[Interest] About usb cameras

[Josiah Bryan]

Assuming you're on *linux*, you really would need to write code to
interface with something like V4L. I've got a project on Google Code that
does something like that - here's the class that actually talks to V4L2:
https://code.google.com/p/livepro/source/browse/trunk/gfxengine/SimpleV4L2.cpp

See the sample app in the devel directory on how to use make a complete app:
https://code.google.com/p/livepro/source/browse/trunk/devel/app-template/MainWindow.cpp

(The CameraThread class uses SimpleV4L2 internally to grab the video from
the camera and display it.)

The linux subsystem that handles video capture, V4L, works equally well
with USB cameras and capture cards. The big question on linux is if linux
has the driver for your webcam.

On *windows,* you would probably need to use vfwcap - the CameraThread
class has code internally to use vfwcap to grab video frames:
https://code.google.com/p/livepro/source/browse/trunk/gfxengine/CameraThread.cpp
(that
class also can grab video from BlackMagic capture cards too, incidentally.)

Granted, all this is rather high-level code and part of a larger code base.
But the code is there in CameraThread (windows) and SimpleV4L2 (linux) to
do the capturing - you can rip the code out and reuse it in your app, or
SVN checkout the code for livepro (the project where all those links above
come from - https://code.google.com/p/livepro/source/checkout) and use the
project itself. If you do use livepro, check out the various apps in the
trunk directory such as simplemon, quietcambeep, switchmon, and various
development code in devel - that all gives you ideas on how to use the
livepro code. The actual "core" of livepro is in the "gfxengine" folder
with a .pri file - thats all you really need to include in your project to
use livepro.

Cheers!
-Josiah




On Mon, Sep 16, 2013 at 10:37 AM, <evazquez at grm.uci.cu> wrote:

> Sorry for my english.
> How to listing usb cameras devices for importing images in qt apps?
>
> _______________________________________________
> Interest mailing list
> Interest at qt-project.org
> http://lists.qt-project.org/mailman/listinfo/interest
>



-- 
Josiah Bryan
765-215-0511
josiahbryan at gmail.com
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