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Noise from HDMI RX (ADV7611, ADV7612), broken HDCP

Question asked by vito on May 6, 2011

Hi,

 

Sometimes HDMI source (using HDCP encryption) when changing the video standard may cause audible

noise (300-1s) on ADV7611, ADV7612. This behaviour was noted on the PS3.

 

The root cause of this problem is on HDMI source device that breaks HDCP encryption, and sends

erroneous packets, such as invalid audio infoframe packets.

 

To avoid noise - broken packets should be ignored, this can be done by setting value of regsiter

HDMI map 0x45[3:0]  to 4 or other value (4 is suggested). Register (0x45[3:0]) called also

PKT_ERR_BURST_FILT allows HDMI packets to be ignored after broken packet is found

and resume trusting+processing them after number of consecutive correct packets (N)

are received.

 

0 = Disabled (default)

N = Consecutive good packets after packet error detected, before allowing dispatch to process new packets

 

Value of N should be possibly small to avoid rejecting too many packets.

 

Best regards,

vito

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