The Reason Behind Digital Radio’s Five Second Delay
If you jumped on the DAB+ digital radio bandwagon when the service officially launched earlier this month, you may have noticed that there’s about a five second delay between it and the old analogue transmission. Jez Ford over at AVHub managed to find out exactly what causes the delay, and it’s quite interesting…
After contacting Joan Warner, CEO of Commercial Radio Australia, Jez got this response:
“There are a number of separate causes of delay in the DAB+ digital radio chain from the studio to the multiplexer site.
“Audio encoding delay – 0.3 seconds. (this is the delay for the encoder to turn audio into DAB+ audio.
Service Multiplexer Buffering delay – 0.4 seconds
Service Multiplexer error protection delay – 0.2 seconds
Ensemble Multiplexer Buffering delay – 0.8 seconds
Ensemble Multiplexer error protection delay – 0.8 seconds
Transmission interleaving delay – 0.768 seconds
I think it’s fascinating that they can pinpoint the length of the delay to 1/1000th of a second in regards to the transmission interleaving delay. That’s just nuts.
Head over to AVHub to check out the full response, as well as a fuller rundown on digital radio’s early setbacks.
[AVHub]
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Comments
So, does this mean the days of watching a live footy game with the radio on in the background (or Roy & HG) will now be out of sync by 5 seconds…
So i can play an FPS with someone 500km away with sound, positions, projectiles, and explosions all in real time (or with under 0.1 second delay)over a conjested network. But a dedicated machine picking up a singnal broadcast (or boosted) from under 10km away takes 5 seconds on hardware that is specifically designed to do nothing but the sole purpose of play sound?
Yay digital…
I’m guessing you don’t have a Digital TV then Paul?
I use to love muting the Origin and listening to Roy & HG call the action. But once I switched to Digital TV that had to stop. Roy & HG were clearly watching the action on an Analog TV, and with Digital TV being about 2-3 secs delayed I was hearing them call a try, but watching the play before the try on the TV. It just became annoying unfortunately.
That was a truly sad night.
Well, we’ll just have to all put in to get Roy & HG a digital television then =)
So if both digital radio and digital tv have a delay… then listening to Roy & HG and watching live sport won’t be an issue as long as both your TV and radio are digital (or both analogue)
I think Digital Radio is a great idea.
If they manually delay the analogue signal broadcast by 5 seconds also this will put the two streams in sync which means radio competitions and the aforementioned football will all be run smoothly.
Yeah Luke Hopkins, that would be good.
All we need to do now is to get the live action at the football or cricket to implement a delay and all will be sweet.
More than 50% of the crowd at these venues listen to the radio commentary whilst watching the game. Looks like analogue will need to remain in operation until we all stop going to live sports.
.. but if Roy and HG are watching the same delayed analogue broadcast (or even the HD) then the digital broadcast will still be 5 sec after that and you will have achieved nothing…wont it?