[Qt-interest] video streaming what any suggestions?

[Trenton Tuggle]

I've had the same problem recently.

Unfortunately, my solution was to create my own video interface layer,  
based on Quicktime.

I chose Quicktime because I needed as close as I could get to a stable  
cross-platform solution.  VLC/GStreamer/etc. would have been options,  
but I've been burned in the past with long-term architectural changes  
and maintenance of APIs with open source video projects.

I first built a simple layer to abstract and control the video, then  
wrote two implementations -- one which opens video files on-disk, the  
other which opens video-input devices.  Output is by emitting  
frameChanged() signals, which allow the client to obtain the current  
QImage of the frame.  To draw to screen, I just use a QLabel and  
setPixmap().  Video files on-disk work on both Windows and Mac, but  
video-input devices are only supported by Quicktime on Mac, AFAIK.

It took me about a week.  Overall, it was pretty simple -- the hardest  
part was learning the old C interface to Quicktime, and getting that  
right for cross-platform (well, Windows+Mac) use.

Unfortunately, I cannot release my source code at this time... but I'm  
still checking licensing options, so I'll let you know.

-Trent Tuggle


On May 12, 2009, at 8:56 PM, Karol Krizka wrote:

> Giancarlo Amati wrote:
>> Hello everybody,
>>
>> I have to write donw a software and I wish to use QT as a GUI. now,
>> the software has to connect to a video camera connected by a
>> USB/Firewire port and shows the video steaming as well as saving  
>> frames.
>>
>> Sorry to bother u with this question but does QT have any class
>> devoted to video management? I heard about Phonon, but yet don't
>> understand if it is just for playing a videoclip or also to show up a
>> video streaming...from a camera.
>>
> I remember some discussion about that a while ago on this list, so I
> suggest you look in the archives. I don't remember the overall
> conclusion, but I understand that at the current moment it is  
> impossible
> to play camera streams with Phonon. However, there is some VLC library
> that will allow you to do it inside Qt.
>
> --
> Cheers,
> Karol Krizka
> http://www.krizka.net
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