AEMeteringModule.h/.m

TheAmazingAudioEngine.xcodeproj/project.pbxproj

@@ -285,6 +285,12 @@
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+		B30958101DA2A59C00F07FB6 /* AEMeteringModule.h in Headers */ = {isa = PBXBuildFile; fileRef = B32E7E541DA2A15C00C91264 /* AEMeteringModule.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		B30958111DA2A5A000F07FB6 /* AEMeteringModule.h in Headers */ = {isa = PBXBuildFile; fileRef = B32E7E541DA2A15C00C91264 /* AEMeteringModule.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		B30958121DA2A5A400F07FB6 /* AEMeteringModule.h in Headers */ = {isa = PBXBuildFile; fileRef = B32E7E541DA2A15C00C91264 /* AEMeteringModule.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		B32E7E591DA2A15C00C91264 /* AEMeteringModule.m in Sources */ = {isa = PBXBuildFile; fileRef = B32E7E551DA2A15C00C91264 /* AEMeteringModule.m */; };
+		B32E7E5A1DA2A15C00C91264 /* AEMeteringModule.m in Sources */ = {isa = PBXBuildFile; fileRef = B32E7E551DA2A15C00C91264 /* AEMeteringModule.m */; };
+		B32E7E5B1DA2A15C00C91264 /* AEMeteringModule.m in Sources */ = {isa = PBXBuildFile; fileRef = B32E7E551DA2A15C00C91264 /* AEMeteringModule.m */; };
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@@ -435,6 +441,8 @@
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+		B32E7E541DA2A15C00C91264 /* AEMeteringModule.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = AEMeteringModule.h; sourceTree = "<group>"; };
+		B32E7E551DA2A15C00C91264 /* AEMeteringModule.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = AEMeteringModule.m; sourceTree = "<group>"; };
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 /* Begin PBXFrameworksBuildPhase section */
@@ -475,6 +483,8 @@
 			children = (
 				4C94E2A31CAE6AFF006EB497 /* AEAudioFileRecorderModule.h */,
 				4C94E2A41CAE6AFF006EB497 /* AEAudioFileRecorderModule.m */,
+				B32E7E541DA2A15C00C91264 /* AEMeteringModule.h */,
+				B32E7E551DA2A15C00C91264 /* AEMeteringModule.m */,
 			);
 			path = Taps;
 			sourceTree = "<group>";
@@ -695,6 +705,7 @@
 				4CB2F2EE1D49ABC6008F745F /* AEManagedValue.h in Headers */,
 				4CE5F4C51CD30A1900322F03 /* AEMainThreadEndpoint.h in Headers */,
 				4C7756A11CD2E5E3004415A2 /* AECircularBuffer.h in Headers */,
+				B30958111DA2A5A000F07FB6 /* AEMeteringModule.h in Headers */,
 				4C9F0F561CB265F90032903E /* AEModule.h in Headers */,
 				4CBCF29F1CFBC3D200CA2EA0 /* AESplitterModule.h in Headers */,
 				4CB2F2E81D49ABC6008F745F /* AEBufferStack.h in Headers */,
@@ -745,6 +756,7 @@
 				4CB2F2EF1D49ABC6008F745F /* AEManagedValue.h in Headers */,
 				4CE5F4C61CD30A1900322F03 /* AEMainThreadEndpoint.h in Headers */,
 				4C7756A21CD2E5E3004415A2 /* AECircularBuffer.h in Headers */,
+				B30958121DA2A5A400F07FB6 /* AEMeteringModule.h in Headers */,
 				4C9F0F9F1CB269C30032903E /* AEModule.h in Headers */,
 				4CBCF2A01CFBC3D200CA2EA0 /* AESplitterModule.h in Headers */,
 				4CB2F2E91D49ABC6008F745F /* AEBufferStack.h in Headers */,
@@ -809,6 +821,7 @@
 				4CDCAD8E1CA5484D008AAEF1 /* AEReverbModule.h in Headers */,
 				4CDCAD531CA3D223008AAEF1 /* AEOscillatorModule.h in Headers */,
 				4CDCAD8A1CA5484D008AAEF1 /* AEParametricEqModule.h in Headers */,
+				B30958101DA2A59C00F07FB6 /* AEMeteringModule.h in Headers */,
 				4CB2F2ED1D49ABC6008F745F /* AEManagedValue.h in Headers */,
 				4CB2F2E11D49ABC6008F745F /* AEArray.h in Headers */,
 				4CDCAD801CA5484D008AAEF1 /* AEHighPassModule.h in Headers */,
@@ -986,6 +999,7 @@
 				4C9F0F3D1CB265F90032903E /* AEAudioUnitOutput.m in Sources */,
 				4C9F0F3E1CB265F90032903E /* AELowPassModule.m in Sources */,
 				4C9F0F3F1CB265F90032903E /* AEHighPassModule.m in Sources */,
+				B32E7E5A1DA2A15C00C91264 /* AEMeteringModule.m in Sources */,
 				4C9F0F401CB265F90032903E /* AEVarispeedModule.m in Sources */,
 				4C9F0F411CB265F90032903E /* AEBandpassModule.m in Sources */,
 				4C9F0F421CB265F90032903E /* AEAudioFileRecorderModule.m in Sources */,
@@ -1038,6 +1052,7 @@
 				4C9F0F871CB269C30032903E /* AEAudioUnitOutput.m in Sources */,
 				4C9F0F881CB269C30032903E /* AELowPassModule.m in Sources */,
 				4C9F0F891CB269C30032903E /* AEHighPassModule.m in Sources */,
+				B32E7E5B1DA2A15C00C91264 /* AEMeteringModule.m in Sources */,
 				4C9F0F8A1CB269C30032903E /* AEVarispeedModule.m in Sources */,
 				4C9F0F8B1CB269C30032903E /* AEBandpassModule.m in Sources */,
 				4C9F0F8C1CB269C30032903E /* AEAudioFileRecorderModule.m in Sources */,
@@ -1094,6 +1109,7 @@
 				4CDCAD911CA5484D008AAEF1 /* AEVarispeedModule.m in Sources */,
 				4CDCAD791CA5484D008AAEF1 /* AEBandpassModule.m in Sources */,
 				4C94E2A61CAE6AFF006EB497 /* AEAudioFileRecorderModule.m in Sources */,
+				B32E7E591DA2A15C00C91264 /* AEMeteringModule.m in Sources */,
 				4CDCADA11CA90FD3008AAEF1 /* AEAudioFilePlayerModule.m in Sources */,
 				4CDCAD481CA3C31C008AAEF1 /* AEUtilities.m in Sources */,
 				4CE5F4D11CD3169C00322F03 /* AEAudioThreadEndpoint.m in Sources */,

