--- trunk/xvidcore/src/bitstream/mbcoding.c 2002/03/26 11:16:08 69 +++ trunk/xvidcore/src/bitstream/mbcoding.c 2002/05/02 00:36:50 153 @@ -1,145 +1,160 @@ + /****************************************************************************** + * * + * This file is part of XviD, a free MPEG-4 video encoder/decoder * + * * + * XviD 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. * + * * + * 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. * + * * + * XviD 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 * + * * + ******************************************************************************/ + + /****************************************************************************** + * * + * mbcoding.c * + * * + * Copyright (C) 2002 - Michael Militzer * + * * + * For more information visit the XviD homepage: http://www.xvid.org * + * * + ******************************************************************************/ + + /****************************************************************************** + * * + * Revision history: * + * * + * 14.04.2002 bframe encoding * + * 08.03.2002 initial version; isibaar * + * * + ******************************************************************************/ + + + +#include #include "../portab.h" #include "bitstream.h" #include "zigzag.h" #include "vlc_codes.h" +#include "mbcoding.h" #include "../utils/mbfunctions.h" -#include /* malloc, free */ - -#define ESCAPE 7167 #define ABS(X) (((X)>0)?(X):-(X)) #define CLIP(X,A) (X > A) ? (A) : (X) -static VLC *DCT3D[2]; +VLC intra_table[524032]; +VLC inter_table[524032]; -VLC *intra_table, *inter_table; -static short clip_table[4096]; +VLC DCT3Dintra[4096]; +VLC DCT3Dinter[4096]; -void create_vlc_tables(void) +void init_vlc_tables(void) { + int32_t k, l, i, intra, last; VLC *vlc[2]; VLC **coeff_ptr; VLC *vlc1, *vlc2; - VLC *DCT3Dintra; - VLC *DCT3Dinter; - - DCT3Dintra = (VLC *) malloc(sizeof(VLC) * 4096); - DCT3Dinter = (VLC *) malloc(sizeof(VLC) * 4096); - vlc1 = DCT3Dintra; vlc2 = DCT3Dinter; - vlc[0] = intra_table = (VLC *) malloc(128 * 511 * sizeof(VLC)); - vlc[1] = inter_table = (VLC *) malloc(128 * 511 * sizeof(VLC)); - - // initialize the clipping table - for(i = -2048; i < 2048; i++) { - clip_table[i + 2048] = i; - if(i < -255) - clip_table[i + 2048] = -255; - if(i > 255) - clip_table[i + 2048] = 255; - } + vlc[0] = intra_table; + vlc[1] = inter_table; - // generate intra/inter vlc lookup table + // generate encoding vlc lookup tables + // the lookup table idea is taken from the excellent fame project by Vivien Chapellier for(i = 0; i < 4; i++) { intra = i % 2; - last = i >> 1; + last = i / 2; - coeff_ptr = coeff_vlc[last + (intra << 1)]; - - for(k = -255; k < 256; k++) { // level - char *max_level_ptr = max_level[last + (intra << 1)]; - char *max_run_ptr = max_run[last + (intra << 1)]; + coeff_ptr = coeff_vlc[last + 2 * intra]; + + for(k = -2047; k < 2048; k++) { // level + int8_t *max_level_ptr = max_level[last + 2 * intra]; + int8_t *max_run_ptr = max_run[last + 2 * intra]; for(l = 0; l < 64; l++) { // run int32_t level = k; uint32_t run = l; - - if(abs(level) <= max_level_ptr[run] && run <= max_run_ptr[abs(level)]) { - - if(level > 0) { - vlc[intra]->code = (coeff_ptr[run][level - 1].code) << 1; - vlc[intra]->len = coeff_ptr[run][level - 1].len + 1; - } - else if(level < 0) { - vlc[intra]->code = ((coeff_ptr[run][-level - 1].code) << 1) + 1; - vlc[intra]->len = coeff_ptr[run][-level - 1].len + 1; - } - else { + + if((abs(level) <= max_level_ptr[run]) && + (run <= (uint32_t)max_run_ptr[abs(level)])) { // level < max_level and run < max_run + vlc[intra]->code = 0; vlc[intra]->len = 0; - } - } else { - if(level > 0) + goto loop_end; + } + else { + if(level > 0) // correct level level -= max_level_ptr[run]; else level += max_level_ptr[run]; - - if(abs(level) <= max_level_ptr[run] && - run <= max_run_ptr[abs(level)]) { - - if(level > 0) { - vlc[intra]->code = (0x06 << (coeff_ptr[run][level - 1].len + 1)) | - (coeff_ptr[run][level - 1].code << 1); - vlc[intra]->len = (coeff_ptr[run][level - 1].len + 1) + 8; - } - else if(level < 0) { - vlc[intra]->code = (0x06 << (coeff_ptr[run][-level - 1].len + 1)) | - ((coeff_ptr[run][-level - 1].code << 1) + 1); - vlc[intra]->len = (coeff_ptr[run][-level - 1].len + 1) + 8; - } - else { - vlc[intra]->code = 0x06; - vlc[intra]->len = 8; - } - } else { - if(level > 0) - level += max_level_ptr[run]; - else - level -= max_level_ptr[run]; - run -= max_run_ptr[abs(level)] + 1; + if((abs(level) <= max_level_ptr[run]) && + (run <= (uint32_t) max_run_ptr[abs(level)])) { - if(abs(level) <= max_level_ptr[run] && - run <= max_run_ptr[abs(level)]) { + vlc[intra]->code = 0x06; + vlc[intra]->len = 8; + goto loop_end; + } + + if(level > 0) // still here? + level += max_level_ptr[run]; // restore level + else + level -= max_level_ptr[run]; + + run -= max_run_ptr[abs(level)] + 1; // and change run + + if((abs(level) <= max_level_ptr[run]) && + (run <= (uint32_t) max_run_ptr[abs(level)])) { - if(level > 0) { - vlc[intra]->code = (0x0e << (coeff_ptr[run][level - 1].len + 1)) | - (coeff_ptr[run][level - 1].code << 1); - vlc[intra]->len = (coeff_ptr[run][level - 1].len + 1) + 9; - } - else if(level < 0) { - vlc[intra]->code = (0x0e << (coeff_ptr[run][-level - 1].len + 1)) | - ((coeff_ptr[run][-level - 1].code << 1) + 1); - vlc[intra]->len = (coeff_ptr[run][-level - 1].len + 1) + 9; - } - else { - vlc[intra]->code = 0x0e; - vlc[intra]->len = 9; - } - } else { - if(level != 0) - run += max_run_ptr[abs(level)] + 1; - else - run++; - - vlc[intra]->code = (uint32_t) ((0x1e + last) << 20) | - (l << 14) | (1 << 13) | ((k & 0xfff) << 1) | 1; - - vlc[intra]->len = 30; - } + vlc[intra]->code = 0x0e; + vlc[intra]->len = 9; + goto loop_end; } + run += max_run_ptr[abs(level)] + 1; + } + + vlc[intra]->code = (uint32_t) ((l << 14) | (0x1e + last) << 20) | + (1 << 13) | ((k & 0xfff) << 1) | 1; + + vlc[intra]->len = 30; + vlc[intra]++; + continue; + +loop_end: + if(level != 0) { + vlc[intra]->code = (vlc[intra]->code << (coeff_ptr[run][abs(level) - 1].len + 1)) | + (coeff_ptr[run][abs(level) - 1].code << 1); + vlc[intra]->len = (coeff_ptr[run][abs(level) - 1].len + 1) + vlc[intra]->len; + + if(level < 0) + vlc[intra]->code += 1; } + vlc[intra]++; } } } - intra_table += 64*255; // center vlc tables - inter_table += 64*255; // center vlc tables for(i = 0; i < 4096; i++) { if(i >= 512) { @@ -167,25 +182,12 @@ } -void destroy_vlc_tables(void) { - - if(intra_table != NULL && inter_table != NULL) { - intra_table -= 64*255; // uncenter vlc tables - inter_table -= 