Dmitri wrote:
On Sun, 2002-05-19 at 16:24, Steven Ellis wrote:
I have been taking a poke around the v4l sources and I
noticed one driver doing the appropriate conversion. I
just wanted to get my head around some of the maths.
The current idea is that the driver MUST NOT do such conversions, unless
they are absolutely necessary (when the camera datastream, for example,
is too different from any standard format). The color conversion, if
needed, should be done by the v4l application (or library) - it will be
of higher quality and better optimized for the CPU. The driver code must
be kept to a minimum. Alan's somewhat minimalistic approach is that the
driver just dumps whatever it gets from the camera into userspace, and
it will be up to the application to sort it out.
Dmitri
There has been some discussion of a standard format conversion library
that application developers may be able to use. The sooner this happens,
the better as I find myself frustrated by the fact that too may (and
some really good) V4L applications only work with a limited subset of
hardware (mostly BT8#8). I personally think that a standard Linux video
API should comprise both a device-level interface (V4L2 perhaps) and an
application level interface that works with it. This way, manufacturers
can write the drivers and application devlopers can write programs that
will work with every (suitable) video device.
Ed "The world is not a BT8#8" T.
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