diff -ruN /Applications/Xcode_26.0.0-beta2.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/Frameworks/AudioToolbox.framework/Headers/AudioConverter.h /Applications/Xcode_26.0.0-beta3.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/Frameworks/AudioToolbox.framework/Headers/AudioConverter.h --- /Applications/Xcode_26.0.0-beta2.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/Frameworks/AudioToolbox.framework/Headers/AudioConverter.h	2025-06-18 05:41:46 +++ /Applications/Xcode_26.0.0-beta3.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/Frameworks/AudioToolbox.framework/Headers/AudioConverter.h	2025-06-28 10:08:50 @@ -190,6 +190,30 @@ outPropertyData is sizeof(AudioFormatListItem), then only the best format is returned. This property may be used for example to discover all the data formats produced by the AAC_HE2 (AAC High Efficiency vers. 2) encoder. + @constant kAudioConverterPropertyPerformDownmix + A UInt32 with 1 meaning to perform a mix from input to output channels, + and 0 meaning to not perform such a mix. See kAudioConverterPropertyChannelMixMap + for more information on how the mix maps inputs to outputs. + Defaults to 0 (no channel mixing). + Note #1: Mixing may be performed in any conversion where the number + and/or layout of input and output channels are not the same, not only + in PCM-to-PCM conversions, and also the number of output channels may + be more or less than the number of input channels. + Note #2: This property is not compatible with kAudioConverterChannelMap, + which is used to map input to output channels without any mixing. + The kAudioConverterChannelMap property cannot be set unless + kAudioConverterPropertyPerformDownmix is first set to 0. + @constant kAudioConverterPropertyChannelMixMap + An array of Float32 values, size equal to the product of the numbers of + input and output channels. Each element's value is a gain to apply, + from 0.0 to 1.0, to one input when mixing it into one output. + The elements are ordered in row-major order, where each row holds the + gains to apply for one input to each output. + Unless explicitly set, a default mix map is used, based on other + properties such as numbers of input and output channels as well as + channel layouts, if known. + This property should not be set unless and until + kAudioConverterPropertyPerformDownmix is first set to 1 (enable channel mixing). */ CF_ENUM(AudioConverterPropertyID) { @@ -223,7 +247,9 @@ kAudioConverterCurrentInputStreamDescription = 'acid', kAudioConverterPropertySettings = 'acps', kAudioConverterPropertyBitDepthHint = 'acbd', - kAudioConverterPropertyFormatList = 'flst' + kAudioConverterPropertyFormatList = 'flst', + kAudioConverterPropertyPerformDownmix = 'dmix', + kAudioConverterPropertyChannelMixMap = 'mmap' }; #if !TARGET_OS_IPHONE