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Old 2004-11-26, 10:40 AM
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RainDawg RainDawg is offline
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Re: Are there different "types" of FLACs?

Thank you for breaking it into two posts...these are two different subjects and should be in two different threads...

Now, there are not different "types" of FLAC files. The compression just tells the encoder how wide or narrow to make it's search for bit-correlation when compressing the file. Higher compression rates will deocde and playback identically, and contain the same audio data, but the filesize will vary depending on the compression rate. The tradeoff is that higher compression rates take a lot longer for your computer to encode and thus there is a point at which the decrease in filesize is so small and the increase encode time so much higher that it becomes pointless to increase the compression any more.

So...now to get into the nitty-gritty of what these rates mean

First, you may want to look at the FLAC documentation to understand this a bit more:
http://flac.sourceforge.net/documentation.html

FLAC actually contains a lot of different variables that have to be set when you wish to encode. Instead of making people set all of these themselves, they created a few optimized default settings for various compression rates, and those are the numbers 1-8. These will simply pass a certain set of values to the encoder to tell it how to make the compression larger or smaller. FLAC frontend allows compression based on these same defualt values.

dbPowerAmp, for some asinine reason, has replaced these with low-medium-high. In fact, you are right, the dbPowerAmp encoder is some form of bastardized FLAC encoder; instead of using the 1-8 default values, it replaces them with it's own presets. I can't find where in the documentation of db what these relate to in terms of what switches they actually pass to FLAC to make the compression. Based on some of my measurements, high is about equal to 8, medium around 5, and low around 2.

It should be noted that dbPowerAmp, FLAC Frontend, and command line FLAC will still reliably encode the audio to a FLAC file, and each will decode back to an identical WAV. The only difference in any of these methods is the options used to create the file, which ultimately is of secondary concern to the fact that they will create acoustically identical, usable FLAC files.

If you like dbPowerAmp, by all means, use it....
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