Using a video capture card instead of a WebCam - // video deinterlacing?

[efrencd]

Hello guys,

We are trying to input live video into the browser using WebRTC. The
thing is that we are not using normal USB Webcams but video capture
cards.

Right now I have attached 2 video capture cards to my system:

1. Decklink Extreme 3d (A professional card able to capture in Full HD
from SDI inputs)
2. A cheap USB analog capturer (WDM 2861) able to capture composite
PAL and NTSC signals.

Well, when I try to to load any of the Chrome Demos from the
WebRTC.org page, for example this: "http://learningthreejs.com/data/
live-video-in-webgl/" in chrome Canary 19.0.1071.0, it display the top
dialog in which I can choose any of the two capture devices I have
attached to my system. The problem is that whatever device I choose
all I get is a black screen. This leads me to some questions:

1. Do you plan to support video capture devices other than USB
Webcams? (I think it would be interesting as It would allow us to
stream TV live shows with a higher quality, for example making us able
to capture Full HD video coming to the card in SDI signals).

2. Do you plan to add a dialog to configure the video capture device?
For example, in the video settings of skype there is a "settings"
button that opens the DirectShow dialog of the video capturer where we
can select the input video mode, resolution, exposure, etc.

3. In case we input an interlaced video signal in the capture card
like PAL or NTSC, the image quality would be decreased because it is
composed of video fields. Do you plan to add a video deinterlacer
functionality in case one of these video modes is used as input?

Thank you and best regards.

[efrencd]

Anything on this?

Has anyone been able to capture video from something that is not a USB webcam using WebRTC?

Thanks!

[Bossman207]

I am having a similar issue.  I have a USB rca connection that when using virtual dub, I can capture video and audio.  When I use something like, you tube webcam capture or windows video maker 2012, I can choose this USB device for line in audio and video for the "webcam" settings.  However, for both instances the video does not pickup, play through, capture, etc... only audio.  It's like there is something about the webcam video feed that differs from the video feed of an external video capture device that I can't figure out or even understand why there would be an incompatibility issue.  What is the difference in capturing a live webcam video than a "live" played back VHS video?

[Harald Alvestrand]

Most webcams capture progressive video.

Because of the long history of video encoding formats, analog video is usually sent interlaced, and some of the digital representations are able to capture in interlaced too.

If you can capture the output of your video capture device to *any* file format, you might want to analyze that file format to figure out if the video is captured interlaced or non-interlaced.

Interlace was a bad idea in the first place, and letting its existence continue into the digital realm is an even worse idea, so if this is the issue, I think you may have to figure out how to deinterlace the video before asking anything else to deal with the format - the capture card may have settings for this.

Or not.

--
 
---
You received this message because you are subscribed to the Google Groups "discuss-webrtc" group.
To unsubscribe from this group and stop receiving emails from it, send an email to discuss-webrt...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

[SProgrammer]

Use Python or Go language to drive VLC (optional). then:

1) Use VLC or Mplayer or Ffmpeg to capture from the card and then convert it into USB video or RTSP stream.

2) then from WebRTC capture that USB instance or RTSP stream which will give you 60 or 50 fps to WebRTC

[Nadav Givoni]

Guys, 

I'm running into a similar issue.  I have a BlackMagic Video card that I'm able to detect using the navigator.mediaDevices.getUserMedia to select the media source.  That said, if I use their tool, Media Express to view an incoming video (in this case I've attached the XBox), and then I open up the web app and select the video card, the incoming stream in Media Express goes black and I don't see anything in the video tag on the page.  Does anyone have any suggestions as to why this is happening? On occasion I have gotten these errors that the "DOMException: Could not start video source".