+ movit::YCbCrLumaCoefficients ycbcr_coefficients = input_state.ycbcr_coefficients[signal_num];
+ bool full_range = input_state.full_range[signal_num];
+
+ if (input_state.ycbcr_coefficients_auto[signal_num]) {
+ full_range = false;
+
+ // The Blackmagic driver docs claim that the device outputs Y'CbCr
+ // according to Rec. 601, but this seems to indicate the subsampling
+ // positions only, as they publish Y'CbCr → RGB formulas that are
+ // different for HD and SD (corresponding to Rec. 709 and 601, respectively),
+ // and a Lenovo X1 gen 3 I used to test definitely outputs Rec. 709
+ // (at least up to rounding error). Other devices seem to use Rec. 601
+ // even on HD resolutions. Nevertheless, Rec. 709 _is_ the right choice
+ // for HD, so we default to that if the user hasn't set anything.
+ if (height >= 720) {
+ ycbcr_coefficients = YCBCR_REC_709;
+ } else {
+ ycbcr_coefficients = YCBCR_REC_601;
+ }
+ }
+
+ // This is a global, but it doesn't really matter.
+ input_ycbcr_format.luma_coefficients = ycbcr_coefficients;
+ input_ycbcr_format.full_range = full_range;
+