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Author Topic: failed to convert  (Read 995 times)

nunisimo

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failed to convert
« on: August 31, 2004, 01:18:59 pm »

hi.

I'm attempting to convert 64kps wma up to 128 and am getting a message of "failed to convert" for no apparent reason.  by the way, do you lose sounds quality when converting to lower compressions rates and then up again?  sorry..i'm a bit naiive with this..

thanks.
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lee269

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Re:failed to convert
« Reply #1 on: August 31, 2004, 02:16:29 pm »

Dunno about 'failed to convert', but there is no point in converting from 64 to 128 anyway - yes, you lose sound quality.

Every time you encode to a lossy format eg wma, mp3, a certain amount of information is thrown away.  This is stuff that you are supposed not to be able to hear - its what allows the filesize to be reduced without an apparent loss in quality.

Mostly of course it works, but if you reduce the bitrate too much you are going to throw away too much and be left with a really poor quality sound. Also, a bit like repeatedly photocopying a piece of paper, if you convert from 64 to 128 you are never going to get back the bits that were thrown away when you converted to 64 in the first place.

If you have the space, best to initially rip your songs to a lossless format, eg ape. With this you can 'uncompress' your files to get exactly what was on the CD, then reconvert it to a lossy format with a quality that suits your ears.

You will get loads of advice here on this from better experts than me, I predict.

Bottom line: Never reencode a wma file you have already ripped. Hope that makes sense.
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nunisimo

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Re:failed to convert
« Reply #2 on: August 31, 2004, 04:28:30 pm »

hi. thank you.

that makes sense. but may i ask what information is added when you go from low to hight bitrates?  i thought it would add more sound depth and remove some crackles i get at 64 bps.

thanks.
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modelmaker

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Re:failed to convert
« Reply #3 on: August 31, 2004, 05:12:06 pm »

The only information that would be "added" is noise.

The 64kbs file doesn't have enough data, so all you're doing when you double the bit rate, is double the crap that's already in the 64kbs file. And evidently MC knows this and therefore won't do the conversion because it would be pointless.

Once you've got a "lossy" file of whatever bit rate it cannot be made better, you have to go back to the original CD and re-rip it.

A "lossy" file is any file that is not an exact copy (bit for bit) of the original CD.

A "lossless" file is a file that reproduces the original CD bit for bit such as wav or ape files.

All "lossy" files are a compromise between quality and memory space. The higher the bit rate the better the quality, but once you choose, you're stuck. The file will never sound any better, so choose carefully.

See this thread: http://yabb.jriver.com/interact/index.php?board=3;action=display;threadid=23316

There's also more info here:  http://www.hydrogenaudio.org/forums/index.php?showforum=15
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Jay.

"Life is what happens when you're making other plans"     John Lennon.
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