Refactor/project maintainability cleanup

JammLab/Models/ScoreDocument.swift → JammLab/Models/NotationScoreModels.swift

@@ -1,27 +1,5 @@
 import Foundation
 
-struct ScoreDocument: Equatable {
-    var title: String?
-    var parts: [ScorePart]
-
-    init(title: String? = nil, parts: [ScorePart]) {
-        self.title = title
-        self.parts = parts
-    }
-}
-
-struct ScorePart: Equatable, Identifiable {
-    var id: String
-    var name: String
-    var measures: [ScoreMeasure]
-
-    init(id: String = "P1", name: String = "Notation", measures: [ScoreMeasure]) {
-        self.id = id
-        self.name = name
-        self.measures = measures
-    }
-}
-
 struct ScoreMeasure: Equatable, Identifiable {
     var number: Int
     var startTime: TimeInterval

JammLab/Services/AudioSampleConverter.swift

@@ -0,0 +1,60 @@
+import AVFoundation
+
+enum AudioSampleConverter {
+    static func monoFloatSamples(from buffer: AVAudioPCMBuffer) -> [Float]? {
+        let frameLength = Int(buffer.frameLength)
+        let channelCount = Int(buffer.format.channelCount)
+        guard frameLength > 0, channelCount > 0 else { return [] }
+        guard buffer.format.commonFormat == .pcmFormatFloat32 else { return nil }
+
+        if buffer.format.isInterleaved {
+            return interleavedMonoFloatSamples(from: buffer, frameLength: frameLength, channelCount: channelCount)
+        }
+
+        return nonInterleavedMonoFloatSamples(from: buffer, frameLength: frameLength, channelCount: channelCount)
+    }
+
+    private static func nonInterleavedMonoFloatSamples(
+        from buffer: AVAudioPCMBuffer,
+        frameLength: Int,
+        channelCount: Int
+    ) -> [Float]? {
+        guard let channels = buffer.floatChannelData else { return nil }
+
+        var mono = Array(repeating: Float(0), count: frameLength)
+        for channel in 0..<channelCount {
+            let data = channels[channel]
+            for index in 0..<frameLength {
+                mono[index] += data[index] / Float(channelCount)
+            }
+        }
+
+        return mono
+    }
+
+    private static func interleavedMonoFloatSamples(
+        from buffer: AVAudioPCMBuffer,
+        frameLength: Int,
+        channelCount: Int
+    ) -> [Float]? {
+        let audioBuffers = UnsafeMutableAudioBufferListPointer(buffer.mutableAudioBufferList)
+        guard let audioBuffer = audioBuffers.first,
+              let data = audioBuffer.mData else {
+            return nil
+        }
+
+        let sampleCount = frameLength * channelCount
+        let interleaved = data.bindMemory(to: Float.self, capacity: sampleCount)
+        var mono = Array(repeating: Float(0), count: frameLength)
+        for frame in 0..<frameLength {
+            let frameOffset = frame * channelCount
+            var sum: Float = 0
+            for channel in 0..<channelCount {
+                sum += interleaved[frameOffset + channel]
+            }
+            mono[frame] = sum / Float(channelCount)
+        }
+
+        return mono
+    }
+}