- int sum = ctx->m.dsp.pix_sum(pix, ctx->m.linesize);
- int varc = (ctx->m.dsp.pix_norm1(pix, ctx->m.linesize) - (((unsigned)sum*sum)>>8)+128)>>8;
+ int sum;
+ int varc;
+
+ if (!partial_last_row && mb_x * 16 <= avctx->width - 16) {
+ sum = ctx->m.dsp.pix_sum(pix, ctx->m.linesize);
+ varc = ctx->m.dsp.pix_norm1(pix, ctx->m.linesize);
+ } else {
+ int bw = FFMIN(avctx->width - 16 * mb_x, 16);
+ int bh = FFMIN((avctx->height >> ctx->interlaced) - 16 * mb_y, 16);
+ sum = varc = 0;
+ for (y = 0; y < bh; y++) {
+ for (x = 0; x < bw; x++) {
+ uint8_t val = pix[x + y * ctx->m.linesize];
+ sum += val;
+ varc += val * val;
+ }
+ }
+ }
+ varc = (varc - (((unsigned)sum * sum) >> 8) + 128) >> 8;
+