analog video to serial converter?

[NeX]

Hi everyone,

I am looking to display the video feed from a standard composite camera, on a display using an FT810 eve chip. the eve chip can display video if it arrives as a series of JPEG stills,

i have tried to find something that can take a composite signal and convert it to a serial data format but i am not even sure what i am looking for exactly.

there are JPEG serial cameras and i know they work with the FTDI chip but that limits me to a small range of cameras. with composite cameras there are so many options.

does anyone have any tips? just the name of something i could search for would be a huge help.

thanks guys!

 

[dknguyen]

I've looked into something similar...and all I have to say is...don't bother. Change the camera or change the screen unless you want to delve into rolling your own analog video digitizer board with an FPGA or "true" high-end DSP to do the digital to JPEG conversion.

Modules to convert composite video to raw digital form are rare and the ICs that do the job are difficult to work with and require serious PCB design with an associated processor to manipulate the output data.

Those JPEG serial cameras are using a function inherent to the silicon on the CMOS camera so there's no pre-existing chips available to roll your own.

The only conceivable way I have seen of pulling this off without turning into several projects unto itself is with a suitable video dev board it but the cost of such dev boards (not to mention you still have to code the thing) is such that should just spend that $1000+ on a different camera or monitor.

 

[ronsimpson]

"usb video capture"
I also have one with 4 video inputs but only one audio input. Works with a PC or Raspberry PI.
There are several different types.

 

[NeX]

thanks for the replies,

the problem is i need video embedded in a graphical user interface, so no matter what display i use i have to merge video with an interface. the camera side of things i could use a Jpeg camera but they are so limited compared to the analog ones that are available.

 

[ronsimpson]

Jpeg camera but they are so limited

define limited. What can not be done?
Do you want real time video or stills.
What CPU are you using? Does it have the ability to use USB?

 

[dknguyen]

thanks for the replies,

the problem is i need video embedded in a graphical user interface, so no matter what display i use i have to merge video with an interface. the camera side of things i could use a Jpeg camera but they are so limited compared to the analog ones that are available.

Yes, provide more details. There are things like the BOB-4 and it could be much easier to replace your current GUI hardware with that than to find a way to make a composite camera work with your GUI hardware. There are also chroma keyer modules used for composite video which are much more readily available that would let you overlay two video streams onto each other.

 

[NeX]

define limited. What can not be done?
Do you want real time video or stills.
What CPU are you using? Does it have the ability to use USB?

i mean limited as in the available options with cameras, composite cameras are cheap, and have a great dynamic range, many optic options as well as waterproofing etc. also an analog signal can be wirelessly transmitted with relatively low latency.

i am after real time video, again analog can provide it with almost no lag. i know the digital conversion process is always going to add some lag but i will have to see how bad it is.

the CPU i haven't decided on, i was considering an Atmel chip, possibly an AT90CAN128, i could always add a USB host to that, but its an extra layer of lag.

 

[NeX]

Yes, provide more details. There are things like the BOB-4 and it could be much easier to replace your current GUI hardware with that than to find a way to make a composite camera work with your GUI hardware. There are also chroma keyer modules used for composite video which are much more readily available that would let you overlay two video streams onto each other.

can you give more details on this "bob-4" ?

i need a device with near instant boot time which is what put me off things like raspberry Pis and i need a graphic intensive interface to fit in with what people expect from user interfaces these days. so i cannot simply use an On Screen Display and overlay text on my video etc. with the FT813 the video becomes scalable and rotatable, i can use it in a boarder or shape it or do whatever i want with it.

 

[ronsimpson]

eve chip can display video if it arrives as a series of JPEG stills

composite signal and convert it to a serial data format

Do you need the picture in JPEG format?

"Serial": Back when LEDs were new, I designed an number of "frame capture boards" that grabbed video (VGA and composite) and converted it to a format (digital) that a computer can understand. (not JPEG) I understand the "analog input" of LCD monitors. There are/were ICs on the market that convert analog video to digital. (8,9 or 10 wires for RED and wires for GREEN and wires for BLUE) The digital output has several formats. (24 wires + 2 syncs + clock) The clock is running at the video rate. OR 8 wires + 2 syncs + clock where the clock is running at 3x the video rate. Depending on the clock rate, video changes every 100nS, there is no FIFO. You can not miss any data.

Now that I think about, there is a one frame FIFO IC that I used some times. It has 9 data lines in and 9 data lines out. Clocks at speeds up to 35mhz. Can hold one picture. It really helped with CPUs that could not process video at full speed.

 

[dknguyen]

The BOB-4 is from Decade Engineering. You can google them. Basically a serial controlled module that overlays monochrome text and vector graphics over composite video. It's more like F-15 HUD graphics though so if you need something that's like a Windows or Linux type GUI then this is not it (but those require things like a rapsberry Pi which means a boot time anyways).

So I'm not sure what you mean by graphic intensive since that does not go hand-in-hand with instant boot time.

It does stuff like this:

 

[NeX]

Do you need the picture in JPEG format?

