VIP alpha blending mixer

Hello,

Are you using the VIP test pattern generator? The Test Pattern Generator 9.0 can only generate RGB and YCbCR and is not supposed to support alpha layers (1 sample per pixel). I suspect you may be sending image packets that are larger than expected to the alpha layers which would cause throughput issues. Obviously, this is assuming that everything else is working fine and that you are using the slave port properly.

You may be able to work around this limitation by setting the test pattern generator to output YCbCr 4:2:2 in sequence and by dividing either the width or the height by 4. The Test Pattern Generator will output wrong control packets but this should be of no consequence since the mixer is not using control packets from the alpha layers. Alternatively, building a custom test pattern generator should be quite straightforward.

vgs