Microsoft KB Archive/307676

= &quot;Unrecognized Codec&quot; Error Message Appears When You Convert MP3 Files in Plus! MP3 Audio Converter =

Article ID: 307676

Article Last Modified on 1/31/2007

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APPLIES TO


 * Microsoft Plus! for Windows XP

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This article was previously published under Q307676



SYMPTOMS
When you use the Microsoft Plus! MP3 Audio Converter to convert an MP3 file to Windows Media Audio (WMA) format, the conversion may fail and report the following error details:

The file cannot be converted because it uses an unrecognized codec.

This behavior may occur even if the codec for the file format is installed on the computer and you can play the file in Microsoft Windows Media Player.



CAUSE
This behavior can occur if the MP3 file uses a sample rate and bit rate combination that is not supported in Plus! MP3 Audio Converter.

For example, if you try to convert a file that uses a sample rate of 11 kilohertz (kHz) and a bit rate of 160 kilobits per second (Kbps), a codec may not be available for Plus! MP3 Audio Converter to use to convert the file. This can occur whenever a file uses a low-quality sample rate and a high-quality bit rate, or a high-quality sample rate and a low-quality bit rate. These combinations are typically not used.



WORKAROUND
To work around this problem, obtain an alternate MP3 source file that uses a more standard sample rate and bit rate combination. If you encoded the MP3 file, consider using a 22-kHz sample rate. Plus! MP3 Audio Converter includes a wide range of codecs and can typically convert the file if you use a sample rate of 22 kHz.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.



MORE INFORMATION
The sample rate for a media file indicates how many times per second the encoder takes a sample of the analog sound to represent it for digital storage and playback. Sample rate is measured in thousands of cycles per second (kHz). The higher the sample rate, the better the sound quality of the resulting file.

The bit rate for a media file indicates its degree of compression. Bit rate is measured in Kbps. The lower the number, the greater the degree of compression, and the smaller the resulting file. Typically, the lower the number, the lower the quality.

Codecs are computer algorithms that are applied to digital media such as audio, video, and image files to compress the files. If you use codecs, files do not use as much disk space when you store them, or as much network bandwidth when they are streamed.

For more information about Plus! for Windows XP, browse to the following Microsoft Web site:

http://www.microsoft.com/windows/plus

Keywords: kberrmsg kbprb KB307676

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