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* * |
* * |
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* Revision history: * |
* Revision history: * |
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* * |
* * |
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* 26.03.2002 interlacing support - modified putvol/vopheaders paramters |
* 28.06.2002 addded BitstreamNumBitsToByteAlign() * |
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* BitstreamShowBitsFromByteAlign() * |
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* 26.03.2002 interlacing support - modified putvol/vopheaders paramters * |
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* 04.03.2002 putbits speedup (Isibaar) * |
* 04.03.2002 putbits speedup (Isibaar) * |
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* 03.03.2002 merged BITREADER and BITWRITER (Isibaar) * |
* 03.03.2002 merged BITREADER and BITWRITER (Isibaar) * |
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* 16.12.2001 inital version * |
* 16.12.2001 inital version * |
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#define S_VOP 3 |
#define S_VOP 3 |
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#define N_VOP 4 |
#define N_VOP 4 |
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// resync-specific |
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#define NUMBITS_VP_RESYNC_MARKER 17 |
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#define RESYNC_MARKER 1 |
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int |
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read_video_packet_header(Bitstream *bs, const int addbits, int * quant); |
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// header stuff |
// header stuff |
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int BitstreamReadHeaders(Bitstream * bs, |
int BitstreamReadHeaders(Bitstream * bs, |
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} |
} |
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// number of bits to next byte alignment |
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static __inline uint32_t |
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BitstreamNumBitsToByteAlign(Bitstream *bs) |
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{ |
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uint32_t n = (32 - bs->pos) % 8; |
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return n == 0 ? 8 : n; |
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} |
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// show nbits from next byte alignment |
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static __inline uint32_t |
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BitstreamShowBitsFromByteAlign(Bitstream *bs, int bits) |
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{ |
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int bspos = bs->pos + BitstreamNumBitsToByteAlign(bs); |
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int nbit = (bits + bspos) - 32; |
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if (bspos >= 32) { |
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return bs->bufb >> (32 - nbit); |
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} else if (nbit > 0) { |
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return ((bs->bufa & (0xffffffff >> bspos)) << nbit) | (bs-> |
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bufb >> (32 - |
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nbit)); |
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} else { |
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return (bs->bufa & (0xffffffff >> bspos)) >> (32 - bspos - bits); |
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} |
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} |
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/* move forward to the next byte boundary */ |
/* move forward to the next byte boundary */ |
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static __inline void |
static __inline void |
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} |
} |
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/* pad bitstream to the next byte boundary */ |
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static void __inline |
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BitstreamPad(Bitstream * const bs) |
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{ |
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uint32_t remainder = bs->pos % 8; |
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if (remainder) { |
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BitstreamForward(bs, 8 - remainder); |
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} |
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} |
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/* read n bits from bitstream */ |
/* read n bits from bitstream */ |
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static uint32_t __inline |
static uint32_t __inline |
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} |
} |
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} |
} |
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static const int stuffing_codes[8] = |
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{ |
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/* nbits stuffing code */ |
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0, /* 1 0 */ |
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1, /* 2 01 */ |
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3, /* 3 011 */ |
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7, /* 4 0111 */ |
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0xf, /* 5 01111 */ |
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0x1f, /* 6 011111 */ |
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0x3f, /* 7 0111111 */ |
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0x7f, /* 8 01111111 */ |
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}; |
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/* pad bitstream to the next byte boundary */ |
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static void __inline |
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BitstreamPad(Bitstream * const bs) |
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{ |
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int bits = 8 - (bs->pos % 8); |
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if (bits < 8) |
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{ |
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BitstreamPutBits(bs, stuffing_codes[bits - 1], bits); |
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} |
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} |
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/* pad bitstream to the next byte boundary |
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alway pad: even if currently at the byte boundary */ |
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static void __inline |
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BitstreamPadAlways(Bitstream * const bs) |
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{ |
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int bits = 8 - (bs->pos % 8); |
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BitstreamPutBits(bs, stuffing_codes[bits - 1], bits); |
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} |
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#endif /* _BITSTREAM_H_ */ |
#endif /* _BITSTREAM_H_ */ |