODEC_ERROR PutBuffer(BITSTREAM *stream);

CODEC_ERROR PutLong(BITSTREAM *stream, BITWORD longword);

// Rewind the bitstream and the associated byte stream
CODEC_ERROR RewindBitstream(BITSTREAM *bitstream);

CODEC_ERROR BitstreamCodecError(BITSTREAM *bitstream);

CODEC_ERROR SkipPayload(BITSTREAM *bitstream, int chunk_size);

// Return the current position of the bitstream pointer in the sample
size_t GetBitstreamPosition(BITSTREAM *stream);

// Align the bitstream to a byte
CODEC_ERROR AlignBitsByte(BITSTREAM *bitstream);

// Align the bitstrean to a longword
CODEC_ERROR AlignBitsWord(BITSTREAM *bitstream);

BITWORD AddBits(BITSTREAM *stream, BITWORD bits, BITCOUNT count);

CODEC_ERROR FlushBitstream(BITSTREAM *bitstream);

uint32_t PopSampleOffsetStack(BITSTREAM *bitstream);

CODEC_ERROR PutByteArray(BITSTREAM *bitstream, const uint8_t *block, size_t size);

#endif