Avermedia Extremcap U3 (CV710)

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irongeek

Member
Just ordered the Extremcap U3. Says it works out of the box with OBS, but I'll let you guys know how well it works. I plan to use my Old Elgato GCHD to get the HDMI feed from my camera, and this to capture slides. Some of the specs have me weirded out though. Does it really need an i7 as the laptop? And a specific video card? Hope it gets here before Friday so I can record my Metasploit class with it.
 
I

irongeek

Member
Never mind, place said it was in stock and it was not. I may put off ordering it till it becomes more common. If anyone does get one, I'd like to hear a report.
 
dodgepong

dodgepong

Administrator
Forum Admin
The most important part is that you have a compatible USB 3.0 port. That's no joke. You need an Intel, Renesas, or Fresco USB 3.0 port or it will not work. And if you want to do encoding at 1080p60, then yes, you will need an i7.

Note that we don't recommend streaming out at 1080p60, even if it's supported by the capture card.
 
dodgepong

dodgepong

Administrator
Forum Admin
For reference, here is the thread: viewtopic.php?f=6&t=9385&p=52568

It looks like some sort of conflict with a BlackMagic device, not an AverMedia issue. I don't see a reason for this to cause problems for people without BlackMagic devices, so I wouldn't go as far as to say that this device does not work in OBS yet as a blanket statement.
 
M

mik3d

New Member
Hows the quality? I see they just lowered the max mbs to 3.0 instead of 6.0mbs so you can achieve 1080 60fps but lose quality.
 
D

DanSyor

New Member
Do you have any means of knowing what the delay in OBS preview window is, using this capture device?
I'm planning to get one of these (or a Micomsoft SC-512N1-L/DVI PCIe 2.0 card, or another PCIe 2.0 card that allows a "no-delay" preview window 1080p60fps, at least with the "recommended" software, RECentral for Avermedia, AmarecTV for Micomsoft) and think it would be a bit of a shame to be forced to play through RECentral preview window and stream/record with OBS using a capture of the preview window (with "Game Capture"?) (for some reason, I don't know if this video capture device can be used at the same time with both OBS and RECentral).

I've seen a review complaining that XSplit preview window was not meant to be used to play through and thus the reviewer had to use an HDMI splitter when streaming with XSplit, but what about OBS? In order to measure, an accurate stopwatch which actually refreshes every 1/60s (<0.017s) (for a 60Hz screen) or just a program with a refresh counter (first frame shows a 0, second a 1, etc.) might be needed, but I could not find one for now...
 
paibox

paibox

heros in an halfshel
The delay is whatever the delay on the device itself is. You can check this by cloning your main monitor to an HDMI output on your computer and connecting that to the Extremecap U3. Then run a timer application (such as wsplit) or some sort of frame counting application to see what the delay is in milliseconds/frames by checking the OBS preview window versus the monitor you are cloning.

The delay on the Micomsoft card is 4-5 frames, it's most likely something similar with the Extrmecap.
 
D

DanSyor

New Member
I used a variant of your javascript code to see what the delay was window capture.
Code: 
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Language" content="en-us">
<title>Clock</title>
</head>

<body style="text-align:center">
<div STYLE="font-family: Arial Black; font-size: 75px" id="txt">
<!-- js stuff here  !--> 
</div>
<div>
<input type="submit" id="start" value="Start"/>
</div>
<div id = "random">
</div>
</body>
<script>
var beg;
var num = 0,
	num16 = 0,
	num17 = 0;

document.getElementById("start").addEventListener('click',startTime,false);
document.getElementById("random").textContent = Math.random() < 1/3;

function startTime()
{
var today=new Date();
var h=today.getHours();
var m=today.getMinutes();
var s=today.getSeconds();
//var fs=today.getMilliseconds()/1000*25;

//var fs=((h*3600000+m*60000+s*1000)+today.getMilliseconds())/16;
var ms=((h*3600000+m*60000+s*1000)+today.getMilliseconds());
if  (!beg) {
	beg = ms;
}
ms-=beg;

