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Intensity Pro - Broadcasting Quality Loss

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Danny Nguyen
Intensity Pro - Broadcasting Quality Loss
on Jun 19, 2009 at 10:59:31 am

Hello everyone. My name is Danny, a Justin.TV broadcaster who goes by the name iMoogle. I recently bought a new computer along with an intensity pro, and have tested it using Adobe Flash Media Live Encoder (FMLE) to upload the stream to JTV. The video is perfectly fine for the first 7-8 minutes of intense action, but after that, many things start to happen:

- The video bitrate show in FMLE starts jumping from very low to very high bitrates, nowhere near the selected bitrate (700kbps). I've seen it jump from 50kbps to a whopping 2000kbps for unknown reasons. It's not very noticeable in the video, but an inconsistent bitrate can never be good. When it streams perfectly fine, it only jumps between the range of 650 and 750.

- The FPS starts to drop dramatically. From a very very steady 30FPS, then gradually down to 28, then 25, then 22, then if I choose to keep the broadcast on even longer, down to 10FPS! But I usually stop the broadcast after around 22 because the video becomes way too choppy for my viewers and I.

- The audio becomes out of sync, and gets more and more delayed the longer I let the FMLE stream to JTV.

Here are some videos of how good it is from the start, then how bad it gets in the end...
GoW2 (360) - http://www.justin.tv/clip/4983dc87147c9fbe **I cussed a bit in this highlight. Just a warning =P
CoD4 (360) - http://www.justin.tv/clip/910b1ec95d278003 **This is after 14 minutes of idling in the lobby.

The strange thing is, that if I stop FMLE, then start it again, it will stream perfectly fine for 7-8 minutes then it will show these symptoms again, gradually getting worse. My computer is pretty good, and my CPU usage never goes over 50% while broadcasting.

Intel Core 2 Quad Q9550
4GB of RAM
Geforce GTX 260
About 3.5 Mbps upload speed (doesn't matter what my FMLE settings are put to. Even if I have a stream of only a total of 400 kbps, the quality will die down after 7 minutes)

I'm going to try broadcasting with my old Dazzle DVC100 capture card and see if FMLE does the same thing.

Any help is appreciated. Thanks!

---
http://www.justin.tv/imoogle


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Danny Nguyen
Re: Intensity Pro - Broadcasting Quality Loss
on Jun 20, 2009 at 10:08:36 am

Update: Even the Dazzle DVC100 capture card lags horribly, just like with the Intensity Pro, after broadcasting for awhile. Something is wrong with my computer, so I've pretty much cancelled out the Intensity Pro as being the source of this problem. I've done so many things, including upgrading from Vista 32bit to Windows 7 64bit, and still no good.


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Joshua Helling
Re: Intensity Pro - Broadcasting Quality Loss
on Jun 30, 2009 at 8:50:18 pm

Hello there,

The issue here is likely due to the encode process. Depending on the parameters of the encode will define how much CPU/Ram overhead will be needed to do that encode in real time.

I am not surprised you are seeing the same issue on the Dazzle as our board. It's doing the same thing, looking at a generic input and doing some encoding.

To fix this, you might need to up your ram, but more likely you will need more powerful CPUs to do this encode in real time.

The fact that the encode seems to happen fine for the first 7 to 8 minutes and then falls apart might even suggest some sort of memory leak. Try keeping your minimum bitrate and maximum bitrate a bit closer together and see if that helps the encode to be less erratic.

Sincerely,

Joshua
Director of Support
Blackmagic Design Inc.


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Tom Brabenec
Re: Intensity Pro - Broadcasting Quality Loss
on Jul 23, 2009 at 4:36:05 am

I didn't get the chance to type up something about this same exact issue, but I'm experiencing this as well. This is pretty well stated, only this happens not only with FME v3 w/ justin.tv but also occurs on http://www.ufragtv.com (which uses TikiLive).

Specs: Q6600, 8GB RAM, Vista x64, 8800GTS, Intensity Pro purchased at BuyDig early June.

So yes, after 10 minutes with the *new* 3.2 drivers for the BMI card, I now get frame drop. It increases over time, consistently, and after 30 minutes it drops to unacceptable levels. This happens with ANY settings and right now I'm thinking there was a bad batch of cards or something. I want to add that with the 3.1.2 drivers, there was less of a frame drop and more actual sound delay (or actually, the sound drifts AHEAD of the video) which progressed to dropped frames and eventually resulted in the same.

I've also tried this in my friends i7-equipped machine and end up with the same results. Baffling, since the card at first works flawlessly for a few minutes! So frustrating. Also to note, there are one or two others on ufragtv that use the BMI card without issues, and THEY are boggled by the situation as well, but I HAVE seen audio delay once or twice crop up in their casts.

I'm going to attempt to now test inside the Blackmagic Media Express app to see if I get the same. Not by recording, but just by watching the feed, which shouldn't have much delay or frame drops *AT ALL*. If I remember correctly, my CPU never went above 20% using that app with any resolution when not recording to the HDD. I'll update my status on this in a bit, but if anyone else has this card, I'd like to hear what hardware you're using. (Gigabyte EP35-DS3P (P35 ICH9R Intel chipset))

I was also told over the phone by BlackMagic that I basically need to prove to them that there's something wrong before they would process an RMA and exchange it. *boggle* - so yeah.. I'll try.

Also to note, this happens with everything I've tried, which is component (360/ps3/8800GTS component dongle) and HDMI (DVI to HDMI from any PC) and I primarily use the input HD to SD down-conversion option. Not using it (and grabbing the full 720/1080 feed) is unusable and pointless for live casting anyway. Hopefully all this made enough sense. :)


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Jay Epperson
Re: Intensity Pro - Broadcasting Quality Loss
on Mar 19, 2010 at 8:24:29 pm

We have been experiencing the exact same thing and not just with the Intensity but with the DeckLink SDI as well. Everything is flawless for the first couple of minutes and then drops down to 5-10fps.

I suspected that perhaps the input processing of these cards may have something to do with this, especially the Intensity's, as afaik its done in software (and the DeckLink's in hardware?) but ruled this out as even with 480i input the same thing happens.

Btw, I can confirm that 1080i/720p input works in FMLE 3.1 (which isn't out yet but I'm a beta tester), however it doesn't mean much with these horrible frame drops. An FMLE developer in the Adobe beta forum mentioned that these issues may be due to a problem with Timestamps. I do not know how this carries over to the Windows side of things as DirectShow and QuickTime are two different animals, but it's worth a mention.

I would really like for someone from Blackmagic to shed some light on this. Thanks in advance!


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Jay Epperson
Re: Intensity Pro - Broadcasting Quality Loss
on Jul 20, 2010 at 10:20:55 pm

After continued headaches using Blackmagic cards for streaming, we decided to go the ViewCast Osprey route. Their HD-SDI offering (the Osprey 700e HD) is 4x more expensive than the Blackmagic Intensity/Decklink SDI cards but it has been an absolute solid performer with auto locking to any SDI signal given to it, test pattern fallback upon signal loss and ability to be used by multiple software at once. We are using an HDMI2SDI converter box to feed the signal into it.

Blackmagic cards are great, but they're just not meant for streaming like the Ospreys. Blackmagic could really tap that market if it wanted to as it's all really a matter of proper firmware and driver support, they already have the hardware. I sure hope they do so I don't have to spend $2000 on an SDI streaming card.


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