+ if (s->cr_threshold) {
+ int x,y, x2, y2, p;
+ int bs = s->cr_size;
+
+ if (!s->ref) {
+ s->ref = av_frame_clone(frame);
+ if (!s->ref) {
+ ret = AVERROR(ENOMEM);
+ goto end;
+ }
+ }
+
+ alt_frame->format = AV_PIX_FMT_YUVA420P;
+ for (y = 0; y < frame->height; y+= bs) {
+ for (x = 0; x < frame->width; x+= bs) {
+ int skip;
+ int sse = 0;
+ for (p = 0; p < 3; p++) {
+ int bs2 = bs >> !!p;
+ int w = FF_CEIL_RSHIFT(frame->width , !!p);
+ int h = FF_CEIL_RSHIFT(frame->height, !!p);
+ int xs = x >> !!p;
+ int ys = y >> !!p;
+ for (y2 = ys; y2 < FFMIN(ys + bs2, h); y2++) {
+ for (x2 = xs; x2 < FFMIN(xs + bs2, w); x2++) {
+ int diff = frame->data[p][frame->linesize[p] * y2 + x2]
+ -s->ref->data[p][frame->linesize[p] * y2 + x2];
+ sse += diff*diff;
+ }
+ }
+ }
+ skip = sse < s->cr_threshold && frame->data[3] != s->ref->data[3];
+ if (!skip)
+ for (p = 0; p < 3; p++) {
+ int bs2 = bs >> !!p;
+ int w = FF_CEIL_RSHIFT(frame->width , !!p);
+ int h = FF_CEIL_RSHIFT(frame->height, !!p);
+ int xs = x >> !!p;
+ int ys = y >> !!p;
+ for (y2 = ys; y2 < FFMIN(ys + bs2, h); y2++) {
+ memcpy(&s->ref->data[p][frame->linesize[p] * y2 + xs],
+ & frame->data[p][frame->linesize[p] * y2 + xs], FFMIN(bs2, w-xs));
+ }
+ }
+ for (y2 = y; y2 < FFMIN(y+bs, frame->height); y2++) {
+ memset(&frame->data[3][frame->linesize[3] * y2 + x],
+ skip ? 0 : 255,
+ FFMIN(bs, frame->width-x));
+ }
+ }
+ }
+ }