[Flac] portable flac recorder

[Brian Willoughby]

On Jul 8, 2010, at 10:59, Free Lunch wrote:
> I have read that the 7xx flac recordings utilize a fairly low level of
> compression, so the space savings are not that great.  Though I have
> not verified that.

I needed to capture some bird sounds for my sister, so I decided to  
check the efficiency of the 7-Series in light of your comments.  They  
do quite well at 24-bit/48 kHz, because there was only a 1.3%  
difference in size between the 7xx FLAC file and the same audio  
compressed with the flac command-line with --best and --no-padding.

In other words, the space savings on 7-Series Sound Devices recorders  
appears to be about as good as it gets.  This is with version 2.65 of  
the 702 firmware.

The actual limitation seems to be sample rate.  Although the 7-Series  
is capable of 192 kHz sampling, it does not allow FLAC encoding at  
that speed, at least not in stereo.  At lower sample rates, such as  
96 kHz, there seems to be enough CPU for typical FLAC compression  
ratios.

Brian Willoughby
Sound Consulting