Hi, I was wondering if it is possible for me to integrate a breakout board which consists of my own NTSC camera that is sent through a video decoder chip to the same port that the VGA camera attaches to. If so does anyone have the pinouts for what the DM355 expects? Also the DM355 can handle a 640x480 (D1) stream encoding to MPEG4 at 30fps correct? Any chance there are libraries for H.264 that can do the same?
Yeah, I've done this, and there are some problems... You would think that you could just connect a decoder with BT656 to the J5 connector and be on your way. But, if you look, you will see lines labeled CMDS_D0 to CMOS_D11. These go over to the DM355 lines YIN2 thru YIN7 and CIN0 to CIN5. Notice YIN0 and YIN1 are not connected to anything. This means you can't do a standard 8 or 10 bit interface. I was stuck do a 6 bit interface, so the picture is not great.
In addition bt.656 uses in band signaling for vertical and horizontal sync. With a 6 bit interface, we can't really make use of the in band signaling, so we have to put the dm355 in generic YCbCr mode and use the actual sync lines coming out of your video decoder.
There is also the issue of frame interlacing... You might have to use a GPIO pin from the dm355 connected to the odd/even frame indication line of your video decoder so you can tell which frame you are receiving, and de-interlace them properly.
And don't forget about the I2C interface.
I think the leopard guys said they were coming out with a analog interface board-- I'm interested to see how they dealt with these issues, or if their board just works on the dm365 board.
It should, but I believe you will only be able to do a six bit interface-- unless I am overlooking something. And you will have to use generic YCbCr mode on the DM355 with external sync connections from the TVP5146. By the way, we used the TVP5150.
i am designing video decoder board using TVP5146 .if we use it in YCbCr for S-video in for analog camera and using
YIN2 to YIN7 and CIN0 to CIN5 lines for the video on DM355 side will it work . Also voltage level on DM355 is 3.3?? could you conform that .
how is your video quality for 640x480 VGA video is it acceptable . in DM355EVM they are using HD,VD and PCLK for synchronization . will it be ok as i think that driver for TVP4146 is written considering these signal only .
Thanks for the help (sorry for the late reply, I have been on vacation), it is a bit disappointing that it isn't possible to do a standard 8/10 bit interface, hopefully someone from the Leopardboard team could clear up interfacing our own video decoders. I guess I am hesitant to buy the leopardboard without being able to confirm that I will be able to interface a 8/10bit video decoder to the preexisting camera port.