www.pudn.com > T264-src-0.02.zip > bitstream.h
/*****************************************************************************
*
* T264 AVC CODEC
*
* Copyright(C) 2004-2005 llcc
* 2004-2005 visionany
*
* This program is free software ; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation ; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY ; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program ; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
****************************************************************************/
/*****************************************************************************
*
* XVID MPEG-4 VIDEO CODEC
* - Bitstream reader/writer inlined functions and constants-
*
* Copyright (C) 2001-2003 Peter Ross
*
* This program is free software ; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation ; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY ; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program ; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id: bitstream.h,v 1.3 2004/09/29 11:30:12 lcgate1 Exp $
*
****************************************************************************/
#ifndef _BITSTREAM_H_
#define _BITSTREAM_H_
/*****************************************************************************
* Constants
****************************************************************************/
/* comment any #defs we dont use */
#define VIDOBJ_START_CODE 0x00000100 /* ..0x0000011f */
#define VIDOBJLAY_START_CODE 0x00000120 /* ..0x0000012f */
#define VISOBJSEQ_START_CODE 0x000001b0
#define VISOBJSEQ_STOP_CODE 0x000001b1 /* ??? */
#define USERDATA_START_CODE 0x000001b2
#define GRPOFVOP_START_CODE 0x000001b3
/*#define VIDSESERR_ERROR_CODE 0x000001b4 */
#define VISOBJ_START_CODE 0x000001b5
#define VOP_START_CODE 0x000001b6
/*#define STUFFING_START_CODE 0x000001c3 */
#define VISOBJ_TYPE_VIDEO 1
/*#define VISOBJ_TYPE_STILLTEXTURE 2 */
/*#define VISOBJ_TYPE_MESH 3 */
/*#define VISOBJ_TYPE_FBA 4 */
/*#define VISOBJ_TYPE_3DMESH 5 */
#define VIDOBJLAY_TYPE_SIMPLE 1
/*#define VIDOBJLAY_TYPE_SIMPLE_SCALABLE 2 */
/*#define VIDOBJLAY_TYPE_CORE 3 */
/*#define VIDOBJLAY_TYPE_MAIN 4 */
/*#define VIDOBJLAY_TYPE_NBIT 5 */
/*#define VIDOBJLAY_TYPE_ANIM_TEXT 6 */
/*#define VIDOBJLAY_TYPE_ANIM_MESH 7 */
/*#define VIDOBJLAY_TYPE_SIMPLE_FACE 8 */
/*#define VIDOBJLAY_TYPE_STILL_SCALABLE 9 */
#define VIDOBJLAY_TYPE_ART_SIMPLE 10
/*#define VIDOBJLAY_TYPE_CORE_SCALABLE 11 */
/*#define VIDOBJLAY_TYPE_ACE 12 */
/*#define VIDOBJLAY_TYPE_ADVANCED_SCALABLE_TEXTURE 13 */
/*#define VIDOBJLAY_TYPE_SIMPLE_FBA 14 */
/*#define VIDEOJLAY_TYPE_SIMPLE_STUDIO 15*/
/*#define VIDEOJLAY_TYPE_CORE_STUDIO 16*/
#define VIDOBJLAY_TYPE_ASP 17
/*#define VIDOBJLAY_TYPE_FGS 18*/
/*#define VIDOBJLAY_AR_SQUARE 1 */
/*#define VIDOBJLAY_AR_625TYPE_43 2 */
/*#define VIDOBJLAY_AR_525TYPE_43 3 */
/*#define VIDOBJLAY_AR_625TYPE_169 8 */
/*#define VIDOBJLAY_AR_525TYPE_169 9 */
#define VIDOBJLAY_AR_EXTPAR 15
#define VIDOBJLAY_SHAPE_RECTANGULAR 0
#define VIDOBJLAY_SHAPE_BINARY 1
#define VIDOBJLAY_SHAPE_BINARY_ONLY 2
#define VIDOBJLAY_SHAPE_GRAYSCALE 3
#define SPRITE_NONE 0
#define SPRITE_STATIC 1
#define SPRITE_GMC 2
#define READ_MARKER() BitstreamSkip(bs, 1)
#define WRITE_MARKER() BitstreamPutBit(bs, 1)
/* vop coding types */
/* intra, prediction, backward, sprite, not_coded */
#define I_VOP 0
#define P_VOP 1
#define B_VOP 2
#define S_VOP 3
#define N_VOP 4
/* resync-specific */
#define NUMBITS_VP_RESYNC_MARKER 17
#define RESYNC_MARKER 1
typedef struct
{
uint32_t bufa;
uint32_t bufb;
uint32_t buf;
uint32_t pos;
uint32_t *tail;
uint32_t *start;
uint32_t length;
uint32_t initpos;
}
Bitstream;
/* initialise bitstream structure */
static void __inline
BitstreamInit(Bitstream * const bs,
void *const bitstream,
uint32_t length)
{
uint32_t tmp;
size_t bitpos;
ptr_t adjbitstream = (ptr_t)bitstream;
/*
* Start the stream on a uint32_t boundary, by rounding down to the
* previous uint32_t and skipping the intervening bytes.
