How to create a .mp4 Video from a collection of QOpenGLFramebufferObjects /QImages / Glunit textures
I am developing a Qt app for iOS, Android & OSX.
I have an
std::vectorof QOpenGLFramebufferObjects. Each
QOpenGLFramebufferObjectcan of course provide its own QImage or a
GLunittexture by doing a takeTexture. So you can also say that I have a collection of
I want to create a
.mp4video file out of these QImages/QOpenGLFramebufferObjects which works on iOS, Android & OSX.
How should I do this? Any examples doing this with Qt? Which classes in Qt should I be looking into?
I am thinking to use ffmpeg or GStreamer whatever works best in Qt. But I want to know how to pass these QImages or Glunit textures to create the video. Is there Qt support to do this without having to use a 3d party library?
Should I use QVideoEncoderSettings to create the video?
Are there any examples in Qt doing this?
Which classes/components in Qt I should be looking into?
Is there something in Qt Multimedia that I can use?
If not then what is the best option wrt to making this work on Android & iOS?
I am using Qt 5.9.1 commercial version on Android & iOS
Something is not clear from your description, do you want your application to record a video file on all three platforms ? Or do you want to generate video files that can be played on all these platforms ?
If the former, what is the source of images ? Are you using widgets or QtQuick ?
@SGaist I want to generate video files that can be played on all 3 platforms.
QImages are are some are
QOpenGLFramebufferObjects which are populated after some processing using OpenGL.
I am using Qt Quick commercial version for Android & iOS. And working on Qt 5.9.1.
Simplistically saying, I just want to create a video file from QImages or Glunit textures whichever option works with Qt.
Well, I'm sorry to say that it's still not that clear, so let me rephrase that: will your application create these video files on iOS and Android ? Or are you creating a desktop only application that should create these video files ?
In any case, QOpenGLFramebufferObject has a toImage method that returns a QImage.
@SGaist Yes. My application will create these video files on iOS and Android. It is not a desktop only application. It is primarily for iOS & Android. But the application runs on MacOS as well which is my development environment.
toImage methodto return a
QImage. I already know that. But my question starts after this.
Rephrasing my question here again:
Consider you have 15
QOpenGLFramebufferObjects in memory. Each one of course can return a
QImage. I wan to create a video (
.mp4) out of these 15
QImages. How do I do this with Qt.
And of course, as I said I am running commercial paid version of Qt based Qt latest 5.9.1 released recently. It is a Qt quick based application.
QMediaRecorder would be the starting point.
Note that there's no system encoder for h264, it's a non free-format.
@SGaist How can I pass
QMediaRecorder& create a video out of it?
Is there a example or some code snippet you could point to?
Note that I don't need audio. I just want to programmatically create a video out of multiple
QImages. And, this is has nothing to do with the camera . I am not trying to get images from camera.
Trying to see the examples of
QMediaRecorder, all of them hooking on to the camera which I don't need to do with my program . Simply, I have some
QImages in memory. Want to create a video from say 10
You need to create a QMediaObject that will provide the images to QMediaRecorder.
Roby Brundle last edited by
Is there an example doing something similar? would be really helpful if you could point to an example doing something close
AFAIK, no. You will have to take some inspiration from the Qt Multimedia sources.