// add a zero in front of numbers<10
m=checkTime(m);
s=checkTime(s);
document.getElementById('txt').innerHTML=h+":"+m+":"+s+"<br>"+num+' <br>'+parseInt(ms);
document.getElementById("random").textContent = 'step 16: ' + num16 + '; step 17: '+num17;
var step;
if (num16>0) {
	var ratio = num17/num16;
	document.getElementById("random").textContent +=' ratio 17/16: ' +parseFloat(num17/num16) ;
	if (ratio > 2) {
		step = 16;
		num16+=1;
	} else if (ratio < 2) {
		step = 17;
		num17+=1;
	}
}
if (!step) {
	if (Math.random() < 1/3) {
		step = 16;
		num16+=1;
	}
	else {
		step = 17;
		num17+=1;
	}
}
num++;
t=setTimeout(function(){startTime()},step);
}

function checkTime(i)
{
if (i<10)
  {
  i="0" + i;
  }
return i;
}
</script>
</html>
On a preview stream capturing at 30fps, preview window seems to be ~30fps*.
On a preview stream capturing at 60fps, preview window seems to be ~60fps. The observed delay (one OBS instance capturing web page with timer, another instance capturing monitor with preview window of the first OBS instance next to actual timer) is like 1 frame per second. It would be awesome to have the same delay with the ExtremeCap.

*For that part, I would like to be able to set different frame rates for actual streaming/recording and on preview window.
Does this mean the rewrite will make it possible?

EDIT: err, had the answer tab opened for a while before posting it so I didn't see paidbox's answer. 4-5 frames seems like a bit too much and not that acceptable to play with the preview window (well, maybe playable but might cause a different gaming experience on a very fast game at high level...) :(
 
D

DanSyor

New Member
A small bump because I just got one (had 20€ off, so final price about the same as LGP or Elgato).

Using RECentral preview Window or OBS one, I get a 3 frames delay, so something around 50ms.
Audio through RECentral preview is fine, but audio through OBS preview (meaning I set audio sound to output to desktop) is horrible. (EDIT: seems fixed when using waveout audio renderer)

Colors look fine with gamma at 0.85, but green still looks very flashy.
 
D

DanSyor

New Member
Another bump...
I had trouble with the device for the past weeks: after some time, the device would suddenly stop working properly, causing corrupt recordings. At the time, I would unplug the device from USB and plug it again and it would work again, but that wasn't neat. I contacted support from AVerMedia. After some inquiry, it appeared that my Intel host driver was outdated (from March 2013). I was provided with a newer Intel host driver and so far, no critical bug.
So, for now, the preview window of RECentral works well (just had to trick with colors to get truer colors, such as black which was kinda grey), with constant framerate of 60fps.
Issues I currently have with OBS (capturing from a Wii U) :
  • colors (in preview window and output files) are not the same than in RECentral, with same settings (settings I can set from the 'configure' button in device properties in OBS) (OBS's gamma didn't help, left it to 1)
  • framerate is not stable, like preview doesn't refresh or something (I can check by watching recorded videos)
That's sad, since NVENC can do a better encoding job than what the RECentral does at same bitrate (which is the only setting regarding quality of a recording RECentral does). (and let's not compare to x264 with crf ≤ 20 and superfast CPU preset, otherwise CPU use can get too close to 100%) (CPU usage while recording with RECentral is not very high, between 40 and 60%; around 20~25% with only its preview window on, no recording)
And OBS can't capture RECentral preview window (with window capture) but I guess that would have been expected, even if I don't really understand why (DirectShow can't capture "DirectShow(?)"? then how can I capture stuff from another OBS instance as long as I don't get full screen with something?).
 
paibox

paibox

heros in an halfshel
The issue where the preview does not display all frames it sends to the encoder is known, but it is unknown as to what causes this. I've tried to investigate it myself, but I've not found anything so far, the recording/stream should still be smooth as butter.

The RECentral window is rendered using a hardware overlay, which can't be captured since Windows itself does not render it, it's done directly on the video card. OBS uses nothing of the sort, so of course you can capture the OBS window.
 
D

DanSyor

New Member
paibox said:
the recording/stream should still be smooth as butter.
Click to expand...
Well, it looks as smooth as the preview window to me. The worst I had is a frame staying on for 15 frames (kept the recording for that)! I'll test with XSplit to check if the same happens, and if so, I'll contact support. Most of the time, it's some groups of frames lasting for 2 frames but that's still annoying, especially while playing.
EDIT: ugh, I didn't remember XSplit (free) would allow that few, don't know if I can do much with that :(

paibox said:
The RECentral window is rendered using a hardware overlay, which can't be captured since Windows itself does not render it, it's done directly on the video card. OBS uses nothing of the sort, so of course you can capture the OBS window.
Click to expand...
Thanks for the info.
 
Last edited:
paibox

paibox

heros in an halfshel
15 frames does sound like some sort of driver/DirectShow filter issue. The issue I was referring to was the preview being "stuck" on the same frame for 2-3 frames somewhat sporadically which causes the preview to look jerky, while the recording is perfectly smooth.

I haven't had a chance to try an U3 myself, so I can't confirm if there are any driver issues with it, unfortunately.
 
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