RGB_to_BT656 encoder

[sid_27]

Hi, I want to convert RGB data in to BT 656 4:2:2 format. So far I have completed color space conversion (to get YCbCr 4:4:4) and chroma resampler (to get YCbCr 4:2:2 BT 601 format). I am stuck up with converting YCrCb 4:2:2 BT 601 format with discreat hsync and vsync into 8-bit BT 656 format with embedded timing codes. Can anyboady suggest how to go about this, or any vhdl, verilog code or reference design or app note will be a great help.

Many Thanks!

 

[aruipksni]

this sounds very simple all you need to do is to inject the proper syncs durin H, V perios, acording to the system (standard yo want to implement) i guess it is an NTSC system with 525 active line. you also need field flag F, for the interlaced video.

 

[TrickyDicky]

If you're moving to embedded codes, you'll need to run your data through a rescaler to move it to the range 16-235, so you dont hit any TRS values.

 

[sid_27]

I have 8-bit luma and 8-bit chroma data, my problem is how do I multiplex it in a 8-bit format with the embedded timing codes.

 

[TrickyDicky]

usually, the clock runs at 2x pixel rate and you run the data Y C Y C Y C

 

[aruipksni]

I have 8-bit luma and 8-bit chroma data, my problem is how do I multiplex it in a 8-bit format with the embedded timing codes.

if you want to do it by yourself you can get video demystified book, it has all the information.
and ofcourse you can get latest standard from itu-r site for free in various lanuages.

https://www.itu.int/rec/R-REC-BT.656/en

 

[lucbra]

small fifo, 2x pixel clock, some resampling, done

 

[sid_27]

Thanks for the response guys, the next thing I will do is, read video demystified book.