static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,

                                                    int16_t *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 first coefficient, no need to add 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 coefficients */

    for (;;) {

        GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);



        if (level != 0) {

            i += run;

            check_scantable_index(s, i);

            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;

            check_scantable_index(s, i);

            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 (((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;

}
