About to take the plunge... Livestreaming!

[Mike Stranks]

I know this is really off-topic, but it's a vanity post really.

I've learnt a great deal about video production and editing during the last 16 months... getting the most out of my editing software and making videos so that people who can't visit a place in person can get some sort of view of updates and changes.

But nothing's been in real-time... at best a couple of hours after an event via a post to YouTube. I've frequently been asked if I can provide a livestream of any event and have had to answer in the negative.

So I'm now at the point of taking the step from multi-camera, multi-mic (ie more than one of each!) videos to the same, but live.

For those who are interested, I'm currently humming and hawing between three ATEM Mini type devices from three different companies. All are about the same price, but have different feature-sets... decisions, decisions.

Rest assured I shan't be presenting real-time videos of me opening a cardboard box and describing the contents but rather offering a 'live broadcast' facility to those putting on events where the audience has to be restricted because of sensible COVID precautions... it ain't over yet...

I'll post an update if I take the plunge and actually do this!

[Hugh Robjohns]

Learning new stuff is what keeps us all young at heart! I look forward to hearing of your adventures and experiences!

[Drew Stephenson]

Definitely something I'm interested in so also keen to hear how you get on.

[Dave Rowles]

I've not gone into multi-camera streaming, but have done single camera live streaming quite a lot during the lockdowns. Mainly for limited audiences via zoom, and education based.

I got a HDMI input device for my MacBook Pro, and there was a, for me, tiny problem with audio/video sync, but only just. In fact I was convinced that I was the only person it bothered as my wife said she couldn't tell.

I used my X32 rack to mix the multi-mic pick up of the drums/bass/guitar, which gave me the added bonus of being able to do a few monitor mixes so I could send different signals around the room as needed. Then USB output to the laptop.

I found it worked really well. I toyed with the idea of doing more but couldn't come up with an idea that seemed worth the effort!

[Mike Stranks]

Audio-syncing is a definite issue and one that's exercised me somewhat over the last few days.

I don't know of any device in the 'less than 4 figures' category that can achieve onboard hardware syncing. Some people seem to solve it by routing their mixed audio through a camera and having that camera' locked' as the audio source, whatever the pictures are doing. That works well and keeps sync, but of course is dependent on the chosen camera having a decent audio set-up.

I had considered going for some sort of hardware delay-line... Lindy and B..ringer have some units at around £70 - the B being much more versatile with all the other stuff you get as part of the package.

I asked a friend, who has a very sophisticated live-streaming set-up for reviews and other stuff, for his thoughts... He pointed out that the software available with all of the ATEMS has a means to dial-in audio delay as well as things like EQ and compression. However, for my application I really need multiview/preview facilities... the cheaper ATEMs don't have any form of preview/multiview output... Interestingly, despite all the gear at his disposal, my friend uses the 'audio thru camera' technique.

I could be mistaken, but I think if you use OBS etc as a streaming front end then you can apply the delay there... but I want to keep things very simple so shall probably eschew that approach and use a platform that just recognises the streaming switcher as a webcam.

As far as people noticing sync issues, I'm not surprised that many people don't notice it. If you're watching on a phone or tablet you may not be so aware and, as we know, we audio people can be shuddering in our shoes at noticed audio issues whereas others around us are responding with 'what issues?'

Thus far I've been using a couple of HDMI-USB devices to link my camcorders into Zoom etc and a separate input audio interface (as opposed to my standard fare - long story!) for mic(s). Excellent results that way... as long as I ignore sync. My experience indicates that at 25fps the video has about a 3-frame lag, but it can vary...

[Hugh Robjohns]

Most digital consoles can dial in a few frames of delay on each output, so although it will take some experimentation to find the required value you could use that approach to re-sync audio with the video encoder's latency. Audio sources into digital console, delayed feed into video system. This has the added benefit that any foldback or talkback routed via the console would be delay-free, too, and local monitoring in sync with real life.

I was asked to record sound at a video event for an up-market conferencing centre recently. It was an outdoor opera performance with a string quintet and four singers -- not the kind of thing the local team have any experience or equipment to cope with; hence my involvement. It was a multicamera shoot -- all networked remote webcams, and to get my sound in sync with the output of the virtual vision mixer I had to dial in 80ms of delay (2 video frames). I was expecting to need more...

