int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near,

                             int point_transform, int ilv)

{

    int i, t = 0;

    uint8_t *zero, *last, *cur;

    JLSState *state;

    int off = 0, stride = 1, width, shift, ret = 0;



    zero = av_mallocz(s->picture_ptr->linesize[0]);

    if (!zero)

        return AVERROR(ENOMEM);

    last = zero;

    cur  = s->picture_ptr->data[0];



    state = av_mallocz(sizeof(JLSState));

    if (!state) {

        av_free(zero);

        return AVERROR(ENOMEM);

    }

    

    state->near   = near;

    state->bpp    = (s->bits < 2) ? 2 : s->bits;

    state->maxval = s->maxval;

    state->T1     = s->t1;

    state->T2     = s->t2;

    state->T3     = s->t3;

    state->reset  = s->reset;

    ff_jpegls_reset_coding_parameters(state, 0);

    ff_jpegls_init_state(state);



    if (s->bits <= 8)

        shift = point_transform + (8 - s->bits);

    else

        shift = point_transform + (16 - s->bits);



    if (shift >= 16) {

        ret = AVERROR_INVALIDDATA;


    }



    if (s->avctx->debug & FF_DEBUG_PICT_INFO) {

        av_log(s->avctx, AV_LOG_DEBUG,

               "JPEG-LS params: %ix%i NEAR=%i MV=%i T(%i,%i,%i) "

               "RESET=%i, LIMIT=%i, qbpp=%i, RANGE=%i\n",

                s->width, s->height, state->near, state->maxval,

                state->T1, state->T2, state->T3,

                state->reset, state->limit, state->qbpp, state->range);

        av_log(s->avctx, AV_LOG_DEBUG, "JPEG params: ILV=%i Pt=%i BPP=%i, scan = %i\n",

                ilv, point_transform, s->bits, s->cur_scan);

    }

    if (get_bits_left(&s->gb) < s->height) {

        ret = AVERROR_INVALIDDATA;


    }

    if (ilv == 0) { 

        if (s->cur_scan > s->nb_components) {

            ret = AVERROR_INVALIDDATA;


        }

        stride = (s->nb_components > 1) ? 3 : 1;

        off    = av_clip(s->cur_scan - 1, 0, stride - 1);

        width  = s->width * stride;

        cur   += off;

        for (i = 0; i < s->height; i++) {

            if (s->bits <= 8) {

                ls_decode_line(state, s, last, cur, t, width, stride, off, 8);

                t = last[0];

            } else {

                ls_decode_line(state, s, last, cur, t, width, stride, off, 16);

                t = *((uint16_t *)last);

            }

            last = cur;

            cur += s->picture_ptr->linesize[0];



            if (s->restart_interval && !--s->restart_count) {

                align_get_bits(&s->gb);

                skip_bits(&s->gb, 16); 

            }

        }

    } else if (ilv == 1) { 

        int j;

        int Rc[3] = { 0, 0, 0 };

        stride = (s->nb_components > 1) ? 3 : 1;

        memset(cur, 0, s->picture_ptr->linesize[0]);

        width = s->width * stride;

        for (i = 0; i < s->height; i++) {

            for (j = 0; j < stride; j++) {

                ls_decode_line(state, s, last + j, cur + j,

                               Rc[j], width, stride, j, 8);

                Rc[j] = last[j];



                if (s->restart_interval && !--s->restart_count) {

                    align_get_bits(&s->gb);

                    skip_bits(&s->gb, 16); 

                }

            }

            last = cur;

            cur += s->picture_ptr->linesize[0];

        }

    } else if (ilv == 2) { 

        avpriv_report_missing_feature(s->avctx, "Sample interleaved images");







    }



    if (s->xfrm && s->nb_components == 3) {

        int x, w;



        w = s->width * s->nb_components;



        if (s->bits <= 8) {

            uint8_t *src = s->picture_ptr->data[0];



            for (i = 0; i < s->height; i++) {

                switch(s->xfrm) {

                case 1:

                    for (x = off; x < w; x += 3) {

                        src[x  ] += src[x+1] + 128;

                        src[x+2] += src[x+1] + 128;

                    }

                    break;

                case 2:

                    for (x = off; x < w; x += 3) {

                        src[x  ] += src[x+1] + 128;

                        src[x+2] += ((src[x  ] + src[x+1])>>1) + 128;

                    }

                    break;

                case 3:

                    for (x = off; x < w; x += 3) {

                        int g = src[x+0] - ((src[x+2]+src[x+1])>>2) + 64;

                        src[x+0] = src[x+2] + g + 128;

                        src[x+2] = src[x+1] + g + 128;

                        src[x+1] = g;

                    }

                    break;

                case 4:

                    for (x = off; x < w; x += 3) {

                        int r    = src[x+0] - ((                       359 * (src[x+2]-128) + 490) >> 8);

                        int g    = src[x+0] - (( 88 * (src[x+1]-128) - 183 * (src[x+2]-128) +  30) >> 8);

                        int b    = src[x+0] + ((454 * (src[x+1]-128)                        + 574) >> 8);

                        src[x+0] = av_clip_uint8(r);

                        src[x+1] = av_clip_uint8(g);

                        src[x+2] = av_clip_uint8(b);

                    }

                    break;

                }

                src += s->picture_ptr->linesize[0];

            }

        }else

            avpriv_report_missing_feature(s->avctx, "16bit xfrm");

    }



    if (shift) { 

        int x, w;



        w = s->width * s->nb_components;



        if (s->bits <= 8) {

            uint8_t *src = s->picture_ptr->data[0];



            for (i = 0; i < s->height; i++) {

                for (x = off; x < w; x += stride)

                    src[x] <<= shift;

                src += s->picture_ptr->linesize[0];

            }

        } else {

            uint16_t *src = (uint16_t *)s->picture_ptr->data[0];



            for (i = 0; i < s->height; i++) {

                for (x = 0; x < w; x++)

                    src[x] <<= shift;

                src += s->picture_ptr->linesize[0] / 2;

            }

        }

    }



end:

    av_free(state);

    av_free(zero);



    return ret;

}