channel - YoYoGames/GMEXT-FMOD GitHub Wiki

Channel

FMOD Object: Channel


This module holds functionality related to Channels, which are a source of audio signal that connects to the ChannelGroup mixing hierarchy.

Create a channel with fmod_system_play_sound or fmod_system_play_dsp.

Functions

This module offers a collection of functions designed to address specific tasks and provide utilities for various purposes. Explore the available functions to make the most of the functionalities provided by this module.


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fmod_channel_set_frequency

🔗 External: False

FMOD Function: Channel::setFrequency


This function sets the frequency or playback rate.

Note

The default frequency is determined by the audio format of the Sound or DSP.

Note

Sounds opened as FMOD_MODE.CREATESAMPLE (not FMOD_MODE.CREATESTREAM or FMOD_MODE.CREATECOMPRESSEDSAMPLE) can be played backwards by giving a negative frequency.


Syntax:

fmod_channel_set_frequency(channel_ref, frequency)
Argument Type Description
channel_ref Real A reference to a channel.
frequency Real The playback rate, expressed in Hertz.



Returns:

N/A



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fmod_channel_get_frequency

🔗 External: False

FMOD Function: Channel::getFrequency


This function retrieves the playback frequency or playback rate.


Syntax:

fmod_channel_get_frequency(channel_ref)
Argument Type Description
channel_ref Real A reference to a channel.



Returns:

Real



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fmod_channel_set_priority

🔗 External: False

FMOD Function: Channel::setPriority


This function sets the priority used for virtual voice ordering.

Note

Priority is used as a coarse grain control for the virtual voice system, lower priority channels will always be stolen before higher ones. For channels of equal priority, those with the quietest fmod_channel_control_get_audibility value will be stolen first.

See the FMOD Virtual Voices guide for more information.


Syntax:

fmod_channel_set_priority(channel_ref, priority)
Argument Type Description
channel_ref Real A reference to a channel.
priority Real The priority value where 0 represents most important and 256 represents least important. The default is 128.



Returns:

N/A



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fmod_channel_get_priority

🔗 External: False

FMOD Function: Channel::getPriority


This function retrieves the priority used for virtual voice ordering.

The function returns the priority value where 0 represents most important and 256 represents least important.

Note

Priority is used as a coarse grain control for the virtual voice system, lower priority channels will always be stolen before higher ones. For channels of equal priority, those with the quietest fmod_channel_control_get_audibility value will be stolen first.


Syntax:

fmod_channel_get_priority(channel_ref)
Argument Type Description
channel_ref Real A reference to a channel.



Returns:

Real

priority



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fmod_channel_set_position

🔗 External: False

FMOD Function: Channel::setPosition


This function sets the current playback position.

Note

Certain FMOD_TIMEUNIT types are always available: FMOD_TIMEUNIT.PCM, FMOD_TIMEUNIT.PCMBYTES and FMOD_TIMEUNIT.MS. The others are format specific such as FMOD_TIMEUNIT.MODORDER / FMOD_TIMEUNIT.MODROW / FMOD_TIMEUNIT.MODPATTERN which is specific to files of type MOD / S3M / XM / IT.

Note

If playing a Sound created with fmod_system_create_stream or FMOD_MODE.CREATESTREAM changing the position may cause a slow reflush operation while the file seek and decode occurs. You can avoid this by creating the stream with FMOD_MODE.NONBLOCKING. This will cause the stream to go into FMOD_OPENSTATE.SETPOSITION state (see fmod_sound_get_open_state) and Sound commands will return FMOD_RESULT.ERR_NOTREADY. fmod_channel_get_position will also not update until this non-blocking set position operation has completed.

Note

Using a VBR source that does not have an associated seek table or seek information (such as MP3 or MOD/S3M/XM/IT) may cause inaccurate seeking if you specify FMOD_TIMEUNIT.MS or FMOD_TIMEUNIT.PCM. If you want FMOD to create a PCM vs bytes seek table so that seeking is accurate, you will have to specify FMOD_MODE.ACCURATETIME when loading or opening the sound. This means there is a slight delay as FMOD scans the whole file when loading the sound to create this table.


Syntax:

fmod_channel_set_position(channel_ref, position, time_unit)
Argument Type Description
channel_ref Real A reference to a channel.
position Real The playback position.
time_unit FMOD_TIMEUNIT The time units in which the position parameter is expressed.



Returns:

N/A



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fmod_channel_get_position

🔗 External: False

FMOD Function: Channel::getPosition


This function retrieves the current playback position.

Note

Certain FMOD_TIMEUNIT types are always available: FMOD_TIMEUNIT.PCM, FMOD_TIMEUNIT.PCMBYTES and FMOD_TIMEUNIT.MS. The others are format specific such as FMOD_TIMEUNIT.MODORDER / FMOD_TIMEUNIT.MODROW / FMOD_TIMEUNIT.MODPATTERN which is specific to files of type MOD / S3M / XM / IT.

Note

If FMOD_TIMEUNIT.MS or FMOD_TIMEUNIT.PCMBYTES are used, the value is internally converted from FMOD_TIMEUNIT.PCM, so the retrieved value may not exactly match the set value.


Syntax:

fmod_channel_get_position(channel_ref, time_unit)
Argument Type Description
channel_ref Real A reference to a channel.
time_unit FMOD_TIMEUNIT The time units in which the position parameter is expressed.



Returns:

Real



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fmod_channel_set_channel_group

🔗 External: False

FMOD Function: Channel::setChannelGroup


This function sets the channelgroup this object outputs to.

Note

A channelgroup may contain many channels.

