Hi,
Let me share my experiments so far and ask some questions....
The RemoteVision card is composed of BT848, GMS80C301 (a kind of the
well know 8051 microcontroler, any idea why this is need?), W27E257
(eprom for 80C301), LM1881 (video sync separator, why?), CD22M6494E
(crosspoint switch from harris, i got datasheet for it's brother
CD22M3494E).
The video inputs are conected to the crosspoint switch, pins X0, X1, X2
etc. The Y0 from switch has a decoupling capacitor to MUX1. MUXOUT has
another cap to Yin.
GPIO pins are conected as following:
0: AX0
1: AX1
2: AX2
3: AX3
4: AY0
5: AY1
6: AY2
7: DATA
8: to microcontroler
9: RESET
10: STROBE
To proper supporting this scheme under bttv i will need some hooks like
"pre_muxsel" and "post_muxsel". This is needed because we are not
programing a MUX, but a xpoint switcher. There may be several multiple
conections across the switch, so before programing a new conection we
have to clean the last one. After writing the address to GPIO we must
pulse the STROBE pin to create a new conection.
Now the card is almost working. I got images and input channel selection
works fine.
Problems:
- i can only grab 352x288 pictures (windows driver can do 640x480). I'm
not aware of how the resolution is changed, i'm just using the 'motion'
program that should be taking care of this. If i change to 640x480 the
image is completely broken, as if there were two different images
interlaced.
- the frame is out of sync, i can see the vertical sync bar. i don't
know how bt848 is supposed to sync with video, maybe this have something
to do with that microcontroller? pll settings also don't seem to make
any difference...
regards,
Miguel Freitas