TheAmazingAudioEngine/Modules/Taps/AEMeteringModule.h

@@ -0,0 +1,50 @@
+//
+//  AEMeteringModule.h
+//  TheAmazingAudioEngine
+//
+//  Created by Leo Thiessen on 2016-04-14.
+//  Copyright © 2016 A Tasty Pixel. All rights reserved.
+//
+//  This software is provided 'as-is', without any express or implied
+//  warranty.  In no event will the authors be held liable for any damages
+//  arising from the use of this software.
+//
+//  Permission is granted to anyone to use this software for any purpose,
+//  including commercial applications, and to alter it and redistribute it
+//  freely, subject to the following restrictions:
+//
+//  1. The origin of this software must not be misrepresented; you must not
+//     claim that you wrote the original software. If you use this software
+//     in a product, an acknowledgment in the product documentation would be
+//     appreciated but is not required.
+//
+//  2. Altered source versions must be plainly marked as such, and must not be
+//     misrepresented as being the original software.
+//
+//  3. This notice may not be removed or altered from any source distribution.
+//
+
+#import "AEModule.h"
+
+typedef struct {
+    float average;
+    float peak;
+} AEMeteringChannelLevels;
+
+typedef struct {
+    int maxChannel;
+    AEMeteringChannelLevels * _Nullable channels;
+} AEMeteringLevels;
+
+@interface AEMeteringModule : AEModule
+
+/*! Initialize with 2 channels. */
+- (instancetype _Nullable)initWithRenderer:(AERenderer * _Nullable)renderer;
+
+/*! Initialize with 1-n number of channels. */
+- (instancetype _Nullable)initWithRenderer:(AERenderer * _Nullable)renderer maxChannel:(int)maxChannel;
+
+/*! Obtain average & peak levels, per channel, since the last access to this property. */
+@property (nonatomic, readonly) AEMeteringLevels * _Nonnull levels;
+
+@end

