The VideoLAN Forums

Hi,

I found some posts about the OpenCV support in VLC. So I decided to give it a try.
(After 2 days compiling packages :/) I got a selfbuild VLC-Player with --enable-opencv.
But now i got stuck. What exactly i need to do to use a OpenCV filter.
I found an opencv_example.ccp and an opencv_wrapper.c but both are not compiled while ./compile
Can I compile them now standalone? How do I add them?
How do I run the example?

( Im also new at OpenCV I just found some tutorials and played around )

Thank you
Lucia Zurasi

If you add --enable-opencv, opencv_example might be build.
To create a new one just take the example and add the OpenCV code you need in the Filter function. This function will be called for each picture before rendering it on the screen.

Humm

I use ./configure --enable-opencv --enable-run-as-root
Then i get: So I think the configuration accepted the opencv

After ./compile i got this warnings:
So i searched for compiled stuff
It seams they are compiled.

But how can I use the example?
I started the new VLCplayer but I cant find some options.

--video-filter opencv_example ?

Hello,

thx @ivoire that argument i missed.
But sadly
I already cheked the video_filter dir and cant find the filters, so i copyed them into.

cp /root/vlc/vlc-1.1.2/modules/video_filter/.libs/libopencv* /usr/local/lib/vlc/plugins/video_filter/ Is there anything else i need to do?

I also found some settings in the advanced options, but everytime i get:
And why vlc try to load the filter twice? also very strange...

Please help
Lucia Zurasi

*push*

No Ideas?

You can add some code on the opencv_example Open function to see what the problem is.

Hi,

Hoping to catch someones attention on this.

I'm trying to run the opencv_example, which from what I understand, inherits from the opencv_wrapper somehow (or, wrapper contains the example, and is configured to load it).

Anyone familiar with this?

I'm using OpenCV-2.2 and vlc-1.1.7. I'm configuring and compiling on Ubuntu 10.10.

I modified opencv_example slightly (changed path to cascade file to appropriate location for linux, and added an argument to cvHaarDetectObjects to get it to compile [minimum square for face identification, cvSize(0,0)].

I modified opencv_wrapper, changing the set_capability and set_subcategory to video_filter2 in the vlc_module_begin block.

when i run the following:

/home/sriney/vlc-1.1.7/vlc --reset-plugins-cache --video-filter=opencv_wrapper v4l2:///dev/video1

I get a segfault

when i run the following:

/home/sriney/vlc-1.1.7/vlc --reset-plugins-cache --video-filter=opencv_example v4l2:///dev/video1

Failed to create video filter2 'opencv_example'

even though the opencv_example is a SUBCAT_VIDEO_VFILTER2

Can anyone say if I'm attempting to execute these cascading filters from the command line properly or not, and whether there are other upgrade issues to consider in the code going to 1.1.7 and vfilter2?

My next exercise is stepping through the debugger. Anyone set up vlc to compile through Eclipse?

Thanks,

Seth

Hi all,

I wanted to add some more information. I read through the code, and I now understand the inheritance/dependence works with the opencv_wrapper and opencv_example.

The filter should be initiated on a stream from the command line as such:

vlc --reset-plugins-cache --video-filter=opencv_wrapper --opencv-filter-name=opencv_example --opencv-verbosity=debug v4l2:///dev/video1

It makes it to the Create function of opencv_wrapper where it returns, but then Segfaults.

I'm going to try to hook up in the debugger in Eclipse.

Seth

Hi All,

I abandoned opencv_wrapper. It seems it was using the old video_filter api (with Render). I trying to hook opencv_example up directly. I read on another post (from 2007) that opencv in vlc hadn't worked in some time. I'm going to try to resurrect it. Any help in converting picture_t to IplImage for processing in OpenCV would be helpful.

thanks,

Seth

Have you found any solution to your problem. I am also trying to make opencv work, but I always get segfaults.