func: static int encode_picture_lossless(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
  
      MpegEncContext * const s = avctx->priv_data;
  
      MJpegContext * const m = s->mjpeg_ctx;
  
      AVFrame *pict = data;
  
      const int width= s->width;
  
      const int height= s->height;
  
      AVFrame * const p= (AVFrame*)&s->current_picture;
  
      const int predictor= avctx->prediction_method+1;
  
  
  
      init_put_bits(&s->pb, buf, buf_size);
  
  
  
      *p = *pict;
  
      p->pict_type= FF_I_TYPE;
  
      p->key_frame= 1;
  
  
  
      ff_mjpeg_encode_picture_header(s);
  
  
  
      s->header_bits= put_bits_count(&s->pb);
  
  
  
      if(avctx->pix_fmt == PIX_FMT_RGB32){
  
          int x, y, i;
  
          const int linesize= p->linesize[0];
  
          uint16_t (*buffer)[4]= (void *) s->rd_scratchpad;
  
          int left[3], top[3], topleft[3];
  
  
  
          for(i=0; i<3; i++){
  
              buffer[0][i]= 1 << (9 - 1);
  
          }
  
  
  
          for(y = 0; y < height; y++) {
  
              const int modified_predictor= y ? predictor : 1;
  
              uint8_t *ptr = p->data[0] + (linesize * y);
  
  
  
              if(s->pb.buf_end - s->pb.buf - (put_bits_count(&s->pb)>>3) < width*3*4){
  
                  av_log(s->avctx, AV_LOG_ERROR, "encoded frame too large\n");
  
                  return -1;
  
              }
  
  
  
              for(i=0; i<3; i++){
  
                  top[i]= left[i]= topleft[i]= buffer[0][i];
  
              }
  
              for(x = 0; x < width; x++) {
  
                  buffer[x][1] = ptr[4*x+0] - ptr[4*x+1] + 0x100;
  
                  buffer[x][2] = ptr[4*x+2] - ptr[4*x+1] + 0x100;
  
                  buffer[x][0] = (ptr[4*x+0] + 2*ptr[4*x+1] + ptr[4*x+2])>>2;
  
  
  
                  for(i=0;i<3;i++) {
  
                      int pred, diff;
  
  
  
                      PREDICT(pred, topleft[i], top[i], left[i], modified_predictor);
  
  
  
                      topleft[i]= top[i];
  
                      top[i]= buffer[x+1][i];
  
  
  
                      left[i]= buffer[x][i];
  
  
  
                      diff= ((left[i] - pred + 0x100)&0x1FF) - 0x100;
  
  
  
                      if(i==0)
  
                          ff_mjpeg_encode_dc(s, diff, m->huff_size_dc_luminance, m->huff_code_dc_luminance); //FIXME ugly
  
                      else
  
                          ff_mjpeg_encode_dc(s, diff, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
  
                  }
  
              }
  
          }
  
      }else{
  
          int mb_x, mb_y, i;
  
          const int mb_width  = (width  + s->mjpeg_hsample[0] - 1) / s->mjpeg_hsample[0];
  
          const int mb_height = (height + s->mjpeg_vsample[0] - 1) / s->mjpeg_vsample[0];
  
  
  
          for(mb_y = 0; mb_y < mb_height; mb_y++) {
  
              if(s->pb.buf_end - s->pb.buf - (put_bits_count(&s->pb)>>3) < mb_width * 4 * 3 * s->mjpeg_hsample[0] * s->mjpeg_vsample[0]){
  
                  av_log(s->avctx, AV_LOG_ERROR, "encoded frame too large\n");
  
                  return -1;
  
              }
  
              for(mb_x = 0; mb_x < mb_width; mb_x++) {
  
                  if(mb_x==0 || mb_y==0){
  
                      for(i=0;i<3;i++) {
  
                          uint8_t *ptr;
  
                          int x, y, h, v, linesize;
  
                          h = s->mjpeg_hsample[i];
  
                          v = s->mjpeg_vsample[i];
  
                          linesize= p->linesize[i];
  
  
  
                          for(y=0; y<v; y++){
  
                              for(x=0; x<h; x++){
  
                                  int pred;
  
  
  
                                  ptr = p->data[i] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap
  
                                  if(y==0 && mb_y==0){
  
                                      if(x==0 && mb_x==0){
  
                                          pred= 128;
  
                                      }else{
  
                                          pred= ptr[-1];
  
                                      }
  
                                  }else{
  
                                      if(x==0 && mb_x==0){
  
                                          pred= ptr[-linesize];
  
                                      }else{
  
                                          PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);
  
                                      }
  
                                  }
  
  
  
                                  if(i==0)
  
                                      ff_mjpeg_encode_dc(s, (int8_t)(*ptr - pred), m->huff_size_dc_luminance, m->huff_code_dc_luminance); //FIXME ugly
  
                                  else
  
                                      ff_mjpeg_encode_dc(s, (int8_t)(*ptr - pred), m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
  
                              }
  
                          }
  
                      }
  
                  }else{
  
                      for(i=0;i<3;i++) {
  
                          uint8_t *ptr;
  
                          int x, y, h, v, linesize;
  
                          h = s->mjpeg_hsample[i];
  
                          v = s->mjpeg_vsample[i];
  
                          linesize= p->linesize[i];
  
  
  
                          for(y=0; y<v; y++){
  
                              for(x=0; x<h; x++){
  
                                  int pred;
  
  
  
                                  ptr = p->data[i] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap
  
  //printf("%d %d %d %d %8X\n", mb_x, mb_y, x, y, ptr);
  
                                  PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);
  
  
  
                                  if(i==0)
  
                                      ff_mjpeg_encode_dc(s, (int8_t)(*ptr - pred), m->huff_size_dc_luminance, m->huff_code_dc_luminance); //FIXME ugly
  
                                  else
  
                                      ff_mjpeg_encode_dc(s, (int8_t)(*ptr - pred), m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
  
                              }
  
                          }
  
                      }
  
                  }
  
              }
  
          }
  
      }
  
  
  
      emms_c();
  
  
  
      ff_mjpeg_encode_picture_trailer(s);
  
      s->picture_number++;
  
  
  
      flush_put_bits(&s->pb);
  
      return pbBufPtr(&s->pb) - s->pb.buf;
  
  //    return (put_bits_count(&f->pb)+7)/8;
  
  }
  