NAME

       SDL_SetAudioStreamInputChannelMap - Set the current input channel map of an audio stream.

SYNOPSIS

       #include <SDL3/SDL_audio.h>

       bool SDL_SetAudioStreamInputChannelMap(SDL_AudioStream *stream, const int *chmap, int count);

DESCRIPTION

       Channel  maps  are  optional;  most  things do not need them, instead passing data in the [order that SDL
       expects](CategoryAudio#channel-layouts).

       The input channel map reorders data that is added to a stream via SDL_PutAudioStreamData.   Future  calls
       to SDL_PutAudioStreamData must provide data in the new channel order.

       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.

       Data  that  was  previously  queued in the stream will still be operated on in the order that was current
       when it was added, which is to say you can put the end of a sound file in one order to a  stream,  change
       orders  for  the  next sound file, and start putting that new data while the previous sound file is still
       queued, and everything will still play back correctly.

       Audio streams default to no remapping applied. Passing a  NULL  channel  map  is  legal,  and  turns  off
       remapping.

       SDL will copy the channel map; the caller does not have to save this array after this call.

       If  count  is  not  equal to the current number of channels in the audio stream's format, this will fail.
       This is a safety measure to make sure a race condition hasn't changed  the  format  while  this  call  is
       setting the channel map.

       Unlike  attempting  to change the stream's format, the input channel map on a stream bound to a recording
       device is permitted to change at any time; any data added to the stream from the device after  this  call
       will have the new mapping, but previously-added data will still have the prior mapping.

FUNCTION PARAMETERS

       stream the SDL_AudioStream to change.

       chmap  the new channel map, NULL to reset to default.

       count  The number of channels in the map.

RETURN VALUE

       for more information.

THREAD SAFETY

       It  is  safe  to  call  this function from any thread, as it holds a stream-specific mutex while running.
       Don't change the stream's format to have a different number of channels from a a different thread at  the
       same time, though!

AVAILABILITY

       This function is available since SDL 3.2.0.

SEE ALSO

       SDL_SetAudioStreamInputChannelMap(3)

Simple Directmedia Layer                           SDL 3.2.20               SDL_SetAudioStreamInputChannelMap(3)