Simple and available video decoders?

Hi,

I want to develop my own video grabber, for some experimentation with video image processing. I wonder if there is a preferred video decoder often used in hobbist like projects?

I looked up some available analog video decoders, like the Texas Instruments TVP5150A, which seems quite easy to use. However they all seem to output only YCrCb, the TVP5150 no different outputting 8-bit ITU-R B.656. I need a chip that can also output raw RGB, since I assume that is what I need in my VRAM bank for simple edge detection and object tracking capabilities.

Any suggestions appreciated.

erik

Reply to
ErikBaluba
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I was going to suggest the Brooktree BT478 but I am not sure if it is still around. It is (was) used on many cheap PC TV add-on cards.

Anyways, you don't need RGB for edge detection. Edge detection can be done in any color space, although some color spaces may be more suitable for the kind of features you are looking for. Grayscale may even be sufficient. Furthermore you can convert between color spaces in software. Google for YUV to RGB or RGB to YUV.

--DF

Reply to
Deefoo

Here, I found this site with lots of info

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?method=4&dsid=1512&dekey=YUV&gwp=8&curtab=1512_1&sbid=lc02b&linktext=YUV

--DF

Reply to
Deefoo

I just finished an NTSC to RGB project last year. I could not find a single-chip solution. I used a double-chip solution -- Analog Devices ADV7181 coupled to an ADV7179. They work very well.

Good luck, Tom

Reply to
tlbs

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The 7181 outputs 8-bit YCrCb . Did you convert to RGB in software?

The 7189 is an encoder, did you need that in your setup?

Reply to
ErikBaluba

We used the 7181 to digitize the NTSC video, then we fed the YCrCb to the 7181 to convert it to individual RGB analog outputs. The 8-bit YCrCb was routed through an FPGA, but that is for future expansion. Right now, the digitized video just passes straight through the FPGA (with a single pipeline delay; i.e. one flip-flop/register). The FPGA also handes the I2C interface to the video chips, for setup.

The YCrCb and clock outputs of the 7181 can be connected straight to the 7179. They are designed to work together. The default settings may be sufficient for your application, so you wouldn't need to have an I2C interface -- just a reset signal.

Analog devices also sells other decoder/encoder chip *pairs* in the same family. Check out

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BTW, I am not an Analog Devices employee or salesman -- I just happen to like some of their product lines.

Tom

Reply to
tlbs

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