Make SampleWriter.init nonisolated so it can load tracks

SJSAssetExportSession.xcodeproj/project.pbxproj

@@ -8,6 +8,7 @@
 
 /* Begin PBXBuildFile section */
 		7B7AE3092C36615700DB7391 /* SampleWriter.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7B7AE3082C36615700DB7391 /* SampleWriter.swift */; };
+		7B9867982C6AF57C001353BC /* AVAsset+sending.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7BC5FC8B2C3BB0180090B757 /* AVAsset+sending.swift */; };
 		7B9BC00E2C305D2C00C160C2 /* SJSAssetExportSession.docc in Sources */ = {isa = PBXBuildFile; fileRef = 7B9BC00D2C305D2C00C160C2 /* SJSAssetExportSession.docc */; };
 		7B9BC0142C305D2C00C160C2 /* SJSAssetExportSession.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 7B9BC0092C305D2C00C160C2 /* SJSAssetExportSession.framework */; };
 		7B9BC0192C305D2C00C160C2 /* SJSAssetExportSessionTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7B9BC0182C305D2C00C160C2 /* SJSAssetExportSessionTests.swift */; };
@@ -16,7 +17,6 @@
 		7BC5FC772C3B8C5A0090B757 /* SendableWrapper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7BC5FC762C3B8C5A0090B757 /* SendableWrapper.swift */; };
 		7BC5FC792C3B90F70090B757 /* AutoDestructingURL.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7BC5FC782C3B90F70090B757 /* AutoDestructingURL.swift */; };
 		7BC5FC8A2C3BAA150090B757 /* ExportSession+Error.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7BC5FC892C3BAA150090B757 /* ExportSession+Error.swift */; };
-		7BC5FC8C2C3BB0180090B757 /* AVAsset+sending.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7BC5FC8B2C3BB0180090B757 /* AVAsset+sending.swift */; };
 		7BC5FC902C3BB2030090B757 /* AudioOutputSettings.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7BC5FC8F2C3BB2030090B757 /* AudioOutputSettings.swift */; };
 		7BC5FC922C3BB4BD0090B757 /* VideoOutputSettings.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7BC5FC912C3BB4BD0090B757 /* VideoOutputSettings.swift */; };
 		7BC5FC942C3BC3AD0090B757 /* CMTime+seconds.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7BC5FC932C3BC3AD0090B757 /* CMTime+seconds.swift */; };
@@ -95,7 +95,6 @@
 			children = (
 				7BC5FC8F2C3BB2030090B757 /* AudioOutputSettings.swift */,
 				7BC5FC912C3BB4BD0090B757 /* VideoOutputSettings.swift */,
-				7BC5FC8B2C3BB0180090B757 /* AVAsset+sending.swift */,
 				7BC5FC932C3BC3AD0090B757 /* CMTime+seconds.swift */,
 				7B9BC0272C30612C00C160C2 /* ExportSession.swift */,
 				7BC5FC892C3BAA150090B757 /* ExportSession+Error.swift */,
@@ -110,6 +109,7 @@
 			isa = PBXGroup;
 			children = (
 				7BC5FC782C3B90F70090B757 /* AutoDestructingURL.swift */,
+				7BC5FC8B2C3BB0180090B757 /* AVAsset+sending.swift */,
 				7BC5FC812C3B9E3D0090B757 /* Resources */,
 				7BC5FC762C3B8C5A0090B757 /* SendableWrapper.swift */,
 				7B9BC0182C305D2C00C160C2 /* SJSAssetExportSessionTests.swift */,
@@ -233,7 +233,6 @@
 				7B7AE3092C36615700DB7391 /* SampleWriter.swift in Sources */,
 				7BC5FC902C3BB2030090B757 /* AudioOutputSettings.swift in Sources */,
 				7B9BC0282C30612C00C160C2 /* ExportSession.swift in Sources */,
-				7BC5FC8C2C3BB0180090B757 /* AVAsset+sending.swift in Sources */,
 				7BC5FC922C3BB4BD0090B757 /* VideoOutputSettings.swift in Sources */,
 				7B9BC00E2C305D2C00C160C2 /* SJSAssetExportSession.docc in Sources */,
 				7BC5FC8A2C3BAA150090B757 /* ExportSession+Error.swift in Sources */,
@@ -246,6 +245,7 @@
 			files = (
 				7B9BC0192C305D2C00C160C2 /* SJSAssetExportSessionTests.swift in Sources */,
 				7BC5FC792C3B90F70090B757 /* AutoDestructingURL.swift in Sources */,
+				7B9867982C6AF57C001353BC /* AVAsset+sending.swift in Sources */,
 				7BC5FC772C3B8C5A0090B757 /* SendableWrapper.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;

