AnsweredAssumed Answered

ADV7513 and media converters

Question asked by RobB Employee on Sep 16, 2016
Latest reply on Sep 16, 2016 by GuenterL

Hi,

 

One of our customers has questions about the ADV7513 used in one of their products.

 

Use-case: Video streams are being generated inside the FPGA and provided towards ADV7513 to bring towards HDMI connector. The following mode/settings are used:

  • We are testing with 1280x720p60 (total 1650x750)
  • Horizontal sync front porch 110, sync width 40
  • Vertical sync front porch 5, sync width 5
  • Output HDMI mode in RGB format, CSC matrix is programmed for jpeg yuv422 to RGB full range

 

A FPGA configures the ADV7513 component.

 

The problem: with the current implementation we can successfully display images onto a LCD monitor or HDMI analyzing device (e.g. Quantumdata 780). We do however experience problems when connecting our devices to media convertors (e.g. blackmagic devices). These media convertors are working with the HDMI generator device (Quantumdata 780) or laptop signal.

When connecting our ADV7513 based device to a monitor, this works fine.

When connecting our device to another custom device, equipped with the ADV7612 HDMI receiver, this works fine.

When inserting Black magic HDMI->SDI and SDI->HDMI mini convertors in between, the monitor doesn’t display video. The Quantum data video analyzer displays a very unstable image, unless we configure the HDMI->SDI convertor to process the video (it actually scales the video to 4:3 aspect ratio), then the video is stable on the quantum data, but the monitor still displays nothing.

 

At this point, one would think the cause is clearly in the Black Magic chain, but when we connect a pc (or the Quantum Data video generator) to the chain, the monitor displays the video just fine.

 

Although the 7513 is configured in full scale RGB, I also tried to clip the values. Clipping works fine, but it makes no differences with the Black magic chain between our device and the monitor.

 

The questions:

Any clues? Is this a signal integrity issue?

Are there any known issues related to compatibility with some other HDMI devices (e.g. Blackmagic devices)

Are there additional tests you advise us to do? Test equipment we could use?

 

In case you need additional information we will be more than willing to provide it.

 

Thanks!

Rob

FAE

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