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MikeS11 / MiSTerFPGA_YC_Encoder

All work releated to the YC / NTSC & PAL Encoder for MiSTerFPGA
MIT License
33 stars 4 forks source link

Why not output Y+C? #5

Closed jotego closed 3 months ago

jotego commented 3 months ago

What is the reasoning behind leaving the addition of luminance and chrominance to the analog circuits outside the FPGA, rather than doing it inside the FPGA?

MikeS11 commented 3 months ago

Hey Jotego! Alexey did try to create a CBVS output and you can try it, but there are hardware limitations. The main reason is the voltage output cap on any analog output to .7V where Chroma can sit at 0.850V, as well as needing to allow a larger bandwidth for chroma. E.g if I tried to fit the colorburst, chroma and luma into 1 output, you get a video output thats not remotely close to spec and it looks pretty bad.

jotego commented 3 months ago

I see, the limitation comes from the external DAC then. Thank you.