# Variable sound drift when playing MP4 in VOD application

**URL:** https://community.wowza.com/t/variable-sound-drift-when-playing-mp4-in-vod-application/499
**Category:** Wowza Streaming Engine
**Created:** [November 22, 2014, 10:45pm UTC](https://community.wowza.com/t/variable-sound-drift-when-playing-mp4-in-vod-application/499 "2014-11-22T22:45:04Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![system](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/system/32/447_2.png) [@system](https://community.wowza.com/u/system)
#### Post date: [November 22, 2014, 10:45pm UTC](https://community.wowza.com/t/variable-sound-drift-when-playing-mp4-in-vod-application/499/1 "2014-11-22T22:45:04Z")

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I have a .mp4 file which reads perfectly with chrome’s builtin player through http (including instant seeking).

When I play it with vlc through rtmp, the sound is about 1 sec early. When I use wowza’s builtin player, the sound is about 3 sec late (rtmp or hds).

The file has been processed with MP4Box, and I also tested with qt-faststart.

Is there a way to have the sound in sync when using wowza?

TIA

greg

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### Author: ![sal\_jefferson](https://avatars.discourse-cdn.com/v4/letter/s/6de8d8/32.png) [@sal\_jefferson](https://community.wowza.com/u/sal_jefferson)
#### Post date: [December 10, 2014, 8:35am UTC](https://community.wowza.com/t/variable-sound-drift-when-playing-mp4-in-vod-application/499/2 "2014-12-10T08:35:20Z")

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Hello Greg.

Try adding the following property to the Streams/Properties in [install-dir]/conf/[application]/Application.xml (be sure to get the correct properties container - there are several in Application.xml):

```auto
<Property>
        <Name>audioLag</Name>
        <Value>250</Value>
        <Type>Integer</Type>
</Property>

```

You can increase/decrease 250 as needed to get the audio synced up.

I hope this helps.

Kind regards,

Salvadore