PDA

View Full Version : which is the Skype frame rate limitation?



drumstudio2000
06-19-2012, 09:00 AM
hi, im researching about webcams to buy and use it among wire cast 4 to do some drum lessons via Skype.
Can anyone tell me which is the Skype frame rate limitation?
Im asking this because I'm looking for a good hd webcam to do my lessons...but it will have no sense to buy a 30fps webcam, if then Skype breaks that into something else...
any advice?
really thanks!
juan

TomSinclair
06-19-2012, 10:08 AM
Juan,

Great question. My experience has been that Skype is limited by your internet connection speed among other factors. If you look at the weekly show StudioTechLive (http://www.studiotech.tv/category/studiotech-live/), you'll see them doing one or more Skype connections at a very good frame rate and HD quality. So, get the best you can afford! -Tom

andrewzarian
06-19-2012, 10:09 AM
Most HD Webcams out there will do 30fps 720p. the Logitech c910/920 and the Microsoft Lifecam Cinema are two of the best out there. Skype will always limit your HD video to 22fps regardless of what camera you are using. The other issue you might face is that Neither the Logitech c910/920 and Lifecam Cinema have driver control on OSX.

andrewzarian
06-19-2012, 10:10 AM
with that said Software like Vidblaster can force skype to run at 30fps. If you are using just a webcam with skype you will be limited to 22fps MAX

TomSinclair
06-19-2012, 10:22 AM
Software like Vidblaster can force skype to run at 30fps.

Really? I was not aware of that. How did you figure that out?

drumstudio2000
06-19-2012, 10:31 AM
Most HD Webcams out there will do 30fps 720p. the Logitech c910/920 and the Microsoft Lifecam Cinema are two of the best out there. Skype will always limit your HD video to 22fps regardless of what camera you are using. The other issue you might face is that Neither the Logitech c910/920 and Lifecam Cinema have driver control on OSX.

thanks! yeah, I'm still looking the pros and cons of these logitech cams running on mac os lion...maybe I will go for the c910 (maybe a couple of them)... would you recommend it? I'm planning to use wire cast 4 to switch between them and add some tittles and so. Eventually, I will record a Skype lesson I will do with them, but Im planning to use wire cast to record... do you think have not a driver control will be a pain, or is just for fun?
thanks!

ps. I didn't know that soft that allows 30fps too.... did you tested it?

cseeman
06-19-2012, 11:44 AM
Wirecast itself can see Logitech C910 at full 1080p30.
There's a third party driver some are using with the C910 on Mac.
Driver
http://www.dm9.se/
Video Demo
http://www.youtube.com/watch?v=EfMDcVe4VEg

drumstudio2000
06-20-2012, 06:37 PM
Juan,

Great question. My experience has been that Skype is limited by your internet connection speed among other factors. If you look at the weekly show StudioTechLive (http://www.studiotech.tv/category/studiotech-live/), you'll see them doing one or more Skype connections at a very good frame rate and HD quality. So, get the best you can afford! -Tom

thanks! I have another question. Do you know if using 2 of these c920 will compromise things like transmission quality, lags, or cpu usage?

thanks!
juan

TomSinclair
06-20-2012, 10:18 PM
Juan, I have no experience with two 920s, but I would guess it would not affect transmission but may impact CPU usage.

andrewzarian
06-21-2012, 01:32 PM
Well if you plan on using two c910s or two c920's you may have an issue. The drivers do not allow you to control the settings for both cameras. What you can do is get one 910 and one 920.

drumstudio2000
06-22-2012, 11:34 AM
Well if you plan on using two c910s or two c920's you may have an issue. The drivers do not allow you to control the settings for both cameras. What you can do is get one 910 and one 920.

hi, thanks for your help.

