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TVP5154 Video Decoder configuration question.

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Posted by Nicholas Lee

on May 21 2009 08:40 AM

[There appears to be no 'video' forum, so I am posting to /etc.]

I am trying to configure the TVP5154's registers to enable it to accept signals from my progressive-scan monochrome camera and output signals in VGA format for later display on an LCD monitor. Please can you help me to determine the correct I2C register settings?

The camera parameters are as follows.
648x492 (Full Frame) @ 30fps, 12.27MHz
Horizontal Active Pixels = 648
Horizontal Total Pixels = 780
Vertical Active Pixels = 492
Vertical Total Pixels = 525
Horizontal Sync = 59
Horizontal Back porch = 54
Horizontal Front porch = 19
Vertical Sync = 6
Vertical Back porch = 20
Vertical Front porch = 7
As you can see, this high-quality camera is neither PAL nor NTSC.

NB: The outputs from the TVP5154 feed into an FPGA in which I am converting the colour space from YCbCr to RGB and I have a tripple frame buffer to go from 30fps to 60fps (VGA).
I need the TVP5154 to convert from 648x492 (Full Frame) @ 30fps, 12.27MHz to a 640x480 VGA image size.

I have read the App note SLEA058 but I still haven't got it working.

Regards,
Nicholas Lee

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Posted by Saeid Sarir

on May 27 2009 14:37 PM

Prodigy30 points

Werner,

TVP5154 is a Video decoder for Composite interlaced TV formats like NTSC or PAL video signals. It is not designed to operate under other progressive resolutions or frame rates or even convert frame rates..

Kindest regards,

Saeid

Posted by Nicholas Lee

on May 28 2009 12:58 PM

Prodigy20 points

Ok, fair enough.

I have now managed to obtain a monochrome PAL format camera instead.

The output of the TVP5154 with this camera is ok for the luminance 'Y' data, but I would have expected the 'Cr' and 'Cb' data to be zeroes using this monochrome camera, but the data is not zero.

However instead of a blank screen for the Cr and Cb channels I see a zebra striped version of the image on one colour channel and a solid bright screen for the other colour channel data.

Do I need to change the register settings to suppress this colour information when I am using a monochrome camera?

Nicholas Lee