On 29 Jan 2001, Gerd Knorr wrote: > > > > For a bt848, when are the risc program(s) generated? When REQBUFS is called, > > > > or when VIDIOC_QBUF is called? > > > > > > QBUF. > > > > Isn't that inefficient? Last time I checked, risc program generation takes > > a significant length of time. > > Depends. Generating the risc code at REQBUFS time means that you'll limited > to a fixed set of buffers. Depending on your application it might save you > a memcopy() if you can put it _anywhere_ and not only to one of the predefined > buffers. Maybe I misunderstood, I thought you had to call REQBUFS before you could use the buffers for DMA? > BTW: This is how bttv works today. It will write new risc code for every > single frame you are capturing. So it can't be that slow as you can capture > full frame rate and have (on fast boxen) still enouth spare CPU time to > compress the video in real time... Ah, well, I can't capture and compress video in real time. I'd rather improve the software instead of buying a faster computer.
