qplay — convert QBASIC play strings to PCM
qplay [-i part] [-q part]
[-r rate] [file...] | aplay -f dat -c 1
qplay will convert QBASIC-style strings for its "PLAY"
command to linear 16-bit raw PCM. Normally, you will be wanting to pipe it
into a raw PCM player like aplay(1) to actually output it to a sound
device. Be sure to lower the volume beforehand to avoid nasty surprises that
come with square waves. By default, bsvplay will mix 1:1 square:sine waves
to give a medium tone hardness.
- -q part
- Part to mix square waves in (default: 1.0)
- -i part
- Part to mix sine waves in (default: 1.0). If -q2 -i1 is specified
for example, the final PCM output will consist of 2/3*squarepcm +
1/3*sinpcm.
- -r rate
- PCM sample rate (default: 48000 Hz)
The file format qplay expects is of course not BASIC, but raw PLAY
command strings. Lines that start with a leading hash mark ('#') are
ignored.
Commands are case insensitive and whitespace is mostly ignored.
The original QBasic manpage is slightly incorrect; below is what qplay
supports.
- on
- Sets the current octave. There are seven octaves, n = 0-6.
- >
- Increases octave by 1. The upper octave limit in QBasic was 6; qplay has a
limit of 9.
- <
- Decreases octave by 1. Octave cannot drop below 0.
- A - G
- Plays a note in the range A-G. The number sign (#) or the plus sign
(+) after a note specifies sharp; a minus sign (-) specifies
flat. N n Plays note n. The range for n is
0-84 (in the seven possible octaves, there are 84 notes); n = 0
means a rest.
- # or +
- Follows a specified note and turns it into a sharp.
- -
- Follows a specified note and turns it into a flat.
- L n
- Sets the length of each note. L4 is a quarter note, L1 is a whole note,
etc. The range for n is 1-64. The length may also follow the note
when a change of length only is desired for a particualr note. For
example, A16 can be equivalent to L16A.
- MN
- Sets "music normal" so that each note will play 7/8 of the time
determined by the length (L).
- ML
- Sets "music legato" so that each note will play the full period
set by lengt (L).
- MS
- Sets "music staccato" so that each note will play 3/4 of the
time determined by the length (L).
- P n
- Specifies a pause, ranging from 1-64. This option corresponds to the
length of each note, set with L n. T n Sets the
"tempo", or the number of L4 quarter notes in one minute. The
range for n is 32-255. The default for n is 120.
- .
- A period after a note causes the note to play 3/2 times the length
determined by L (length) times T (tempo). The period has the same meaning
as in a musical score. Multiple periods can appear after a note. Each
period adds a length equal to one-half the length of the previous period.
For example, the command A. plays 1 + 1/2, or 3/2 times the length,
and A.. plays 1 + 1/2 + 1/4, or 7/4 times the length. Periods can
appear after a pause (P). In this case, the pause length is scaled in the
same way notes are scaled.
- X(var)
- Play the string in the variable var.
Variable definitions in qplay syntax are for example:
$var = "CDEF";
and they must stand on a single line.
echo "L16O2CDEFGAB>CDEFGAB>L4C" | qplay - | aplay -fdat -c1
will play a tone ladder.