✨ Support background music

CMTime+Extensions.swift

@@ -0,0 +1,26 @@
+//
+//  CMTime+Extensions.swift
+//  MTTransitions
+//
+//  Created by Jim Wang on 2022/11/28.
+//
+
+import CoreMedia
+import Foundation
+
+extension CMTime {
+
+    static func makeLoopTime(timeRange: CMTimeRange, at: CMTime = .zero, until: CMTime) -> [(at: CMTime, timeRange: CMTimeRange)] {
+        let duration = timeRange.duration
+        var t = at
+        var times = [(at: CMTime, timeRange: CMTimeRange)]()
+        while t < until {
+            let adjustedDuration = CMTimeMinimum(CMTimeSubtract(until, t), duration)
+            let adjustedTimeRange = CMTimeRange(start: timeRange.start, duration: adjustedDuration)
+            times.append((at: t, timeRange: adjustedTimeRange))
+            t = CMTimeAdd(t, adjustedDuration)
+        }
+        return times
+    }
+
+}

MTTransitions.podspec

@@ -13,7 +13,7 @@ Pod::Spec.new do |s|
   s.swift_version   = '5.0'
   s.source_files    = 'Source/**/*.{swift,metal,h}'
   s.resource  = 'Source/**/Assets.bundle'
-  s.ios.deployment_target = '10.0'
+  s.ios.deployment_target = '13.0'
   s.xcconfig = { 'MTL_HEADER_SEARCH_PATHS' => '${PODS_CONFIGURATION_BUILD_DIR}/MetalPetal/MetalPetal.framework/Headers'}
 
   s.weak_frameworks = 'MetalKit'

MTTransitionsDemo.xcodeproj/project.pbxproj

@@ -47,6 +47,7 @@
 		A3F2636A243EF67B00A093D2 /* PickImageTransitionViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = A3F26369243EF67B00A093D2 /* PickImageTransitionViewController.swift */; };
 		FBB33DD328461993006FA36F /* TimelineSampleViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = FBB33DD228461993006FA36F /* TimelineSampleViewController.swift */; };
 		FBD7D02D2847486500E62822 /* APLCompositionDebugView.m in Sources */ = {isa = PBXBuildFile; fileRef = FBD7D02C2847486500E62822 /* APLCompositionDebugView.m */; };
+		FBE7123C29348D6500BC77FB /* audio1_trimmed.mp3 in Resources */ = {isa = PBXBuildFile; fileRef = FBE7123B29348D6500BC77FB /* audio1_trimmed.mp3 */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
@@ -96,6 +97,7 @@
 		FBD7D02A2847486400E62822 /* MTTransitionsDemo-Bridging-Header.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "MTTransitionsDemo-Bridging-Header.h"; sourceTree = "<group>"; };
 		FBD7D02B2847486500E62822 /* APLCompositionDebugView.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = APLCompositionDebugView.h; sourceTree = "<group>"; };
 		FBD7D02C2847486500E62822 /* APLCompositionDebugView.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = APLCompositionDebugView.m; sourceTree = "<group>"; };
+		FBE7123B29348D6500BC77FB /* audio1_trimmed.mp3 */ = {isa = PBXFileReference; lastKnownFileType = audio.mp3; path = audio1_trimmed.mp3; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -154,6 +156,7 @@
 			children = (
 				A3C9E22024373E4D002F82D9 /* audio1.mp3 */,
 				A3C9E1F42431D640002F82D9 /* audio2.mp3 */,
+				FBE7123B29348D6500BC77FB /* audio1_trimmed.mp3 */,
 				A369F7DC242A035C00546190 /* cut1.mp4 */,
 				A369F7DD242A035C00546190 /* cut2.mp4 */,
 				A3CFA84A242B96E900F2E660 /* cut3.mp4 */,
@@ -293,6 +296,7 @@
 				A3E0AD2D2205BEA6002DD092 /* 5.jpg in Resources */,
 				A3E0AD282205BEA6002DD092 /* 8.jpg in Resources */,
 				A3913EC3242886280083E7D3 /* clip1.mp4 in Resources */,
+				FBE7123C29348D6500BC77FB /* audio1_trimmed.mp3 in Resources */,
 				A3E0AD2F2205BEA6002DD092 /* 6.jpg in Resources */,
 				A3E0AD272205BEA6002DD092 /* 3.jpg in Resources */,
 				A374124121F98D9B0019F3A3 /* LaunchScreen.storyboard in Resources */,
@@ -491,7 +495,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 13.0;
 				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
 				MTL_FAST_MATH = YES;
 				ONLY_ACTIVE_ARCH = YES;
@@ -546,7 +550,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 13.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				MTL_FAST_MATH = YES;
 				SDKROOT = iphoneos;
@@ -565,7 +569,7 @@
 				CODE_SIGN_STYLE = Manual;
 				DEVELOPMENT_TEAM = F6J8B455GU;
 				INFOPLIST_FILE = "$(SRCROOT)/MTTransitionsDemo/Supporting Files/Info.plist";
-				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 13.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -589,7 +593,7 @@
 				CODE_SIGN_STYLE = Manual;
 				DEVELOPMENT_TEAM = F6J8B455GU;
 				INFOPLIST_FILE = "$(SRCROOT)/MTTransitionsDemo/Supporting Files/Info.plist";
-				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 13.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",

