🐛 iOS pause audio/video output incorrect about react-native-vision-camera HOT 6 CLOSED

diff --git a/ios/Core/CameraSession+Video.swift b/ios/Core/CameraSession+Video.swift
index 00ff941b1d4cee15323f1f960a19a14613acab01..69e57e4092d99104793b994e9273a37dd301c18f 100644
--- a/ios/Core/CameraSession+Video.swift
+++ b/ios/Core/CameraSession+Video.swift
@@ -157,11 +157,12 @@ extension CameraSession {
   func pauseRecording(promise: Promise) {
     CameraQueues.cameraQueue.async {
       withPromise(promise) {
-        guard self.recordingSession != nil else {
+        guard let recordingSession = self.recordingSession else {
           // there's no active recording!
           throw CameraError.capture(.noRecordingInProgress)
         }
         self.isRecording = false
+        try recordingSession.pause(clock: self.captureSession.clock)
         return nil
       }
     }
@@ -173,11 +174,12 @@ extension CameraSession {
   func resumeRecording(promise: Promise) {
     CameraQueues.cameraQueue.async {
       withPromise(promise) {
-        guard self.recordingSession != nil else {
+        guard let recordingSession = self.recordingSession else {
           // there's no active recording!
           throw CameraError.capture(.noRecordingInProgress)
         }
         self.isRecording = true
+        try recordingSession.resume(clock: self.captureSession.clock)
         return nil
       }
     }
diff --git a/ios/Core/RecordingSession.swift b/ios/Core/RecordingSession.swift
index 85e9c622573143bd38f0b0ab6f81ad2f40e03cc3..8c4836c97b562bbda362c14f314a0ce96f113d2a 100644
--- a/ios/Core/RecordingSession.swift
+++ b/ios/Core/RecordingSession.swift
@@ -33,6 +33,8 @@ class RecordingSession {
 
   private var startTimestamp: CMTime?
   private var stopTimestamp: CMTime?
+  private var pauseTimestamp: CMTime?
+  private var pauseTimestampOffset: CMTime?
 
   private var lastWrittenTimestamp: CMTime?
 
@@ -67,7 +69,12 @@ class RecordingSession {
           let startTimestamp = startTimestamp else {
       return 0.0
     }
-    return (lastWrittenTimestamp - startTimestamp).seconds
+
+    if let pauseTimestampOffset = pauseTimestampOffset {
+      return (lastWrittenTimestamp - startTimestamp - pauseTimestampOffset).seconds
+    } else {
+      return (lastWrittenTimestamp - startTimestamp).seconds
+    }
   }
 
   init(url: URL,
@@ -158,6 +165,8 @@ class RecordingSession {
     // Start the sesssion at the given time. Frames with earlier timestamps (e.g. late frames) will be dropped.
     assetWriter.startSession(atSourceTime: currentTime)
     startTimestamp = currentTime
+    pauseTimestamp = nil
+    pauseTimestampOffset = nil
     ReactLogger.log(level: .info, message: "Started RecordingSession at time: \(currentTime.seconds)")
 
     if audioWriter == nil {
@@ -195,6 +204,56 @@ class RecordingSession {
     }
   }
 
+  /**
+   Record pause timestamp to calculate timestamp offset using the current time of the provided synchronization clock.
+   The clock must be the same one that was passed to start() method.
+   */
+  func pause(clock: CMClock) throws {
+    lock.wait()
+    defer {
+      lock.signal()
+    }
+
+    let currentTime = CMClockGetTime(clock)
+    ReactLogger.log(level: .info, message: "Pausing Asset Writer(s)...")
+
+    guard pauseTimestamp == nil else {
+      ReactLogger.log(level: .error, message: "pauseTimestamp is already non-nil")
+      return
+    }
+
+    pauseTimestamp = currentTime
+  }
+
+  /**
+   Update pause timestamp offset using the current time of the provided synchronization clock.
+   The clock must be the same one that was passed to start() method.
+   */
+  func resume(clock: CMClock) throws {
+    lock.wait()
+    defer {
+      lock.signal()
+    }
+
+    let currentTime = CMClockGetTime(clock)
+    ReactLogger.log(level: .info, message: "Resuming Asset Writer(s)...")
+
+    guard let pauseTimestamp = pauseTimestamp else {
+      ReactLogger.log(level: .error, message: "Tried resume but recording has not been paused")
+      return
+    }
+
+    let pauseOffset = currentTime - pauseTimestamp
+    self.pauseTimestamp = nil
+    if let currentPauseTimestampOffset = pauseTimestampOffset {
+      pauseTimestampOffset = currentPauseTimestampOffset + pauseOffset
+      ReactLogger.log(level: .info, message: "Current pause offset is \(pauseTimestampOffset!.seconds)")
+    } else {
+      pauseTimestampOffset = pauseOffset
+      ReactLogger.log(level: .info, message: "Current pause offset is \(pauseTimestampOffset!.seconds)")
+    }
+  }
+
   /**
    Appends a new CMSampleBuffer to the Asset Writer.
    - Use clock to specify the CMClock instance this CMSampleBuffer uses for relative time
@@ -238,12 +297,32 @@ class RecordingSession {
     }
 
     // 3. Actually write the Buffer to the AssetWriter
+    let buf: CMSampleBuffer
+    if let pauseTimestampOffset = pauseTimestampOffset {
+      // let newTime = timestamp - pauseTimestampOffset
+      var count: CMItemCount = 0
+      CMSampleBufferGetSampleTimingInfoArray(buffer, entryCount: 0, arrayToFill: nil, entriesNeededOut: &count)
+      var info = [CMSampleTimingInfo](repeating: CMSampleTimingInfo(duration: CMTimeMake(value: 0, timescale: 0), presentationTimeStamp: CMTimeMake(value: 0, timescale: 0), decodeTimeStamp: CMTimeMake(value: 0, timescale: 0)), count: count)
+      CMSampleBufferGetSampleTimingInfoArray(buffer, entryCount: count, arrayToFill: &info, entriesNeededOut: &count)
+
+      for i in 0..<count {
+        info[i].decodeTimeStamp = info[i].decodeTimeStamp - pauseTimestampOffset
+        info[i].presentationTimeStamp = info[i].presentationTimeStamp - pauseTimestampOffset
+      }
+
+      var out: CMSampleBuffer?
+      CMSampleBufferCreateCopyWithNewTiming(allocator: nil, sampleBuffer: buffer, sampleTimingEntryCount: count, sampleTimingArray: &info, sampleBufferOut: &out)
+      buf = out!
+    } else {
+      buf = buffer
+    }
     let writer = getAssetWriter(forType: bufferType)
     guard writer.isReadyForMoreMediaData else {
       ReactLogger.log(level: .warning, message: "\(bufferType) AssetWriter is not ready for more data, dropping this Frame...")
       return
     }
-    writer.append(buffer)
+    writer.append(buf)
+    ReactLogger.log(level: .info, message: "append \(bufferType) Buffer (at \(timestamp.seconds) seconds)...")
     lastWrittenTimestamp = timestamp
 
     // 4. If we failed to write the frames, stop the Recording