static inline void decode_subband_slice_buffered(SnowContext *s, SubBand *b, slice_buffer * sb, int start_y, int h, int save_state[1]){ const int w= b->width; int y; const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16); int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT); int qadd= (s->qbias*qmul)>>QBIAS_SHIFT; int new_index = 0; if(b->ibuf == s->spatial_idwt_buffer || s->qlog == LOSSLESS_QLOG){ qadd= 0; qmul= 1<<QEXPSHIFT; } /* If we are on the second or later slice, restore our index. */ if (start_y != 0) new_index = save_state[0]; for(y=start_y; y<h; y++){ int x = 0; int v; IDWTELEM * line = slice_buffer_get_line(sb, y * b->stride_line + b->buf_y_offset) + b->buf_x_offset; memset(line, 0, b->width*sizeof(IDWTELEM)); v = b->x_coeff[new_index].coeff; x = b->x_coeff[new_index++].x; while(x < w){ register int t= ( (v>>1)*qmul + qadd)>>QEXPSHIFT; register int u= -(v&1); line[x] = (t^u) - u; v = b->x_coeff[new_index].coeff; x = b->x_coeff[new_index++].x; } } /* Save our variables for the next slice. */ save_state[0] = new_index; return; }