Sound effects

How a sound effect is put together from its SOUND.INI section, how it fades and pans with its place on screen, and how it competes for a voice.

Added in 0.2.0Changed in 0.2.0

Each sound effect is defined by its section in SOUND.INI. Every time the game plays the sound, that section decides which samples play, at what pitch and loudness, how far away the sound is heard, and whether it loops.

[MYGUN]
Sounds=MYGUN2 MYGUN3  ; body samples; RANDOM draws one for each play
Control=RANDOM INTERRUPT
Priority=NORMAL
Range=12              ; cells beyond the edge of the view where the sound falls silent
Limit=3               ; copies of MYGUN that may play at once

The section takes effect only for a sound ID registered under [SoundList], as SOUND.INI describes.

Attack, body and decay

Each play has up to three parts: an attack sample, the body, and a decay sample. Control= decides which Sounds= samples form the body and how one is chosen.

Attack samples come from the start of the list and decay samples from its end, counted by Attack= and Decay=. Without Attack=, ATTACK in Control= counts one sample, and a Control= line without ATTACK counts none. Decay= and DECAY work the same way. When several are listed, one of each is drawn at random. They are used only when the list has at least one sample left over for the body. Otherwise the whole list is body, and no attack or decay plays.

A play draws one pitch shift from FShift= and one loudness change from VShift=. Both stay the same for every sample in that play, including every cycle of a loop.

Loops and delays

With LOOP in Control=, the body repeats Loop= times, or with Loop=0 until the game stops the sound. The attack plays once before the first cycle. Without Delay=, the cycles follow one another with no gap.

With Delay=, each gap between cycles is a silence of random length from the Delay= range. PREDELAY in Control= adds one such silence before the first sample, whether or not the sound loops.

Each cycle after a Delay= gap competes for a voice again, as described under Voices and priority. A cycle that is refused ends the loop.

The decay plays after the last cycle, so a loop plays it only when Loop= is above 0. The game stops an endless loop by fading it out, and its decay sample does not play.

Placed sounds

A sound played at a place in the world, such as an animation’s sound, fades and pans with where that place is on screen. A sound played without a place, such as a button click, plays centered at the loudness the game asks for.

A placed sound is at full loudness anywhere inside the view. Outside the view, its loudness falls in a straight line to silence at Range= cells beyond the edge. The distance used is the larger of the horizontal distance and twice the vertical distance, so that Range= counts cells in both directions. A sound that has faded below one twentieth of full is not started, so it falls silent slightly short of Range=.

The pan follows the place’s horizontal position: centered in the middle of the view, and fully to one side at that edge of the view and beyond.

Type= changes how the distance is judged:

LOCAL measures the distance from the center of the view instead of its edge.
GLOBAL stops the fade at MinVolume=. A MinVolume= below 0.05 (5 percent) does not keep the sound audible, because anything quieter than one twentieth is cut off.
SHROUD or UNSHROUDED silences the sound while its cell is unrevealed. SHROUDED silences it once its cell has been revealed.

While a placed sound plays, its loudness and pan follow the view as it scrolls. Once it fades below one twentieth of full, it stops and does not return when the view comes back.

An endless loop left at a waypoint by Play Sound Effect At is the exception. It stays at its waypoint and stops while the waypoint is out of range. Whenever the waypoint is in range and the loop is not playing, it starts again without its attack sample.

These loops are kept in a save game and resume after a load, also without their attack sample.

Voices and priority

Limit= caps how many copies of one sound play at once. Copies still waiting to start, or silent between the cycles of a delayed loop, count toward it. At the limit, a new copy that is louder than the quietest copy replaces it. A new copy about as loud as the quietest replaces it only with INTERRUPT in Control=. Any other new copy is refused.

Up to Channels= sound effects play at once. Music, speech and movie sound do not count toward that number.

When every voice is busy, a new sound can take the voice of the playing sound with the lowest Priority=. Among equals it takes the quietest, or the oldest when they are within a tenth of each other in loudness. It takes that voice when its priority is higher, or when the priorities are equal and the playing sound is more than a tenth quieter. Otherwise the new sound is refused.

A copy that replaces a playing copy under Limit= takes that copy’s place, so it does not need to outrank anything. A copy that Limit= refuses never competes for a voice.

A refused sound does not play. If its Control= includes QUEUE, a sound refused when the game plays it keeps trying for up to two seconds before it is dropped. QUEUE does not cover a PREDELAY sound refused when its predelay ends, or a later cycle of a delayed loop.

Loudness

A sound’s level is its Volume= multiplied by its VShift= draw and by one more factor. For a placed sound, that factor is the distance fade. For a sound without a place, it is the loudness the game asks for. The result is capped at full loudness.

The SoundVolume option then scales every sound effect, including those already playing.

While a movie from Play Ingame Movie… plays in the radar, sound effects play at half level.

Levels follow the loudness curve of the original game’s DirectSound playback, so a sound the game plays at half level sounds as it did there. On that curve, half level is about 10 dB quieter than full.

The mixer compresses peaks above nine tenths of full scale, so a loud mix does not clip harshly.

Samples

A sound’s samples are loaded when the sound first plays. Each name in Sounds= is looked up through the normal file search, which covers loose files and every mounted archive. The extensions are tried in order: .WAV, .OGG, .FLAC, .MP3, then .AUD, and the first file that decodes is used.

A sample must be mono or stereo, and no larger than eight megabytes once decoded to 16-bit audio. That is about 47 seconds of 44.1 kHz stereo. A larger sample does not load.

A sample that cannot be loaded is left out of the play. When the body is one chosen sample, the next body sample in the list plays in its place.

A decoded sample stays in memory while any play uses it. After that it stays until decoded samples take more than 64 megabytes, when the least recently used ones are dropped first.

Filter keysRuntime effect

16 of 16

Key	Description	Value	When omitted
`Sounds`Sounds		string	Computed
`Priority`TeamType, Sounds	How firmly a team holds its members against other teams, or how hard a sound competes for a playback channel.	integer	Varies by type
`Volume`Sounds, Themes	The share of full loudness a sound effect or a music track is played at.	string	`1.0`
`MinVolume`Sounds		string	`0`
`Range`WeaponType, Sounds	How far the weapon may be fired, in cells, or how far from the view a sound is still heard.	distance (cells)	Varies by type
`Limit`Sounds		integer	`3`
`Loop`Sounds		integer	`0`
`Delay`Sounds		string	`0`
`FShift`Sounds		string	`0`
`VShift`Sounds		string	`0`
`Type`No effect in some scopesSuperWeaponType, multiplayer settings, Sounds	A superweapon's hard-coded behavior, the object kind named for the playback trap under the sync-bug settings, or where a sound is heard from.	string	Varies by type
`Control`Sounds		string	`NORMAL`
`Attack`Sounds		integer	Context-dependent
`Decay`Sounds		integer	Context-dependent
`Channels`Sounds		integer	`16`
`SoundVolume`client settings	The volume of sound effects, as a fraction from 0 to 1.	floating point	`.7`

History

Changed0.2.0In development
Stop placed sounds from crowding out other sound commands
Added0.2.0In development
Place sound effects in the view