*/
bitpos = ((sizeof(uint32_t)-1) & (size_t)bitstream);
adjbitstream = adjbitstream - bitpos;
bs->start = bs->tail = (uint32_t *) adjbitstream;
tmp = *bs->start;
#ifndef ARCH_IS_BIG_ENDIAN
BSWAP(tmp);
#endif
bs->bufa = tmp;
tmp = *(bs->start + 1);
#ifndef ARCH_IS_BIG_ENDIAN
BSWAP(tmp);
#endif
bs->bufb = tmp;
bs->buf = 0;
bs->pos = bs->initpos = bitpos*8;
bs->length = length;
}
/* reset bitstream state */
static void __inline
BitstreamReset(Bitstream * const bs)
{
uint32_t tmp;
bs->tail = bs->start;
tmp = *bs->start;
#ifndef ARCH_IS_BIG_ENDIAN
BSWAP(tmp);
#endif
bs->bufa = tmp;
tmp = *(bs->start + 1);
#ifndef ARCH_IS_BIG_ENDIAN
BSWAP(tmp);
#endif
bs->bufb = tmp;
bs->buf = 0;
bs->pos = bs->initpos;
}
/* reads n bits from bitstream without changing the stream pos */
static uint32_t __inline
BitstreamShowBits(Bitstream * const bs,
const uint32_t bits)
{
int nbit = (bits + bs->pos) - 32;
if (nbit > 0) {
return ((bs->bufa & (0xffffffff >> bs->pos)) << nbit) | (bs->
bufb >> (32 -
nbit));
} else {
return (bs->bufa & (0xffffffff >> bs->pos)) >> (32 - bs->pos - bits);
}
}
/* skip n bits forward in bitstream */
static __inline void
BitstreamSkip(Bitstream * const bs,
const uint32_t bits)
{
bs->pos += bits;
if (bs->pos >= 32) {
uint32_t tmp;
bs->bufa = bs->bufb;
tmp = *((uint32_t *) bs->tail + 2);
#ifndef ARCH_IS_BIG_ENDIAN
BSWAP(tmp);
#endif
bs->bufb = tmp;
bs->tail++;
bs->pos -= 32;
}
}
/* number of bits to next byte alignment */
static __inline uint32_t
BitstreamNumBitsToByteAlign(Bitstream *bs)
{
uint32_t n = (32 - bs->pos) % 8;
return n == 0 ? 8 : n;
}
/* show nbits from next byte alignment */
static __inline uint32_t
BitstreamShowBitsFromByteAlign(Bitstream *bs, int bits)
{
int bspos = bs->pos + BitstreamNumBitsToByteAlign(bs);
int nbit = (bits + bspos) - 32;
if (bspos >= 32) {
return bs->bufb >> (32 - nbit);
} else if (nbit > 0) {
return ((bs->bufa & (0xffffffff >> bspos)) << nbit) | (bs->
bufb >> (32 -
nbit));
} else {
return (bs->bufa & (0xffffffff >> bspos)) >> (32 - bspos - bits);
}
}
/* move forward to the next byte boundary */
static __inline void
BitstreamByteAlign(Bitstream * const bs)
{
uint32_t remainder = bs->pos % 8;
if (remainder) {
BitstreamSkip(bs, 8 - remainder);
}
}
/* bitstream length (unit bits) */
static uint32_t __inline
BitstreamPos(const Bitstream * const bs)
{
return((uint32_t)(8*((ptr_t)bs->tail - (ptr_t)bs->start) + bs->pos - bs->initpos));
}
static void __inline
BitstreamFlush(Bitstream* const bs)
{
if (bs->pos) {
uint32_t b = bs->buf;
#ifndef ARCH_IS_BIG_ENDIAN
BSWAP(b);
#endif
*bs->tail = b;
}
}
/*
* flush the bitstream & return length (unit bytes)
* NOTE: assumes no futher bitstream functions will be called.
