Monday, October 08, 2012

Low-Cost Sportscasting with Skype!

During my time at WEOS/WHWS (2007-11) we carried a LOT of live sportscasts, usually over 100 each academic year.  As such, I got to know a lot of different ways to get audio reliably from the field back to the studios.   Towards the end, one technology we started looking more at was simply using a netbook and Skype to get audio back to the studio.   Can it be done?  Yes it can!  But there are some minor caveats - read on to see how it works...

Acer Aspire One - netbook

The SILK codec that Skype uses is pretty good quality...certainly good enough for broadcast.  The delay was low enough (just barely) for bidirectional communication.  With a good internet bandwidth, the connection was fairly reliable.  And the software was free.  With a little luck, the whole system could be assembled for very little cash, especially if you could finagle the laptop for cheap/free from your campus IT department.

The two biggest catches were the reliability of the internet connection, and the need for external mixing.  The former I can't say much about here, save that with 4G hotspots, things have gotten pretty solid on that front for SOME areas of the country on SOME carriers.  It's impossible to know for sure until you try it in a live situation, so have some kind of backup ready (see below).

The external mixing was a pain.  Very, very few portable mixers are designed to handle more than one headphone output (i.e. multiple headsets).  So you need a laptop, a hotspot, a mic mixer, a headphone mixer, headsets and maybe an additional laptop for playing sound effects, underwriting spots, promos, etc.  That's pretty clunky, and requires a high degree of training to deal with inevitable problems.

Logitech H530 USB headset
A better solution would be USB headsets and microphones.  This means you just need the laptop and your mics/headsets, nothing else.  Much less clunky, much more portable.  But it's tricky: you have to virtually mix all your sound sources.   I have recently done a proof-of-concept using the following:

  • Two sets of Logitech H530 USB headsets.
  • eMachines T1842 Windows XP desktop computer.   Old and slow, good test source for proof-of-concept but you'll want something with a lot of processor power and RAM to ensure no dropouts.
  • Winamp 5.33
  • Skype
  • Virtual Audio Cable (VAC) 4.12 software
  • iPhone 4GS (running iOS4) with Skype
  • Two (free) accounts on Skype: one for the remote end, one for the studio.

For Macs, on OSX there is a built-in virtual mixing function called Aggregate Devices.  For Windows, you'll need third-party software; I used Virtual Audio Cable (VAC) 4.12 (it's not free, but it's pretty cheap...$25 to $50 depending on the support level you choose...and there's a free limited trial you can use for proof-of-concept on your own gear).

Update: Feb.2014: I found a free/donationware program called VB-Audio Cable, seems to work well on 64bit Windows 7, at least.  The setup will be different than described below, but the overall concept should be roughly similar, even if the implementation is completely different.

I chose the Logitech H530 because there's easy-to-use-by-touch controls for volume up/down and mute on the headset itself, and on Windows XP and up, the driver will automatically install just from plugging in the headset to a USB port.  AND it will seamlessly recognize two headsets and label the second accordingly.

Using VAC's Audio Repeaters for Skype
Audio Repeater window
Once you install VAC, for two headsets you'll need a minimum of two virtual cables created by four "Audio Repeater MMC" instances from the VAC start menu.

USB Microphones
Two instances will combine your Logitech USB Headset and Logitech USB Headset (2) under Wave In into one virtual audio source for Skype to use: call this Virtual Cable 1 under Wave Out for both instances. You should be able to use the default settings for all save one: Channel Config should be set to Mono.

USB Headphones
The other two instances combine the Skype call's output (from the studio) into one virtual cable so both headsets hear the same thing from the studio.   This time your Wave In is Virtual Cable 2 for both instances, and then Wave Out goes to Logitech USB Headset and Logitech USB Headset (2).

For each of the four instances, when you set one up, click the instance's START button (lower-right corner of the instance's window) and then start another instance by clicking (Windows) Start > Programs > Virtual Audio Cable > Audio Repeater MMC.

Remember: for each additional headset, you'll need two more instances of Audio Repeater MMC running.   But for additional microphones (like "crowd sound" mics) with no headphones, you only need one additional instance - follow the guidelines under "USB Microphones" above.

Now open Skype and click Tools > Options, and under General > Audio Settings change the Microphone to be set to Virtual Cable 1 and the Speakers to be Virtual Cable 2.

It's a little complicated, but perfectly logical:  now all your USB mics are getting virtually combined into one audio input (going to the studio), and all your USB headphones are getting the same virtual audio output (coming from the studio).

