12-02-2019, 09:16 AM
From the camera the signal passes through ISP which can reduce resolution, and further through VIPP, which actually 16 phase scalar of 7/5 taps. I.e. - we have 2 consistently included scalers which on the polyphase filter can reduce the picture twice. 1/4 turns out. Typical scalers, except the polyphase filter, usually are able to throw out lines, sometimes 2 that significantly expands possibilities of scaling. Unfortunately, the VIPP node (scaler) in the datasheet is not described and is not clear whether he can throw out lines. Try to read the text of a driver of sunxi-scaler and to twist its settings through IOCTL. Maybe it will turn out, and can is not present.