cropped / cut image with generic bt878 card=77

[schweini]

Hello,

I finally got my hands on a really generic bt878 card, that abrely has anything more than the bt878 chip on it. after much trial and error, "rmmod bt878ñrmmod bttv; modprobe bttv card=77" at least gives me something resembling images on all four inputs, even though the modprobe takes ages, because it seems to try to autodetect the i2c chipset (which the card doesn't have, or, according to some other posts, isn´t really necessary for zoneminder).

But all images seem to 'wrap around' badly, meaning that the top 10% of the image appear at the bottom of the image, with some random noise as the border between the bottom part of the image, and the wrapped-around top part of it. this border also jumps up and down by about 5% of the image's height (which makes motion detection useless, obviously).

i uploaded a screencap of ZM illustrating the issue to http://gometa.org/xawtv.png

it seems to me that maybe this is a resolution issue, but i tried any conceivable resolution i found in the v4l docs, and that didn't help. TV norms (NTSC, PAL, etc.) didn't seem to change anything, either.
So, anyone have a clue what i am doing wrong? I am forcing the card type to 77, because that was the only option i found that actually kind of worked, but maybe there some other card types that i could try? Or maybe something else to change the resolution?

here's the dmesg output:

[175126.173433] bttv: driver version 0.9.16 loaded
[175126.173445] bttv: using 8 buffers with 2080k (520 pages) each for capture
[175126.174414] bttv: Bt8xx card found (0).
[175126.174535] bttv0: Bt878 (rev 17) at 0000:01:09.0, irq: 17, latency: 64, mmio: 0xe3800000
[175126.174686] bttv0: using: GrandTec Multi Capture Card (Bt878) [card=77,insmod option]
[175126.174857] bttv0: gpio: en=00000000, out=00000000 in=00f360ff [init]
[175132.751263] bttv0: using tuner=-1
[175132.751277] bttv0: i2c: checking for TDA9875 @ 0xb0... not found
[175139.143971] bttv0: i2c: checking for TDA7432 @ 0x8a... not found
[175145.537582] bttv0: i2c: checking for TDA9887 @ 0x86... not found
[175151.934290] bttv0: registered device video0
[175151.939146] bttv0: registered device vbi0
[175151.939596] bttv0: PLL: 28636363 => 35468950 .. ok

Thanks for any help!

P.S.: is there a way to tell modprobe NOT to autodetect the i2c chip? it really does take too long to load...[/quote][/url]

[jameswilson]

have a look for the setting in config that alters the number of grabbed frames, chnage it from 1 to 2 or 3.
This will badly affect framerate but should solve your problem.

Sounds like you have a serious sync issue on one of your cams ie somethings wrong with it