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ADV7441A - 1920x1200 shrink

Question asked by Janos on Oct 30, 2014
Latest reply on Nov 13, 2014 by DaveD



I run into a product that is delivered to a customer, it is a general DVI recorder, which is capable to record whatever input resolution.

They are connecting a special industrial source with 1920x1200 resolution, but the image size they get (and also reported by the HDMI identification) is 960x1200 (half the width.)

All other resolution works fine.


The "supposed" resolution is:


pixel clock (Mhz), 154 MHz

Horizontal pixels (viewable), 1900

horizontal Pixels (total),    2060

Horiz front porch,              48

H sync Width,                   32

H.back porch,                   80                  

vertical active pixels,       1200

V. front porch,                  3

V. sync width,                   6

V back porch.                   26



Unfortunately as this is a ready product I have no access to the registers.

I have tested it with a Win 7 NVIDIA card running 1920x1200. It is ok here on my desk ...


Is it maybe that the circuit detects this as a" pixel repeated" source ? (HDMI_PIXEL_REPETITION)

Datasheet says

"When the ADV7441A receives this type of video format, it automatically discards repeated pixel data, based on the Pixel Repetition field available in the AVI InfoFrame. "

I guess we have no such frame, is it possible that it is misinterpreted somehow?




Any idea ?