Microsoft KB Archive/926675

= Audio may not be synchronized with video playback when you play a video in Windows Vista =

Article ID: 926675

Article Last Modified on 3/15/2007

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APPLIES TO


 * Windows Vista Business
 * Windows Vista Enterprise
 * Windows Vista Home Basic
 * Windows Vista Home Premium
 * Windows Vista Ultimate
 * Windows Vista Enterprise 64-bit edition
 * Windows Vista Home Basic 64-bit edition
 * Windows Vista Home Premium 64-bit edition
 * Windows Vista Ultimate 64-bit edition
 * Windows Vista Business 64-bit edition

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SYMPTOMS
When you play a video or a DVD in Windows Vista, the audio part of the playback may not be synchronized with the video playback.



CAUSE
You may experience this issue if one of the following conditions is true:
 * The computer processor has characteristics that prevent it from playing the video at the selected frame rate or resolution.
 * The computer has a processor that has power management features, and the active Windows Vista power plan slows the processor to maximize battery life.

Playback of multimedia content may require large quantities of processor resources. These kinds of multimedia include high-definition video, DVD video, and some audio formats. The processor may be unable to deliver the required performance for video playback depending on the resolution and frame rate of the video. Audio playback may not be synchronized with the video playback.

Additionally, Windows Vista enables processor power management features that reduce processor performance to help extend computer battery life. By default, Windows Vista reduces processor performance when the active power plan is set to Power Saver, and when the computer is running on battery power.



WORKAROUND
To work around this problem, change the active power plan to Balanced or to High Performance.

Note If you change the power plan to Balanced or to High Performance, you may reduce the battery life of the computer.

To change the active power plan to Balanced or to High Performance, follow these steps:
 * 1) Click Startvistastartbutton.jpg], type power in the Start Search box, and then click Power Options in the Programs list.

If you are prompted for an administrator password or confirmation, type your password or click Continue.
 * 1) Under Select a power plan, click Balanced or click High performance.

Note The computer manufacturer may have changed the names of the Windows Vista power plans.



MORE INFORMATION
By default, Windows Vista enables processor performance states when the active power plan is set to Balanced or to Power Saver. Processor performance states enable Windows to reduce processor performance to help extend system battery life.

In the default Balanced power plan, Windows Vista uses all potential processor performance states based on workload demand. In the default Power Saver power plan, Windows Vista keeps the processor at the lowest performance state to maximize system battery life.

For more information about power plans in Windows Vista, search for &quot;power plans frequently asked questions&quot; in Windows Vista Help and Support.

Keywords: kbenv kbexpertisebeginner kbhardware kbsound kbtshoot kbprb KB926675

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