These days Ive reviewed a posted tons of messages on forums and youtube...about if c920 works or not on mac lion...and still have not a solid answer... there are people that said DO NOT BUY a c920, IT WILL NOT WORK on lion...other, YES, BUY IT!!!!

so, Ive decided to go for two c910 and not to take any risks... Ive read your comment...and now I'm in trouble again LOL... I would love to buy a c910 and a c920...but...do you know if c920 will work ok on mac lion??

thanks!!
juan

cseeman
06-22-2012, 11:54 AM
Any UVC compliant webcam will "work." Will it work well given that there are no Mac specific drivers? You generally will NOT be able to take advantage of some of the 920 specific features. It's not worth the extra money if you're using it on the Mac.

I don't know if the third party driver will control more than one webcam.

Wirecast itself will at least take advantage of a webcam's in built resolution. It does a better job of that than other programs I know of. Wirecast polls the webcam and presents its inbuilt resolutions. If you change to another model webcam you'll get a different resolution set. It will only show the results of one webcam so having matching webcams help.

For example, Two C910s will show all the resolutions available and allow you to set each one individually.
If you were to use a C910 and 9000 though both cameras may only offer the C910 resolutions which would be a mess for the 9000.
Matching webcams are best. Two C910s or Two Lifecam Cinema Studios would be good if you have the USB2 buses.
Keep in mind you MUST have the USB2 bandwidth. For HD webcams you really need TWO USB buses (that's BUSES NOT PORTS). In many laptops there may be two or more ports going to a single bus. My 2011 15" MBP has two buses. The Facetime webcam is on one of the buses though but you can deliberately knock down its bandwidth by dropping the frame size. Frame size, impacts bandwidth on the bus.

Also when Wirecast developed webcam detection they also examined the inbuilt compression in the webcam. It pics the codec (MJPEG I believe) which gives you the better frame rate (I believe the other is a higher bandwidth YUV variant). The result is that you can get 1080 30fps from any webcam capable of that.

drumstudio2000
06-22-2012, 12:54 PM
Any UVC compliant webcam will "work." Will it work well given that there are no Mac specific drivers? You generally will NOT be able to take advantage of some of the 920 specific features. It's not worth the extra money if you're using it on the Mac.

I don't know if the third party driver will control more than one webcam.

Wirecast itself will at least take advantage of a webcam's in built resolution. It does a better job of that than other programs I know of. Wirecast polls the webcam and presents its inbuilt resolutions. If you change to another model webcam you'll get a different resolution set. It will only show the results of one webcam so having matching webcams help.

For example, Two C910s will show all the resolutions available and allow you to set each one individually.
If you were to use a C910 and 9000 though both cameras may only offer the C910 resolutions which would be a mess for the 9000.
Matching webcams are best. Two C910s or Two Lifecam Cinema Studios would be good if you have the USB2 buses.
Keep in mind you MUST have the USB2 bandwidth. For HD webcams you really need TWO USB buses (that's BUSES NOT PORTS). In many laptops there may be two or more ports going to a single bus. My 2011 15" MBP has two buses. The Facetime webcam is on one of the buses though but you can deliberately knock down its bandwidth by dropping the frame size. Frame size, impacts bandwidth on the bus.

Also when Wirecast developed webcam detection they also examined the inbuilt compression in the webcam. It pics the codec (MJPEG I believe) which gives you the better frame rate (I believe the other is a higher bandwidth YUV variant). The result is that you can get 1080 30fps from any webcam capable of that.

thanks for your detailed information cseeman!
I have a mcbookpro i5 13 inches, early 2011

on serial number info it says
USB: - 2 ports (USB 2.0)
FireWire: - 1 port (FW800).
Display port: - Mini DisplayPort.
Card Slot: - SDXC card slot
Thunderbolt: - Yes

but it says nothing about buses...how can I be shure how many of this I have?

Given the info you commented, ti seems to me that buy 2 c910 will be appropriate for my plan to do some SKYPE drum lessons... do you recommend me to buy 2 c910 to work on wire cast?

what about andrewzarian user said on my post:
"Well if you plan on using two c910s or two c920's you may have an issue. The drivers do not allow you to control the settings for both cameras. What you can do is get one 910 and one 920"?

