Multiple Blackmagic capture devices on Macbook Pro
Man on a quest here ... to make a robust multi-cam system on a 2020 Macbook pro.
The question I have reached is - can I successfully run 2 UltraStudio Recorder 3G capture devices into the same laptop running Wirecast and enjoy stability? If yes, can I push it to three?
Some background on the journey to here ...
I was running a Magewell SDI capture into a 2013 USB 3 macbook, on a switched feed from a Roland V1 SDI. All good, but I’m now a run-and-gun streamer so looking for faster setup and less load to move in and out.
I Recently got a 2020 Macbook, which is Thunderbolt 3 ports - so had to convert the Magewell from USB 3 to USB C. I then added two Magewell HDMI capture devices - also USB 3 on converters for a total of 3 inputs.
Unwittingly, I had unlocked the gates of hell.
I started with Livestream Studio as Vimeo give it away. But a lot of crashes and some weird problems. The biggest was the audio from the HDMI sources (cams 2 and 3) becoming confused. Sometimes cam 2 carried cam 3 audio - sometimes they switched over. Sometimes there was no audio.
This was sorted on Magewell advice to change the HDMI sources to identify by serial number instead of generic name - it seems the Mac was having trouble mapping them properly, as this did indeed solve the audio issue.
Magewell also said they don’t recommend attaching more than one of their devices to the same USB bus. I’m still not sure if my 2020 MB has just the one, or more than one .... ?
So I went back to two cameras - one on SDI and one on a HDMI device.
But I still had crashes and found studio buggy, so paid to use Wirecast - which I have never regretted. Awesome tool.
I started with 2 cameras and got that working. So full of bravado I added back in camera 3, which worked - until it didn’t! Often it would work fine, but on a bad day I’d have Freezes, stuttery vision and audio sync issues (like 50 seconds out!). I’ve literally had clients in tears on bad days.
So I went back to two cams again and seem to be able to make that work reliably. But I really need 3.
I thought about again using my Roland V1, but that takes away some flexibility I need if I run all cameras through it. My Sony Z280 delivers its SDI signal about 100 milliseconds faster than my GH5s, which is turn about 40 milliseconds faster than my plain GH5 (about 3 frames at 25fps which is just enough to show).
I cant correct for this on the Roland but can in Wirecast (I believe) if I bring the Sony in via the SDI capture and bring in the two GH5s via the Roland (already switched between cam 2 and 3).
But that’s a bit of an awkward workflow. I’ve now spotted a Roland 2 channel switcher called a v-02, which you can operate via a footpedal! It is much smaller and easier than the V1 and looks suited for a 2 input world with 3 cameras. But I’m trying to figure out if that is my best option.
I’m still using those same Magewell devices - and I eye them off with suspicion. I don’t like the old USB running through converters but I’ve had no alternate devices to swap in for testing.
However, the Blackmagic Recorder 3G looks like it Is worth a try - and I could buy 3 for the cost of one Magewell! On face value, stepping up to a thunderbolt 3 connection has to be a better world than USB 3 converted to C.
I saw in a recent post that CraigS mentioned these, and his opinion carries weight around here! So I’m about to order 2 - or should that be 3?
My ideal world is 3 capture devices feeding 3 cameras into Wirecast with no freezes, crashes or problems.
Will the Blackmagic recorders give me that?
Thanks for joining me on my journey!
Unless the power availability on the ports and the need by Blackmagic devices has changed, there is likely a limit to using to BMD UltraStudio Recorder G. Only two may work due to power requirements. The third can be Magewell though. Both ioGear and ATEN make an HDMI to USB-C device that supports up to 1080p60. It seems there's a similar device from Pengo as well. We haven't tested them so we don't officially support.
Mickey Carson said:
I've been using a caldigit
Mickey Carson said:
I do run 2 of them with a mini monitor at the same time.
Thanks for that. That would mean that using the dock allows for three Ultra Studio devices. That the dock is powered likely alleviates the TB bus power limit.
CraigS Hey Craig - those Blackmagic recorders are in short supply here in Australia, but I'm hoping to have them to try out in the next few days.
I'm really leaning toward only using two capture cards - one using my Roland V1 to make a sub-mix of the two cameras next to me at the rear of the venue and one feeding in the wireless (Bolt) camera from front and mobile. I might even end up with all my cameras on the Roland if I need to run a monitor out (which I talk about below).
