PRB: Problems with MPEG-1 Layer 2 Audio Performance on Fixed Point Platforms for Windows CE (298859)


The information in this article applies to:

  • Microsoft Windows CE Operating System, Versions 3.0
This article was previously published under Q298859

SYMPTOMS

Playback of Moving Picture Expert Group (MPEG)-1 layer 2 audio consumes a large amount of CPU resources on integer-only platforms (platforms with no hardware floating decimal point support). During MPEG-1 video playback, there is a significant degradation in the video quality because of resource starvation by the audio codec.

CAUSE

This problem can be directly traced to the MPEG-1 codec's default use of floating point, which must be emulated on integer platforms.

RESOLUTION

The MPEG-1 codec has an integer mode of operation that can be enabled through the registry. The following key must be added on the path shown:

[HKEY_LOCAL_MACHINE\Software\Microsoft\Multimedia\DirectShow\MPEG Audio Decoder] "AudioQuarterInt"=dword:00000001

Setting this key will enable integer decoding of layer 1 and layer 2 audio with bandwidth of 11 kHz.
Modification Type:MinorLast Reviewed:12/27/2003
Keywords:kbprb KB298859
©2003 Microsoft Corporation. All rights reserved.