Maybe you can help me to finally be sure what pair of cams to buy, and to know how many buses do I have on my mac...
really really thanks!
juan

ps i did a capture of some specifications of my mac. this means I have 2 buses? I can't figure it out
66

cseeman
06-22-2012, 01:18 PM
Wirecast is drawing the USB bus information from that but puts it in a much easier to understand format.

Open Wirecast 4.1.3 (must be that version) and open Sources/Show USB Devices. Then select the Show All Devices checkbox.
It will show you the bus numbers. Some buses are internal (they have no impact on the ports).
Using a single C910 put it in one port and see what number it shows. Then move it to the next port and see if it moves to another number. You will probably need to select Refresh after changing the port or, to be save. quit and start Wirecast again.

BTW this works on both Mac and Windows.
It's a major feature given how problematic webcam and USB2 bus use is.

drumstudio2000
06-22-2012, 01:40 PM
I have wirecast 4.1.2....hum! on Sources only shows this
http://img707.imageshack.us/img707/7563/capturadepantalla201206i.png

I haven't yet the c910, so I can't follow your instructions... (no webcams, in fact, only the inbuilt FaceTime)

There is another way to know how many buses do I have?

cseeman
06-22-2012, 01:45 PM
Update to Wirecast 4.1.3.
That's Source Settings. 4.1.3 added Show USB Devices specifically to address USB buses and bandwidth.

I'd implore people to always stay current. Telestream sometimes includes major features with x.x.x updates. This was one of them. Certainly one can downgrade if there's an issue.

drumstudio2000
06-22-2012, 01:59 PM
thanks, I will. but I think I HAVE ONLY ONE BUS... Ive connected an usb adapter in one port, and my mouse on the other, and on my mac info says:
http://img207.imageshack.us/img207/4944/capturadepantalla201206pd.png

there is a way to have 2 hd webcams on my mac? or there is a way to add another bus to use them?

or how can I expect that 2 c910 works if I have only one bus?
your comments are really helpful to me, thanks!

cseeman
06-22-2012, 02:05 PM
C910 at HD resolution will be a problem unless you have two buses.

The drivers would give you control over such things as white balance and focus. I don't know if the third party driver has been tested for two cameras. I know Stephan Heywood at TheTechBuzz and I think Joe De Max have tested it so they might know.

drumstudio2000
06-22-2012, 02:09 PM
yes, I have mailed stephan a few days ago about c910 and wire cast...but never answered me...who else will know something on this?

drumstudio2000
06-22-2012, 02:13 PM
my idea is to use two webcams among wire cast to do Skype one on one drum lessons.
my intend is to have good resolution, but maybe not to have hd isn't too bad... if it allows the student to see me with good resolution and without lags...what do you think? buying 2 c910 will be throw my money to the trash?

cseeman
06-22-2012, 02:20 PM
yes, I have mailed stephan a few days ago about c910 and wire cast...but never answered me...who else will know something on this?

See my post. I believe Joe De Max hangs here as well.

cseeman
06-22-2012, 02:24 PM
my idea is to use two webcams among wire cast to do Skype one on one drum lessons.
my intend is to have good resolution, but maybe not to have hd isn't too bad... if it allows the student to see me with good resolution and without lags...what do you think? buying 2 c910 will be throw my money to the trash?

Depends on whether you have two buses. Two C910 on one bus would be difficult. You can drop the resolution but if the Facetime camera is on the same bus (even if it's not being used) it ties up bandwidth. You'd have to use very low resolution. If your MBP has a Firewire port why not get a used DV camera? It might cost a bit more than a webcam but you'd have a lot more control and very good quality.

drumstudio2000
06-22-2012, 02:29 PM
thanks! I actually have a dsrl cannon t3i...dont know for sure if it work as webcam, since on tele stream forum said I could forget about it, it will don't work, and that I sure have to buy c910...but none warned me about buses like you...

cseeman
06-22-2012, 02:37 PM
t3i doesn't have a clean HDMI out. If you use the A/V out you'd need a convertor to firewire or USB.

Buses wouldn't be an issue on 15" MBP 2011 and newer as it has two. I'm not sure about the 13" though.