flac question

[jvgig]

When ripping to flac, I am guessing that since it is lossless, the compression rate only affects the time needed to process the file? If I am correct in that statement, will portable players struggle to open highly compressed flacs? If not, is it recommended that you just rip to flac in its most compressed state?

Thanks

[vegaman]

Yes, the higher compression rates take more power to decode, I've never had a problem with level 8 compression on the portable players I've used though. Currently a rockboxed iMod.
I see lower compression rates as a waste of space, so the best bet is probably to test and make sure your player has no problem with level 8.

[diego]

-Yes, it only affects the time to process the file.

-I think the higher compression setting only takes more power to encode but is almost the same to lower settings when decoding.

-Personally, I always compress at level 8.

[krmathis]

The different flags (0-8) have these affects:
* Compression level 0 = larger files, 8 = smaller files.
* Compression level 8 = faster encoding, 8 = slower encoding.

They have minor affect on decoding time though. Which have been the goal of the developer.

[E.B.M.Head]

With the original FLAC Encoder there should be no Problems with -8.
Even with Flake (alternative FLAC Encoder) you can go without Problems up to -10, but -11, -12 and -99 are too much for some portable devices.

[Goit]

Originally Posted by E.B.M.Head

With the original FLAC Encoder there should be no Problems with -8.
Even with Flake (alternative FLAC Encoder) you can go without Problems up to -10, but -11, -12 and -99 are too much for some portable devices.

So Flake goes to -99? How small do file sizes get with 99? How does it compare to monkey's insane?

[E.B.M.Head]

Well it depends on the music of course.
Flake is the FLAC encoder that is also used in FFmpeg and it goes to -12, but there is also a hidden experimental mode that is -99 which gives the best compression.
I did a little comparision, here are the results that I got from a short track that a friend did compose:
Original Wav File : 16.397.324 bytes (100%)
Shorten : 10.815.229 bytes (65.96%)
Apple Lossless : 10.294.163 bytes (62.78%)
FLAC -8 : 10.165.271 bytes (61.99%)
Flake -99 : 10.036.912 bytes (61.21%)
TTA : 10.017.700 bytes (61.09%)
WavPack -hh -x6 : 9.850.046 bytes (60.07%)
Monkey Audio extreme : 9.763.716 bytes (59.54%)
OptimFrog --experimental : 9.757.201 bytes (59.50%)
OptimFrog --maximumcompression : 9.667.377 bytes (58.96%)

Encoding Speed: Shorten > TTA > FLAC -8 >> WavPack -hh -x6 > Flake -99 > OptimFrog --experimental >>> OptimFrog --maximumcompression

ALAC and Monkey Audio have been packed with Max, so it's not fair to compare the speed to the CLI encoders (which are faster). Anyway: ALAC was a little bit faster than FLAC -8 but definitely slower than TTA, Monkey Audio was a little slower than OptimFrog --experimental.

OptimFrog --maximumcompression gives the best compression ratio, but is unusable (unless you don't mind that a 1:32 min track takes about 10 minutes to encode on a iMac G5 2.0 GHz).
IMHO Flake -99 isn't worth the extra encoding time when you can get better compression results with TTA or WavPack in less time.

Note: This was only a short test. For a serious test you have to use different genre tracks and repeat the time taking several times.