[GEM-dev] [pix_video]: how to free the device?

[Matteo Sisti Sette]

IOhannes m zmoelnig escribió:

>> And the common interface should probably be the one currently adopted by
>> pix_videoDS which is superior to the one currently adopted by pix_video
>> on Mac and Linux in that:
> 
> i'm not so aware of superiorness.
>

Well I meant it's a better interface (in my opinion) because of the 
advantages I mentioned.

>> 1) "open <ndevice>" and "close <ndevice>" is better than "device
>> <ndevice>" since it allows you to close a device without opening another
>> one
> 
> otoh, "close <ndevice>" is clearly faulty, as it allows you to close a
> device that is not even open...

Yeah sorry, it is not "close <ndevice>" but "close" without arguments: 
it closes the currently open device.
Of course you could send the message when no device is open, but that 
shoud simply generate an error message: the fact that an error can be 
generated doesn't mean that the interface is faulty. Even "device 
<ndevice>" (which is just equivalent to a "close" [if a device is open] 
followed by "open <ndevice>") may generate an error if you try to open a 
device that is not available because in use by another application or 
because it just doesn't exist (like "open 999")


> as written in before "i have added an open/close" message now for the
> new [pix_video] implementation, neither of which (currently) takes any
> arguments.

I don't understand: what does a "open" message without argument mean? 
Which device does it open?
Or is it equivalent to pix_videoDS's float (enable/disable) method??

> 
>> 2) it accepts a float (1/0) to enable/disable pix_video, i.e. turn it
>> on/off which is not the same as opening/closing the device
> 
> nevertheless, the exact naming of the methods is the least of my worries
> now.

Nor do I worry about names; the relevant thing is that pix_videoDS has 
(A) methods to open/close a device and (B) a method to turn the object 
on and off, i.e. start/stop generating the output. Whatever you call 
them, A and B are not the same thing and it's useful to have both.




-- 
Matteo Sisti Sette
matteosistisette at gmail.com
http://www.matteosistisette.com