topic Re: imx6 CSI progressive BT.656 input frame rate issue in i.MX Processors

imx6 CSI progressive BT.656 input frame rate issue

tieliu — Tue, 03 Nov 2015 10:29:24 GMT

Dear all,

I am using TW8836 to convert DTV progressive video into progressive BT.656 signal, and using imx6 CSI to capture it. The TW8836 BT.656 output stream cannot fix the F bit to 0 for progressive BT.656. Instead, the even and odd frames are having F=0 and F=1 respectively. Unfortunately, when I capture this progressive stream in imx6, the CSI can only recognize one particular set of SAV / EAV H/V/F code(either even frame or odd frame). As a result, I can only capture half of the frame rate comparing to my original DTV video.

(For example, for a 60fps video I can only get 30fps captured stream in V4L2, no matter I set IPU_CSI_CCIR_CODE_1 to 0x40010 or 0xD0018, )

Could anybody please kindly teach me, how to program CSI so that the F bit can be ignored?

Thank you,

Best regards

Tie

Re: imx6 CSI progressive BT.656 input frame rate issue

igorpadykov — Tue, 10 Nov 2015 13:40:39 GMT

Hi Tie

unfortunately there is no way to program IPU CSI so that the F bit can be ignored,

in general one can program it for input as generic data.

Best regards

igor

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Re: imx6 CSI progressive BT.656 input frame rate issue

tieliu — Wed, 11 Nov 2015 01:35:42 GMT

Hi Igor

Thanks a lot for the answer. I guess I have to figure out ways fixing F-bit in the progressive stream using TW8836 register setting. (TW8836 vendor suggested fixing TW8836 register 0x067 bit5 to 1 and 0x068 bit7 to 1 but unfortunately it does not work out in my case, probably because my DTV progressive source has varying F-bit as input already).

Tie