TheAmazingAudioEngine/Modules/Taps/AEMeteringModule.m

@@ -0,0 +1,141 @@
+//
+//  AEMeteringModule.m
+//  TheAmazingAudioEngine
+//
+//  Created by Leo Thiessen on 2016-04-14.
+//  Copyright © 2016 A Tasty Pixel. All rights reserved.
+//
+//  This software is provided 'as-is', without any express or implied
+//  warranty.  In no event will the authors be held liable for any damages
+//  arising from the use of this software.
+//
+//  Permission is granted to anyone to use this software for any purpose,
+//  including commercial applications, and to alter it and redistribute it
+//  freely, subject to the following restrictions:
+//
+//  1. The origin of this software must not be misrepresented; you must not
+//     claim that you wrote the original software. If you use this software
+//     in a product, an acknowledgment in the product documentation would be
+//     appreciated but is not required.
+//
+//  2. Altered source versions must be plainly marked as such, and must not be
+//     misrepresented as being the original software.
+//
+//  3. This notice may not be removed or altered from any source distribution.
+//
+
+#import "AEMeteringModule.h"
+@import Accelerate;
+
+/*!
+ * Audio level metering data
+ */
+typedef struct __audio_meters_t {
+    int      maxChannel;
+    int      capacity;
+    double * chanMeanAccumulator;
+    int      chanMeanBlockCount;
+    float *  chanPeak;
+    float *  chanAverage;
+    BOOL     reset;
+} audio_meters_t;
+
+@interface AEMeteringModule () {
+    AEMeteringLevels levelsStruct;
+    audio_meters_t   metersStruct;
+}
+@end
+
+@implementation AEMeteringModule
+
+- (instancetype _Nullable)initWithRenderer:(AERenderer * _Nullable)renderer {
+    if ( !(self = [super initWithRenderer:renderer]) ) {
+        return nil;
+    }
+    [self _setupWithMaxChannel:2]; // default of 2 channels, aka "stereo"
+    return self;
+}
+
+- (instancetype _Nullable)initWithRenderer:(AERenderer * _Nullable)renderer maxChannel:(int)maxChannel {
+    if ( maxChannel < 1 || !(self = [super initWithRenderer:renderer]) ) {
+        return nil;
+    }
+    [self _setupWithMaxChannel:maxChannel];
+    return self;
+}
+
+- (void)_setupWithMaxChannel:(int)maxChannel {
+    metersStruct.maxChannel          = maxChannel;
+    metersStruct.capacity            = maxChannel;
+    metersStruct.chanMeanAccumulator = calloc(maxChannel, sizeof(double));
+    metersStruct.chanMeanBlockCount  = 0;
+    metersStruct.chanPeak            = calloc(maxChannel, sizeof(float));
+    metersStruct.chanAverage         = calloc(maxChannel, sizeof(float));
+    metersStruct.reset               = NO;
+
+    levelsStruct.maxChannel = maxChannel;
+    levelsStruct.channels   = calloc(maxChannel, sizeof(AEMeteringChannelLevels));
+
+    self.processFunction = AEMeteringModuleProcess;
+}
+
+- (void)dealloc {
+    if ( levelsStruct.channels ) {
+        free(levelsStruct.channels);
+    }
+    free(metersStruct.chanMeanAccumulator);
+    free(metersStruct.chanPeak);
+    free(metersStruct.chanAverage);
+}
+
+- (void)rendererDidChangeNumberOfChannels {
+    int newChannelCount = self.renderer.numberOfOutputChannels;
+    if ( newChannelCount <= metersStruct.capacity ) {
+        metersStruct.maxChannel = newChannelCount;
+        levelsStruct.maxChannel  = newChannelCount;
+        if ( levelsStruct.channels ) {
+            for ( int i = newChannelCount; i < metersStruct.capacity; ++i ) { // Zero out any unused capacity
+                levelsStruct.channels[i].average = 0;
+                levelsStruct.channels[i].peak = 0;
+            }
+        }
+    }
+}
+
+- (AEMeteringLevels * _Nonnull)levels {
+    if ( levelsStruct.channels ) {
+        for ( int i = 0; i < metersStruct.maxChannel; ++i ) {
+            levelsStruct.channels[i].average = metersStruct.chanAverage[i];
+            levelsStruct.channels[i].peak = metersStruct.chanPeak[i];
+        }
+        metersStruct.reset = YES;
+    }
+    return &levelsStruct;
+}
+
+static void AEMeteringModuleProcess(__unsafe_unretained AEMeteringModule * self,
+                                    const AERenderContext * _Nonnull context) {
+    const AudioBufferList * abl = AEBufferStackGet(context->stack, 0);
+    if ( !abl ) return;
+
+    if ( self->metersStruct.reset ) {
+        self->metersStruct.reset = NO;
+        self->metersStruct.chanMeanBlockCount = 0;
+        vDSP_vclr(self->metersStruct.chanPeak, 1, self->metersStruct.capacity);
+        vDSP_vclr(self->metersStruct.chanAverage, 1, self->metersStruct.capacity);
+        vDSP_vclrD(self->metersStruct.chanMeanAccumulator, 1, self->metersStruct.capacity);
+    }
+
+    float peak, avg;
+    for ( int i = 0; i < abl->mNumberBuffers && i < self->metersStruct.maxChannel; ++i ) {
+        peak = 0, avg = 0;
+        vDSP_maxmgv((float*)abl->mBuffers[i].mData, 1, &peak, context->frames);
+        if ( peak > self->metersStruct.chanPeak[i] ) { self->metersStruct.chanPeak[i] = peak; }
+        vDSP_meamgv((float*)abl->mBuffers[i].mData, 1, &avg, context->frames);
+        self->metersStruct.chanMeanAccumulator[i] += avg;
+        if ( i == 0 ) { self->metersStruct.chanMeanBlockCount++; }
+        self->metersStruct.chanAverage[i] = self->metersStruct.chanMeanAccumulator[i] / (double)self->metersStruct.chanMeanBlockCount;
+    }
+}
+
+@end

TheAmazingAudioEngine/TheAmazingAudioEngine.h

@@ -52,6 +52,7 @@ extern "C" {
 #import <TheAmazingAudioEngine/AEPeakLimiterModule.h>
 #import <TheAmazingAudioEngine/AEVarispeedModule.h>
 #import <TheAmazingAudioEngine/AEAudioFileRecorderModule.h>
+#import <TheAmazingAudioEngine/AEAudioMeteringModule.h>
 #if TARGET_OS_IPHONE
 #import <TheAmazingAudioEngine/AEReverbModule.h>
 #endif
@@ -350,4 +351,4 @@ extern "C" {
 
 #ifdef __cplusplus
 }
-#endif
+#endif