Audio Video Sync Problem

kingofclubs · 06-26-2004, 10:28 AM

arialWith the new digital televisions and improved video processing it is becoming more frequent to have fixed delays in video that make the audio appear to be ahead of the picture by as much as 4 frames (133.3ms). This is not to be confused with inherent delay problems coming from the cable or satellite company's transmissions (which can only compound the problem). In addition to this, some digital technologies, like direct view LCD televisions already have inherent delays of as much as 15-20 milliseconds, prior to any video processing. Some plasma screens even need to put data into internall memory before displaying picture, which can result in 20-60 milliseconds of delay.
Compounding this problem even further is the potential for varying delay times associated with what scaling or deinterlacing functions of video processing are engaged at any particular time (switching from 480p to 1080i inputs for example).
Mid-priced and higher-end displays already come with audio delay circuitry built in to match the audio and video signals and prevent lip sync. Unfortunately, many lower-end models do not, and even the higher end units do not account for the problems that occur when you route audio through a home theater processor or receiver.
Some are talking about a converter box to resolve the problem in the fall of 2004. I have been in contect with some techs that are aware of the problem and will post an exact date as soon as I have one. kingofclubs

gbelk · 12-17-2007, 01:30 PM

Any updates available on this issue would be greatly appreciated. Just installed DishNetwork HD VIP 722 wired directly to a Vizio 52" 1080P HDTV with HDMI 6ft cable and have this lip sync problem.

Have spoken to Dish techs and they have gone thru my settings/setup remotely and they have no answers.

Any ideals, suggestions would be greatly appreciated,
thanks,
gbelk

06-26-2004, 10:28 AM	#1
kingofclubs What is HD? Join Date: Jun 2004 Posts: 2	Audio Video Sync Problem arialWith the new digital televisions and improved video processing it is becoming more frequent to have fixed delays in video that make the audio appear to be ahead of the picture by as much as 4 frames (133.3ms). This is not to be confused with inherent delay problems coming from the cable or satellite company's transmissions (which can only compound the problem). In addition to this, some digital technologies, like direct view LCD televisions already have inherent delays of as much as 15-20 milliseconds, prior to any video processing. Some plasma screens even need to put data into internall memory before displaying picture, which can result in 20-60 milliseconds of delay. Compounding this problem even further is the potential for varying delay times associated with what scaling or deinterlacing functions of video processing are engaged at any particular time (switching from 480p to 1080i inputs for example). Mid-priced and higher-end displays already come with audio delay circuitry built in to match the audio and video signals and prevent lip sync. Unfortunately, many lower-end models do not, and even the higher end units do not account for the problems that occur when you route audio through a home theater processor or receiver. Some are talking about a converter box to resolve the problem in the fall of 2004. I have been in contect with some techs that are aware of the problem and will post an exact date as soon as I have one. kingofclubs

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12-17-2007, 01:30 PM	#2
gbelk gbelk Join Date: Dec 2007 Location: Central Arkansas Posts: 2	Any updates available on this issue would be greatly appreciated. Just installed DishNetwork HD VIP 722 wired directly to a Vizio 52" 1080P HDTV with HDMI 6ft cable and have this lip sync problem. Have spoken to Dish techs and they have gone thru my settings/setup remotely and they have no answers. Any ideals, suggestions would be greatly appreciated, thanks, gbelk