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📄 mpeg12.c

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            } 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 MIN_CACHE_BITS < 19            UPDATE_CACHE(re, &s->gb);#endif            if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)                break;#if MIN_CACHE_BITS >= 19            UPDATE_CACHE(re, &s->gb);#endif        }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 = &ff_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;        }#if MIN_CACHE_BITS < 19        UPDATE_CACHE(re, &s->gb);#endif        /* 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 MIN_CACHE_BITS < 19            UPDATE_CACHE(re, &s->gb);#endif            if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)                break;#if MIN_CACHE_BITS >= 19            UPDATE_CACHE(re, &s->gb);#endif        }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 = &ff_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;        }#if MIN_CACHE_BITS < 19        UPDATE_CACHE(re, &s->gb);#endif        /* 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 MIN_CACHE_BITS < 19            UPDATE_CACHE(re, &s->gb);#endif            if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)                break;#if MIN_CACHE_BITS >= 19            UPDATE_CACHE(re, &s->gb);#endif        }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 = &ff_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;    }#if MIN_CACHE_BITS < 19    UPDATE_CACHE(re, &s->gb);#endif    /* 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_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)>>1;                level= -level;            }else{                level= ((level*2+1)*qscale)>>1;            }        }        block[j] = level;#if MIN_CACHE_BITS < 19        UPDATE_CACHE(re, &s->gb);#endif        if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)            break;#if MIN_CACHE_BITS >=19        UPDATE_CACHE(re, &s->gb);#endif    }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_intra(MpegEncContext *s,                               DCTELEM *block,                               int n){    int level, dc, diff, i, j, run;    int component;    RLTable *rl;    uint8_t * const scantable= s->intra_scantable.permutated;    const uint16_t *quant_matrix;    const int qscale= s->qscale;    int mismatch;    /* DC coef */    if (n < 4){        quant_matrix = s->intra_matrix;        component = 0;    }else{        quant_matrix = s->chroma_intra_matrix;        component = (n&1) + 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 - s->intra_dc_precision);    dprintf(s->avctx, "dc=%d\n", block[0]);    mismatch = block[0] ^ 1;    i = 0;    if (s->intra_vlc_format)        rl = &ff_rl_mpeg2;    else        rl = &ff_rl_mpeg1;    {        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 ^ 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, 12); SKIP_BITS(re, &s->gb, 12);                i += run;                j = scantable[i];                if(level<0){                    level= (-level*qscale*quant_matrix[j])>>4;                    level= -level;                }else{                    level= (level*qscale*quant_matrix[j])>>4;                }            }            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;        }        CLOSE_READER(re, &s->gb);    }    block[63]^= mismatch&1;    s->block_last_index[n] = i;    return 0;}static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,                               DCTELEM *block,                               int n){    int level, dc, diff, j, run;    int component;    RLTable *rl;    uint8_t * scantable= s->intra_scantable.permutated;    const uint16_t *quant_matrix;    const int qscale= s->qscale;    /* DC coef */    if (n < 4){        quant_matrix = s->intra_matrix;        component = 0;

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