mpeg12.c

mpeg4 video codec mpeg4 video codec

    return val;
}

static inline int decode_dc(GetBitContext *gb, int component)
{
    int code, diff;

    if (component == 0) {
        code = get_vlc2(gb, dc_lum_vlc.table, DC_VLC_BITS, 2);
    } else {
        code = get_vlc2(gb, dc_chroma_vlc.table, DC_VLC_BITS, 2);
    }
    if (code < 0){
        av_log(NULL, AV_LOG_ERROR, "invalid dc code at\n");
        return 0xffff;
    }
    if (code == 0) {
        diff = 0;
    } else {
        diff = get_xbits(gb, code);
    }
    return diff;
}

static inline int mpeg1_decode_block_intra(MpegEncContext *s, 
                               DCTELEM *block, 
                               int n)
{
    int level, dc, diff, i, j, run;
    int component;
    RLTable *rl = &rl_mpeg1;
    uint8_t * const scantable= s->intra_scantable.permutated;
    const uint16_t *quant_matrix= s->intra_matrix;
    const int qscale= s->qscale;

        /* DC coef */
        component = (n <= 3 ? 0 : n - 4 + 1);
    diff = decode_dc(&s->gb, component);
        if (diff >= 0xffff)
            return -1;
        dc = s->last_dc[component];
        dc += diff;
        s->last_dc[component] = dc;
    block[0] = dc<<3;
        dprintf("dc=%d diff=%d\n", dc, diff);
    i = 0;
    {
        OPEN_READER(re, &s->gb);    
        /* now quantify & encode AC coefs */
        for(;;) {
            UPDATE_CACHE(re, &s->gb);
            GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
            
            if(level == 127){
                break;
            } else if(level != 0) {
                i += run;
                j = scantable[i];
                level= (level*qscale*quant_matrix[j])>>4;
                level= (level-1)|1;
                level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
                LAST_SKIP_BITS(re, &s->gb, 1);
            } else {
                /* escape */
                run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
                UPDATE_CACHE(re, &s->gb);
                level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
                if (level == -128) {
                    level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
                } else if (level == 0) {
                    level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
                }
                i += run;
                j = scantable[i];
                if(level<0){
                    level= -level;
                    level= (level*qscale*quant_matrix[j])>>4;
                    level= (level-1)|1;
                    level= -level;
    } else {
                    level= (level*qscale*quant_matrix[j])>>4;
                    level= (level-1)|1;
                }
            }
            if (i > 63){
                av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
                return -1;
            }

            block[j] = level;
        }
        CLOSE_READER(re, &s->gb);
    }
    s->block_last_index[n] = i;
   return 0;
}

static inline int mpeg1_decode_block_inter(MpegEncContext *s, 
                               DCTELEM *block, 
                               int n)
{
    int level, i, j, run;
    RLTable *rl = &rl_mpeg1;
    uint8_t * const scantable= s->intra_scantable.permutated;
    const uint16_t *quant_matrix= s->inter_matrix;
    const int qscale= s->qscale;

    {
        OPEN_READER(re, &s->gb);
        i = -1;
        /* special case for the first coef. no need to add a second vlc table */
        UPDATE_CACHE(re, &s->gb);
        if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
            level= (3*qscale*quant_matrix[0])>>5;
            level= (level-1)|1;
            if(GET_CACHE(re, &s->gb)&0x40000000)
                level= -level;
            block[0] = level;
            i++;
            SKIP_BITS(re, &s->gb, 2);
            if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
                goto end;
    }

    /* now quantify & encode AC coefs */
    for(;;) {
            GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
            
            if(level != 0) {
                i += run;
                j = scantable[i];
                level= ((level*2+1)*qscale*quant_matrix[j])>>5;
                level= (level-1)|1;
                level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
                SKIP_BITS(re, &s->gb, 1);
            } else {
            /* escape */
                run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
                UPDATE_CACHE(re, &s->gb);
                level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
            if (level == -128) {
                    level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
            } else if (level == 0) {
                    level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
            }
                i += run;
                j = scantable[i];
                if(level<0){
                    level= -level;
                    level= ((level*2+1)*qscale*quant_matrix[j])>>5;
                    level= (level-1)|1;
                    level= -level;
        } else {
                    level= ((level*2+1)*qscale*quant_matrix[j])>>5;
                    level= (level-1)|1;
                }
        }
            if (i > 63){
                av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
            return -1;
            }

        block[j] = level;
            if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
                break;
            UPDATE_CACHE(re, &s->gb);
    }
end:
        LAST_SKIP_BITS(re, &s->gb, 2);
        CLOSE_READER(re, &s->gb);
    }
    s->block_last_index[n] = i;
    return 0;
}

static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n)
{
    int level, i, j, run;
    RLTable *rl = &rl_mpeg1;
    uint8_t * const scantable= s->intra_scantable.permutated;
    const int qscale= s->qscale;

