March 09, 2012
Experts' Experts: Lip-Flap — Why your expensive TV's audio and video are out of sync
I've noticed for years now, especially when watching shows like PTI, that the sound and video are way out of sync on both my HDTVs.
Sometimes the lips stop moving and words keeping coming for up to a second, an awfully long delay when you're watching.
When it gets that disturbing I stop looking at the screen and just listen.
I've noticed this doesn't happen when I watch a DVD, so I figure it must not be the TV's fault but, rather, something to do with the way the TV signal makes its way to me.
Sure enough, that's the case, according to Wikipedia.
I've read that a lot of people think their TV is broken when this asynchrony happens — but it's not.
Excerpts from Wikipedia's entry on lip-flap appear below.
Audio to video synchronization (also known as audio video sync, audio/video sync, AV-sync, lip sync, or by the lack of it: lip sync error, lip-flap) refers to the relative timing of audio (sound) and video (image) parts during creation, post-production (mixing), transmission, reception and play-back processing. When sound and video have a timing related cause and effect, AV-sync can be an issue in television, videoconferencing, or film.
Digital or analog audio streams or video files usually contains some sort of explicit AV-sync timing, either in the form of interleaved video and audio data or by explicit relative time-stamping of data. The processing of data must respect the relative data timing by e.g. stretching between or interpolation of received data. If the processing does not respect the AV-sync error, it will increase whenever data gets lost, because of transmission errors or because of missing or mis-timed processing.
Viewer experience of incorrectly synchronized AV-sync
The result typically leaves a filmed or televised character moving his or her mouth when there is no spoken dialog to accompany it, hence the term "lip flap" or "lip-sync error". The resulting audio video sync error can be annoying to the viewer and can even lead to the viewer's not enjoying the program, to the program's not being effective, and to the speakers being perceived negatively. The lack of effectiveness problems are of particular concern when product commercials and political candidates are viewed.
Because of these annoyances, AV-sync error is of concern to the television programming industry, including television stations, networks, advertisers and program production companies. Unfortunately the advent of high definition flat panel display technologies (LCD, DLP and plasma), which can delay video more than audio, have moved the problem into the viewer's home and beyond control of the television programming industry alone. Consumer products companies now offer audio delay adjustments to compensate for video delay changes in TV's, a/v receivers, and several companies manufacture dedicated digital audio delays made exclusively for lip-sync error correction.
Effect of no explicit AV-sync timing
• A/V sync errors are becoming a significant problem in the digital television industry because of the use of large amounts of video signal processing in television production, television broadcasting and pixelated television displays such as LCD, DLP and plasma displays, which utilize complex video signal processing to convert the resolution of the incoming video signal to the native resolution of the pixelated display, for example converting standard definition video to be displayed on a high definition display. "Lip-flap" may exceed 200 ms at times.
• In the television field, audio video sync problems are commonly caused when significant amounts of video processing is performed on the video part of the television program.
• Typical sources of significant video delays in the television field include video synchronizers and video compression encoders and decoders. Particularly troublesome encoders and decoders are used in MPEG compression systems utilized for broadcasting digital television and storing television programs on consumer and professional recording and playback devices.
• In broadcast television, it is not unusual for lip-sync error to vary by over 100 ms (several video frames) from time to time.
What a pleasure it is to have Wikipedia as a resource from which I can quote as extensively and as often as I wish without any fear of blowback.
Good luck, by the way, with trying to fix the lip-flap problem with a little brown box like the guy in the video up top: from what I've read, these aftermarket add-ons work some of the time on some TVs, but it's anyone's guess whether they'll work on yours.
Magic Wand TV Remote
"Harry Potter fans can now control any TV with a flick of the wrist using this magic wand TV remote control."
"Thirteen different gestures do everything from turn the TV on and off to changing the volume or channel."
Wrote John Letzing of Dow Jones Newswires:
Google has consolidated its online bookstore, music service and software apps into a single site called "Play," as the company seeks to centralize its growing array of digital media offerings.
Google made Play available on Tuesday, and says the site is home to more than 450,000 apps in addition to songs, books and movies.
The move creates a media hub similar in form to Apple Inc.'s iTunes service, which also consolidates multiple media types.
The company says the new Play site will help users understand where to go to find different Google offerings, rather than having to find and pull them from disparate places.
No end of fun.
Fair warning: there goes the day.
"Completely dreamy pillow looks like the real thing, right down to the delicious detailing."
10.5"H x 23"W x 2"D.
Italian Wired LOL Cats
Res ipsa loquitur.
That makes four in row.
What, you say I said "big cats?"
You want a big cat, use AirPlay and send it to your HDTV.
Now go away, I've got work to do.
That's right, Gray Cat – you just can't please 'em all.
[art direction by David Moretti; via Coverjunkie]
L'Odyssée de Cartier
Named best fashion film of the 2012 Paris Collections by the Wall Street Journal's fashion writers.
A seven-figure budget will do that.
That's three posts in a row today featuring big cats: I'm gonna try to extend the streak.
Cheetah running robot breaks world speed record
Wrote John Markoff in Tuesday's New York Times, "A design firm financed by the Pentagon has broken a 23-year-old speed record for legged robots. Boston Dynamics, founded by Marc Raibert, a former M.I.T. roboticist, released a video on YouTube on Monday of its four-legged Cheetah prototype running on a treadmill at 18 miles per hour. The treadmill is designed to support speeds up to 50 m.p.h., but the company said it planned to test the Cheetah outside the lab as soon as possible. The previous record was 13.1 m.p.h., set at M.I.T. in 1989. Boston Dynamics, based in Waltham, Mass., has designed a range of mobile robots with financing from the Defense Advance Research Projects Agency. Previous designs, like BigDog, have been machines intended to follow walking soldiers in the field with loads of up to 1,000 pounds. The company said that while Cheetah was a research project, both military and civilian applications were possible, including emergency rescue and the navigation of rugged terrain."
An excerpt from the YouTube caption: "Cheetah is a new robot being developed by with funding from DARPA's Maximum Mobility and Manipulation program. This version of the Cheetah is a lab prototype with offboard power and a boom that planarizes its motion. Testing on a free-running version of the Cheetah that will run 'unplugged' in the field starts later this year."
Does Andrew Chase know about this?
Transformer USB Drive
Does Andrew Chase know about this?