Webcam support in Squeak (for OLPC)

[Jonathan Corbet]

Diego Gomez Deck <DiegoGomezDeck at consultar.com> wrote:

> The Squeak V4L code fallback to use read(), but the performance is not
> good.

I'm curious as to why that is.  The read() interface is not the
preferred way to go, but it should not perform notably worse than using
mmap(). 

> This situation shots those questions:
> 
> - Can the cafe driver capture using MMAP?

The driver supports the V4L2 streaming interface using in-kernel
buffers; it does not currently support user-space buffers.

> - In affirmative case, where I can find a piece of code that make it
> works? (NOTE: The capture.c example provided by the V4L2 api DOESN'T
> work on the OLPC).

I've never actually tried capture.c, but a quick glance suggests that it
should work as long as you don't use the -u flag.  Could you tell me
what problems you have run into (off-list might be best) and we'll take
it from there?

Thanks,

jon

Jonathan Corbet / LWN.net / corbet at lwn.net