Note

Channels may only output to a single channelgroup. This operation will remove it from the previous group first.


Syntax:

fmod_channel_set_channel_group(channel_ref, channel_group_ref)
Argument Type Description
channel_ref Real A reference to a channel.
channel_group_ref Real A reference to the channelgroup to use as the output group.



Returns:

N/A



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fmod_channel_get_channel_group

🔗 External: False

FMOD Function: Channel::getChannelGroup


This function retrieves the ChannelGroup this object outputs to.


Syntax:

fmod_channel_get_channel_group(channel_ref)
Argument Type Description
channel_ref Real A reference to a channel.



Returns:

Real



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fmod_channel_set_loop_count

🔗 External: False

FMOD Function: Channel::setLoopCount


This function sets the number of times to loop before stopping.

Note

The 'mode' of the sound or channel must be FMOD_MODE.LOOP_NORMAL or FMOD_MODE.LOOP_BIDI for this function to work.


Syntax:

fmod_channel_set_loop_count(channel_ref, loop_count)
Argument Type Description
channel_ref Real A reference to a channel.
loop_count Real The number of times to loop before stopping where 0 represents "oneshot", 1 represents "loop once then stop" and -1 represents "loop forever".



Returns:

N/A



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fmod_channel_get_loop_count

🔗 External: False

FMOD Function: Channel::getLoopCount


This function retrieves the number of times to loop before stopping.

The returned value is the times to loop before stopping where 0 represents "oneshot", 1 represents "loop once then stop" and -1 represents "loop forever".

Note

This is the current loop countdown value that will decrement as it plays until reaching 0. You can reset it with fmod_channel_set_loop_count.


Syntax:

fmod_channel_get_loop_count(channel_ref)
Argument Type Description
channel_ref Real A reference to a channel.



Returns:

Real



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fmod_channel_set_loop_points

🔗 External: False

FMOD Function: Channel::setLoopPoints


This function sets the loop start and end points.

Loop points may only be set on a channel playing a sound, not a channel playing a DSP (See fmod_system_play_dsp).

Note

Valid FMOD_TIMEUNIT types are FMOD_TIMEUNIT.PCM, FMOD_TIMEUNIT.MS, FMOD_TIMEUNIT.PCMBYTES. Any other time units return FMOD_RESULT.ERR_FORMAT. If FMOD_TIMEUNIT.MS or FMOD_TIMEUNIT.PCMBYTES are used, the value is internally converted from FMOD_TIMEUNIT.PCM, so the retrieved value may not exactly match the set value.

The Channel's mode must be set to FMOD_MODE.LOOP_NORMAL or FMOD_MODE.LOOP_BIDI for loop points to affect playback.

See also: Streaming Issues


Syntax:

fmod_channel_set_loop_points(channel_ref, loop_start, loop_start_type, loop_end, loop_end_type)
Argument Type Description
channel_ref Real A reference to a channel.
loop_start Real The loop start point.
loop_start_type FMOD_TIMEUNIT The time units in which the loop_start parameter is expressed.
loop_end Real The loop end point.
loop_end_type FMOD_TIMEUNIT The time units in which the loop_end parameter is expressed.



Returns:

N/A



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fmod_channel_get_loop_points

🔗 External: False

FMOD Function: Channel::getLoopPoints


This function retrieves the loop start and end points.

Note

Valid FMOD_TIMEUNIT types are FMOD_TIMEUNIT.PCM, FMOD_TIMEUNIT.MS, FMOD_TIMEUNIT.PCMBYTES. For all other time units fmod_last_result returns FMOD_RESULT.ERR_FORMAT. If FMOD_TIMEUNIT.MS or FMOD_TIMEUNIT.PCMBYTES are used, the value is internally converted from FMOD_TIMEUNIT.PCM, so the retrieved value may not exactly match the set value.


Syntax:

fmod_channel_get_loop_points(channel_ref, loop_start_type, loop_end_type)
Argument Type Description
channel_ref Real A reference to a channel.
loop_start_type FMOD_TIMEUNIT The time units in which to return loop_start
loop_end_type FMOD_TIMEUNIT The time units in which to return loop_end



Returns:

FmodLoopPoints



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fmod_channel_is_virtual

🔗 External: False

FMOD Function: Channel::isVirtual


This function retrieves whether the channel is being emulated by the virtual voice system.

If true is returned, the channel is silent / emulated. If false is returned, the channel is audible / real.

See the FMOD Virtual Voices guide for more information.


Syntax:

fmod_channel_is_virtual(channel_ref)
Argument Type Description
channel_ref Real A reference to a channel.



Returns:

Boolean



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fmod_channel_get_current_sound

🔗 External: False

FMOD Function: Channel::getCurrentSound


This function retrieves the currently playing sound.

Note

The function may return 0 if no sound is playing.


Syntax:

fmod_channel_get_current_sound(channel_ref)
Argument Type Description
channel_ref Real A reference to a channel.



Returns:

Real



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fmod_channel_get_index

🔗 External: False

FMOD Function: Channel::getIndex


This function retrieves the index of this object in the system channel pool.

Note

This value is in the range [0, max_channels value passed to fmod_system_init - 1].


Syntax:

fmod_channel_get_index(channel_ref)
Argument Type Description
channel_ref Real A reference to a channel.



Returns:

Real



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fmod_channel_get_system_object

🔗 External: False

FMOD Function: ChannelControl::getSystemObject


This function retrieves the system that created this object.


Syntax:

fmod_channel_get_system_object(channel_ref)
Argument Type Description
channel_ref Real A reference to a channel.



Returns:

Real



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