Qt Multimedia status on Android

[BogDan]

Hello George,

>________________________________
> From: George Tavares <tavares.george at gmail.com>
>To: necessitas-devel at kde.org
>Sent: Thursday, May 3, 2012 11:13 PM
>Subject: Re: Qt Multimedia status on Android
> 
>
>Hello BogDan
>
>I am making some work with android multimedia  too, but in Camera support and I make some progress that I can share with you.
>

Maybe we should join forces ?:)


>
>I started with QtCamera.java/androidcamjni.cpp available in your sdk, and tried direct render the image previews received in androidcamjni.cpp to a QDeclarativeItem. The performance was not good.
>
>I look in QtCamera.java and saw that frames are encoded to jpeg , and later loaded to QImage,  I decided elimate this step, sending the bytearrey of preview direct to CPP side and use a Method from Ketai project! (decodeYUV420SP) to decode frame. After running, it continue slow.
>

:)

>
>However, I am running qt with opengl enabled, then I decided upload YUV frame like a texture and make de YUV decode in a shader. It now it is fast. I can't see differences in my camera   support  (800x600) and the camera from Android application. 
>
>I have only one problem implementing the shader. the YUV format appears like that:
>YYYYYYYYY
>UVUV
>
>When I tried to load this like textures, I choose first load in two textures, one with Y component of type GL_LUMINANCE  and other with UV component with a type GL_LUMINANCE_ALPHA . In fragment shader I tried load these components but the GL_LUMINANCE_ALPHA has some kind of bug that the components are not load correctly. Then I decided to unscramble the image in this format:
>YYYYYYYYY
>UUVV
>
>Then I load the U and V texture separately. 
>

Great, can you please share with us the shader sources ?

As I sad I already have the texture, the problem is how to display it on a non-gl widget ...
Using OpenGL for rendering everything it can be a solution but sadly on android we 

are limited to a single windowsurface, so the UI is (extremely) limited to a single 

Top Level Widget, this means you can't use controls which needs another TLW
(e.g. dialog, combobox, etc.). 

Check http://code.google.com/p/android-lighthouse/issues/detail?id=4#c24 for 

more informations.



Thanks,


Cheers,
BogDan.

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