i.MX ProcessorsのトピックRe: CVBS output PAL format is cropped

CVBS output PAL format is cropped

flto — Tue, 17 Mar 2015 08:44:52 GMT

Hi,

I try to output video on a CVBS display (from iMX53 with linux-2.6-imx-rel_imx_2.6.35_11.09.01 kernel from Freescale).

The display accepts PAL video format, so I use this kernel command line arguments :

video=mxcdi1fb:TV-PAL tve ldb=off

Thus my /dev/fb0 is displayed on the screen... but not entirely !

The image is cropped by about 30 pixels (left and right) and 15 pixels (top & bottom) [This is a rough estimation]

With an old TV, the image is cropped almost the same (but not exactly) and not cropped top and bottom when in 16:9 mode.

Does anyone know about CVBS, and has an idea why this happens ?

Here is fbset output:

$ fbset

mode "720x576-25"

        # D: 13.500 MHz, H: 15.625 kHz, V: 25.000 Hz

        geometry 720 576 720 1728 32

        timings 74074 132 11 22 26 1 1

        accel false

        rgba 8/16,8/8,8/0,8/24

endmode

Re: CVBS output PAL format is cropped

jamesbone — Mon, 30 Mar 2015 18:45:41 GMT

Can you please share what pins, or configuration you are using for the CVBS output,? are you using the TV Encoder output?

Re: CVBS output PAL format is cropped

flto — Tue, 31 Mar 2015 07:55:17 GMT

Here is related schematics :

Re: CVBS output PAL format is cropped

Kanstantsin1 — Mon, 27 May 2024 19:25:56 GMT

Hi @flto Have you resolved the issue?

I have stumbled to the same problem and don't know how to solve it.

Can you share with your way to solve?

Re: CVBS output PAL format is cropped

Kanstantsin1 — Mon, 27 May 2024 19:27:40 GMT

I have the same problem. ADV7391.

BT656-PAL configuration. But I see the cropped video even when I switch on COLOR-BAR-PATTERN

Re: CVBS output PAL format is cropped

Kanstantsin1 — Thu, 30 May 2024 19:06:56 GMT

So, I have resolved it in such way:

I fill only 656x544 at the center of the 720x576 screen. And leave black fields.

BTW: I have found that: different devices show different region of the image. For example PC-capture-card shows almost whole 720x576 image.