In this second instalment, I seek to expose some of the video production industry & manufacturers half-truths that comes to light in the wake of a series of product announcements like those at NAB…
I think it is safe to say that I’ve done my fair share of multi-camera live switched and webcast events. I started switching back in 1999 and webcasting as an operator in 2010, although I did live switch the official launch webcast for the Truth and Reconciliation Commission town hall meeting in Winnipeg, Manitoba back in 2009, the on-demand stream of which is no longer live.
I started as a neophyte, working under and alongside seasoned pros in the field, who increasingly gave me opportunities to show my stuff while giving me just enough rope to hang myself… There are some ligature marks but I’m still here so apparently I passed inspection.
The South Hall at the Las Vegas Convention Centre was all abuzz with folks talking about both disciplines. Some folks obviously knew their stuff while others were looking to get into the game for a fraction of the cost of what I perceive to be a comprehensive solution. And the manufacturers had products to appeal to them ALL!
One of the exciting products for me was a new hardware series by LiveStream, my live webcast solution of choice.
The LiveStream Studio HD500 is an interesting solution on a lot of fronts. It has the core capabilities to do 5 source live switching for webcast and has a built in titler and playback engine. As well, there are (limited) audio mixing capabilities.
I am looking very seriously at picking up one or more up for my highly mobile live event webcast model. A tremendous amount of bang for the buck.
Where the solution fails is where most folks are going to try to use it – simultaneous webstreaming with output to venue screens in an IMAG (Image MAGnification) scenario.
Upon talking to the kind folks at LiveStream, there is a 6 frame delay internally from input to output. This is to facilitate syncing non-synchronous sources, the ability to enable live keying and other such mundane tasks that the average user doesn’t want to consider.
The problem is, we can SEE 2 or more frames of delay of video from audio.
In a live webcast, the audio and video are received simultaneously and in sync. No issue there.
In a live-to-screen environment, one of two things happens:
- The operator is using only the LiveStream HD500 box for both audio and video mixing and output to screens and house audio, in which case the speaker has to deal with a very unnatural delay hearing their own voice back. For seasoned pros like LiveStream’s demo artist, this isn’t an issue. For the average person, this is massively disconcerting. Imagine your keynote speaker being completely distracted during their presentation and losing their place.
- More likely, the room audio will be handled by an A/V company supplying the room with mixed audio to speakers arranged around the room or in the ceiling. Your video feed to the projectors is now going to be 6 frames (or 1/5th of a second) minimum delayed to the screens. Depending on the exact signal path to the projectors or video displays, you may need to add 2 or more frames of delay to that. For people in the first several rows, this is incredibly distracting. As you get further and further back in the room, it becomes less of an issue because it takes time for sound to travel through the air but let me tell you, 6 – 8 frames of video latency is an eternity in live event.
I agonize over video latency in my practice. At a recent Vancouver Community College convocation event, I had my latency down to 2 frames from my position in the balcony to the rear projection screen on stage and one of those frames was incurred converting HD-SDI to DVI for the projector. You can see the delay if you look REALLY hard in my 720P60 recording of the event when the screen is in the shot.
I get compliments everywhere I go on my professionalism and attention to detail, especially around latency and audio considerations in general. I very often choose to work in 720P60 for live projection instead of 1080i30 to halve the delay time, which is ALWAYS incurred in frames, not fractions of seconds.
The LiveStream solution is fantastic! I am buying at least one if not multiples, but it must be used appropriately and frankly too many new practitioners only see what it can do for the price and not what it does in the real world.
I worked on a live recording of my friend’s dad’s band in a church environment over a year ago on Vancouver Island and the inhouse A/V guy bent my ear to get some ideas on how to minimize latency; they had a parishioner who was very upset about the lip sync issues in the sanctuary. After spending an hour looking through every phase of the setup, I concluded they were 2 frames latent at the projectors (consumer/boardroom projectors flown behind screens). My opinion was there was no way they were going to get any better results.
Then I asked an informed question:
“Where does the parishioner sit? He sits in the front row, doesn’t he?”
The A/V tech and I both smiled. We knew what the solution was.
I got an email two weeks later that the gentleman now had a “place of honour” in the back row next to the sound booth and said “whatever we had done had fixed it!”
Sometimes you CAN teach an old dog new tricks.
Thanks for reading!