On Wed, Jun 16, 2010 at 11:11 AM, Patrick Beeson <beeson.p@gmail.com> wrote:
>
>
> On 06/16/2010 10:05 AM, Jack O'Quin wrote:
>>
>> I think what's happing is that the camera lies and says it accepts
>> "absolute" (i.e. float) values. The driver, seeing "absolute_capable
>> == true", tries to set the values using
>> dc1394_feature_set_absolute_value() instead of
>> dc1394_feature_set_value().
>>
>> Not sure how to handle this in a portable fashion that works for all
>> cameras.
>
> That's exactly what happens.  Except that is doesn't fully lie.  It return
> back the float of FPS (0.0001-16.0) for get_absolute_boundaries, but for
> get_boundaries, it returns back integers of 3-1150 (you don't have the
> get_boundaries call in that branch by the way, you always use 0-4095).  So
> it can READ absolute values, but the set_absolute_value for shutter isn't
> working, even though it works for other features.  Don't exactly see why
> yet.

The camera's tech manual says it supports *both* "absolute" (float)
and "relative" (unsigned int) values for shutter.  I assumed (naively)
that when absolute is available that would be better to use.

Still not sure why set_absolute_value() is not working. There don't
seem to be many absolute camera features around, yet. Does anyone have
a camera other than the Sony XCD series with an absolute feature
value?

-- 
 joq