64*255; // uncenter vlc tables - - free(intra_table); - free(inter_table); - } - - if(DCT3D[0] != NULL && DCT3D[1] != NULL) { - free(DCT3D[0]); - free(DCT3D[1]); - } - -} - -static __inline void CodeVector(Bitstream *bs, int16_t value, int16_t f_code, Statistics *pStat) +static __inline void CodeVector(Bitstream *bs, + int32_t value, + int32_t f_code, + Statistics *pStat) { + const int scale_factor = 1 << (f_code - 1); const int cmp = scale_factor << 5; @@ -195,12 +197,12 @@ if(value > (cmp - 1)) value -= 64 * scale_factor; - pStat->iMvSum += value * value; - pStat->iMvCount++; + pStat->iMvSum += value * value; + pStat->iMvCount++; - if (value == 0) + if (value == 0) { BitstreamPutBits(bs, mb_motion_table[32].code, mb_motion_table[32].len); - else { + } else { uint16_t length, code, mv_res, sign; length = 16 << f_code; @@ -228,71 +230,83 @@ if(f_code) BitstreamPutBits(bs, mv_res, f_code); - } + } + } -static __inline void CodeCoeff(Bitstream *bs, int16_t qcoeff[64], VLC *table, - const uint16_t *zigzag, uint16_t intra) { +static __inline void CodeCoeff(Bitstream *bs, + const int16_t qcoeff[64], + VLC *table, + const uint16_t *zigzag, + uint16_t intra) +{ + uint32_t j, last; short v; VLC *vlc; j = intra; - last = 1 + intra; + last = intra; - while((v = qcoeff[zigzag[j++]]) == 0); + while(j < 64 && (v = qcoeff[zigzag[j]]) == 0) j++; do { + vlc = table + 64 * 2047 + (v << 6) + j - last; + last = ++j; + // count zeroes - vlc = table + (clip_table[2048+v] << 6) + j - last; - last = j + 1; - while(j < 64 && (v = qcoeff[zigzag[j++]]) == 0); + while(j < 64 && (v = qcoeff[zigzag[j]]) == 0) j++; // write code if(j != 64) { BitstreamPutBits(bs, vlc->code, vlc->len); } else { - vlc += 64*511; + vlc += 64 * 4095; BitstreamPutBits(bs, vlc->code, vlc->len); break; } } while(1); + } -static void CodeBlockIntra(const MBParam * pParam, const MACROBLOCK *pMB, - int16_t qcoeff[][64], Bitstream * bs, Statistics * pStat) +static void CodeBlockIntra(const FRAMEINFO * frame, + const MACROBLOCK *pMB, + int16_t qcoeff[6*64], + Bitstream * bs, + Statistics * pStat) { + uint32_t i, mcbpc, cbpy, bits; cbpy = pMB->cbp >> 2; - // write mcbpc - if(pParam->coding_type == I_VOP) { - mcbpc = ((pMB->mode >> 1) & 3) | ((pMB->cbp & 3) << 2); + // write mcbpc + if(frame->coding_type == I_VOP) { + mcbpc = ((pMB->mode >> 1) & 3) | ((pMB->cbp & 3) << 2); BitstreamPutBits(bs, mcbpc_intra_tab[mcbpc].code, mcbpc_intra_tab[mcbpc].len); } else { - mcbpc = (pMB->mode & 7) | ((pMB->cbp & 3) << 3); + mcbpc = (pMB->mode & 7) | ((pMB->cbp & 3) << 3); BitstreamPutBits(bs, mcbpc_inter_tab[mcbpc].code, mcbpc_inter_tab[mcbpc].len); } // ac prediction flag if(pMB->acpred_directions[0]) - BitstreamPutBits(bs, 1, 1); + BitstreamPutBits(bs, 1, 1); else - BitstreamPutBits(bs, 0, 1); + BitstreamPutBits(bs, 0, 1); - // write cbpy + // write cbpy BitstreamPutBits (bs, cbpy_tab[cbpy].code, cbpy_tab[cbpy].len); // write dquant - if(pMB->mode == MODE_INTRA_Q) + if(pMB->mode == MODE_INTRA_Q) BitstreamPutBits(bs, pMB->dquant, 2); // write interlacing - if (pParam->global_flags & XVID_INTERLACING) + if (frame->global_flags & XVID_INTERLACING) { BitstreamPutBit(bs, pMB->field_dct); } @@ -301,46 +315,57 @@ for(i = 0; i < 6; i++) { if(i < 4) - BitstreamPutBits(bs, dcy_tab[qcoeff[i][0] + 