$VER: delfinampeg.device 1.6 (Sat 17-May-2003)
#features
-plays MPEG audio files with almost no CPU load
(Delfina's DSP56002 does all the decoding and playback)
-supports MPEG-1 layer II and III
-standard "mpeg.device" API
(code based on melodympeg.device by Thorsten Hansen)
-free software
(full source code included, of course)
#requirements
-CPU 68020+
-AmigaOS V37+
-Delfina DSP board
-developed on A1200 - OS3.1/68030+882 40MHz/16MBFastRAM/Delfina1200DSP
-tested on various machines with Delfina 1200, Lite, Plus or Flipper
#recommended
-application that uses mpeg.device (such as AMPlifier, Frogger and others)
-some MPEG audio files :)
#changes since previous release
-fixed interference with serial I/O (interrupt timing problem)
#how to use
Copy delfinampeg.device to your "devs:" drawer.
Configure an application program to make use of it, for instance:
AMPlifier http://www.katodev.de
Configuration -> Audio I/O -> MPEG audio player -> Decoder
MPEG device: delfinampeg.device
Unit: 0
Buffersize: 128 (recommended)
Blocksize: 16 (recommended)
set Layer I/II and Layer III to "Hardware" decoding
Frogger http://frogger.rules.pl
use the option ADECODER with mode DELFINA
AmigaAMP http://www.amigaamp.de
get the "MHI driver for mpeg.device" from Aminet: mus/play/mhimdev.lha
follow the installation instructions in the README file
Especially owners of the slower Delfinas (i.e. Lite) might be interested
in the configuration options of delfinampeg.device, which can be used to
sacrifice some playback quality in order to reduce DSP load. The device
reads them from the environment variable DELFINAMPEG during OpenDevice().
The options are:
L2MONO...........mp2 files: decode left channel only
L2RATE <number>..mp2 files: play at specified rate (given in kHz)
L3MONO...........mp3 files: decode left channel only
L3RATE <number>..mp3 files: play at specified rate (given in kHz)
The given playback rate is automatically rounded to the nearest available
Delfina rate (16, 27, 32, 48 kHz; Delfina 1200/Plus: 12, 24, 36, 48 kHz).
example:
> setenv DELFINAMPEG l3rate 32
(play mp3 files at 32 kHz)
> copy ENV:DELFINAMPEG ENVARC:
(save settings to disk)
#known problems
-delfinampeg.device only recognizes MPEG-1 audio files.
not supported: MPEG-2 or mixed audio/video files.
-please read the README for DelfMPEG (Aminet: mus/play/DelfMPEG.lha)
in the "known problems" you find a list of bugs in the official Delfina
drivers (delfina.library).
-equalizer and visual effect plugins of AMPlifier are currently not
supported. this is not a feature of the mpeg.device. AMPlifier needs to
copy the decoded audio data back from the sound board to main memory,
which it can only do with the Melody boards but not with Delfina.
#acknowledgements
delfinampeg.device uses ideas/code from:
-MPEG Audio Layer II decoder by Fredrik Noring and Tomas Berndtsson
(an mp2 player for Atari Falcon, DSP56K code)
-amp11 by Niklas Beisert (clean and fast C++ code)
-FalcAMP by Denis "STGhost" Huguet and David "Splash" Carrere
(an mp3 player for Atari Falcon, DSP56K code)
-reference code by MPEG Software Simulation Group ("the original" C code)
-melodympeg.device by Thorsten Hansen
#author
mailto: smack42web.de
delfinampeg.device - mpeg.device for Delfina DSP
Copyright (C) 2000-2003 Michael Henke
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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