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#7961 - 24/04/2000 11:18 64kbps MP3s... Invalid?
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31571
Loc: Seattle, WA
So I download the Daikatana Demo (yes, it went gold, Satan must be double-checking his thermostat right about now), and I notice in its directory structure that the music tracks are just loose MP3 files. A couple of them aren't bad, too. So I squirt them into the Empeg, and it doesn't like them, claiming that they're invalid MP3 files.

MP3Trim says there's nothing wrong with the frames or the data. Is it just that the player doesn't like such low-bitrate MP3 files? Or is the valid-file-check algorithm just a little too agressive?

Tony Fabris
Empeg #144
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Tony Fabris

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#7962 - 24/04/2000 13:09 Re: 64kbps MP3s... Invalid? [Re: tfabris]
corby
journeyman

Registered: 05/10/1999
Posts: 89
Judging from Rob's post on the subject, I would guess that it has nothing to do with 64kbps.

Seems very odd to me that they would use such a format for a computer game. I am no audiophile, but 64kbps sounds awful to me, and CD-quality sound seems more the norm today for games. I assume they used 64kbps to save CPU, but it seems like they could get much better quality if they didn't use a format with aggressive compression like MP3. On a CD distribution they should have room to spare.

Corby
SN#320, 6-Gig Blue


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#7963 - 24/04/2000 14:17 Re: 64kbps MP3s... Invalid? [Re: corby]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31571
Loc: Seattle, WA
I am no audiophile, but 64kbps sounds awful to me, and CD-quality sound seems more the norm today for games.

Actually, the files sound pretty darn good considering that they're compressed all the way down to 64kbps. I was surprised. I guess it's the style of music or something, but they sounded great for in-game music.

On a CD distribution they should have room to spare.

Yes, but the files in question were from the downloadable demo, not the final CD version. It's possible that the files might be higher quality on the CD.

Tony Fabris
Empeg #144
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Tony Fabris

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#7964 - 25/04/2000 04:15 Re: 64kbps MP3s... Invalid? [Re: tfabris]
mac
addict

Registered: 20/05/1999
Posts: 411
Loc: Cambridge, UK
The player uses only the first 32K of the file to decide if it is an MP3 or not. If it doesn't find two consecutive valid MP3 frames in that part of the file it decides that the file isn't an MP3 file and gives up. The file may be being identified as invalid because it has rubbish (possibly a large ID3v2 tag) on the beginning of the file or it uses space between frames to store other information.

I've personally got a tool in development that removes junk from MP3 files. Some of the stuff it uses may make its way into emplode in the future. At the moment it is Linux command line program - I intend to make it compilable for Windows and to add a simple GUI for Linux and Windows in the future. Unfortunately I don't get much time to do my own development these days so it isn't really in a releasable state :(

--
Mike Crowe
I may not be speaking on behalf of empeg above :-)
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Mike Crowe

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#7965 - 25/04/2000 07:56 Re: 64kbps MP3s... Invalid? [Re: mac]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31571
Loc: Seattle, WA
The file may be being identified as invalid because it has rubbish (possibly a large ID3v2 tag) on the beginning of the file or it uses space between frames to store other information.

Neither of those appear to be the case with these files. They seem to be very standard files without any garbage between the frames, and no V2 tags. In fact the files had no tags at all until I added them.

There is one other thing I noticed. They are 22khz files instead of 44khz. Does that have something to do with it?

Tony Fabris
Empeg #144
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Tony Fabris

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