    {
        OPEN_READER(re, &s->gb);
        i = -1;
        /* special case for the first coef. no need to add a second vlc table */
        UPDATE_CACHE(re, &s->gb);
        if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
            level= (3*qscale)>>1;
            level= (level-1)|1;
            if(GET_CACHE(re, &s->gb)&0x40000000)
                level= -level;
            block[0] = level;
            i++;
            SKIP_BITS(re, &s->gb, 2);
            if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
                goto end;
        }

        /* now quantify & encode AC coefs */
        for(;;) {
            GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
            
            if(level != 0) {
                i += run;
                j = scantable[i];
                level= ((level*2+1)*qscale)>>1;
                level= (level-1)|1;
                level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
                SKIP_BITS(re, &s->gb, 1);
            } else {
                /* escape */
                run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
                UPDATE_CACHE(re, &s->gb);
                level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
                if (level == -128) {
                    level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
                } else if (level == 0) {
                    level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
                }
                i += run;
                j = scantable[i];
                if(level<0){
                    level= -level;
                    level= ((level*2+1)*qscale)>>1;
                    level= (level-1)|1;
                    level= -level;
                }else{
                    level= ((level*2+1)*qscale)>>1;
                    level= (level-1)|1;
                }
            }

            block[j] = level;
            if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
                break;
            UPDATE_CACHE(re, &s->gb);
        }
end:
        LAST_SKIP_BITS(re, &s->gb, 2);
        CLOSE_READER(re, &s->gb);
    }
    s->block_last_index[n] = i;
    return 0;
}


static inline int mpeg2_decode_block_non_intra(MpegEncContext *s, 
                                        DCTELEM *block, 
                                        int n)
{
    int level, i, j, run;
    RLTable *rl = &rl_mpeg1;
    uint8_t * const scantable= s->intra_scantable.permutated;
    const uint16_t *quant_matrix;
    const int qscale= s->qscale;
    int mismatch;

    mismatch = 1;

    {
        OPEN_READER(re, &s->gb);
        i = -1;
        if (n < 4) 
            quant_matrix = s->inter_matrix;
        else
            quant_matrix = s->chroma_inter_matrix;
            
        /* special case for the first coef. no need to add a second vlc table */
        UPDATE_CACHE(re, &s->gb);
        if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
            level= (3*qscale*quant_matrix[0])>>5;
            if(GET_CACHE(re, &s->gb)&0x40000000)
                level= -level;
            block[0] = level;
            mismatch ^= level;
            i++;
            SKIP_BITS(re, &s->gb, 2);
            if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
                goto end;
    }

    /* now quantify & encode AC coefs */
    for(;;) {
            GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
            
            if(level != 0) {
                i += run;
                j = scantable[i];
                level= ((level*2+1)*qscale*quant_matrix[j])>>5;
                level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
                SKIP_BITS(re, &s->gb, 1);
            } else {
            /* escape */
                run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
                UPDATE_CACHE(re, &s->gb);
                level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);

                i += run;
                j = scantable[i];
                if(level<0){
                    level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
                    level= -level;
        } else {
                    level= ((level*2+1)*qscale*quant_matrix[j])>>5;
                }
        }
            if (i > 63){
                av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
            return -1;
        }
            
        mismatch ^= level;
        block[j] = level;
            if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
                break;
            UPDATE_CACHE(re, &s->gb);
        }
end:
        LAST_SKIP_BITS(re, &s->gb, 2);
        CLOSE_READER(re, &s->gb);
    }
    block[63] ^= (mismatch & 1);
    
    s->block_last_index[n] = i;
    return 0;
}

static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s, 
                               DCTELEM *block, 
                               int n)
{
    int level, i, j, run;
    RLTable *rl = &rl_mpeg1;
    uint8_t * const scantable= s->intra_scantable.permutated;
    const int qscale= s->qscale;
    OPEN_READER(re, &s->gb);
    i = -1;

    /* special case for the first coef. no need to add a second vlc table */
    UPDATE_CACHE(re, &s->gb);
    if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
        level= (3*qscale)>>1;
        if(GET_CACHE(re, &s->gb)&0x40000000)
            level= -level;
        block[0] = level;
        i++;
        SKIP_BITS(re, &s->gb, 2);
        if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
            goto end;
    }

    /* now quantify & encode AC coefs */
    for(;;) {
        GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
        
        if(level != 0) {
            i += run;
            j = scantable[i];
            level= ((level*2+1)*qscale)>>1;
            level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
            SKIP_BITS(re, &s->gb, 1);
        } else {
            /* escape */
            run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
            UPDATE_CACH