how to make use of flac 1.3.1 in latest audacity 2.1.1 under linux mint 64bit?
Either:
build Audacity from the source code and specify the local library for Flac (included in the full Audacity source code)
or
build Audacity from the source code with the Flac 1.3.1 development library installed on your machine,
or
Install the command line Flac 1.3.1 encoder on your machine and use the “external program” option when exporting (http://manual.audacityteam.org/o/man/exporting_to_an_external_program.html)
ok, i have installed flac_1.3.1-4_amd64.deb right now https://launchpad.net/ubuntu/wily/amd64/flac/1.3.1-4
it would be great if someone could help me with the commandline for external flac.
thank you in advance
What version of Flac is your build of Audacity currently using? Do you really need to use an updated version?
yes, i need to 
it is version 1.3.0, my archive is 1.3.1, so it would be a regression.
besides, curious to see flac not being mentioned in the manual at all?
There is no difference in Flac format between 1.3.0 and 1.3.1. The main differences are a few small encoding/decoding speed improvements to the encoder/decoder.
yes, i know. but as i pointed out already, i would like the version to conform to my archive and also make use of the few small improvements.
The base reference is the page Steve referred to: Audacity Manual.
That doesn’t have FLAC examples, but the version of that page for the next 2.1.2 release of Audacity does have FLAC examples.
See FLAC - FLAC command line tool for FLAC command-line syntax and options.
Assuming you default-installed FLAC, this Audacity command exports a FLAC file without any options:
/usr/bin/flac - -o "%f"
This command exports a FLAC file, specifying TITLE and ARTIST tags:
/usr/bin/flac - -T "TITLE=Bohemian Rhapsody" -T "ARTIST=Queen" -o "%f"
This assumes you specify the file name for the exported file in “Name:” in Export Audio.
Gale
hi gale,
thank you for your help. indeed, flac 1.3.1 is default installed to /usr/bin/flac.
so with: /usr/bin/flac - -o “%f.flac” i could export to flac.
curiously the flac file still states version 1.3.0 20130526?
Did you install flac_1.3.1-4_amd64.deb or something else?
On Ubuntu 14.04 I built the source package “flac_1.3.1.orig.tar.xz” linked to on Debian -- Error and installed it to /usr/local. Although the README says flac 1.3.1, the flac binary produced appears to be 1.3.0 (at least by executing “flac” at the command-line). So it is not Audacity’s fault that it writes a file with 1.3.0 as the flac version number.
I tested it on Windows (where the release build of Audacity uses libflac 1.3.1). If I point (external program) to a 1.3.0 version of flac.exe, the flac version in the exported file does change to 1.3.0.
You could build and install http://downloads.xiph.org/releases/flac/flac-1.3.1.tar.xz. I will try that later.
Or, If your system flac (used to be) 1.3.0, how is your library of flac files already written with 1.3.1? Is there a flac 1.3.1 binary somewhere else on your computer that you could link to?
Gale
It also installs a flac binary that declares libflac 1.3.0 in the encoded file. Sorry, I don’t know if this is expected when you have system libflac 1.3.0. I would not expect that to happen.
If you compile http://downloads.xiph.org/releases/flac/flac-1.3.1.tar.xz you don’t need to install it. You can point Audacity to the 1.3.1 flac binary that gets built in the src/flac/ folder. That binary actually declares 1.3.1 in the encoded file.
So for example if you built flac in your Downloads folder, the default command would be:
home/<your user name>/Downloads/flac-1.3.1/src/flac/flac - -o "%f"
Gale
i swichted over to linux 
as i am still a novice to linux, i would rather prefer a deb download than building on my own.
so i guess that means i have no chance than using 1.3.0 until that ‘flac mystery’ is somewhat solved? 
Sometimes you just have to compile on Linux, for one reason or another. It is good to learn.
As I asked, what app is writing the flac 1.3.1 files that you already have? It may already have a flac 1.3.1 binary on your computer that you can point Audacity to. Or are all those other FLAC files downloaded from the internet?
It is not an Audacity bug. You could ask on the Linux Mint forums about why this happens. Please let us know how they answer you.
It is only a few steps to compile flac.
Download http://downloads.xiph.org/releases/flac/flac-1.3.1.tar.xz and extract it into your Downloads folder. It should extract to a folder called “flac-1.3.1” inside the Downloads folder.
Open a terminal. It opens in your home folder. Type:
cd Downloads/flac-1.3.1
which changes into the “Downloads/flac-1.3.1” directory. Then hit ENTER or RETURN on your keyboard. To send any command on the screen you must hit ENTER or RETURN.
Then type:
./configure
and ENTER/RETURN.
When configure completes, type:
make
and ENTER/RETURN.
Gale