DSP parameter indexes are not exposed

[melody-rs]

steam-audio/fmod/src/spatialize_effect.cpp

Lines 34 to 393 in d747565

	enum Params
	{
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_DATA`
	*
	* World-space position of the source. Automatically written by FMOD Studio.
	*/
	SOURCE_POSITION,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_DATA`
	*
	* Overall linear gain of this effect. Automatically read by FMOD Studio.
	*/
	OVERALL_GAIN,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_INT`
	*
	* **Range**: 0 to 2.
	*
	* How to render distance attenuation.
	*
	* - `0`: Don't render distance attenuation.
	* - `1`: Use a distance attenuation value calculated using the default physics-based model.
	* - `2`: Use a distance attenuation value calculated using the curve specified in the FMOD Studio UI.
	*/
	APPLY_DISTANCEATTENUATION,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_INT`
	*
	* **Range**: 0 to 2.
	*
	* How to render air absorption.
	*
	* - `0`: Don't render air absorption.
	* - `1`: Use air absorption values calculated using the default exponential decay model.
	* - `2`: Use air absorption values specified in the \c AIRABSORPTION_LOW, \c AIRABSORPTION_MID, and
	* \c AIRABSORPTION_HIGH parameters.
	*/
	APPLY_AIRABSORPTION,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_INT`
	*
	* **Range**: 0 to 2.
	*
	* How to render directivity.
	*
	* - `0`: Don't render directivity.
	* - `1`: Use a directivity value calculated using the default dipole model, driven by the
	* \c DIRECTIVITY_DIPOLEWEIGHT and \c DIRECTIVITY_DIPOLEPOWER parameters.
	* - `2`: Use the directivity value specified in the \c DIRECTIVITY parameter.
	*/
	APPLY_DIRECTIVITY,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_INT`
	*
	* **Range**: 0 to 2.
	*
	* How to render occlusion.
	*
	* - `0`: Don't render occlusion.
	* - `1`: Use the occlusion value calculated by the game engine using simulation, and provided via the
	* \c SIMULATION_OUTPUTS parameter.
	* - `2`: Use the occlusion value specified in the \c OCCLUSION parameter.
	*/
	APPLY_OCCLUSION,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_INT`
	*
	* **Range**: 0 to 2.
	*
	* How to render transmission.
	*
	* - `0`: Don't render transmission.
	* - `1`: Use the transmission values calculated by the game engine using simulation, and provided via the
	* \c SIMULATION_OUTPUTS parameter.
	* - `2`: Use the transmission values specified in the \c TRANSMISSION_LOW, \c TRANSMISSION_MID, and
	* \c TRANSMISSION_HIGH parameters.
	*/
	APPLY_TRANSMISSION,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_BOOL`
	*
	* If true, reflections are rendered, using the data calculated by the game engine using simulation, and provided
	* via the \c SIMULATION_OUTPUTS parameter.
	*/
	APPLY_REFLECTIONS,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_BOOL`
	*
	* If true, pathing is rendered, using the data calculated by the game engine using simulation, and provided
	* via the \c SIMULATION_OUTPUTS parameter.
	*/
	APPLY_PATHING,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_INT`
	*
	* **Range**: 0 to 1.
	*
	* Controls how HRTFs are interpolated when the source moves relative to the listener.
	*
	* - `0`: Nearest-neighbor interpolation.
	* - `1`: Bilinear interpolation.
	*/
	HRTF_INTERPOLATION,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* Not currently used.
	*/
	DISTANCEATTENUATION,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_INT`
	*
	* **Range**: 0 to 4.
	*
	* Type of distance attenuation curve preset to use when \c APPLY_DISTANCEATTENUATION is \c 1.
	*
	* - `0`: Linear squared rolloff.
	* - `1`: Linear rolloff.
	* - `2`: Inverse rolloff.
	* - `3`: Inverse squared rolloff.
	* - `4`: Custom rolloff.
	*/
	DISTANCEATTENUATION_ROLLOFFTYPE,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 10000.
	*
	* Minimum distance value for the distance attenuation curve.
	*/
	DISTANCEATTENUATION_MINDISTANCE,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 10000.
	*
	* Maximum distance value for the distance attenuation curve.
	*/
	DISTANCEATTENUATION_MAXDISTANCE,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 1.
	*
	* The low frequency (up to 800 Hz) EQ value for air absorption. Only used if \c APPLY_AIRABSORPTION is set to
	* \c 2. 0 = low frequencies are completely attenuated, 1 = low frequencies are not attenuated at all.
	*/
	AIRABSORPTION_LOW,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 1.
	*
	* The middle frequency (800 Hz - 8 kHz) EQ value for air absorption. Only used if \c APPLY_AIRABSORPTION is set
	* to \c 2. 0 = middle frequencies are completely attenuated, 1 = middle frequencies are not attenuated at all.
	*/
	AIRABSORPTION_MID,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 1.
	*
	* The high frequency (8 kHz and above) EQ value for air absorption. Only used if \c APPLY_AIRABSORPTION is set to
