/***************************************************************************** * * XVID MPEG-4 VIDEO CODEC * - Bitstream reader/writer inlined functions and constants- * * Copyright (C) 2001-2002 - Peter Ross * * This program is an implementation of a part of one or more MPEG-4 * Video tools as specified in ISO/IEC 14496-2 standard. Those intending * to use this software module in hardware or software products are * advised that its use may infringe existing patents or copyrights, and * any such use would be at such party's own risk. The original * developer of this software module and his/her company, and subsequent * editors and their companies, will have no liability for use of this * software or modifications or derivatives thereof. * * 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 1.13 2002-09-21 03:07:56 suxen_drol 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 SLICE_START_CODE 0x000001b7 //#define EXT_START_CODE 0x000001b8 #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_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 VO_START_CODE 0x8 #define VOL_START_CODE 0x12 #define VOP_START_CODE 0x1b6 #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, const int addbits, int * quant); // header stuff int BitstreamReadHeaders(Bitstream * bs, DECODER * dec, uint32_t * rounding, uint32_t * quant, uint32_t * fcode_forward, uint32_t * fcode_backward, uint32_t * intra_dc_threshold); void BitstreamWriteVolHeader(Bitstream * const bs, const MBParam * pParam, const FRAMEINFO * frame); void BitstreamWriteVopHeader(Bitstream * const bs, const MBParam * pParam, const FRAMEINFO * frame, int vop_coded); /***************************************************************************** * Inlined functions ****************************************************************************/ /* initialise bitstream structure */ static void __inline BitstreamInit(Bitstream * const bs, void *const bitstream, uint32_t length) { uint32_t tmp; bs->start = bs->tail = (uint32_t *) bitstream; tmp = *(uint32_t *) bitstream; #ifndef ARCH_IS_BIG_ENDIAN BSWAP(tmp); #endif bs->bufa = tmp; tmp = *((uint32_t *) bitstream + 1); #ifndef ARCH_IS_BIG_ENDIAN BSWAP(tmp); #endif bs->bufb = tmp; bs->buf = 0; bs->pos = 0; 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 = 0; } /* 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 void __inline 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 uint32_t __inline BitstreamNumBitsToByteAlign(Bitstream *bs) { uint32_t n = (32 - bs->pos) % 8; return n == 0 ? 8 : n; } // show nbits from next byte alignment static uint32_t __inline 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 void __inline 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 8 * ((ptr_t)bs->tail - (ptr_t)bs->start) + bs->pos; } /* 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 = (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; } 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; } } /* pad bitstream to the next byte boundary */ static void __inline BitstreamPad(Bitstream * const bs) { uint32_t remainder = bs->pos % 8; if (remainder) { BitstreamForward(bs, 8 - remainder); } } /* 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); } } #endif /* _BITSTREAM_H_ */