Best way to sync video (TV) with audio (radio) - Embedded.com

Best way to sync video (TV) with audio (radio)

In certain respects, things used to be a lot simpler in the old days. Take synchronizing images and sound, for example. In the case of traditional movie films, the analog soundtrack was included on the film itself, thereby ensuring that the two were fully synchronized. Similarly, in the case of video like VHS, audio tracks were recorded along the top edge of the tape, thereby ensuring synchronization with the images.

Things are more complicated these days, with audio and video being processed by largely separate subsystems, which goes some way to explain why — when you are watching a modern television program — people's lips often appear to move completely independently of the words they are saying (much like watching a badly dubbed Godzilla movie from Japan circa 20 years ago).


(Source: pixabay.com)

It seems a tad ironic that we have such amazing home entertainment systems these days — with high-definition video (which is already moving to 4K x 2K) and surround-sound audio — yet we appear to be incapable of getting the sound to be synchronized with the images. As a somewhat related problem, if I have the same program playing on multiple televisions in my house — say the family room and the kitchen — there's a noticeable delay between the two systems resulting in a very annoying echo-type effect. It makes you want to cry.

I seem to recall that there's a lot of work going on at the moment to sort this problem out by associating time-stamps with both the audio and video and then delaying one or the other to ensure that they are fully synchronized but (a) I forget the details and (b) that's not what I wanted to talk to you about.

The thing is that I was chatting to a friend-of-a-friend the other day, and he posed an interesting problem. It seems that he prefers to watch American football on his television while listening to the commentary on his radio.

I was a bit puzzled as to why he wanted to do this, but he explained that both the game (on the TV) and the commentary (on the radio) are transmitted in real time — however the commentary continues when the TV breaks for adverts, and he prefers to listen to the ongoing discussions about the plays and suchlike rather than watching adverts for things like hemorrhoid creams (and who amongst our number would argue with this philosophy?).

The problem comes with regard to our definition of “real time” because — even though the video and audio are going out “live” — they are traveling and being processed via different systems, which means that there can ensue quite a large miss-sync amounting to multiple seconds in some cases.

So, this friend-of-a-friend was asking as to the best way to address this problem. My knee-jerk suggestion was to forget the football and instead watch Dr. Who, but it seems this is not a satisfactory solution (you just can't please some people).

So, is this guy “one in a million,” or is this a common problem to which there's already an existing solution? Alternatively, does any possible solution spring into your mind? If so, please share it with the rest of us in the comments below.

16 thoughts on “Best way to sync video (TV) with audio (radio)

  1. “Max, I think most decent AV Systems come with the ability to to either advance or retard the audio stream to help elevate the sync issue. I know I had to adjust this no my sky box, but once set it seems to cater for most content. There are the odd excepti

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  2. “MaxnnI have noticed several similar effects, but they don't impact my life quite as badly as they do to your friend.nnMy friendly cable provider will occasionally get the sync so far off that the dialog is completely out of sync wit the characters utt

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  3. “Hi Max,nThis is a problem that goes far beyond just Lip Sync. nThe very foundation and act of being British and always having your watch synchronised to the nations premier Time Keeper BIG BEN is now degraded by the time delays introduced by transmissio

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  4. “Do you remember “The Speaking Clock”? That number you would call on the telephone and the voice saying “On the third beep it will be x hours, y minutes, and z seconds precisely …. beep, beep, beep”nnDo the telephone companies still do that, or has

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  5. “I use an “atomic clock” something like this onenhttp://www.amazon.ca/Crosse-Technology-WT-8005U-W-Atomic-Digital/dp/B002VRUN2U/ref=pd_sim_sbs_86_1?ie=UTF8&dpID=41KZmw4nZqL&dpSrc=sims&preST=_AC_UL160_SR160%2C160_&refRID=0Y2T2RBGKYD0MJGH2HXRnn”

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  6. “This clock (and ones like it) receive time signals sent out by NIST and use that signal to synchronize. Not sure if that signal (or equivalent) can be received much outside the US/Canada. I had a clock like that. It took forever to sync up (and didn't ha

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  7. “I do remember the Telephone company's “Time service”. When I was growing up my dad used to call the time number every Sunday morning before church and check all of our families' clocks and watches.”

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  8. “Re GPS clocks…nI mostly know about them because the company I work for makes them. They're priced for the industrial market so a bit out of the normal household budget. On the other hand, Adafruit has a tutorial on how to make one using an Arduino…n

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  9. “Hi Max,nThis is not such a new problem – it was very common in the days of “analog” TV.nWhenever a video signal went through a “frame synchroniser” (to synchronise an incoming video feed with a receiving television station's internal synchronisation

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