Overview

Request 420 (accepted)

A basic decoder for Apple Lossless Audio Codec files.

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

alac_decoder.changes Added
x
 
1
@@ -0,0 +1,4 @@
2
+-------------------------------------------------------------------
3
+Sat Mar 30 21:02:24 UTC 2013 - dap.darkness@gmail.com
4
+
5
+- Initial package.
6
alac_decoder.spec Added
69
 
1
@@ -0,0 +1,67 @@
2
+#
3
+# spec file for package alac_decoder
4
+#
5
+# Copyright (c) 2004 David Hammerton (source)
6
+# (c) 2013 Perlow Dmitriy A. (spec file)
7
+#
8
+# Please submit bugfixes or comments via https://bugs.links2linux.org
9
+#
10
+
11
+Name:           alac_decoder
12
+Version:        0.2.0
13
+Release:        0
14
+License:        MIT
15
+Summary:        A basic decoder for Apple Lossless Audio Codec files
16
+Url:            http://craz.net/programs/itunes/alac.html
17
+Group:          Productivity/Multimedia/Sound/Editors and Convertors
18
+Source:         http://craz.net/programs/itunes/files/alac_decoder-%{version}.tgz
19
+Source1:        LICENSE
20
+
21
+BuildRequires:  glibc-devel
22
+BuildRequires:  make
23
+
24
+BuildRoot:      %{_tmppath}/build-%{name}-%{version}
25
+
26
+%description
27
+Located here is a basic decoder for Apple Lossless Audio Codec files (ALAC).
28
+ALAC is a proprietary lossless audio compression scheme. Apple never released
29
+any documents on the format.
30
+What I provide here is a C implementation of a decoder, written from reverse
31
+engineering the file format. It turns out that most of the algorithms in the
32
+codec are fairly well known. ALAC uses an adaptive FIR prediction algorithm
33
+and stores the error values using a modified rice or golumb algorithm.
34
+Further details are in alac.c. 
35
+
36
+Although an encoder is not provided, by using the decoder as a sort of
37
+specification it should be fairly trivial to write an encoder. By exploiting
38
+other lossless audio encoders, such as FLAC, the task will be much easier.
39
+Although one wouldn't be able to copy the compression algorithms verbatim, as
40
+adaptive compression is used in ALAC and not in FLAC. There are, however, a
41
+bunch of academic papers on the issue. 
42
+
43
+The program located here will not be able to handle all ALAC files, it can
44
+only handle mono or stereo files. ALAC allows up to 8 channels. It should be
45
+trivial to finish the implementation once I find files that I can test it
46
+with. The ALAC decoder supports both 16 and 24 bit sample sizes. 
47
+
48
+The decoder is fairly self explanatory, it can read an ALAC stream from either
49
+a file or from stdin, and write it as raw PCM data or as a WAV file to either
50
+stdout or a file. In theory one should be able to stream data to the decoder.
51
+
52
+%prep
53
+%setup -q -n %{name}
54
+cp %{SOURCE1} .
55
+
56
+%build
57
+make CFLAGS="%{optflags}" %{?_smp_mflags}
58
+
59
+%install
60
+mkdir -p %{buildroot}%{_bindir}
61
+%{__install} alac %{buildroot}%{_bindir}
62
+
63
+%files
64
+%defattr(-,root,root)
65
+%doc README LICENSE
66
+%{_bindir}/alac
67
+
68
+%changelog
69
LICENSE Added
21
 
1
@@ -0,0 +1,18 @@
2
+Copyright (c) 2004 David Hammerton. 
3
+ 
4
+Permission is hereby granted, free of charge, to any person obtaining a copy
5
+of this software and associated documentation files (the "Software"), to deal
6
+in the Software without restriction, including without limitation the rights
7
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8
+copies of the Software, and to permit persons to whom the Software is
9
+furnished to do so, subject to the following conditions: 
10
+ 
11
+The above copyright notice and this permission notice shall be included in
12
+all copies or substantial portions of the Software. 
13
+ 
14
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
18
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
19
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
20
\ No newline at end of file
21
alac_decoder-0.2.0.tgz Added
Refresh
Refresh
Request History
Dmitriy A. Perlow's avatar

dap created request about 12 years ago

A basic decoder for Apple Lossless Audio Codec files.


Stefan Botter's avatar

jsjhb accepted request over 12 years ago

thanks