SJSAssetExportSession/SampleWriter.swift

@@ -45,12 +45,12 @@ actor SampleWriter {
     private var videoInput: AVAssetWriterInput?
     private var isCancelled = false
 
-    init(
+    nonisolated init(
         asset: sending AVAsset,
         audioOutputSettings: sending [String: (any Sendable)],
-        audioMix: AVAudioMix?,
+        audioMix: sending AVAudioMix?,
         videoOutputSettings: sending [String: (any Sendable)],
-        videoComposition: AVVideoComposition,
+        videoComposition: sending AVVideoComposition,
         timeRange: CMTimeRange? = nil,
         optimizeForNetworkUse: Bool = false,
         outputURL: URL,
@@ -67,10 +67,14 @@ actor SampleWriter {
         let writer = try AVAssetWriter(outputURL: outputURL, fileType: fileType)
         writer.shouldOptimizeForNetworkUse = optimizeForNetworkUse
 
-        let audioTracks = try await asset.sendTracks(withMediaType: .audio)
+        let audioTracks = try await asset.loadTracks(withMediaType: .audio)
-        try Self.validateAudio(tracks: audioTracks, outputSettings: audioOutputSettings, writer: writer)
+        // Audio is optional so only validate output settings when it's applicable.
-        let videoTracks = try await asset.sendTracks(withMediaType: .video)
+        if !audioTracks.isEmpty {
-        try Self.validateVideo(tracks: videoTracks, outputSettings: videoOutputSettings, writer: writer)
+            try Self.validateAudio(outputSettings: audioOutputSettings, writer: writer)
+        }
+        let videoTracks = try await asset.loadTracks(withMediaType: .video)
+        guard !videoTracks.isEmpty else { throw Error.setupFailure(.videoTracksEmpty) }
+        try Self.validateVideo(outputSettings: videoOutputSettings, writer: writer)
         Self.warnAboutMismatchedVideoSize(
             renderSize: videoComposition.renderSize,
             settings: videoOutputSettings
@@ -85,8 +89,8 @@ actor SampleWriter {
         self.duration = duration
         self.timeRange = timeRange ?? CMTimeRange(start: .zero, duration: duration)
 
-        try setUpAudio(audioTracks: audioTracks)
+        try await setUpAudio(audioTracks: audioTracks)
-        try setUpVideo(videoTracks: videoTracks)
+        try await setUpVideo(videoTracks: videoTracks)
     }
 
     func writeSamples() async throws {
@@ -281,11 +285,9 @@ actor SampleWriter {
     // MARK: Input validation
 
     private static func validateAudio(
-        tracks: [AVAssetTrack],
         outputSettings: [String: any Sendable],
         writer: AVAssetWriter
     ) throws {
-        guard !tracks.isEmpty else { return } // Audio is optional so this isn't a failure.
         guard !outputSettings.isEmpty else { throw Error.setupFailure(.audioSettingsEmpty) }
         guard writer.canApply(outputSettings: outputSettings, forMediaType: .audio) else {
             throw Error.setupFailure(.audioSettingsInvalid)
@@ -293,11 +295,9 @@ actor SampleWriter {
     }
 
     private static func validateVideo(
-        tracks: [AVAssetTrack],
         outputSettings: [String: any Sendable],
         writer: AVAssetWriter
     ) throws {
-        guard !tracks.isEmpty else { throw Error.setupFailure(.videoTracksEmpty) }
         guard writer.canApply(outputSettings: outputSettings, forMediaType: .video) else {
             throw Error.setupFailure(.videoSettingsInvalid)
         }

SJSAssetExportSession/VideoOutputSettings.swift

@@ -5,7 +5,7 @@
 //  Created by Sami Samhuri on 2024-07-07.
 //
 
-public import AVFoundation
+import AVFoundation
 
 public struct VideoOutputSettings {
     public enum H264Profile {

SJSAssetExportSessionTests/AVAsset+sending.swift

@@ -1,6 +1,6 @@
 //
 //  AVAsset+sending.swift
-//  SJSAssetExportSession
+//  SJSAssetExportSessionTests
 //
 //  Created by Sami Samhuri on 2024-07-07.
 //

SJSAssetExportSessionTests/SJSAssetExportSessionTests.swift

@@ -5,7 +5,7 @@
 //  Created by Sami Samhuri on 2024-06-29.
 //
 
-import AVFoundation
+internal import AVFoundation
 @testable import SJSAssetExportSession
 import Testing