Request 420 (accepted)

Overview

Request 420 (accepted)

A basic decoder for Apple Lossless Audio Codec files.

Created by dap about 12 years ago
In state accepted

Submit alac_decoder

Submit package home:dap / alac_decoder to package Multimedia / alac_decoder

alac_decoder.changes Added

alac_decoder.spec Added

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+#
+# spec file for package alac_decoder
+#
+# Copyright (c) 2004 David Hammerton (source)
+# (c) 2013 Perlow Dmitriy A. (spec file)
+#
+# Please submit bugfixes or comments via https://bugs.links2linux.org
+#
+
+Name:           alac_decoder
+Version:        0.2.0
+Release:        0
+License:        MIT
+Summary:        A basic decoder for Apple Lossless Audio Codec files
+Url:            http://craz.net/programs/itunes/alac.html
+Group:          Productivity/Multimedia/Sound/Editors and Convertors
+Source:         http://craz.net/programs/itunes/files/alac_decoder-%{version}.tgz
+Source1:        LICENSE
+
+BuildRequires:  glibc-devel
+BuildRequires:  make
+
+BuildRoot:      %{_tmppath}/build-%{name}-%{version}
+
+%description
+Located here is a basic decoder for Apple Lossless Audio Codec files (ALAC).
+ALAC is a proprietary lossless audio compression scheme. Apple never released
+any documents on the format.
+What I provide here is a C implementation of a decoder, written from reverse
+engineering the file format. It turns out that most of the algorithms in the
+codec are fairly well known. ALAC uses an adaptive FIR prediction algorithm
+and stores the error values using a modified rice or golumb algorithm.
+Further details are in alac.c. 
+
+Although an encoder is not provided, by using the decoder as a sort of
+specification it should be fairly trivial to write an encoder. By exploiting
+other lossless audio encoders, such as FLAC, the task will be much easier.
+Although one wouldn't be able to copy the compression algorithms verbatim, as
+adaptive compression is used in ALAC and not in FLAC. There are, however, a
+bunch of academic papers on the issue. 
+
+The program located here will not be able to handle all ALAC files, it can
+only handle mono or stereo files. ALAC allows up to 8 channels. It should be
+trivial to finish the implementation once I find files that I can test it
+with. The ALAC decoder supports both 16 and 24 bit sample sizes. 
+
+The decoder is fairly self explanatory, it can read an ALAC stream from either
+a file or from stdin, and write it as raw PCM data or as a WAV file to either
+stdout or a file. In theory one should be able to stream data to the decoder.
+
+%prep
+%setup -q -n %{name}
+cp %{SOURCE1} .
+
+%build
+make CFLAGS="%{optflags}" %{?_smp_mflags}
+
+%install
+mkdir -p %{buildroot}%{_bindir}
+%{__install} alac %{buildroot}%{_bindir}
+
+%files
+%defattr(-,root,root)
+%doc README LICENSE
+%{_bindir}/alac
+
+%changelog

LICENSE Added

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+Copyright (c) 2004 David Hammerton. 
+ 
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions: 
+ 
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software. 
+ 
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
\ No newline at end of file

alac_decoder-0.2.0.tgz Added

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Request History

dap created request about 12 years ago

A basic decoder for Apple Lossless Audio Codec files.

jsjhb accepted request over 12 years ago

thanks