MTTransitionsDemo/Samples/TimelineSampleViewController.swift

@@ -112,8 +112,8 @@ class TimelineSampleViewController: UIViewController {
     }
 
     private func setupVideoPlaybacks() {
-        guard let clip1 = loadVideoAsset(named: "clip1"),
-              let clip2 = loadVideoAsset(named: "clip2") else {
+        guard let clip1 = loadAsset(named: "clip1"),
+              let clip2 = loadAsset(named: "clip2") else {
                   return
               }
         clips = [clip1, clip2]
@@ -174,20 +174,26 @@ class TimelineSampleViewController: UIViewController {
     private func makeComposition(renderSize: CGSize = CGSize(width: 720, height: 720)) {
         let timeline = Timeline()
         timeline.renderSize = renderSize
-        let resource1 = AVAssetResource(asset: loadVideoAsset(named: "clip1")!, selectedTimeRange: nil)
-        let resource2 = AVAssetResource(asset: loadVideoAsset(named: "clip2")!, selectedTimeRange: nil)
-        let resource3 = AVAssetResource(asset: loadVideoAsset(named: "clip3")!, selectedTimeRange: nil)
+        let resource1 = AVAssetResource(asset: loadAsset(named: "clip1")!, selectedTimeRange: nil)
+        let resource2 = AVAssetResource(asset: loadAsset(named: "clip2")!, selectedTimeRange: nil)
+        let resource3 = AVAssetResource(asset: loadAsset(named: "clip3")!, selectedTimeRange: nil)
         let resource4 = { () -> Resource in
             let image = UIImage(named: "wallpaper01.jpg")!
             let ciImage = CIImage(cgImage: image.cgImage!)
-            return ImageResource(image: ciImage, duration: CMTime(seconds: 5, preferredTimescale: 1000))
+            return MTTransitions.ImageResource(image: ciImage, duration: CMTime(seconds: 5, preferredTimescale: 1000))
         }()
         timeline.clips = [
             Clip(resource: resource1),
             Clip(resource: resource2),
             Clip(resource: resource3),
             Clip(resource: resource4)
         ]
+        timeline.backgroundAudioClip = { () -> Clip in
+            let audioResource = AVAssetResource(
+                asset: loadAsset(named: "audio1_trimmed", withExtension: "mp3")!
+            )
+            return Clip(resource: audioResource)
+        }()
         timeline.transitionProvider = DefaultTransitionProvider(effect: effect, seconds: 0.5)
 
         let composition = MTTimelineComposition(timeline: timeline)
@@ -331,7 +337,7 @@ extension TimelineSampleViewController {
 // MARK: - Helper
 extension TimelineSampleViewController {
 
-    private func loadVideoAsset(named: String, withExtension ext: String = "mp4") -> AVURLAsset? {
+    private func loadAsset(named: String, withExtension ext: String = "mp4") -> AVURLAsset? {
         guard let url = Bundle.main.url(forResource: named, withExtension: ext) else {
             return nil
         }

Podfile

@@ -1,4 +1,4 @@
-platform:ios, '10.0'
+platform:ios, '13.0'
 use_frameworks!
 
 target 'MTTransitionsDemo' do

Podfile.lock

@@ -21,8 +21,8 @@ EXTERNAL SOURCES:
 
 SPEC CHECKSUMS:
   MetalPetal: f4325f3a0dbccdcd1b39e385a9c19d4cc9e803c8
-  MTTransitions: f4818ba485abc477545af4ee483c00b717dfd76e
+  MTTransitions: de56179ff6ba1a4e67bbc627288c957beafc0ffc
 
-PODFILE CHECKSUM: 1c191667b33e66fe3cb9571c46a03b195023b8c4
+PODFILE CHECKSUM: 3cc245b6f1621658d112bb04b7d0547211c12e77
 
 COCOAPODS: 1.11.3