"Serial": Back when LEDs were new, I designed an number of "frame capture boards" that grabbed video (VGA and composite) and converted it to a format (digital) that a computer can understand. (not JPEG) I understand the "analog input" of LCD monitors. There are/were ICs on the market that convert analog video to digital. (8,9 or 10 wires for RED and wires for GREEN and wires for BLUE) The digital output has several formats. (24 wires + 2 syncs + clock) The clock is running at the video rate. OR 8 wires + 2 syncs + clock where the clock is running at 3x the video rate. Depending on the clock rate, video changes every 100nS, there is no FIFO. You can not miss any data.

Now that I think about, there is a one frame FIFO IC that I used some times. It has 9 data lines in and 9 data lines out. Clocks at speeds up to 35mhz. Can hold one picture. It really helped with CPUs that could not process video at full speed.

it supports bitmap too, but jpeg would allow for a much faster frame rate,

that sounds interesting, do you have any part numbers i could search? i guess what would be great would be if there is a chip out there that can take digital image information and add a jpeg compression onto it. i imagine thats what happens in some digital cameras.

 

[NeX]

The BOB-4 is from Decade Engineering. You can google them. Basically a serial controlled module that overlays monochrome text and vector graphics over composite video. It's more like F-15 HUD graphics though so if you need something that's like a Windows or Linux type GUI then this is not it (but those require things like a rapsberry Pi which means a boot time anyways).

So I'm not sure what you mean by graphic intensive since that does not go hand-in-hand with instant boot time.

It does stuff like this:

i have been thinking about on screen displays, but its kind of the opposite of what i want to do. i want the video to be part of an interface rather than a full screen video with the interface on top. the FT813 can produce a pretty impressive GUI with rotation, scaling, transparency and video etc but also has an instant boot time. i have already used one to design an interface and i am happy with the graphic quality and response times etc. i just want to add in video from a camera without having to use a Jpeg camera.

 

[dknguyen]

i have been thinking about on screen displays, but its kind of the opposite of what i want to do. i want the video to be part of an interface rather than a full screen video with the interface on top. the FT813 can produce a pretty impressive GUI with rotation, scaling, transparency and video etc but also has an instant boot time. i have already used one to design an interface and i am happy with the graphic quality and response times etc. i just want to add in video from a camera without having to use a Jpeg camera.

Oh, you're using one of those pre-packaged GUI modules kinda like EarthLCD or ReachTech. Ehhh, yeah that's tough and ultimately the reason I never went with either of them and went with the BOB-4. The easiest method is buying a video chroma-key module but that in that case you still have a full video screen (or a cropped part of one that cannot be repositioned).

 

[NeX]

Oh, you're using one of those pre-packaged GUI modules kinda like EarthLCD or ReachTech. Ehhh, yeah that's tough and ultimately the reason I never went with either of them and went with the BOB-4. The easiest method is buying a video chroma-key module but that in that case you still have a full video screen (or a cropped part of one that cannot be repositioned).

na i am building my own board which is centered around the FT813 chip. i have built a protoboard for now so i can develop it and its working great, but i want to bring up a video feed in the GUI and thats where the problem is.

 

[dknguyen]

na i am building my own board which is centered around the FT813 chip. i have built a protoboard for now so i can develop it and its working great, but i want to bring up a video feed in the GUI and thats where the problem is.

It's basically the same problem since all the commands a functionality are analogous, just one has already been rolled into an LCD. If you insist on that route you're going probably to have to get a composite to digital/RGB IC from some place like Analog Devices, figure out how to use it and build it onto your board with an FPGA and code it to capture a frame and convert it to JPEG before passing it on.

Here's a free JPEG encoder IP core.
https://opencores-jpegencoder.readthedocs.io/en/latest/

I recommend the FPGA modules made by Trenz unless you're capable of mounting or paying to have mounted BGAs. Specifically, this line which you can buy from Digikey or straight from them:
https://shop.trenz-electronic.de/en/Products/Trenz-Electronic/TE07XX-Artix-7/TE0725-Artix-7/

The 100T version gets you the most minimal module with the most FPGA for the best price by far of any module out there (the entire module is cheaper than buying the FPGA on it's own).

If the FPGA isn't enough to buffer the frame then you're going to need a frame buffer IC (like one made by Avnerlogic). Or you can use DRAM, but you don't want to wire that up for the same reason you don't want to use an FPGA chip from scratch. In that case, go with one of the other Trenz Artix-7 FPGA modules with DRAM on them, that is the ones actually made by Trenz.

 

[dknguyen]

Oh, it slipped my mind but you could also use an STM32F7 or STM32H7 with a hardware JPEG encoder which may or may not be easier than using an FPGA. You'll still need the digitizer IC, obviously.

Whether you need the frame buffer or not is dependent on whether the digitizer IC provides the exact interface and format that the MCU wants and whether it can keep up. If not, then you will need an FPGA anyways to manage things. You may or may not need a frame buffer depending on the details of everything else.