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Recommendation for Video card / device / computer for High Quality Stream
I am currently using the ATEM TVS via the USB program output into Livestream’s Procaster software. We are running full HD into the system on all 6 camera angles.
Everything works great except for the level of quality that I can get to using my Macbook Pro 2010 (2.7 GHz i7, 8GB RAM). If I try to stream at a certain quality level (or the multi-stream option for mobile) the CPU maxes out and Livestream quits.
My question is, does anyone know of a better computer configuration and/or dedicated video capture / scaling device that I can put between the ATEM and my Macbook Pro to take care of all the video downscaling?
I’m sure a Mac Pro tower would fix it with certain processor upgrades and a good video card but is there anything more economical to boost the processing to work with the Macbook?
Do you think the Blackmagic H.264 PRO Recorder may help which would take the SDI program output from the TVS and go into the computer again using USB 2.0?
Thanks for any tips/suggestions.
Matt
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8 Replies
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Hi Matt,
the H264 recorder won’t help you with that because it is the same device that already sits inside your Atem TVS. The TVS has the H264 recorder built in.
Interesting to hear that the procaster recognizes the TVS at all, because the encoding is done inside the TVS (it outputs a H264 stream over USB2). I think the Procaster software reencodes the H264 stream coming from the TVS with another bitrate / resolution. That should result in a degraded image because you add two steps of compression where you only need one.
The solution could be to get a supported SDI card for a PC or a Desktop Mac. If you take a look at the livestream.com site you will find several cards that are certified by livestream.com.
But you could also use a cheap BMD Decklink SDI card. Make sure to get a decent PC or Mac that can handle the HD encoding. That eats a lot of CPU power and you need a recent system for that. Then run SDI from TVS to SDI In of the card and do the compression inside the PC/Mac.
You could also try out some different settings of the H264 encoder inside the TVS. For a full HD stream you should use at least 3-5MBit to make it look OK. Set the TVS to that rate and use the same parameters inside the Procaster. Maybe the Procaster won’t reencode if it is the same format.
Otherwise set the encoding rate on the TVS as high as you can (20MBit in TVS control software – 30MBit with MXLight) and reencode it with the desired settings inside Procaster. But there is a little “bug” in the H264 recorder: It discards every second line and does some weird deinterlacing with that. BMD knows about this fact but there has been no solution to this. So you will lose resolution if you use the USB2 output no matter what you do.
Cheers
Andreas
RegardsAndreas
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Entertainment Producer IHK
mindandvision -
Andreas,
Thank you for the tips. I wasn’t aware that the SDI program output from the TVS was uncompressed. I wonder if the HDMI program output is also uncompressed? Assuming only the SDI.
You are also correct in the fact that Livestream does need to take the h.264 feed and re-encode it to new streams. In many cases it wants to re-encode to 2 or 3 separate streams (one high quality or HD, one medium quality, and one mobile quality). I’m sure that takes a lot of CPU to handle.
I would be happy with just one feed through Livestream (just the high quality, not even HD) but it doesn’t seem to give me that option.
Thanks again,
Matt -
Matt,
HDMI is also uncompressed. The only compressed output of the TVS is the USB2 out.
You can indeed configure the Procaster to just output one HD stream or any resolution you like. But even with just one HD stream you need a very powerful CPU:
Quad Core i7-2600 series CPU or better
8GB RAM
5Mbps or better upload bandwidth
Dedicated video card, 512MB VRAM
Windows Vista / Windows 7Check the settings of your Procaster software again and configure it to output only one stream in a resolution that your computer can handle.
Cheers
Andreas
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Entertainment Producer IHK
mindandvision -
Hi Matt! Were you able to find a solution that worked for you? I’ve run into the same problem (TVS to macbook pro with i7, only able to stream at Normal quality through livestream for producers). The new quad core minis look promising- wish there was a way to try them out and see.
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Yes I was actually. I just ran a webcast and the newest Macbook Pro with 4 cores (I forget the GHz) was able to handle high quality and HD. We unfortunately had to switch to a slightly older Macbook Pro 4 core machine made earlier in 2012 with less memory and GHz and it did not survive in HD for very long.
Check out the quality of our feed here but please note that the only cameras that were HD direcly into the Blackmagic were the static wide angle shots and the host shots. The action shots we’re all re-broadcasted from slower machines.
https://new.livestream.com/OceanPaddlerLive/events/1589895
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Thanks for the reply! Quality looks great- 4 cores it is then! I have a friend willing to lend me his previous generation iMac (quad core) to test out HD on, so now I’m pumped that it will likely be perfect.
Thanks again!
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Hi All,
Can we clarify if we’re talking about using the USB h264 stream out of the TVS or the HDMI / SDI uncompressed feed?
Being able to use the h264 feed off the USB port as an audio / video source in livestream would open up quite a few options for my workflow and I haven’t been able to see anywhere where this was confirmed (or denied).
thanks,
-eric
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I was referring to the USB h.264 compressed stream as you assumed. The uncompressed SDI/HDMI program output would probably require some even heavier hardware to capture and re-encode.
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