static int draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { SliceContext *slice = link->dst->priv; int y2, ret = 0; if (slice_dir == 1) { for (y2 = y; y2 + slice->h <= y + h; y2 += slice->h) { ret = ff_draw_slice(link->dst->outputs[0], y2, slice->h, slice_dir); if (ret < 0) return ret; } if (y2 < y + h) return ff_draw_slice(link->dst->outputs[0], y2, y + h - y2, slice_dir); } else if (slice_dir == -1) { for (y2 = y + h; y2 - slice->h >= y; y2 -= slice->h) { ret = ff_draw_slice(link->dst->outputs[0], y2 - slice->h, slice->h, slice_dir); if (ret < 0) return ret; } if (y2 > y) return ff_draw_slice(link->dst->outputs[0], y, y2 - y, slice_dir); } return 0; }