Surface Android fMP4 writer failures

package/android/src/main/java/com/mrousavy/camera/core/CameraError.kt

@@ -110,6 +110,8 @@ class UnknownCaptureError(wasImageCaptured: Boolean) :
   CameraError("capture", "unknown", "An unknown error occurred while trying to capture an Image! Was Image captured: $wasImageCaptured")
 class RecorderError(name: String, extra: Int) :
   CameraError("capture", "recorder-error", "An error occured while recording a video! $name $extra")
+class FragmentedRecorderError(message: String, cause: Throwable? = null) :
+  CameraError("capture", "fragmented-recorder-error", message, cause)
 class NoRecordingInProgressError :
   CameraError("capture", "no-recording-in-progress", "There was no active video recording in progress! Did you call stopRecording() twice?")
 class InsufficientStorageError : CameraError("capture", "insufficient-storage", "There is not enough storage space available.")

package/android/src/main/java/com/mrousavy/camera/core/FragmentedRecordingManager.kt

@@ -20,7 +20,8 @@ import java.io.File
  */
 class FragmentedRecordingManager(
     private val encoder: MediaCodec,
-    private val muxer: HlsMuxer
+    private val muxer: HlsMuxer,
+    private val onError: (CameraError) -> Unit
 ) : MediaCodec.Callback(), ChunkedRecorderInterface {
 
     companion object {
@@ -36,6 +37,7 @@ class FragmentedRecordingManager(
             bitRate: Int,
             options: RecordVideoOptions,
             outputDirectory: File,
+            onError: (CameraError) -> Unit,
             segmentDurationSeconds: Int = DEFAULT_SEGMENT_DURATION_SECONDS
         ): FragmentedRecordingManager {
             val mimeType = options.videoCodec.toMimeType()
@@ -81,11 +83,12 @@ class FragmentedRecordingManager(
             )
             muxer.setSegmentDuration(segmentDurationSeconds * 1_000_000L)
 
-            return FragmentedRecordingManager(codec, muxer)
+            return FragmentedRecordingManager(codec, muxer, onError)
         }
     }
 
     private var recording = false
+    private var failed = false
     private var muxerStarted = false
     private var trackIndex = -1
 
@@ -100,6 +103,17 @@ class FragmentedRecordingManager(
         recording = true
     }
 
+    private fun failRecording(message: String, cause: Throwable) {
+        if (failed) {
+            return
+        }
+
+        failed = true
+        recording = false
+        Log.e(TAG, message, cause)
+        onError(FragmentedRecorderError(message, cause))
+    }
+
     override fun finish() {
         synchronized(this) {
             recording = false
@@ -138,7 +152,10 @@ class FragmentedRecordingManager(
 
             val buffer = encoder.getOutputBuffer(index)
             if (buffer == null) {
-                Log.e(TAG, "getOutputBuffer returned null")
+                failRecording(
+                    "Failed to write fragmented MP4 sample: output buffer was null",
+                    RuntimeException("getOutputBuffer returned null")
+                )
                 encoder.releaseOutputBuffer(index, false)
                 return
             }
@@ -146,7 +163,7 @@ class FragmentedRecordingManager(
             try {
                 muxer.writeSampleData(trackIndex, buffer, bufferInfo)
             } catch (e: Exception) {
-                Log.e(TAG, "Error writing sample", e)
+                failRecording("Failed to write fragmented MP4 sample", e)
             }
 
             encoder.releaseOutputBuffer(index, false)
@@ -154,16 +171,22 @@ class FragmentedRecordingManager(
     }
 
     override fun onError(codec: MediaCodec, e: MediaCodec.CodecException) {
-        Log.e(TAG, "Codec error: ${e.message}")
+        synchronized(this) {
+            failRecording("Fragmented MP4 encoder error", e)
+        }
     }
 
     override fun onOutputFormatChanged(codec: MediaCodec, format: MediaFormat) {
         synchronized(this) {
             Log.i(TAG, "Output format changed: $format")
 
-            trackIndex = muxer.addTrack(format)
+            try {
-            muxer.start()
+                trackIndex = muxer.addTrack(format)
-            muxerStarted = true
+                muxer.start()
+                muxerStarted = true
+            } catch (e: Exception) {
+                failRecording("Failed to start fragmented MP4 muxer", e)
+            }
         }
     }
 }

package/android/src/main/java/com/mrousavy/camera/core/HlsMuxer.kt

@@ -273,7 +273,10 @@ class HlsMuxer(
         // Write init segment
         val initBytes = buildInitSegment(format)
         val initFile = File(outputDirectory, "init.mp4")
-        FileOutputStream(initFile).use { it.write(initBytes) }
+        FileOutputStream(initFile).use { output ->
+            output.write(initBytes)
+            output.fd.sync()
+        }
 
         // Log frame rate metadata for debugging
         val defaultSampleDuration = timescale / fps

package/android/src/main/java/com/mrousavy/camera/core/RecordingSession.kt

@@ -72,6 +72,7 @@ class RecordingSession(
       bitRate,
       options,
       outputPath,
+      onError,
       SEGMENT_DURATION_SECONDS
     )
   } else {