Winamp settings - click to enlarge
Adding Winamp to the Mix
Now if you want to get fancy and play pre-recorded audio from the field back to the studio too, you can do that using Winamp.   Actually you can probably do it with all sorts of different programs, but I used Winamp for the test.

Open Winamp.  Press CTRL+P to open the preferences.  Scroll down to Plug-Ins and click Output.  On the right, there should be DirectSound output (and probably a version number).  Click DirectSound to highlight it, then the Configure button.   In the new window that appears, under the Device tab, there's a pull-down menu.  Click it to expand it, and then click Virtual Cable 1.

That puts Winamp's output into the same virtual mix that your headsets are feeding into Skype with.  Be forewarned, though, adding Winamp adds a lot of processor load and that can screw up your audio with dropouts - test this extensively before going live on the air to make sure your laptop can handle it.

Making the Call
Assuming your laptop is running and you've got solid internet connectivity of some kind, be it wired ethernet, wifi internet, or a 3G/4G hotspot, you should be ready.   Connect your Skype to the studio's Skype and talk away.  Skype is pretty good about automatically adjusting the mic volume levels up and down, but do try to avoid getting TOO loud on an exciting play.  There's an art to sounding excited without just shouting more loudly, after all.

Also bear in mind that these are headset mics designed for VoIP calls like Skype, not for broadcast.  Odds are pretty good this will not have as good audio fidelity as a Comrex Access or TieLine iMix G3 with some nice Beyer DT290 headsets will.  But it's a heckuva lot cheaper, too!

Backups, Backups, Backups!
The biggest problem with this setup is that Skype has very limited ability to deal with poor network conditions.  If the bandwidth gets even a little bit tight, you'll have annoying audio dropouts.  Or worse, you'll just lose the call entirely.   You'll want to be prepared for that with one of two means...maybe both:

  1. A regular telephone/cellphone call to the studio's phone hybrid.   Make the call at the beginning of the game, plug your cellphone into the charger, and then just leave the phone - still connected - on the table front of you.  Preferably on speakerphone mode.  That way if the Skype call fails, the engineer at the studio can switch over to your phone call for backup audio while he tries to fix the problem and/or call you for help/diagnostics.   In fact, have one sportscaster's (the play-by-play person) cellphone devoted to this purpose.  The other sportscaster (the color commentator) keeps his/her cellphone on vibrate but handy, and the engineer at the studio knows to call the color commentator in the event of a problem...that way the play-by-play person can keep going and provide game coverage while the engineer and color commentator try to fix the problem.  Remember, the show must go on!
  2. A one-way webcast with lots of buffering.  You can use Windows Media Encoder or the Shoutcast DSP/DNAS or - for Macs - Rogue Amoeba's NiceCast (all are free) to create a one-way webcast that the station can play.   You'll want to intentionally turn up all possible means of buffering to ensure a dropout-free connection, thus making it so the webcast is running several seconds (if not a few minutes) behind "real time"...but that's okay, it's a one-way webcast anyways so your sportscasters cannot hear anything coming back from the studio regardless.  If you need to coordinate between sportscaster and studio for underwriting/promo breaks, you do it by having the sportscaster say an agreed-upon catchphrase like "back in 60 seconds here on WXYZ Radio, home of the (insert sports team name here)!!"   The sportscaster uses a stopwatch to wait exactly 60 seconds, then says "We're back on WXYZ..." and continues the sportscast.   This gives the engineer in the studio an exact window of 60 seconds (or however much time the sportscaster calls for) to play promos or spots or whatever.   The fact that there's a 2 minute delay from the webcast becomes irrelevant.

Skype On The Cheap
As mentioned, a device like a Comrex Access, Tieline iMix G3 or Telos Zephyr I/P is always preferable: it'll give you superior audio mixing and far greater control over your internet codec/buffering/etc.   But such methods are also significantly more expensive!   Here's a quick rundown of how cheap the Skype method can be:
  • Acer Aspire One netbook computer / $300 - or a comparable laptop may be available for free from campus IT (or even use your sportscaster's personal machine).
  • A computer back at the studio wired into your mix board / $free?  You probably already have this, but if not, another Aspire One netbook will suffice nicely.
  • Logitech H530 USB headsets / $30 each at Staples.
  • Samson Q1U handheld cardioid mic / $50 each at Sweetwater (for crowd sound)
  • Virtual Audio Cable 4.12 / $25 online (or for Macs, Aggregate Devices is free with OSX Leopard & up)
  • Winamp / free
  • Skype 4.x / free
Total cost could easily be $150 for a two-person professional-grade sportscaster setup.

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