As an aside, back in my BBC days when working with a radio-camera alongside cabled cameras, it was common to hear shouts from the production gallery of 'Sound not in sync!' whenever the radio-cam was on air. People always notice the early sound relative to the (delayed) radio-cam pictures (the radio link and synchroniser adding two or three frames of delay)

Our standard retort was 'Camera not in sync'... because that was the real problem, of course... but 'they' never seemed to 'get it'.

In those days it wasn't practical to delay all the cabled cameras to time-align with the radio-camera, but if we delayed the sound a frame or two the early sound was much less noticeable on the radio cam images, and few people find slightly late sound on the cabled camera images objectionable -- because that's how we experience real life anyway, light travelling considerably faster than sound!

[Mike Stranks]

Thanks Hugh

It slipped my mind to mention that I may experiment using my Zoom F4 to provide some audio delay, although as this will be primarily an 'on location' facility I'd like to keep the amount of ancillary gear that needs to be taken to a sensible minimum.

People tend to think it wasn't such a good idea after all if they see you arriving with a trolley load of gear and needing more than 30 mins to set up.

[Dave Rowles]

Most digital consoles can dial in a few frames of delay on each output, so although it will take some experimentation to find the required value you could use that approach to re-sync audio with the video encoder's latency. Audio sources into digital console, delayed feed into video system. This has the added benefit that any foldback or talkback routed via the console would be delay-free, too, and local monitoring in sync with real life.

See, this is why I like being part of this forum. It manages to point out the solution to a problem that I really should have thought of at the time. :p

No idea why I didn't think of that!

[Mattsong]

Due to the pandemic I have been involved in a lot of multi camera and multi channel audio recordings. We have had to deal with these sync issues so I would like to share some of our solutions. I highly recommend the solution that has been presented of syncing the audio and video in camera first.
There are multiple points where the audio and video will drift out of sync.
1. The camera. Most DSLR and mirrorless cameras will have a processing delay when sending out through the HDMI port. Broadcast cameras have SDI output so it is not delayed. By running your mixed audio into the camera it will sync these two together. The HDMI will be delayed but in sync. Also it is advisable to record this in camera as a master A cam file.
2. The video switcher. There is usually a processing delay for the video especially if all cameras are not using the same frame rate and standards or the switcher is not set to the same standard as the camera. ATEM switchers use a frame buffer to convert which causes a delay but if the audio and video are in integrated into the same HDMI, the overall delay is still in sync. Sync is relative. If possible record the output of the switched program feed.
3. The encoding hardware or software. The encoder has to separate the audio and video to compress to mp3 or AAC for the audio and h.264 or other codecs for the video. Video processing takes longer and you can lose sync. This is where you can use the audio delay in the software and hardware encoder to compensate for any sync issues the processing has created.
4. The streaming services. Some streaming services re-encode once again to offer multiple bandwidth etc. Generally this is pretty good but ALWAYS check the final output of the stream that the viewer will see, not just what you are sending out.
I hope this helps.
We did have a recent project with a third party using their streaming setup and the sync issue arose due to the encoding software. The quick fix was to delay the audio from mixing board which was a bandaid to fix the problem. It worked and the stream was fine and the client was happy. I will never do this again. The audio to the camera was out of sync, the audio at the switcher was out of sync, but the stream was in sync. Maybe I need to listen to my own advice.
I hope this helps and please ask for any more details.

[Mike Stranks]

Thanks Mattsong... helpful insights.

Welcome to the Forum!

For anyone who's interested in this video stuff, RGBlink launched a new product today, the MiniPro. Builds on what they've already done with the Mini and Mini+ and incorporates nifty PTZ controls.

(I stumbled across their product launch Livestream this afternoon... one of several launches today by them.)

[Mattsong]

Thanks for the welcome and I hope this helps. You mentioned that you have a Zoom f4. You could take the 1/8 out into the 1/8 input of the main camera to sync the audio. I know as audio pros, this is not the connector of choice, but it does work. I did this with a Tasman recorder into a Panasonic GH series camera for many years and it worked well.
Let us know how this all works out for you.

[Mike Stranks]

Thanks for the welcome and I hope this helps. You mentioned that you have a Zoom f4. You could take the 1/8 out into the 1/8 input of the main camera to sync the audio. I know as audio pros, this is not the connector of choice, but it does work. I did this with a Tasman recorder into a Panasonic GH series camera for many years and it worked well.
Let us know how this all works out for you.

