+/* UtVideo interlaced mode treats every two lines as a single one,
+ * so restoring function should take care of possible padding between
+ * two parts of the same "line".
+ */
+static void restore_median_il(uint8_t *src, int step, int stride,
+ int width, int height, int slices, int rmode)
+{
+ int i, j, slice;
+ int A, B, C;
+ uint8_t *bsrc;
+ int slice_start, slice_height;
+ const int cmask = ~(rmode ? 3 : 1);
+ const int stride2 = stride << 1;
+
+ for (slice = 0; slice < slices; slice++) {
+ slice_start = ((slice * height) / slices) & cmask;
+ slice_height = ((((slice + 1) * height) / slices) & cmask) - slice_start;
+ slice_height >>= 1;
+
+ bsrc = src + slice_start * stride;
+
+ // first line - left neighbour prediction
+ bsrc[0] += 0x80;
+ A = bsrc[0];
+ for (i = step; i < width * step; i += step) {
+ bsrc[i] += A;
+ A = bsrc[i];
+ }
+ for (i = 0; i < width * step; i += step) {
+ bsrc[stride + i] += A;
+ A = bsrc[stride + i];
+ }
+ bsrc += stride2;
+ if (slice_height == 1)
+ continue;
+ // second line - first element has top predition, the rest uses median
+ C = bsrc[-stride2];
+ bsrc[0] += C;
+ A = bsrc[0];
+ for (i = step; i < width * step; i += step) {
+ B = bsrc[i - stride2];
+ bsrc[i] += mid_pred(A, B, (uint8_t)(A + B - C));
+ C = B;
+ A = bsrc[i];
+ }
+ for (i = 0; i < width * step; i += step) {
+ B = bsrc[i - stride];
+ bsrc[stride + i] += mid_pred(A, B, (uint8_t)(A + B - C));
+ C = B;
+ A = bsrc[stride + i];
+ }
+ bsrc += stride2;
+ // the rest of lines use continuous median prediction
+ for (j = 2; j < slice_height; j++) {
+ for (i = 0; i < width * step; i += step) {
+ B = bsrc[i - stride2];
+ bsrc[i] += mid_pred(A, B, (uint8_t)(A + B - C));
+ C = B;
+ A = bsrc[i];
+ }
+ for (i = 0; i < width * step; i += step) {
+ B = bsrc[i - stride];
+ bsrc[i + stride] += mid_pred(A, B, (uint8_t)(A + B - C));
+ C = B;
+ A = bsrc[i + stride];
+ }
+ bsrc += stride2;
+ }
+ }
+}
+