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Subject: Re: MPEG Audio format

Re: MPEG Audio format

From: Thom Johansen <thomj_at_pvv.ntnu.no>
Date: 2006-01-13

Bluechip wrote:

> Pretty much got a proper core written for an Audio file processor now.
>
> I have another simple question about MPEG Audio files.
>
> Am I ever likely to encounter an MPEG Audio file which will contain
> AUDIO frames which differ in VERSION, LAYER, SAMPLERATE and/or
> CHANNELS? Eg. Some frames are 48KHz and other frames are 44.1KHz
> ...or some frames in Stereo, some in Joint-Stereo?
>
> I have been unable to find any documentation which explicitly states
> whether this should or shouldn't be allowed by the MPEG standard, and
> nothing to say explicitly whether any players do or don't support this
> type of change.

When it comes to sample rate, layer and version switching, I think you're
reasonably safe, though it is probably legal. Stereo mode I think you will
find encoders may switch from frame to frame.

Thom
Received on Fri Jan 13 23:21:54 2006


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