Decoding FLAC efficiency question

[paulgj]

Hello,

I was just wondering if decoding a FLAC -8 compression file will take more CPU than decoding a standard -5 file?  I would like to get my FLAC tracks as small as possible without hindering the playback performance.

Currently using a 5.5g iPod Video.

Thanks!

[Toxikator]

In my experience it's the same speed, at least insofar as the playback remains gapless. Of course, ENcoding takes much longer.

[Llorean]

The proper test would be to go to the 'Audio Thread' screen in the debug menu, and watch the boost ratio while repeating a 5 song, then watch the boost ratio while repeating the same song on 8, and see how much higher it is.

[preglow]

Hello,
I was just wondering if decoding a FLAC -8 compression file will take more CPU than decoding a standard -5 file?  I would like to get my FLAC tracks as small as possible without hindering the playback performance.
Thanks!

It will use more CPU, but not by extreme amounts.

[senab]

Plus the file will only be slightly smaller and take double as long to encode. Stick with -5 (or lower)  

[DefineByte]

Encoding time for -8 has halved just recently.

[jaybeee]

Encoding time for -8 has halved just recently.

yep, v1.1.4 has seen some great improvements, including decoding speeds apparently (not halving like the encoding though).

@paulgj: I see you asked the question on here & HA.org   clicky

Is Firon's post true that the FLAC v1.1.4 code would need to be integrated into Rockbox to notice any v1.1.4 improvements? (I'm guessing it would).

[Lear]

Is Firon's post true that the FLAC v1.1.4 code would need to be integrated into Rockbox to notice any v1.1.4 improvements? (I'm guessing it would).

The FLAC decoder in Rockbox isn't based on the official FLAC code, so the changes in FLAC don't really apply. But Rockbox should still be able to decode all FLAC files, so any increases in compression efficiency wouldn't require any changes to Rockbox. Decoding is already pretty well optimized, AFAIK.

[senab]

Rockbox uses ffmpeg's decoder as far as I can see. But why is libFLAC in the source tree aswell?

[linuxstb]

Rockbox uses ffmpeg's decoder as far as I can see. But why is libFLAC in the source tree aswell?

The first FLAC codec in Rockbox was based on libFLAC, but was later replaced with the vastly more efficient decoder from ffmpeg.

libFLAC was removed from the source a couple of months ago - where are you still seeing it?