adlib-sample

=                             7888888888888888889
=                             4  AdLib Samples  6
=                             1222222222222222223
|
| AdLib synthesis is a method of music creation originally provided by
| Yamaha's YM3812 chip, that used to exist in most soundcards, especially
| Sound Blaster compatibles, in the 1990s. In Schism Tracker, AdLib support
| is provided through emulation.
|
| AdLib allows for producing impressive music while using very little
| storage, because all instruments are synthesized by the hardware, instead
| of being stored as PCM data like other tracker samples are. The synthesis
| method used in AdLib is frequency modulation, hence it is also called FM
| synthesis.
|
| AdLib consists of 9 melodic channels, each of which has the following
| properties, most of which can be changed on the sample editing screen:
|
|   Frequency, Octave, Note On/off
|                These properties are automatically managed
|                by Schism Tracker when the music plays, and
|                are not part of the sample editor.
|
|   Synthesis mode (Additive synthesis)
|                Whether the sample is synthesized using FM, or whether
|                the two operators' outputs are simply summed together.
|
|   Feedback level
|                This property allows the modulator to modulate its own
|                output. High levels of feedback are usually used to
|                create percussive instruments.
|
|   Two oscillators (called "operators"), one called "Modulator" and
|   the other called "Carrier", each having the following properties:
|
|         Frequency multiplier
|                Specifies the value by which the frequency produced by
|                the individual oscillator is multiplied. Though the
|                values displayed in the sample editor are indicated
|                as 0..15, the actual values they correspond to are
|                1/2, 1..10, 10, 12, 12, 15 and 15.
|
|         Waveform
|                Four possible waveforms exist for each channel:
|                 0 = sinewave                 _     _
|                                             / \   / \
|                                                \_/   \_/
|                 1 = half sinewave            _     _
|                                             / \___/ \___
|
|                 2 = polarized sinewave       _  _  _  _
|                                             / \/ \/ \/ \
|
|                 3 = half polarized sinewave  .  .  .  .
|                                             /|_/|_/|_/|_
|         Volume(0-63)
|                 The volume level of this operator. The volume levels
|                 are logarithmic, so a reduction of 8 in volume
|                 corresponds to approximately half quieter signal.
|
|         Attack, decay, sustain, release
|                 These properties control the volume envelope of the
|                 instrument.
|
|                 Attack = how quickly the volume reaches the maximum level
|                          when the instrument is triggered
|                 Decay  = at which rate the volume decays immediately
|                          after the attack phase
|                 Sustain = at which rate the volume decays while it is
|                           still keyed on (this number only affects if
|                           the Sustain sound flag is set)
|                 Release = at which rate the volume decays after the
|                           instrument is no longer keyed on
|
|         Volume Vibrato (Tremolo)
|                 Automatic volume vibrato for the instrument on/off
|
|         Pitch Vibrato
|                 Automatic pitch vibrato for the instrument on/off
|
|         Envelope scaling per key
|                 If this property is set, then the envelope rates are
|                 scaled according to the key that is played: lower pitches
|                 decay slower, and higher pitches decay faster. This is
|                 useful for e.g. piano type instruments.
|
|         Volume scaling per key
|                 Similarly as envelope scaling, this property controls
|                 the rate on which the volume level is scaled by the
|                 pitch that is played.
|
|   The combined outcome of all these settings for both the Operator
|   and the Carrier determines how the sample will sound.
|
|   If you want to create a new AdLib sample from scratch, use an empty
|   sample slot, and press Alt-Z. Set attack=15, decay=2, sustain=7 for
|   both operators, and experiment from there changing each property
|   as you like.
|
|   IMPORTANT NOTE: AdLib instruments can currently only be
|   loaded from / saved to S3M files! They are not supported
|   by any other format supported by Schism Tracker, and thus,
|   if you save your AdLib module in e.g. IT format, the AdLib
|   instruments will be lost.
|
|   References:
|       - Wikipedia article at http://en.wikipedia.org/wiki/Yamaha_YM3812
|       - OPL2 emulator by Tatsuyuki Satoh and Jarek Burczynski