/***************************************************************************** * * XVID MPEG-4 VIDEO CODEC * - Bitstream reader/writer inlined functions and constants- * * Copyright (C) 2001-2003 - Peter Ross * * This file is part of XviD, a free MPEG-4 video encoder/decoder * * XviD 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 1.17.2.3 2003-04-04 22:13:35 edgomez Exp $ * ****************************************************************************/ #ifndef _BITSTREAM_H_ #define _BITSTREAM_H_ #include "../portab.h" #include "../decoder.h" #include "../encoder.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_SIMPLE_FBA 13 */ #define VIDOBJLAY_TYPE_ASP 17 /*#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 /***************************************************************************** * Prototypes ****************************************************************************/ int read_video_packet_header(Bitstream *bs, DECODER * dec, const int addbits, int *quant, int *fcode_forward, int *fcode_backward, int *intra_dc_threshold); /* header stuff */ int BitstreamReadHeaders(Bitstream * bs, DECODER * dec, uint32_t * rounding, uint32_t * reduced_resolution, uint32_t * quant, uint32_t * fcode_forward, uint32_t * fcode_backward, uint32_t * intra_dc_threshold, WARPPOINTS * gmc_warp); void BitstreamWriteVolHeader(Bitstream * const bs, const MBParam * pParam); void BitstreamWriteVopHeader(Bitstream * const bs, const MBParam * pParam, const FRAMEINFO * const frame, int vop_coded); void BitstreamWriteUserData(Bitstream * const bs, uint8_t * data, const int length); /* 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)); } /* * 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) { uint32_t b = bs->buf; #ifndef ARCH_IS_BIG_ENDIAN BSWAP(b); #endif *bs->tail = b; 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); } #endif /* _BITSTREAM_H_ */