255].code, - dcy_tab[qcoeff[i][0] + 255].len); + BitstreamPutBits(bs, + dcy_tab[qcoeff[i*64 + 0] + 255].code, + dcy_tab[qcoeff[i*64 + 0] + 255].len); else - BitstreamPutBits(bs, dcc_tab[qcoeff[i][0] + 255].code, - dcc_tab[qcoeff[i][0] + 255].len); + BitstreamPutBits(bs, + dcc_tab[qcoeff[i*64 + 0] + 255].code, + dcc_tab[qcoeff[i*64 + 0] + 255].len); if(pMB->cbp & (1 << (5 - i))) { bits = BitstreamPos(bs); - CodeCoeff(bs, qcoeff[i], intra_table, scan_tables[pMB->acpred_directions[i]], 1); + CodeCoeff(bs, + &qcoeff[i*64], + intra_table, + scan_tables[pMB->acpred_directions[i]], + 1); bits = BitstreamPos(bs) - bits; pStat->iTextBits += bits; } } + } -static void CodeBlockInter(const MBParam * pParam, const MACROBLOCK *pMB, - int16_t qcoeff[][64], Bitstream * bs, Statistics * pStat) +static void CodeBlockInter(const FRAMEINFO * frame, + const MACROBLOCK *pMB, + int16_t qcoeff[6*64], + Bitstream * bs, + Statistics * pStat) { + int32_t i; uint32_t bits, mcbpc, cbpy; - mcbpc = (pMB->mode & 7) | ((pMB->cbp & 3) << 3); + mcbpc = (pMB->mode & 7) | ((pMB->cbp & 3) << 3); cbpy = 15 - (pMB->cbp >> 2); // write mcbpc - BitstreamPutBits(bs, mcbpc_inter_tab[mcbpc].code, mcbpc_inter_tab[mcbpc].len); + BitstreamPutBits(bs, mcbpc_inter_tab[mcbpc].code, mcbpc_inter_tab[mcbpc].len); // write cbpy BitstreamPutBits(bs, cbpy_tab[cbpy].code, cbpy_tab[cbpy].len); // write dquant - if(pMB->mode == MODE_INTER_Q) + if(pMB->mode == MODE_INTER_Q) BitstreamPutBits(bs, pMB->dquant, 2); // interlacing - if (pParam->global_flags & XVID_INTERLACING) + if (frame->global_flags & XVID_INTERLACING) { BitstreamPutBit(bs, pMB->field_dct); DEBUG1("codep: field_dct: ", pMB->field_dct); @@ -363,8 +388,8 @@ // code motion vector(s) for(i = 0; i < (pMB->mode == MODE_INTER4V ? 4 : 1); i++) { - CodeVector(bs, pMB->pmvs[i].x, pParam->fixed_code, pStat); - CodeVector(bs, pMB->pmvs[i].y, pParam->fixed_code, pStat); + CodeVector(bs, pMB->pmvs[i].x, frame->fcode, pStat); + CodeVector(bs, pMB->pmvs[i].y, frame->fcode, pStat); } bits = BitstreamPos(bs); @@ -372,22 +397,26 @@ // code block coeffs for(i = 0; i < 6; i++) if(pMB->cbp & (1 << (5 - i))) - CodeCoeff(bs, qcoeff[i], inter_table, scan_tables[0], 0); + CodeCoeff(bs, &qcoeff[i*64], inter_table, scan_tables[0], 0); bits = BitstreamPos(bs) - bits; pStat->iTextBits += bits; + } -void MBCoding(const MBParam * pParam, MACROBLOCK *pMB, - int16_t qcoeff[][64], - Bitstream * bs, Statistics * pStat) +void MBCoding(const FRAMEINFO * frame, + MACROBLOCK *pMB, + int16_t qcoeff[6*64], + Bitstream * bs, + Statistics * pStat) { + int intra = (pMB->mode == MODE_INTRA || pMB->mode == MODE_INTRA_Q); - if(pParam->coding_type == P_VOP) { + if(frame->coding_type == P_VOP) { if(pMB->cbp == 0 && pMB->mode == MODE_INTER && - pMB->mvs[0].x == 0 && pMB->mvs[0].y == 0) + pMB->mvs[0].x == 0 && pMB->mvs[0].y == 0) { BitstreamPutBit(bs, 1); // not_coded return; @@ -397,18 +426,158 @@ } if(intra) - CodeBlockIntra(pParam, pMB, qcoeff, bs, pStat); + CodeBlockIntra(frame, pMB, qcoeff, bs, pStat); + else + CodeBlockInter(frame, pMB, qcoeff, bs, pStat); + +} + +/*************************************************************** + * bframe encoding start + ***************************************************************/ + +/* + mbtype + 0 1b direct(h263) mvdb + 1 01b interpolate