Tue Apr 14 22:33:14 2020 UTC ()
Import audio/alac from wip

A basic decoder for Apple Lossless Audio Codec files.


(js)
diff -r1.593 -r1.594 pkgsrc/audio/Makefile
diff -r0 -r1.1 pkgsrc/audio/alac/DESCR
diff -r0 -r1.1 pkgsrc/audio/alac/Makefile
diff -r0 -r1.1 pkgsrc/audio/alac/PLIST
diff -r0 -r1.1 pkgsrc/audio/alac/distinfo
cvs diff -r1.593 -r1.594 pkgsrc/audio/Makefile (expand / switch to unified diff)

--- pkgsrc/audio/Makefile 2020/04/14 04:36:39 1.593
+++ pkgsrc/audio/Makefile 2020/04/14 22:33:14 1.594
@@ -1,27 +1,28 @@ @@ -1,27 +1,28 @@
1# $NetBSD: Makefile,v 1.593 2020/04/14 04:36:39 tpaul Exp $ 1# $NetBSD: Makefile,v 1.594 2020/04/14 22:33:14 js Exp $
2# 2#
3 3
4COMMENT= Audio tools 4COMMENT= Audio tools
5 5
6SUBDIR+= SDL2_mixer 6SUBDIR+= SDL2_mixer
7SUBDIR+= SDL_mixer 7SUBDIR+= SDL_mixer
8SUBDIR+= SDL_sound 8SUBDIR+= SDL_sound
9SUBDIR+= abcde 9SUBDIR+= abcde
10SUBDIR+= abcmidi 10SUBDIR+= abcmidi
11SUBDIR+= adplay 11SUBDIR+= adplay
12SUBDIR+= adplug 12SUBDIR+= adplug
13SUBDIR+= aeneas 13SUBDIR+= aeneas
14SUBDIR+= aiomixer 14SUBDIR+= aiomixer
 15SUBDIR+= alac
15SUBDIR+= alacconvert 16SUBDIR+= alacconvert
16SUBDIR+= alsa-lib 17SUBDIR+= alsa-lib
17SUBDIR+= alsa-plugins-oss 18SUBDIR+= alsa-plugins-oss
18SUBDIR+= alsa-plugins-pulse 19SUBDIR+= alsa-plugins-pulse
19SUBDIR+= alsa-utils 20SUBDIR+= alsa-utils
20SUBDIR+= alure 21SUBDIR+= alure
21SUBDIR+= amaroc 22SUBDIR+= amaroc
22SUBDIR+= amarok 23SUBDIR+= amarok
23SUBDIR+= amp 24SUBDIR+= amp
24SUBDIR+= ampache 25SUBDIR+= ampache
25SUBDIR+= amsynth 26SUBDIR+= amsynth
26SUBDIR+= applerecords 27SUBDIR+= applerecords
27SUBDIR+= ardour 28SUBDIR+= ardour
File Added: pkgsrc/audio/alac/DESCR
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.
File Added: pkgsrc/audio/alac/Makefile
# $NetBSD: Makefile,v 1.1 2020/04/14 22:33:14 js Exp $

DISTNAME=	alac_decoder-0.2.0
CATEGORIES=	audio
MASTER_SITES=	https://web.archive.org/web/20150510210401if_/http://craz.net/programs/itunes/files/
EXTRACT_SUFX=	.tgz

MAINTAINER=	js@pkgsrc.org
HOMEPAGE=	https://web.archive.org/web/20150319040222/craz.net/programs/itunes/alac.html
COMMENT=	Basic decoder for Apple Lossless Audio Codec files (ALAC)
LICENSE=	mit

WRKSRC=		${WRKDIR}/alac_decoder
BUILD_TARGET=	alac

INSTALLATION_DIRS+=	bin

do-install:
	${INSTALL_PROGRAM} ${WRKSRC}/alac ${DESTDIR}${PREFIX}/bin/alac

.include "../../mk/bsd.pkg.mk"
File Added: pkgsrc/audio/alac/PLIST
@comment $NetBSD: PLIST,v 1.1 2020/04/14 22:33:14 js Exp $
bin/alac
File Added: pkgsrc/audio/alac/distinfo
$NetBSD: distinfo,v 1.1 2020/04/14 22:33:14 js Exp $

SHA1 (alac_decoder-0.2.0.tgz) = a620f6293ef2d9490927d21ec341bbeff13eabe8
RMD160 (alac_decoder-0.2.0.tgz) = 72664dff4eeff6e484314f625f74337e60ba39fb
SHA512 (alac_decoder-0.2.0.tgz) = 4b37d4fe37681bfccaa4a27fbaf11eb2a1fba5f14e77d219a6d9814ff44d1168534d05eb19443dd2fd11e6fcdf4da3a22e3f3c79314cb7a6767c152351b13e29
Size (alac_decoder-0.2.0.tgz) = 19019 bytes