Video waveform monitor

[jpa]

@Hfuy

It really does need that variable display. Doing a “maximum value” would require keeping a table of all the previous scanline values at that sample, and calculating whether a particular sample was the biggest. Or, you could just write all the scanlines to the display, but again that would require a non-destructive putcolumn() which added to the existing frame buffer.

Well… there is a getcolumn() also. But it will be quite slow if for every scanline you read and update all the lines on the screen… using putpixel() might work though.

You could keep an array (400 items or so) of the maximum values, and update that for every scanline. Then once in a while draw that to the screen.

@Hfuy

Looks like I might end up having to do it in C, then. Is the frame buffer accessible as memory in C, or is it specialised?

Nope, frame buffer is in the LCD’s own memory.

I don’t think C will simplify any of the difficulties here… it might improve the eventual performance a little, but the fundamental problems are the same.