Re: Re: v4l2 + mmap()

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"Nemosoft Unv." wrote:
> but I´m missing one detail: what happens when program can´t
> dequeue fast enough (or deliberately throttles the framerate).
> More specifically: when the queue is full, do you drop the
> last frame captured, or the oldest?

To be honest, I never thought of doing it that way. It's not specified.
I believe the API will permit the driver to do it either way. I assumed
the driver will skip a frame if there is no available buffer to put it
in.

Reusing the oldest filled buffer seems just as easy, but it buys you
nothing, IMHO. If you need low latency then use fewer buffers. If you're
capturing to a file, then it simply doesn't matter which frame is the
one that gets dropped.

Bill.





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