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QOA - QOA sounds for every Amiga: a datatype
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WHAT IT IS
QOA ("Quite OK Audio", qoaformat.org) is a compressed sound
format: a fifth of the size of plain 16-bit sound, sounding
nearly the same, and simple enough to decode on a 68000. This
package teaches the Amiga to play it:
qoa.datatype plays QOA sounds in every program that plays
sounds through datatypes: MultiView, a double-
click on Workbench, file managers, AmigaGuide,
browsers
One build for every Amiga, from a 68000 up, with OS 3.0 or
later. About 6 KB.
FEATURES
- Stereo on OS 3.5, 3.9 and 3.2 (sound.datatype 44 and later);
files with more channels play their first two, front left and
right
- Mono on OS 3.0 and 3.1, whose sound.datatype has no stereo:
all the channels are mixed into one
- 44.1 and 48 kHz files play at the right speed: Paula plays at
most about 28 kHz, so faster sound is averaged down to half (a
third, a quarter...) while it is decoded, instead of playing
slow
- Fast: the per-sample loop is hand-written 68000 assembly. On
the real A1200 (Emu68, OS 3.2) a minute of 44.1 kHz stereo
opens in 0.8 seconds
- Little memory: the file is read a frame (at most 16 KB) at a
time and decoded straight into the 8-bit sound; only that is
held, about 2.5 times the file's size in stereo, half that in
mono
- Save as 8SVX: MultiView's Save As writes an 8SVX with the
right rate and length in its header
- Safe with broken files: every frame is checked before it is
decoded; a damaged file plays up to the damage. The same
samples as the reference decoder (qoa.h) on 1,100 test files,
whole and damaged
- Recognised by its first bytes ("qoaf"), whatever the file is
called
Not played: "streaming" QOA files (no length in the header) and
files with more than 8 channels.
On a plain 68000 or 68020 the whole sound is decoded before it
plays, which takes longer than it plays: encode at 22 kHz (see
qoa.doc), and keep long songs for faster Amigas.
INSTALLATION
Classes/DataTypes/qoa.datatype to SYS:Classes/DataTypes/
Devs/DataTypes/QOA to DEVS:DataTypes/
Then AddDataTypes REFRESH, or restart the Amiga. The full manual
is qoa.doc.
SOURCE
https://github.com/creep-ltx/AmigaDatatypes (folder qoa, MIT)
HISTORY
0.1b1 (17.10.2026) - the first version
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