The DOS decoder is designed to run on low-end systems.
64Kbps files can be played on a 486DX-50 and 80Kbps files on a
486DX2-66. Higher bit rates require more computer. A 4/586 in the
100 MHz range or a Pentium 60 may or may not play the highest bit rate
files. The limits of each marginal computer must be determined
empirically. A 586-133 should play any MP3 with power to spare.
This program was created to put old Pentium-class computers back to work as
dedicated MP3 players. Click here for
instructions on building the best DOS-based MP3-playing computer possible.
MPR will play all MP3 files on your computer (up
to 10,000 songs) in random order, with no repeated songs. Playback may
be interrupted and resumed at any time. Play history is updated after
each song has finished playing and is loaded each time the program is
started. No song will ever be repeated. Playlists are neither
required nor supported. Target applications are background music
generators, automotive embedded players and automated radio stations.
At this time only Soundblaster 16 and compatible sound cards are supported.
ID3 tags are supported if they reside at the head of the
file. Artist (TPE2), Album (TALB) and Title (TIT2) will be displayed if
Invocation and options:
Default Soundblaster parameters: Port 220, DMA 5, IRQ 5.
It would be a real good idea to have a viable "BLASTER=" environment string
defined, as these defaults will only work about half the time.
Once operating, <ESC> exits, <N> plays the next song and <P>
pauses (Any key to resume).
The MP3 search path can be specified on the command line (MPR
d:\clas\mp3\;e:\rock\mp3\;etc), or defined with an environment string
(MP3PATH=...). In either case, the syntax is exactly like the normal DOS
SET PATH=... If the path is specified on the command line, no file
history is maintained.
Command line options (not case sensitive):
Play one song (that is the number: one)
Delay during startup
Print these options
Abort with LPT1 ACK
Test decode only
Set mixer master volume
Write decoded stream as a .WAV
Play one song (-1)
will play the song or songs (*wildcard) specified on the command line and
exit. This option also selects linear playback. Random playback is
disabled and no file history is maintained.
Delay during startup (-D) will beep and delay 5 seconds before playing the
first song. This is handy for stand-alone or embedded machines that
start up from AUTOEXEC.BAT. The 5-second delay gives the user a chance
to stop playback for maintenance or whatever without wasting a song. The
beep is also a good indicator that the thing booted and is running when there
is no monitor. If this option is selected, there will also be a beep
when the program is terminated.
prints a single line containing the command-line options and exits.
Abort with LPT1 ACK (-L) allows for orderly shutdown in a system without a
keyboard. A simple push button switch from ACK (pin 10) to ground (pins
18-25) on printer port 1 can be used to emulate the function of the ESC key.
Test decode only (-T) decodes the file or files specified on the command
line (*wildcard) and ignores the decoded data. This option also selects
linear playback. Random playback is disabled and no songs-played history
file is maintained.
Set mixer master volume (-Vx) sets the volume to the value specified by a
single hex character (0-F) following the command. To set the volume to
12, the command line option would be -VC.
Write out .WAV file (-W) decodes the file and writes the decoded data to a
.WAV file, with the same DOS filename as the .MP3 file. Wildcards may be
specified on the command line. For example, MPR -w * would convert all
files in a directory to .WAV. This option also selects linear
playback. Random playback is disabled and no songs-played history is
File play history is stored in the directory archive bits of the files that
have been played. The assumption is that copying files to the MP3
computer sets the archive bit for each file. When a file has finished
playing, its archive bit is cleared. When all files have been played,
the archive bits for all files in the MP3 path are set and playback resumes
from the full set of files. Any other program on the MP3 computer that
fiddles around with the archive bits of the MP3 files will scramble the play