Re: [Audacity-devel] Adding "Import Audio" support on ARM

[Richard A. <ri...@au...>]

On Thu, 2012-03-29 at 11:06 +0530, Ajay Garg wrote:
> I have been trying since 3 days to get the "Import Audio" to work in
> armv7l-based F14.
> For this, I have followed these steps ::

> a)
> I first tried with the simple audacity package.
> In this when I tried to "Import Audio", it said "This version of
> Audacity was not compiled with MP3 files support".

What format file are you trying to import? Audacity's best guess is that
it's an MP3 file, but you don't say that. Fedora build audacity with MP3
_importing_ disabled at compile time (via the --without-libmad configure
script option) for patent reasons. You can confirm this by looking the
build details tab of the About Audacity box (Help > About).

> b)
> I then downloaded "audacity-freeworld-1.3.12-0.1.3.beta.fc14.src.rpm";
> "rpm -ivh audacity-freeworld-1.3.12-0.1.3.beta.fc14.src.rpm"
Really, do we have to use the beta from 12 months and three releases
ago? 

> and ran
> 
> ./configure --with-portmixer="local"
> make
So it auto-detected what libraries it could find and turned the rest
off. That summary of what libraries were in use at the end of configure
would be really handy at this point. Hopefully the basics were in place
so that audacity can be compiled, but that depends on you having a lot
of -devel packages installed, which aren't installed by default.

> c) 
> This generated the "audacity" binary in
> "~/rpmbuild/SOURCES/audacity-src-1.3.12-beta".
Oh good, you have the mandatory build dependencies if that worked.

> 
> d)
> Now when I ran audacity, I was asked to set the location of "lame" and
> "ffmpeg" libraries.
So it found enough (basically headers) to activate those optional
features.

> e)
> I then compiled and installed "libmp3lame*" (from
> "lame-3.98.4-1.fc14.src.rpm") 
> and
>                                            "libavformat.so.52" (from
> "ffmpeg-0.7.11.tar.bz2")
> libraries.
LAME isn't relevant - it's an MP3 _encoder_ which is only used for
export. You want to _import_ audio, so you don't need it.

FFMPEG might be useful - it can _decode_ MP3 files, but isn't the
default way to do so. However getting FFMPEG working is a lot harder
than getting libmad working

> f)
> After that when I set the location of these libraries in "Edit ->
> Preferences -> Libraries", it recognised LAME (as "MP3 Library
> Version: LAME 3.98.4");
> but it still says FFmpeg Library Version: FFmpeg library not found,
> EVEN THOUGH I HAVE LOCATED THE PATH OF "libavformat.so.52".

A case of barking up the wrong tree. What you need (assuming you do have
an MP3 file to import) is to build audacity with libmad support for MP3
_decoding_. This needs the usual suspects:
* libmad installed
* libmad-devel installed
* --with-libmad configure option

At the end of the configure you can verify that you do have libmad MP3
importing enabled in the summary, before you start your build.

./configure --help is your friend.

Richard