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Topic: -A option (Read 5249 times) previous topic - next topic
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-A option

I am now in the process of moving from ALAC to FLAC. i did lots of reading about command options and what i am looking for is best compression time is less of an issue, i did saw in later posts the use of -A "tukey(0,5)" options, but it is beyond me to understand its function, can you please clarify it for me? any other options i should use beyond the obvious -8 ?

-A option

Reply #1 –
Quote from: brb on
i did saw in later posts the use of -A "tukey(0,5)" options, but it is beyond me to understand its function, can you please clarify it for me? any other options i should use beyond the obvious -8 ?

The "tukey(0,5)" was to correct a bug in FLAC 1.1.3 release. For the latest release you should use the "--best" option to achieve the maximum compression ratio.

-A option

Reply #2 –
The -A option is described in detail here:

http://flac.sourceforge.net/documentation_...ons_apodization

Basically it is an attempt to compress subframes with the user supplied function, in this case the function would be "tukey(0,5)". You can specify as many as you like but for each function that you add it makes the encoding time increase. That's about as much as I understand of it, if I understand it correctly.

I would suggest that you just follow Egor's advice and just use "-8" or "--best" for maximum compression and not worry about anything else.

-A option

Reply #3 –
Agreed.  Zoom has explained it well.

The extra time required to encode is not really worth the effort.  Here is a very small comparison (there are probably others in the thread).  Note that -8 (or --best) is using -A tukey(0.5) and -8 -Ax2, as stated in the post, is using -A tukey(0.5) -A flattop.  The more windows you add the slower the encode and the less the benefit.  Josh took a lot of data to come up with -A tukey(0.5) as the default, and it works very well in most situations.
I'm on a horse.

-A option

Reply #4 –
Thanks for your help guys --best it is.

-A option

Reply #5 –
I found the following script here on the forums for recoding FLAC files:

Code: [Select]
@echo off
set encoder="C:\Program Files\FLAC\flac.exe"
for /r "." %%d in (.) do (cd %%d & for %%f in (*.flac) do %encoder% -8 -V -f -A "tukey(0,5)" "%%f")


This was made for version 1.1.3. Should I change something here for the newest version? Should -8 be replaced with --best? Should I remove -A "tukey(0,5)"?

-A option

Reply #6 –
I'll try to get more detailed information on that as soon as possible.

-A option

Reply #7 –
Quote from: MiSP on
I found the following script here on the forums for recoding FLAC files:[...]

This was made for version 1.1.3. Should I change something here for the newest version? Should -8be replaced with --best? Should I remove -A "tukey(0,5)"?

Yes, remove the -A "tukey(0,5)" part.
The --best option is mapped to -8 currently (so there is no compression ratio improvement for the current 1.2.1 version).

-A option

Reply #8 –
Quote from: Egor on
Yes, remove the -A "tukey(0,5)" part.
The --best option is mapped to -8 currently (so there is no compression ratio improvement for the current 1.2.1 version).

Thanks.

I'll use the --best option, because I'm sure the intention is that it's being remapped to the best compression should there ever be better compression rates.