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Weird Video problem - Printable Version

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Weird Video problem by crossmr on 03-19-2010 at 12:48 PM

I decided I wanted to set up my camcorder as a webcam. I've come across a weird issue.
When I use my logitech webcam the preview in the wizard as well as what I see when I send video and do a video call are all identical.

When I use the camcorder through my TV Tuner, it isn't.
The preview shows a normal full view. But when I send video (not a video call) it shows some kind of cropped and zoomed block. I 'm not even sure how it is doing it, since the zoom is mechanical on the camcorder.
When I do a video call the video is like the preview full frame, however its of significantly less quality.

(on a side note the "video call" quality is crap compared to just sending video on both sides and enabling an audio call, but with no full screen)

I cannot figure out why Windows live messenger is cropping and zooming the video in "send" video. It doesn't do this with the logitech.
Anyone know what might be up with this or how to improve the quality of the video call?

I'll show you a comparison attached


RE: Weird Video problem by CookieRevised on 03-20-2010 at 09:55 AM

I think it all comes down to resolution. A typical webcam has a significant lower resolution than a camera.

What Messenger probably does with sending video is taking the resolution it can support and cropping the rest. It does this inteligently and uses the middle of the image, opposed to topleft corner, because usually the subject you want to show is in the middle (thus nothing is zoomed in, the image simply has a lower resolution, but it is shown in the same space - it appears to be zoomed in - PS: this is also called a "digital zoom", but actually nothing is zoomed in; the individual pixels are just bigger).

Roughly the same goes for video call. Here it tries to push the entire image into the same space. Doing that it needs to scale down the image because the resolution is way too high, and thus the 'quality' drops.

Reason why Video Call is lower quality than Send Video is because Video Call is meant for viewing (video) and talking (voice) at the same time in a bidirectional way. The most important thing here is communicating (and thus voice). Video quality is therefor not as important compared to Send Video, where the video quality is more important (and voice is less), also Send Video is meant as a one-way communication. Remember that all the data needs to be pushed over the net (and MS' servers), the more data, the more traffic. To compensate and keep the amount of data flow roughly the same, some 'inteligent' decisions are made based upon what is the most important (and thus what needs the bigger slice of the data traffic flow).

Or something like that...

PS: Often people compare Messenger's video chat with stuff like Skype, and can't understand why MS can't do the same thing. But there are major differences in how those things work. The whole setup of Messenger uses servers for example, Skype not. Skype pushes everything it can thru your connection and thus it might slow down other (internet) stuff, Messenger tries to be more 'polite'. As with many things, different methods have both advantages and disadvantages. Nevertheless, MS does recognize that they need to step up a bit on video quality though (compared to competitors). But this is a slow process, as it also requires a lot of hardware change. In the next version of Messenger you'll already see some major improvements in this regards.


RE: Weird Video problem by crossmr on 03-27-2010 at 12:19 AM

Thanks. For some reason I didn't get notified of the reply to this.
Shouldn't the quality be up to the user? I mean if our connections can handle an audio call, and both "sending" video at high quality shouldn't we be allowed to do a full quality video call?
Seems a little silly.

I actually wanted to try skype, but their TV tuner "auto-tunes" as soon as you choose the Tuner and I can't get it to choose the video input. At least WLM doesn't try to tune it and just takes the last channel you had it set to.
off to the skype forums for me.


RE: Weird Video problem by CookieRevised on 03-27-2010 at 07:04 AM

quote:
Originally posted by crossmr
Shouldn't the quality be up to the user? I mean if our connections can handle an audio call, and both "sending" video at high quality shouldn't we be allowed to do a full quality video call?
The quality will increase if your connection can handle it. Messenger has some intelligent checking for that, but you will never be able to do a "full quality video call" as you call it. The quality of a handcam is way too high for that.

It is also possible that you might have a overall speedy connection, but that the connection to Messenger's servers is relative slowish. Hence you get lower 'quality'.

I doubt even Skype will be able to do a "full quality video call". Although the quality would be better than what Messenger offers because of the reasons I gave in previous post (Skype works in a different way).