INTERACT FORUM
More => Old Versions => Media Center 12 (Development Ended) => Topic started by: ballen on September 03, 2007, 06:36:13 am
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I have over 1100 "ape" files that I'd like to convert to "flac" for DAP compatibility.
Not knowing how MC's "convert" function works in detail, will I have to "re-rip" my files or can I convert my ape files directly to flac without losing any audio quality?
I've become confused by some info obtained thru the web regarding decompressing to "wav" first but this was a generic statement and I don't know if MC already does this thru the "convert" function.
Any insight would be greatly appreciated,
ballen
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MC can convert your APE files to Flac files seamlessly, while maintaining all your tags.
You will of course need to install the Flac plugins if you have not already done so.
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Conversions are quick and painless, so long as you can get the FLAC encoder to install. Sigh, that's for another thread...
Both ape and flac are lossless so there's no question of a degredation in sound quality as there is when one of the codecs is lossy.
As to how it actually works, ie the files get converted to wave first, I don't know.
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make sure your memory is good.
Ideally a conversion from one losslesss format to the other would verify that the wav output by either was identical. That however isn't trivial to do.
unless some one knows of a way to compare the checksums internally generated by the ape & corresponding Flac file.
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As to how it actually works, ie the files get converted to wave first, I don't know.
You'd have to ask Scot this (I suspect it does not) but that's mostly academic. Lossless --> Lossless means no quality loss, so long as the encoder isn't broken in some way. MC ensures bit-perfect output, so you don't have to worry about MC messing it up by running it through a DSP or anything similar. It is completely irrelevant (other than speed of conversion and disk space concerns) whether it goes through an intermediary WAV file first.
Testing it would be fairly trivial... Simply compare the fingerprint on WAV files extracted from the source APE and the resulting FLAC. I'm sure Alex could explain how in more detail.
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Testing it would be fairly trivial... Simply compare the fingerprint on WAV files extracted from the source APE and the resulting FLAC. I'm sure Alex could explain how in more detail.
Cept no one is offering an automated way to do it, unless you wan't to play with batch files.
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Cept no one is offering an automated way to do it, unless you wan't to play with batch files.
Well... I assumed you wouldn't want to test every single one. Either the conversion process works and is bit-perfect, or it doesn't, I would guess. You could do a few test files and check them manually, and then if all came out good, proceed with the massive conversion.
You're right though... Some sort of verify procedure would be nice, assuming it DOES make mistakes sometimes. If it never does, then I hardly see the point.
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That's the problem, you can't be sure it will always be 100%. If your equipment is very good then chances are more. I've read cases where faulty cabling could flip bytes here & there, bad memory could also do that. Bad HD sectors tho much rarer nowadays can also do the same.
I was suggesting a method to use the checksums stored internally in both formats as a quicker way of achieving the same. Say you start from APE or FLAC, both these formats contain a checksum, by default for integrity testing, then you convert either to Wav and finally compress to either. The resulting lossless file will also contain a checksum. If it can be shown that these checksums are equivalent, you get to see an OK, which truly means your conversion was 100%.
Think of it as a *secure* lossless conversion.
The reason for this is you are storing in lossless and the idea is provided it was ripped securely, then you have an identical or lossless rip in which ever lossless format you choose. There is a certain expectation that a conversion would also be 100%.
It remains to be seen whether the checksums used by APE or FLAC are even similar enough to be compared in this manner, it just saves an extra decode to wav from the target format. If you have a large amount of files to convert, then it could shave off 20% of the time.
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Think of it as a *secure* lossless conversion.
Ahhh... I see.
Just because you're paranoid, don't mean they're not after you.
;) ;D
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Even paranoids have enemies.
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I use the Binary Comparator plugin from this (http://www.foobar2000.org/components/index.html) page for verifying that my lossless conversions are flawless.
The plugin decodes the selected files and compares the first half of the selection with the second half. It produces a textual report. I think it compares each decoded PCM sample separately so it doesn't need a huge amount of free memory or disk space.
Unfortunately the plugin is not compatible with MC so I have to use it with another program. (... a hint for our fine plugin developers. A similar plugin for MC would be very useful.)
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Wow, quite a number of replies.
At first I thought my question would be considered a stupid one (ie. lossless to lossless won't lose signal quality by definition of lossless) but I see that others have some semblance of doubt such as I have. I'm glad the subject has been addressed.
Thanks everyone for your input on the matter.
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I believe the FLAC MD5 checksum is for the original WAV (audio portion only). Not sure about APE.