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Lip Sync Problems with New Digital Displays?

Posted by simoniker on from the kung-fu-movie-syndrome dept.

An anonymous reader writes "With all of the new digital TV displays flying out the door, its easy to to think that life is good on the road to high definition. But, as Audioholics reports today, cheaper displays are using inexpensive processors that result in video delays of up to 60 milliseconds (that's about 2 frames of video). This means that the video processing (deinterlacing, video scaling, etc) delays the picture so that the audio is out of sync. Add to this inherent delays in some LCD and plasma units and the problem can be more than a little noticeable. As of right now only a few manufacturers are building audio lip-sync delay into their products to compensate."

11 of 311 comments (clear)

  1. why do companies do this? by trmj · · Score: 4, Insightful

    "As of right now only a few manufacturers are building audio lip-sync delay into their products to compensate."

    So once again, another company is working around the problem instead of fixing it. This seems to be a bad trend in technology these days.

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    1. Re:why do companies do this? by brokenwndw · · Score: 5, Insightful

      How exactly is this a work-around? Will you really notice if the entire feed is delayed by a fraction of a second? It seems to me like the right thing to do-- impose an external constraint that the audio and video feeds should be synchronized rather than count on the processors to be fast enough to make the difference unnoticeable. It should help in the future if people want more sophisticated transformations to be applied to either component of the stream.

    2. Re:why do companies do this? by rsmith-mac · · Score: 4, Insightful

      I really wouldn't call this a work-around; at the very least, there's a physical limit you have to deal with when it comes to pixel response of LCD panels, and you can only minimize the time needed to digitially process an image, you can't remove it. The fact of the matter is that audio has to be delayed in order to compensate for the greater complexity of video, there's nothing else you can do.

    3. Re:why do companies do this? by Tiroth · · Score: 4, Insightful

      What if the audio is coming through your stereo, not the TV? The the delay does nothing for you.

    4. Re:why do companies do this? by nacturation · · Score: 4, Insightful

      So once again, another company is working around the problem instead of fixing it.

      One man's workaround is another man's fix. Here, the problem is that video lags the audio by a fraction of a second. So there's two solutions to this problem: play the video with less delay or play the audio with more delay. Adding delay to the audio costs close to $0 because it just needs to be buffered for the 60ms it takes for the video to be shown. Speeding up the video might double the cost of the display as you might need parallel video processors which break up the incoming signal by physical region. Or you might need to find a faster display technology which hasn't been invented yet.

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    5. Re:why do companies do this? by lowe0 · · Score: 2, Insightful

      Sure. If you've got one of these sweet new HDTV's, you've likely got a DVD player as well. My DVD player sends its video to one place (TV), and its audio somewhere else (Dolby/DTS receiver). How does an audio delay on the TV fix my problem?

      If this is to be worked around, it needs to be in the receiver or (better yet) the DVD player. Of course, not everyone has a receiver, and not every high-def source is a DVD player (satellite, Xbox, etc.) so there's no one good solution to this.

  2. Audio Delay by 455 · · Score: 4, Insightful
    What good is building an audio delay if your sound goes through other components (ie. Big amp)? Wouldn't the sound then still be off? These people should be working to increase the processing technology, not slowing down the audio tech.

    booo I say

  3. This will hurt video games by tepples · · Score: 5, Insightful

    Video games depend on low latency between input (at the gamepad) and output (at the CRT and speakers). Video game systems manufactured for sale in the United States after 2006 will include some sort of digital TV output. These digital TV sets introduce a significant latency into the chain. So what will happen?

  4. Try playing Nintendo on such a TV by tepples · · Score: 5, Insightful

    Will you really notice if the entire feed is delayed by a fraction of a second?

    If the feed is coming from a video game console that's responding to live user input, I'll certainly notice llaagg. A delay of 60ms can spell the difference between a hit and a miss, adversely affecting game scores.

  5. Because quality is job 9873937.2 by CarrionBird · · Score: 2, Insightful
    It doesn't matter anymore if a customer is pissed off about the quality of your product, there are 99 other ones in line behind him.

    If you buy model X and it sucks, that won't stop me from purchasing X because nobody researches this stuff beforehand. I just go to the guy in the TV department and he points me to model X and I buy it.

    The market does nothing to punish poor quality.
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    1. Re:Because quality is job 9873937.2 by MikeMo · · Score: 2, Insightful
      The market does nothing to punish poor quality.

      Hence Microsoft.