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 (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 (ilv == 0) { 
        if (s->cur_scan > s->nb_components) {
        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");
        ret = AVERROR_PATCHWELCOME;
    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;