Of course! Thanks!

Because I never use that I'd forgotten about it. Obvious now you mention it.

Things are starting to coalesce...

[Mike Stranks]

RGBlink Mini has just been ordered...

For what I need, multiview preview is essential... entry-level ATEM doesn't have that.

As it will often not be me pressing the buttons, simplicity of operation and lack of oo-er controls is highly desirable. RGBlink has that.

The built in multiview screen is a big plus for on the road... tiny I know, but does save taking a monitor for times when a mini-rig is of the essence.

Once it arrives I shall do some audio experimenting and report back...

Watch this space...

[Mattsong]

The RGB link looks like a nice compact piece of kit. Multiview is essential even if it is really tiny.
I thought I would share a couple of live-streams we did in the fall.
This is from an artist Lucette. There is an opening act Amy Nelson and Lucette is about an hour in. For the astute audio fan, the big blue van in the background is the Rolling Stones Mobile.
https://amplify.nmc.ca/video/watch-rbc- ... y-lucette/
The other video is a great classical group, Land’s End playing in a blues bar for a Sunday brunch. Fun to shoot a classical ensemble.
https://amplify.nmc.ca/video/watch-stin ... -ensemble/
This was all done at the National Music Centre in Calgary.
Enjoy.

[James Perrett]

For the astute audio fan, the big blue van in the background is the Rolling Stones Mobile.

Watched a few excerpts from the video and, to the untrained eye, it looks pretty good. Interestingly I've just spent this afternoon transferring some 2" tapes that were recorded by Mick McKenna with the Rolling Stones Mobile.

[Mattsong]

Lots of great music recorded on the RSM. It is now part of the living museum at the National Music Centre in Calgary.

[Mike Stranks]

Quick update....

The RGBlink Mini arrived yesterday and I gave it a workout this afternoon with two cameras and an iPad.

The built-in preview screen is good to make sure you've got a good link, but I think it would simply be too small for field work... we shall see. Today I hooked-up to a 24" TV with the HDMI output on the Mini set to 'Preview'. That was good...

So first impressions are of a versatile little unit which will do what I want... now to order some more HDMI cables...

Oh! I should add that I did my first one-camera plus mic livestream the other day. Surprisingly easy and uncomplicated through my YouTube channel. It was just a 'private' stream for proof of concept...

[Humf]

Sounds good Mike. I think we’ve chatted on this topic on t’other thread?

My one bit of advice when it comes to live-streaming, is to test, test again and when you’ve got it right, have a sleep and then test again. You get the point!

When you’ve got a setup that’s been through the above, don’t change a single thing. I’ve been caught out once or twice trying to make, what I thought were little changes, to be tripped up.

I use a variety of either audio fed back into the camera OR a frame or two or delay on my ATEM switcher. Seems to work. Mixing and matching between wireless & wired audio sources is a bit of a headache but easily solvable if not mixed together, which is often the case in my situ (eg. Wireless lavs ‘v’ a stereo pair on an organ or choir). I’ve recently purchased a zoom f6 because I’m tired of either lumping around an x32 rack or being limited to a stereo pair of xlr inputs on my camera (if a single cam is sufficient but 3 or more mics needed). An F8n or Sound Devices unit probably would’ve been my first choice but budget limited and Hugh’s review reassured me. Plus as a solo shooter (streamer?!) the concept of worrying less about incorrect gain settings means I can be confident of fixing in post. Although I realise the ‘live’ mix needs to be decent. Shame about the unbalanced 3.5mm output but otherwise it wins on features at the price. I’ve just bought a small cheeseplate which lifts the unit sufficiently to clear the chunky manfrotto head I have. So my single cam setup has just had a major upgrade. I now need to test, test, test!

[Humf]

One other thing I’ve heard about but not yet explored...

Using an audio embedder. That way the audio is sent out from the X32 via AES, into an embedder via SPDIF, and into the ATEM as HDMI, without any need for D/A & A/D conversion. Not sure if this is worth the effort but sounds interesting.

[Mattsong]

Glad to hear that the RGBlink Mini seems to be working for you. When you connected to the external monitor and set it to Preview, do you get the multiview display on the external monitor?
Most of my experience has been with the Blackmagic ATEM switchers, which have worked well, but they are pricier.