Amarok is based on XINE, so most of its decoders rely on xine and libxine
$ sudo yum install amarok-extras-nonfree
Downloading Packages:
(1/11): amarok-extras-non 100% |=========================| 3.8 kB 00:00
(2/11): xine-lib-arts-1.1 100% |=========================| 12 kB 00:00
(3/11): libgpod-0.6.0-3.f 100% |=========================| 235 kB 00:01
(4/11): rhythmbox-0.11.3- 100% |=========================| 5.0 MB 00:09
(5/11): sg3_utils-libs-1. 100% |=========================| 42 kB 00:00
(6/11): xine-lib-1.1.15-1 100% |=========================| 2.7 MB 00:04
(7/11): libtunepimp-extra 100% |=========================| 97 kB 00:01
(8/11): kipi-plugins-0.1. 100% |=========================| 8.8 MB 00:12
(9/11): amarok-1.4.10-1.f 100% |=========================| 13 MB 00:19
(10/11): libmtp-0.2.4-1.f 100% |=========================| 84 kB 00:00
(11/11): xine-lib-extras- 100% |=========================| 584 kB 00:07
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for Ubuntu, I also have this problem,
to solve:
$ sodu apt-get install libxine-extracodecs
or
$ sodu apt-get install libxine1-ffmpeg
Reference:
http://amarok.kde.org/wiki/Download:Fedora