I could not find any good resource about circuits for generating composite video from the luma and chroma along with explanation how it works and why they are build like that. I saw few with bjt and fews components...any idea? thank u
Hi. I will try to better expose my case. Yes I learned how the composite signal is generated. Basically I have an old chip that generate a sync+lum signal and color which are feed to an RF modulator which generate an s-video signal/composite.
I would like to :
- understand how this circuits works.
- if it's possible from these sync+lum and color to generate RGB/Vga/hdmi
I am not searching for a solutions just hints. I was able on to find a book about op-amp how to generate composite from RGB ( block diagram).
I started reading this one https://www.tinaja.com/ebooks/tvtcb.pdf hope will find some good info
If this is just an educational exercise, I would start with just reading about VGA. It has the five required signals, R, G, B, H, V, already separated.
If this is just an educational exercise, I would start with just reading about VGA. It has the five required signals, R, G, B, H, V, already separated.
The other "information" that all transmission systems need, is where each "colour" goes,
this is "commonly" a start of page / frame / line , for a "pixel"
How this information is encoded , is system dependent,
So PAL TV of old, transmitted Luma as an amplitude above "black" reference
Luma , as a phase shift
Timing, as a level / edge
Black level as a DC level at a certain point in the timing,
Now when it comes to digital systems,
they can just digitise the analog information, as in SDI
or they can packetize, such as MPEG