Altera_Forum
Honored Contributor
10 years agoAvalon-ST video conversion from 2-symbols per beat to 2-symbols per beat
Good evening,
I`m having trouble converting the output from an HDMI video input core to a suitable signal for my video pipeline. If I keep all components in 2 pixels per beat mode (1 pixel = 24 bit RGB = 3 x 8-bit symbols), everything is working fine. However some components like the Scaler only work with 1 pixel per beat. I tried two solutions to convert my 2 beats per clock stream to a one clock per beat stream. Solution 1: QSYS component that uses the following components clocked video data from HDMI -> clocked video input (2 pixels per beat) -> avalon-st timing adapter (ready latency 1 to 0) -> avalon-st data format adapter (6 symbols per beat to 3 symbols per beat) -> timing adapter (ready latency 0 to 1) -> video monitor component 1 -> frame buffer -> video monitor 2 Result: data arrives at monitor 1, but most of it is invalid. error: waiting for sink. but downstream framebuffer is verified to be working alright. Solution 2: Verilog component that puts the 2-pixels-per-clock clocked video input with dual clock frame buffer: 2-1-symbol.v is attached. Result: works in some cases (e.g. direct output to monitor or direct loop-back to HDMI output,butnot reliably. especially if i try to apply scaling after this module, the whole pipeline pretty much stops working. This should be a pretty common problem, maybe it's trivial and I just don't see it. Any idea is highly appreciated. Thank you! Klaus