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Merged
hm21 merged 1 commit into from
Apr 7, 2026
+44 −25
Merged

attempt to fix crash in extractToWav() #113

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53 changes: 31 additions & 22 deletions ios/Classes/src/features/audio/ExtractAudio.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,7 @@ class NoAudioTrackException: NSError, @unchecked Sendable {
userInfo: [NSLocalizedDescriptionKey: "No audio track found in video"]
)
}

required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
Expand All @@ -26,7 +26,7 @@ class NoAudioTrackException: NSError, @unchecked Sendable {
/// - Provides progress tracking during extraction
/// - Supports cancellation of active extraction jobs
class ExtractAudio {

/// Extracts audio from a video file asynchronously.
///
/// This method uses AVAssetExportSession for fast Passthrough export,
Expand All @@ -44,7 +44,7 @@ class ExtractAudio {
onComplete: @escaping (FlutterStandardTypedData?) -> Void,
onError: @escaping (Error) -> Void
) -> AudioExtractJobHandle {

// Check if WAV format is requested - requires transcoding
let outputExtension = config.getOutputExtension().lowercased()
if outputExtension == "wav" {
Expand All @@ -55,7 +55,7 @@ class ExtractAudio {
onError: onError
)
}

// Use passthrough export for other formats
return extractPassthrough(
config: config,
Expand All @@ -64,34 +64,34 @@ class ExtractAudio {
onError: onError
)
}

/// Extracts audio using passthrough (no transcoding) for M4A, AAC, CAF formats.
private static func extractPassthrough(
config: AudioExtractConfig,
onProgress: @escaping (Double) -> Void,
onComplete: @escaping (FlutterStandardTypedData?) -> Void,
onError: @escaping (Error) -> Void
) -> AudioExtractJobHandle {

var exportSession: AVAssetExportSession?
var progressTimer: Timer?
var isCancelled = false

// Execute extraction on background queue
DispatchQueue.global(qos: .userInitiated).async {
do {
// Load source video asset
let sourceURL = URL(fileURLWithPath: config.inputPath)
let asset = AVURLAsset(url: sourceURL)

// Wait for tracks to be loaded
let loadSemaphore = DispatchSemaphore(value: 0)
var loadError: Error?

asset.loadValuesAsynchronously(forKeys: ["tracks", "duration"]) {
let tracksStatus = asset.statusOfValue(forKey: "tracks", error: nil)
let durationStatus = asset.statusOfValue(forKey: "duration", error: nil)

if tracksStatus == .failed || durationStatus == .failed {
loadError = NSError(
domain: "ExtractAudio",
Expand All @@ -101,13 +101,13 @@ class ExtractAudio {
}
loadSemaphore.signal()
}

loadSemaphore.wait()

if let error = loadError {
throw error
}

// Determine output file location
let outputURL: URL
if let outputPath = config.outputPath {
Expand All @@ -117,14 +117,14 @@ class ExtractAudio {
let filename = "audio_\(Date().timeIntervalSince1970).\(config.getOutputExtension())"
outputURL = tempDir.appendingPathComponent(filename)
}

// Remove existing file if present
try? FileManager.default.removeItem(at: outputURL)

// Determine output file type based on extension
let fileExtension = outputURL.pathExtension.lowercased()
let outputFileType: AVFileType

switch fileExtension {
case "m4a":
outputFileType = .m4a
Expand Down Expand Up @@ -198,7 +198,7 @@ class ExtractAudio {
userInfo: [NSLocalizedDescriptionKey: "Failed to create export session"]
)
}

exportSession = session
session.outputURL = outputURL
session.outputFileType = outputFileType
Expand Down Expand Up @@ -330,7 +330,8 @@ class ExtractAudio {
var assetReader: AVAssetReader?
var assetWriter: AVAssetWriter?
var isCancelled = false

var sessionStarted = false

DispatchQueue.global(qos: .userInitiated).async {
do {
// Load source video asset
Expand Down Expand Up @@ -410,7 +411,7 @@ class ExtractAudio {
AVLinearPCMBitDepthKey: 16,
AVLinearPCMIsFloatKey: false,
AVLinearPCMIsBigEndianKey: false,
AVLinearPCMIsNonInterleaved: false
AVLinearPCMIsNonInterleaved: false,
]

let readerOutput = AVAssetReaderTrackOutput(track: audioTrack, outputSettings: readerOutputSettings)
Expand Down Expand Up @@ -499,9 +500,7 @@ class ExtractAudio {
userInfo: [NSLocalizedDescriptionKey: "Failed to start writing"]
)
}

writer.startSession(atSourceTime: .zero)


// Calculate total duration for progress
let totalDuration = CMTimeGetSeconds(timeRange.duration)

Expand All @@ -517,6 +516,11 @@ class ExtractAudio {
writerInput.requestMediaDataWhenReady(on: processingQueue) {
while writerInput.isReadyForMoreMediaData && !isCancelled {
if let sampleBuffer = readerOutput.copyNextSampleBuffer() {
if !sessionStarted {
writer.startSession(atSourceTime: CMSampleBufferGetPresentationTimeStamp(sampleBuffer))
sessionStarted = true
}

// Update progress
let currentTime = CMSampleBufferGetPresentationTimeStamp(sampleBuffer)
let elapsed = CMTimeGetSeconds(currentTime) - CMTimeGetSeconds(timeRange.start)
Expand All @@ -531,6 +535,11 @@ class ExtractAudio {
}
} else {
// No more samples
if !sessionStarted && !isCancelled {
// Fallback session start if no samples were found
writer.startSession(atSourceTime: timeRange.start)
sessionStarted = true
}
writerInput.markAsFinished()
break
}
Expand Down
16 changes: 13 additions & 3 deletions macos/Classes/src/features/audio/ExtractAudio.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -347,6 +347,7 @@ class ExtractAudio {
var assetReader: AVAssetReader?
var assetWriter: AVAssetWriter?
var isCancelled = false
var sessionStarted = false

DispatchQueue.global(qos: .userInitiated).async {
do {
Expand Down Expand Up @@ -398,6 +399,7 @@ class ExtractAudio {
}

// Calculate time range
// Use the audio track's actual timeRange for full extraction
// Audio tracks may not start at zero due to encoding delays or sync adjustments
var timeRange: CMTimeRange
if let startUs = config.startUs, let endUs = config.endUs {
Expand Down Expand Up @@ -522,9 +524,7 @@ class ExtractAudio {
userInfo: [NSLocalizedDescriptionKey: "Failed to start writing"]
)
}

writer.startSession(atSourceTime: .zero)


// Calculate total duration for progress
let totalDuration = CMTimeGetSeconds(timeRange.duration)

Expand All @@ -540,6 +540,11 @@ class ExtractAudio {
writerInput.requestMediaDataWhenReady(on: processingQueue) {
while writerInput.isReadyForMoreMediaData && !isCancelled {
if let sampleBuffer = readerOutput.copyNextSampleBuffer() {
if !sessionStarted {
writer.startSession(atSourceTime: CMSampleBufferGetPresentationTimeStamp(sampleBuffer))
sessionStarted = true
}

// Update progress
let currentTime = CMSampleBufferGetPresentationTimeStamp(sampleBuffer)
let elapsed =
Expand All @@ -555,6 +560,11 @@ class ExtractAudio {
}
} else {
// No more samples
if !sessionStarted && !isCancelled {
// Fallback session start if no samples were found
writer.startSession(atSourceTime: timeRange.start)
sessionStarted = true
}
writerInput.markAsFinished()
break
}
Expand Down
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