TimecodeInterval: Added init(cmTime:) and cmTime property

Sources/TimecodeKit/TimecodeInterval/TimecodeInterval Rational CMTime.swift

@@ -0,0 +1,35 @@
+//
+//  TimecodeInterval Rational CMTime.swift
+//  TimecodeKit • https://github.com/orchetect/TimecodeKit
+//  © 2022 Steffan Andrews • Licensed under MIT License
+//
+
+#if canImport(CoreMedia)
+
+import Foundation
+import CoreMedia
+
+@available(macOS 10.7, iOS 4.0, tvOS 9.0, watchOS 6.0, *)
+extension TimecodeInterval {
+    /// Initialize from a time duration represented as a rational fraction.
+    /// A negative fraction will produce a negative time interval.
+    ///
+    /// - Throws: ``ValidationError``
+    public init(
+        _ cmTime: CMTime,
+        at rate: TimecodeFrameRate,
+        limit: Timecode.UpperLimit = ._24hours,
+        base: Timecode.SubFramesBase = .default(),
+        format: Timecode.StringFormat = .default()
+    ) throws {
+        let fraction = Fraction(cmTime)
+        try self.init(fraction, at: rate, limit: limit, base: base, format: format)
+    }
+
+    /// Returns the rational fraction for the timecode interval as `CMTime`.
+    public var cmTime: CMTime {
+        CMTime(rationalValue)
+    }
+}
+
+#endif

Tests/TimecodeKit-Unit-Tests/Unit Tests/TimecodeInterval/TimecodeInterval Rational CMTime Tests.swift

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+//
+//  TimecodeInterval Rational CMTime Tests.swift
+//  TimecodeKit • https://github.com/orchetect/TimecodeKit
+//  © 2022 Steffan Andrews • Licensed under MIT License
+//
+
+#if shouldTestCurrentPlatform
+
+import XCTest
+@testable import TimecodeKit
+import CoreMedia
+
+class TimecodeInterval_Rational_CMTime_Tests: XCTestCase {
+    override func setUp() { }
+    override func tearDown() { }
+
+    func testTimecodeInterval_init_cmTime() throws {
+        let ti = try TimecodeInterval(
+            CMTime(value: 60, timescale: 30),
+            at: ._24
+        )
+
+        XCTAssertEqual(ti.sign, .plus)
+
+        XCTAssertEqual(
+            ti.absoluteInterval,
+            try TCC(s: 2).toTimecode(at: ._24)
+        )
+    }
+
+    func testCMTime() throws {
+        let ti = try TimecodeInterval(
+            TCC(s: 2).toTimecode(at: ._24)
+        )
+
+        let cmTime = ti.cmTime
+
+        XCTAssertEqual(cmTime.seconds.sign, .plus)
+        XCTAssertEqual(cmTime.value, 2)
+        XCTAssertEqual(cmTime.timescale, 1)
+    }
+}
+
+#endif