Qt video call streaming

Davita

Hi

I'm completely new to Qt mobile, I even don't have a solid mobile dev experience, so sorry if I'm asking something obvious.

I need to develop a mobile app that should have the ability to receive a call like functionality (over internet, not GSM call). When answered, it should start streaming audio and video from our server. The call should be one way only, meaning, that stream goes from server to device, but never from device to server.

So my questions is:

Is this possible in Qt? I chose Qt because I' familiar with it and I want to support desktop, android and ios. maybe windows phone later.
Is it possible to receive a call when the screen is shut off? Or I need some licensing/certification from os provider for that?

Many thanks in advance :)

mrdebug

Maybe the questions are more than one.

Which kind of stream have you got? If you have an h264 stream for example you have to embed FFMpeg (I have experience on this).
Maybe you application will not opened as full screen. In this case I never tried to write a background applications for mobile with Qt.

Davita

Hi. Thanks for your post. Actually I haven't decided stream type yet. It will be acquired from raspberry camera module. I'm not even sure what type of streams it supports, I just ordered it yesterday and waiting for arrival to play with it.

So you say there's no other way except the app to run in background forever and wait for a call? Won't the OS kill my app? I remember that Android had a feature to start a background process when several types of activities would happen, such as receiving an sms message for example.

mrdebug

On what kind of application are you working on?

I know raspberry pi. I use it in some applications, using the on board camera and usb video capture device.
If you want to use the on board camera you can use raspicam as video grabber and as embedded library.
Imho you have to use your own software for video streaming.
Maybe raspberry pi has an on board h264 hard encoding but I'm not sure.
If you use x264 software encoder the frame rate is too slow. I use for example mjpeg.
An already made software for video grabber is available in my website, for raspberry pi amd i386 and a client for Android and iOS.

Yes, maybe is possible to start an activity on event. Are you sure that this kind of features is available in Qt?

Davita

Thanks again @mrdebug

Yes, that's the camera module I'm going to use with my project. I haven't decided yet which encoding/codec i'm going to use, my main concern at the moment is how to start my app when a call is made. The app shouldn't be running all the time, only when the call is made. But I've got no idea how to do that :(

Thanks and sorry for my broken English