RVCamera Demo for Webcam not showing up on Windows tablet

[darvin]

I just had some good progress in programming with the rvmedia suite . but currently I´m stuck in an issue regarding my front and rear camera on a windows tablet:

The tablet runs Windows 11 Pro.
I use the Webcam demo and also the WebcamMulti demo
Both run on my developer notebook as expected (webcam [just one] is shown on the app window)
Now I run the same exe on my Windows tablet and it shows both cams (front and rear named GC8034 and GC5035) --> this is correct so far

But when I select those cams I get the progress points and nothing happens any more...?

Any suggestions what could be wrong?

[Sergey Tkachenko]

Please check WebCam demo and try different video modes.
Are there modes that work?

[darvin]

Good evening,

Yes I have already tried the WebCamera demo as well and had the same results. No matter what I selected on the tablet, I got same results with each configuration.

Interesting that the "Camera" app from Microsoft works as expected.

Could it be some design-time setting/params in the RVCamera component?

tnx!

[Sergey Tkachenko]

Camera app may use different API for accessing local cameras (RVMedia uses DirectX).

Try compilng the application wih the compiler define CAMERA_SAVELOG
Make sure that the platform is Windows 32-bit.
Project | Options, page Building | Delphi compiler, Add CAMERA_SAVELOG to Conditional defines.
Rebuild the project. Run. Send me a log file to email richviewgmailcom.

[darvin]

Thanks for your suggestion. I followed your guidelines and started the WebCamera project. There was no debug\ output at all. But I tried some variants of the webcamera project, probably this helps to find the issue:

1. I started Webcamera VCL project and the option "1920x1440 16bits YUY2"shoed the webcam video on the screen.
2. I changed to another configuration and the dots came up with missing video.
3. Going back to the setting under 1.) had now the same behaviour - only dots running. So I assume that some lib crashed.
4. Testing the Webcamera FMX projoect with the setting under 1.) failed as well.
5. Calling the Webcamera VCL project exe again showed the webcamera video properly.

So there is also a different behaviour in the VCL and FMX project.
BTW: I tried this executables both as admin and normal operation - no difference.

[darvin]

Just went through the blog and found a similar post (at least the result on the desktop):
viewtopic.php?p=41495&hilit=webcam#p41495

I checked the DirectX with DxDiag but no fail.
And I checked with the webcamtests.com site and got no failures.

[darvin]

Quick update:

I tested the webcam with this gstreamer command line: gst-launch-1.0 mfvideosrc device-index=0 ! autovideosink sync=false
The video was clear and it worked via Direct3D11

A switch from device index 0 to device index 1 was also positive (switch between front and rear webcam)

[darvin]

Update:

I made a small test program showing the camera modes and selecting a specific one (1280x720, 16bpp, YUY2).
On my Windows 10 Pro developer notebook this configuration works fine.
On my Windows 11 pro tablet this configuration does not work and shows the animated dots only (even if I wait for a bunch of minutes).

[Sergey Tkachenko]

Well, RVMedia FMX and VCL shares the same code for Windows webcam, but FMX version does one additional switch of video mode. It may be the reason why it does not show video initially.

Still, I need additional information from logs.
Do you use full source code version, and the project is for Windows 32-bit?
Logs cannot be enabled in a trial version. And special actions are needed to recompile RVMedia for Windows 64-bit.

PS: you can use GStreamer in RVMedia. You can assign

Code: Select all

RVCamera1.FFMpegProperty.UseFFmpeg := False;
RVCamera1.GStreamerProperty.UserGStreamer := True;
RVCamera1.GStreamerProperty.LaunchString := 'mfvideosrc device-index=0';

[darvin]

Sorry to ask this probably silly question. But what has to be defined aside with launchstring to run the gstreamer code. If I set VideoDeviceIndex to 0 I still get the errorous behaviour.

What do I need to additionally set in the RVCamera component to run the gstreamer launchstring? Only setting these params keeps the RVCamView in "No Video" mode.. as there is no video source or as the stream did not start...

BTW: gst_mxvc was successfully loaded as long as the mfvideosource is not supported by mingw. I refer to viewtopic.php?t=11342

[darvin]

Found the problem!

You have to set the device type to rvdtRTSP. Now the camview works fine for me! I can even switch the cam side by changing the device-index!

Thanks for your support!!!