	* \c 2. 0 = high frequencies are completely attenuated, 1 = high frequencies are not attenuated at all.
	*/
	AIRABSORPTION_HIGH,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 1.
	*
	* The directivity attenuation value. Only used if \c APPLY_DIRECTIVITY is set to \c 2. 0 = sound is completely
	* attenuated, 1 = sound is not attenuated at all.
	*/
	DIRECTIVITY,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 1.
	*
	* Blends between monopole (omnidirectional) and dipole directivity patterns. 0 = pure monopole (sound is emitted
	* in all directions with equal intensity), 1 = pure dipole (sound is focused to the front and back of the source).
	* At 0.5, the source has a cardioid directivity, with most of the sound emitted to the front of the source. Only
	* used if \c APPLY_DIRECTIVITY is set to \c 1.
	*/
	DIRECTIVITY_DIPOLEWEIGHT,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 4.
	*
	* Controls how focused the dipole directivity is. Higher values result in sharper directivity patterns. Only used
	* if \c APPLY_DIRECTIVITY is set to \c 1.
	*/
	DIRECTIVITY_DIPOLEPOWER,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 1.
	*
	* The occlusion attenuation value. Only used if \c APPLY_OCCLUSION is set to \c 2. 0 = sound is completely
	* attenuated, 1 = sound is not attenuated at all.
	*/
	OCCLUSION,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_INT`
	*
	* **Range**: 0 to 1.
	*
	* Specifies how the transmission filter is applied.
	*
	* - `0`: Transmission is modeled as a single attenuation factor.
	* - `1`: Transmission is modeled as a 3-band EQ.
	*/
	TRANSMISSION_TYPE,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 1.
	*
	* The low frequency (up to 800 Hz) EQ value for transmission. Only used if \c APPLY_TRANSMISSION is set to \c 2.
	* 0 = low frequencies are completely attenuated, 1 = low frequencies are not attenuated at all.
	*/
	TRANSMISSION_LOW,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 1.
	*
	* The middle frequency (800 Hz to 8 kHz) EQ value for transmission. Only used if \c APPLY_TRANSMISSION is set to
	* \c 2. 0 = middle frequencies are completely attenuated, 1 = middle frequencies are not attenuated at all.
	*/
	TRANSMISSION_MID,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 1.
	*
	* The high frequency (8 kHz and above) EQ value for transmission. Only used if \c APPLY_TRANSMISSION is set to
	* \c 2. 0 = high frequencies are completely attenuated, 1 = high frequencies are not attenuated at all.
	*/
	TRANSMISSION_HIGH,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 1.
	*
	* The contribution of the direct sound path to the overall mix for this event. Lower values reduce the
	* contribution more.
	*/
	DIRECT_MIXLEVEL,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_BOOL`
	*
	* If true, applies HRTF-based 3D audio rendering to reflections. Results in an improvement in spatialization
	* quality when using convolution or hybrid reverb, at the cost of slightly increased CPU usage.
	*/
	REFLECTIONS_BINAURAL,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 10.
	*
	* The contribution of reflections to the overall mix for this event. Lower values reduce the contribution more.
	*/
	REFLECTIONS_MIXLEVEL,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_BOOL`
	*
	* If true, applies HRTF-based 3D audio rendering to pathing. Results in an improvement in spatialization
	* quality, at the cost of slightly increased CPU usage.
	*/
	PATHING_BINAURAL,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_FLOAT`
	*
	* **Range**: 0 to 10.
	*
	* The contribution of pathing to the overall mix for this event. Lower values reduce the contribution more.
	*/
	PATHING_MIXLEVEL,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_DATA`
	*
	* **DEPRECATED**
	*
	* Pointer to the `IPLSimulationOutputs` structure containing simulation results.
	*/
	SIMULATION_OUTPUTS,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_BOOL`
	*
	* If true, applies HRTF-based 3D audio rendering to the direct sound path. Otherwise, sound is panned based on
	* the speaker configuration.
	*/
	DIRECT_BINAURAL,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_DATA`
	*
	* (FMOD Studio 2.02+) The event's min/max distance range. Automatically set by FMOD Studio.
	*/
	DISTANCE_ATTENUATION_RANGE,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_INT`
	*
	* Handle of the `IPLSource` object to use for obtaining simulation results. The handle can
	* be obtained by calling `iplFMODAddSource`.
	*/
	SIMULATION_OUTPUTS_HANDLE,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_INT`
	*
	* **Range**: 0 to 2.
	*
	* Controls the output format.
	*
	* - `0`: Output will be the format in FMOD's mixer.
	* - `1`: Output will be the format from FMOD's final output.
	* - `2`: Output will be the format from the event's input.
	*/
	OUTPUT_FORMAT,
	/** The number of parameters in this effect. */
	NUM_PARAMS
	};