I've built up from a single source testing streaming recording and sync as I went and everything seems solid in that dual configuration. The problem with the third input - in my previous experience - is that it will work fine, until it doesn't. I've done several jobs in a row with 3 and all was well - but boy, when it goes bad it goes really bad. (I don't think this is a Wirecast problem - I reckon its the hardware).
While I have you .....
I've been streaming off a single 4G/5G modem - which sometimes gives me 400 down and 80 up! But the cursed thing drops out and I go offline, so I am going to have to go to a bonded system - I've just ordered a Teradek Vidiu go with the nodes to give me three networks at once.
But it makes using Wirecast harder - I think? I want to keep it in my workflow as it is great mixer.
I saw a post from you from a year or so back saying it might be possible to send a clean Live window to the multiviewer for feeding into an external encoder - anything more you can tell me about doing that? The people who sold me the Vidiu are suggesting a Blackmagic Ultrastudio Monitor would do the job?
Craig Saunders said:
I saw a post from you from a year or so back saying it might be possible to send a clean Live window to the multiviewer for feeding into an external encoder
The recommended workflow would be to use Wirecast Pro Blackmagic (or AJA) video out but you can set Multi-Viewer to Live Broadcast Out only. Audio would be using monitor (not live) out since Wirecast would be sending a feed for monitoring. The computer would be using the GPU out to a device it thinks is a monitor. Using a GPU that has an HDMI out port is best. Given the GPU is involved with other tasks that it may prioritize sometimes there can be minor issues. Because so much of this is really system specific it's hard to get too specific other than to test and see if the results are good (or good enough).
Mickey Carson said:
One problem with using the multiviewer, if you pop into another application, like email to retrieve a stream key, your multiview will dissappear sometimes.
Disable Hide all displays when application is in the background
Mickey Carson said:
One thing you will find using the BMD output is that the audio does not sync up with video. Lip sync is off when using a typical audio interface or analog output. You have to use the embedded audio on the BMD out if you don't want to add delay in your mixer. This has caused me a little distress because of everywhere I distribute this feed in my work flow. Not all of my destinations can use the embedded audio.
Please clarify if you mean BMD into Wirecast or Wirecast Pro BMD out?
Wirecast has device specific input delay settings.
Mickey Carson said:
the output via a BMD mini monitor.
Please clarify. Wirecast Pro Video Out? Wirecast Pro Video Out uses Wirecast's Live Output audio. Multi-Viewer out is not reliable for downstream integration.
Update ... I believe my quest may be over!
huge thanks to CraigS and Mickey Carson for their insights - they held the answers I needed. These forums are very useful.
So ... I am now running 3 cameras to a macbook pro and a BM video monitor to a Vidiu Go with bonded connection. It encodes H264 720p 25fps very nicely.
My macbook ports are:
2. BM monitor
3. Magewell SDI Usb
4. Caldigit T3 hub with one Magewell HDMI and one BM recorder (and an external mixer via 3.5mm plug)
At idle, with live icons, CPU is about 8% - hitting record for a high res .mov only bumps it up to around 12%.
in my tests so far this system feels rock solid, without even a hint of any ‘let me think about that’ moments. In effect, I have removed many of the places where Wirecast has to interact with the Mac architecture leaving it to just ... work!
So happy .... thanks guys!
I'm glad that configuration is working for you, Craig. I know it's a pain to get everything up and running and not crashing!
I'm pretty sure that all Thunderbolt 3 docks are limited to 87W, as it was the max that was agreed upon when the specs were ratified. I think there's an article on the Caldigit website that I read about it.
If the dongles ever become a problem here's my solution: I went with a Sonnet Echo Express SE1 Thunderbolt 3 enclosure with a Decklink 8k Pro capture card. I've got up to four sources that I can capture at once, and it works great. I have my 2019 16" MBP connected to two external monitors (extra screen for me, and a screen for the talent to see the Wirecast live output), the TB3 enclosure (I have a USB C hub connected to the TB3 passthrough on the enclosure for Ethernet), and also my power brick. My cameras are connected via SDI to the capture card. The initial investment was a bit pricey, but I'm really happy with how solid it's been working.
I've seen other setups with a 3 slot Sonnet enclosure completely packed with capture cards, so I know there's plenty of room for expansion with a single MBP.