mc+q dbquant, mvdf, mvdb + 2 001b backward mc+q dbquant, mvdb + 3 0001b forward mc+q dbquant, mvdf +*/ + +void put_bvop_mbtype(Bitstream * bs, int value) +{ + switch(value) + { + case 0 : BitstreamPutBit(bs, 1); + return; + + case 1 : BitstreamPutBit(bs, 0); + BitstreamPutBit(bs, 1); + return; + + case 2 : BitstreamPutBit(bs, 0); + BitstreamPutBit(bs, 0); + BitstreamPutBit(bs, 1); + return; + + case 3 : BitstreamPutBit(bs, 0); + BitstreamPutBit(bs, 0); + BitstreamPutBit(bs, 0); + BitstreamPutBit(bs, 1); + return; + + default : ; // invalid! + + } + +} + +/* + dbquant + -2 10b + 0 0b + +2 11b +*/ + +void put_bvop_dbquant(Bitstream *bs, int value) +{ + switch (value) + { + case 0 : BitstreamPutBit(bs, 0); + return; + + case -2 : BitstreamPutBit(bs, 1); + BitstreamPutBit(bs, 0); + return; + + case 2 : BitstreamPutBit(bs, 1); + BitstreamPutBit(bs, 1); + return; + + default : ; // invalid + } +} + + + +void MBCodingBVOP(const MACROBLOCK * mb, + const int16_t qcoeff[6*64], + const int32_t fcode, + const int32_t bcode, + Bitstream * bs, + Statistics * pStat) +{ + int i; + +/* ------------------------------------------------------------------ + when a block is skipped it is decoded DIRECT(0,) + hence are interpolated from forward & backward frames + ------------------------------------------------------------------ */ + + if (mb->mode == 5) + { + BitstreamPutBit(bs, 1); // skipped + return; + } + + BitstreamPutBit(bs, 0); // not skipped + + if (mb->cbp == 0) + { + BitstreamPutBit(bs, 1); // cbp == 0 + } else - CodeBlockInter(pParam, pMB, qcoeff, bs, pStat); + { + BitstreamPutBit(bs, 0); // cbp == xxx + } + + put_bvop_mbtype(bs, mb->mode); + + if (mb->cbp) + { + BitstreamPutBits(bs, mb->cbp, 6); + } + + if (mb->mode != MODE_DIRECT && mb->cbp != 0) + { + put_bvop_dbquant(bs, 0); // todo: mb->dquant = 0 + } + + if (mb->mode == MODE_INTERPOLATE || mb->mode == MODE_FORWARD) + { + CodeVector(bs, mb->pmvs[0].x, fcode, pStat); + CodeVector(bs, mb->pmvs[0].y, fcode, pStat); + } + + if (mb->mode == MODE_INTERPOLATE || mb->mode == MODE_BACKWARD) + { + CodeVector(bs, mb->b_pmvs[0].x, bcode, pStat); + CodeVector(bs, mb->b_pmvs[0].y, bcode, pStat); + } + + if (mb->mode == MODE_DIRECT) + { + // TODO: direct + } + + for (i = 0; i < 6; i++) + { + if (mb->cbp & (1 << (5 - i))) + { + CodeCoeff(bs, &qcoeff[i*64], inter_table, scan_tables[0], 0); + } + } } + /*************************************************************** * decoding stuff starts here * ***************************************************************/ int get_mcbpc_intra(Bitstream * bs) { + uint32_t index; while((index = BitstreamShowBits(bs, 9)) == 1) @@ -417,22 +586,28 @@ index >>= 3; BitstreamSkip(bs, mcbpc_intra_table[index].len); + return mcbpc_intra_table[index].code; + } int get_mcbpc_inter(Bitstream * bs) { + uint32_t index; while((index = CLIP(BitstreamShowBits(bs, 9), 256)) == 1) BitstreamSkip(bs, 9); - BitstreamSkip(bs, mcbpc_inter_table[index].len); + BitstreamSkip(bs, mcbpc_inter_table[index].len); + return mcbpc_inter_table[index].code; + } int get_cbpy(Bitstream * bs, int intra) { + int cbpy; uint32_t index = BitstreamShowBits(bs, 6); @@ -443,10 +618,12 @@ cbpy = 15 - cbpy; return cbpy; + } int get_mv_data(Bitstream * bs) { + uint32_t index; if(BitstreamGetBit(bs)) @@ -472,10 +649,12 @@ BitstreamSkip(bs, TMNMVtab2[index].len); return TMNMVtab2[index].code; + } int get_mv(Bitstream * bs, int fcode) { + int data; int res; int mv; @@ -490,10 +669,12 @@ mv = ((ABS(data) - 1) * scale_fac) + res + 1; return data < 0 ? -mv : mv; + } int get_dc_dif(Bitstream * bs, uint32_t dc_size) { + int code = BitstreamGetBits(bs, dc_size); int msb = code >> (dc_size - 1); @@ -501,10 +682,12 @@ return (-1 * (code^((1 << dc_size) - 1))); return code; + } int get_dc_size_lum(Bitstream * bs) { + int code, i; code = BitstreamShowBits(bs, 11); @@ -518,11 +701,13 @@ BitstreamSkip(bs, dc_lum_tab[code].len); return dc_lum_tab[code].code; + } int get_dc_size_chrom(Bitstream * bs) { + uint32_t code, i; code = BitstreamShowBits(bs, 12); @@ -535,102 +720,12 @@ } return 3 - BitstreamGetBits(bs, 2); -} - -int get_coeff(Bitstream * bs, int *run, int *last, int intra, int short_video_header) -{ - uint32_t mode; - const VLC *tab; - int32_t level; - - if(short_video_header) // inter-VLCs will be used for both intra and inter blocks - intra = 0; - - tab = &DCT3D[intra][BitstreamShowBits(bs, 12)]; - - if(tab->code == -1) - goto error; - - BitstreamSkip(bs, tab->len); - - if(tab->code != ESCAPE) { - if(!intra) - { - *run = (tab->code >> 4) & 255; - level = tab->code & 15; - *last = (tab->code >> 12) & 1; - } - else - { - *run = (tab->code >> 8) & 255; - level = tab->code & 255; - *last = (tab->code >> 16) & 1; - } - return BitstreamGetBit(bs) ? -level : level; - } - - if(short_video_header) - { - // escape mode 4 - H.263 type, only used if short_video_header = 1 - *last = BitstreamGetBit(bs); - *run = BitstreamGetBits(bs, 6); - level = BitstreamGetBits(bs, 8); - - if (level == 0 || level == 128) - DEBUG1("Illegal LEVEL for ESCAPE mode 4:", level); - - return (level >= 128 ? -(256 - level) : level); - } - - mode = BitstreamShowBits(bs, 2); - - if(mode < 3) { - BitstreamSkip(bs, (mode == 2) ? 2 : 1); - - tab = &DCT3D[intra][BitstreamShowBits(bs, 12)]; - if (tab->code == -1) - goto error; - BitstreamSkip(bs, tab->len); - - if (!intra) { - *run = (tab->code >> 4) & 255; - level = tab->code & 15; - *last = (tab->code >> 12) & 1; - } - else - { - *run = (tab->code >> 8) & 255; - level = tab->code & 255; - *last = (tab->code >> 16) & 1; - } - - if(mode < 2) // first escape mode, level is offset - level += max_level[*last + (!intra<<1)][*run]; // need to add back the max level - else if(mode == 2) // second escape mode, run is offset - *run += max_run[*last + (!intra<<1)][level] + 1; - - return BitstreamGetBit(bs) ? -level : level; - } - - // third escape mode - fixed length codes - BitstreamSkip(bs, 2); - *last = BitstreamGetBits(bs, 1); - *run = BitstreamGetBits(bs, 6); - BitstreamSkip(bs, 1); // marker - level = BitstreamGetBits(bs, 12); - BitstreamSkip(bs, 1); // marker - - return (level & 0x800) ? (level | (-1 ^ 0xfff)) : level; - -error: - *run = VLC_ERROR; - return 0; } - void get_intra_block(Bitstream * bs, int16_t * block, int direction, int coeff) { + const uint16_t * scan = scan_tables[ direction ]; int level; int run; @@ -652,10 +747,12 @@ } coeff++; } while (!last); + } void get_inter_block(Bitstream * bs, int16_t * block) { + const uint16_t * scan = scan_tables[0]; int p; int level; @@ -679,4 +776,5 @@ } p++; } while (!last); + }