Author Topic: FLAC  (Read 10363 times)

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Offline rob_hutton

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FLAC
« on: August 16, 2006, 11:51:42 am »
When I encode to FLAC with other Flac encoders e.g. jet audio, the files size is considerably smaller than when I encode with Phatnoise,

So does any one know?
Is the quality the same?
What is the best encoder to encode to FLAC?
And do they play on Phatnoise the same?

Thanks

Offline sbingner

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Re: FLAC
« Reply #1 on: August 16, 2006, 07:19:02 pm »
FLAC is lossless, so whatever file is smaller is the best.  Any FLAC file unless not actually a FLAC file will have exactly the same quality because the decode is identical to the origial.

Sam

Offline S80_UK

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Re: FLAC
« Reply #2 on: August 17, 2006, 07:52:19 am »
sbigner is correct.

Some FLAC encoders have a quality setting.  But that should not affect the quality of the data in the file.  It generally affects the amount of processing time / memory that the encoder is allowed to use.  More time and effort gives slightly (like a few percent) smaller files.  The decoded output in all cases should be identical to the original.  The decoder algorithm on the Phatbox should handle all flac files correctly and gve the same results regardless of the encoder used.

I recently did some tests for another project to archive some CDs which I had ripped to WAV files.  I ran a binary compare of the original file against the decoded output (command line...  "fc /b file_a.flac file_b.flac >> results.txt") and there were absolutely no differences.  The FLAC encode / decode process even preserves the time-stamp info on the original file.

If you are seeing files "considerably smaller" this may suggest that they are not FLAC but something else with a .flac file extension.  Although it can also vary with the encoder and the source material.  I have seen huge variations in compression factor depending on the source material.

Offline cz6y48

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Re: FLAC
« Reply #3 on: April 10, 2007, 09:12:25 am »

Some FLAC encoders have a quality setting.  But that should not affect the quality of the data in the file.  It generally affects the amount of processing time / memory that the encoder is allowed to use.  More time and effort gives slightly (like a few percent) smaller files.  The decoded output in all cases should be identical to the original.  The decoder algorithm on the Phatbox should handle all flac files correctly and gve the same results regardless of the encoder used.


Just to be clear for the readers:

The FLAC standard is asymmetrically weighted to favor decoding speed.  What that means is that (for the most part) no matter what compression ratio the file was encoded under, the “horsepower” for decoding should be about the same.

There are some great websites out there that talk about the compression ratio vs time to compress with recommendations but I just use the highest flac compression available because even on my relatively old PC, each song only takes a few seconds to compress.  Since I use paranoid settings on my ripper, it sometimes takes hours to rip a CD.  Spending a few extra seconds compressing the files as much as possible doesn't seem like a big deal.

Offline S80_UK

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Re: FLAC
« Reply #4 on: April 10, 2007, 10:54:07 am »
Since I use paranoid settings on my ripper, it sometimes takes hours to rip a CD.  Spending a few extra seconds compressing the files as much as possible doesn't seem like a big deal.

For info - there is generally very little difference in the degree of compression between the highest Q settings.  Q8 may save 1% or 2% on space over Q5, but will take much longer (like more than twice as long).  Agreed, it's not a big deal for a few songs - but I recently re-ripped my entire CD collection (600+discs) and then you need all the speed you can get!

The latest FLAC encoders (1.1.3 / 1.1.4) offer some useful improvement in encode speed over earlier versions since some of the core functionality is now more optimised for the native word size of the processor running the compression.