###### (This function is part of SDL_mixer, a separate library from SDL.) # MIX_SetTrackOutputChannelMap Set the current output channel map of a track. ## Header File Defined in [](https://github.com/libsdl-org/SDL_mixer/blob/main/include/SDL3_mixer/SDL_mixer.h) ## Syntax ```c bool MIX_SetTrackOutputChannelMap(MIX_Track *track, const int *chmap, int count); ``` ## Function Parameters | | | | | ------------------------ | --------- | ---------------------------------------------- | | [MIX_Track](MIX_Track) * | **track** | the track to change. | | const int * | **chmap** | the new channel map, NULL to reset to default. | | int | **count** | The number of channels in the map. | ## Return Value (bool) Returns true on success or false on failure; call SDL_GetError() for more information. ## Remarks Channel maps are optional; most things do not need them, instead passing data in the order that SDL expects. The output channel map reorders track data after transformations and before it is mixed into a mixer group. This can be useful for reversing stereo channels, for example. Each item in the array represents an input channel, and its value is the channel that it should be remapped to. To reverse a stereo signal's left and right values, you'd have an array of `{ 1, 0 }`. It is legal to remap multiple channels to the same thing, so `{ 1, 1 }` would duplicate the right channel to both channels of a stereo signal. An element in the channel map set to -1 instead of a valid channel will mute that channel, setting it to a silence value. You cannot change the number of channels through a channel map, just reorder/mute them. Tracks default to no remapping applied. Passing a NULL channel map is legal, and turns off remapping. SDL_mixer will copy the channel map; the caller does not have to save this array after this call. ## Thread Safety It is safe to call this function from any thread. ## Version This function is available since SDL_mixer 3.0.0. ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategorySDLMixer](CategorySDLMixer)