steam-audio/fmod/src/reverb_effect.cpp

Lines 26 to 51 in d747565

	enum Params
	{
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_BOOL`
	*
	* If true, applies HRTF-based 3D audio rendering to reverb. Results in an improvement in spatialization quality
	* when using convolution or hybrid reverb, at the cost of slightly increased CPU usage.
	*/
	BINAURAL,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_INT`
	*
	* **Range**: 0 to 2.
	*
	* Controls the output format.
	*
	* - `0`: Output will be the format in FMOD's mixer.
	* - `1`: Output will be the format from FMOD's final output.
	* - `2`: Output will be the format from the event's input.
	*/
	OUTPUT_FORMAT,
	/** The number of parameters in this effect. */
	NUM_PARAMS
	};

steam-audio/fmod/src/mix_return_effect.cpp

Lines 26 to 51 in d747565

	enum Params
	{
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_BOOL`
	*
	* If true, applies HRTF-based 3D audio rendering to mixed reflected sound. Results in an improvement in
	* spatialization quality, at the cost of slightly increased CPU usage.
	*/
	BINAURAL,
	/**
	* **Type**: `FMOD_DSP_PARAMETER_TYPE_INT`
	*
	* **Range**: 0 to 2.
	*
	* Controls the output format.
	*
	* - `0`: Output will be the format in FMOD's mixer.
	* - `1`: Output will be the format from FMOD's final output.
	* - `2`: Output will be the format from the event's input.
	*/
	OUTPUT_FORMAT,
	/** The number of parameters in this effect. */
	NUM_PARAMS
	};

These parameter enums aren't defined outside of their source cpp file, so they don't show up in doxygen:

In order to properly use SteamAudio's FMOD integration you have to set DSP parameters. Because SteamAudio doesn't expose its parameter indexes, they have to be hardcoded.
Even the Unity plugin does this:

steam-audio/unity/src/project/SteamAudioUnity/Assets/Plugins/SteamAudio/Scripts/FMODStudio/FMODStudioAudioEngineSource.cs

Line 33 in d747565

const int kSimulationOutputsParamIndex = 33;

Currently to get the parameter indexes you either have to dig through the SteamAudio source code or use FMOD::DSP::getParameterInfo

[lakulish]

@melody-rs Thanks for pointing this out, I've committed a fix for the issue. You can build the docs locally to see the fixed version, until the docs on the website are updated.

[melody-rs]

@lakulish That might've fixed the documentation, but that doesn't fix the issue of having to hardcode parameter indexes. They should be defined inside steamaudio_fmod.h as well, like FMOD does:

steam-audio/fmod/include/fmod/fmod_dsp_effects.h

Lines 342 to 368 in d747565

	typedef enum
	{
	FMOD_DSP_PAN_MODE,
	FMOD_DSP_PAN_2D_STEREO_POSITION,
	FMOD_DSP_PAN_2D_DIRECTION,
	FMOD_DSP_PAN_2D_EXTENT,
	FMOD_DSP_PAN_2D_ROTATION,
	FMOD_DSP_PAN_2D_LFE_LEVEL,
	FMOD_DSP_PAN_2D_STEREO_MODE,
	FMOD_DSP_PAN_2D_STEREO_SEPARATION,
	FMOD_DSP_PAN_2D_STEREO_AXIS,
	FMOD_DSP_PAN_ENABLED_SPEAKERS,
	FMOD_DSP_PAN_3D_POSITION,
	FMOD_DSP_PAN_3D_ROLLOFF,
	FMOD_DSP_PAN_3D_MIN_DISTANCE,
	FMOD_DSP_PAN_3D_MAX_DISTANCE,
	FMOD_DSP_PAN_3D_EXTENT_MODE,
	FMOD_DSP_PAN_3D_SOUND_SIZE,
	FMOD_DSP_PAN_3D_MIN_EXTENT,
	FMOD_DSP_PAN_3D_PAN_BLEND,
	FMOD_DSP_PAN_LFE_UPMIX_ENABLED,
	FMOD_DSP_PAN_OVERALL_GAIN,
	FMOD_DSP_PAN_SURROUND_SPEAKER_MODE,
	FMOD_DSP_PAN_2D_HEIGHT_BLEND,
	FMOD_DSP_PAN_ATTENUATION_RANGE,
	FMOD_DSP_PAN_OVERRIDE_RANGE
	} FMOD_DSP_PAN;

Also, open source distribution of the FMOD headers might not be allowed:
https://qa.fmod.com/t/distributing-fmod-headers/21708/5