*/
static uint32_t __inline
BitstreamLength(Bitstream * const bs)
{
uint32_t len = (uint32_t)((ptr_t)bs->tail - (ptr_t)bs->start);
if (bs->pos)
len += (bs->pos + 7) / 8;
/* initpos is always on a byte boundary */
if (bs->initpos)
len -= bs->initpos/8;
return len;
}
/* move bitstream position forward by n bits and write out buffer if needed */
static void __inline
BitstreamForward(Bitstream * const bs,
const uint32_t bits)
{
bs->pos += bits;
if (bs->pos >= 32) {
uint32_t b = bs->buf;
#ifndef ARCH_IS_BIG_ENDIAN
BSWAP(b);
#endif
*bs->tail++ = b;
bs->buf = 0;
bs->pos -= 32;
}
}
/* read n bits from bitstream */
static uint32_t __inline
BitstreamGetBits(Bitstream * const bs,
const uint32_t n)
{
uint32_t ret = BitstreamShowBits(bs, n);
BitstreamSkip(bs, n);
return ret;
}
/* read single bit from bitstream */
static uint32_t __inline
BitstreamGetBit(Bitstream * const bs)
{
return BitstreamGetBits(bs, 1);
}
/* write single bit to bitstream */
static void __inline
BitstreamPutBit(Bitstream * const bs,
const uint32_t bit)
{
if (bit)
bs->buf |= (0x80000000 >> bs->pos);
BitstreamForward(bs, 1);
}
/* write n bits to bitstream */
static void __inline
BitstreamPutBits(Bitstream * const bs,
const uint32_t value,
const uint32_t size)
{
uint32_t shift = 32 - bs->pos - size;
if (shift <= 32) {
bs->buf |= value << shift;
BitstreamForward(bs, size);
} else {
uint32_t remainder;
shift = size - (32 - bs->pos);
bs->buf |= value >> shift;
BitstreamForward(bs, size - shift);
remainder = shift;
shift = 32 - shift;
bs->buf |= value << shift;
BitstreamForward(bs, remainder);
}
}
static const int stuffing_codes[8] =
{
/* nbits stuffing code */
0, /* 1 0 */
1, /* 2 01 */
3, /* 3 011 */
7, /* 4 0111 */
0xf, /* 5 01111 */
0x1f, /* 6 011111 */
0x3f, /* 7 0111111 */
0x7f, /* 8 01111111 */
};
/* pad bitstream to the next byte boundary */
static void __inline
BitstreamPad(Bitstream * const bs)
{
int bits = 8 - (bs->pos % 8);
if (bits < 8)
BitstreamPutBits(bs, stuffing_codes[bits - 1], bits);
}
/*
* pad bitstream to the next byte boundary
* alway pad: even if currently at the byte boundary
*/
static void __inline
BitstreamPadAlways(Bitstream * const bs)
{
int bits = 8 - (bs->pos % 8);
BitstreamPutBits(bs, stuffing_codes[bits - 1], bits);
}
static void __inline
BitstreamPadZero(Bitstream * const bs)
{
int bits = 8 - (bs->pos % 8);
if (bits < 8)
BitstreamPutBits(bs, 0, bits);
}
////////////////////////////////////////////////////////////
// exp-golomb
static void __inline
eg_write(Bitstream* const bs, int32_t code_num)
{
int32_t tmp = code_num + 1;
int32_t m, info;
if (code_num != 0)
{
m = 0;
while (tmp)
{
tmp >>= 1;
m ++;
}
m --;
info = code_num + 1 - (1 << m);
BitstreamPutBits(bs, 1, m + 1);
BitstreamPutBits(bs, info, m);
}
else
{
BitstreamPutBits(bs, 1, 1);
}
}
static int32_t __inline
eg_read(Bitstream* const bs)
{
int32_t m, info;
m = 0;
while (!BitstreamGetBit(bs))
{
m ++;
}
info = BitstreamGetBits(bs, m);
return (1 << m) + info - 1;
}
#define eg_write_ue eg_write
#define eg_read_ue eg_read
#define eg_write_direct BitstreamPutBits
#define eg_write_direct1 BitstreamPutBit
#define eg_read_direct BitstreamGetBits
#define eg_init BitstreamInit
#define eg_align BitstreamPadZero
#define bs_t Bitstream
#define eg_len BitstreamLength
#define eg_flush BitstreamFlush
static void __inline
eg_write_se(Bitstream* const bs, int32_t k)
{
int32_t code_num;
code_num = (k > 0) ? (k << 1) - 1 : (-k) << 1;
eg_write_ue(bs, code_num);
}
static int32_t __inline
eg_read_se(Bitstream* const bs)
{
int32_t k;
int32_t code_num = eg_read_ue(bs);
k = (code_num & 1) ? (code_num + 1) >> 1 : -(code_num >> 1);
return k;
}
static void __inline
eg_write_te(Bitstream* const bs, int32_t code_num, int32_t x)
{
x == 1 ? BitstreamPutBit(bs, !code_num) : eg_write_ue(bs, code_num);
}
static int32_t __inline
eg_read_te(Bitstream* const bs, int32_t x)
{
return x == 1 ? (!BitstreamGetBit(bs)) : eg_read_ue(bs);
}
static uint32_t __inline
eg_size_ue(Bitstream* const bs, int32_t code_num)
{
int32_t tmp = code_num + 1;
int32_t m;
if (code_num != 0)
{
m = 0;
while (tmp)
{
tmp >>= 1;
m ++;
}
m --;
return m + m + 1;
}
else
{
return 1;
}
}
static uint32_t __inline
eg_size_se(Bitstream* const bs, int32_t k)
{
int32_t code_num;
code_num = (k > 0) ? (k << 1) - 1 : (-k) << 1;
return eg_size_ue(bs, code_num);
}
static uint32_t __inline
eg_size_te(Bitstream* const bs, int32_t k, int32_t x)
{
return x == 1 ? 1 : eg_size_ue(bs, k);
}
/*
static void __inline
eg_write_me(Bitstream* const bs, int32_t cbp)
{
}
static int32_t __inline
eg_read_me(Bitstream* const bs)
{
}
*/
#endif /* _BITSTREAM_H_ */