The getter 'length' was called on null.

[trey-rosius]

Hi,

I'm actually running your example code. Here's the flutter version i'm using

Flutter 1.16.3 • channel master • https://github.com/flutter/flutter.git
Framework • revision be3a4b37b3 (4 weeks ago) • 2020-03-26 18:08:05 -0700
Engine • revision b2bdeb3f0f
Tools • Dart 2.8.0 (build 2.8.0-dev.17.0 1402e8e1a4)

And i get this exception when video compression starts.

E/Transcoder( 5243): Fatal error while transcoding, this might be invalid format or bug in engine or Android.
E/Transcoder( 5243): java.lang.UnsupportedOperationException: Output channel count (6) not supported.
E/Transcoder( 5243): 	at com.otaliastudios.transcoder.transcode.internal.AudioEngine.<init>(AudioEngine.java:83)
E/Transcoder( 5243): 	at com.otaliastudios.transcoder.transcode.AudioTrackTranscoder.onDecoderOutputFormatChanged(AudioTrackTranscoder.java:56)
E/Transcoder( 5243): 	at com.otaliastudios.transcoder.transcode.BaseTrackTranscoder.drainDecoder(BaseTrackTranscoder.java:240)
E/Transcoder( 5243): 	at com.otaliastudios.transcoder.transcode.BaseTrackTranscoder.transcode(BaseTrackTranscoder.java:165)
E/Transcoder( 5243): 	at com.otaliastudios.transcoder.engine.Engine.transcode(Engine.java:373)
E/Transcoder( 5243): 	at com.otaliastudios.transcoder.Transcoder$1.call(Transcoder.java:134)
E/Transcoder( 5243): 	at com.otaliastudios.transcoder.Transcoder$1.call(Transcoder.java:124)
E/Transcoder( 5243): 	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
E/Transcoder( 5243): 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
E/Transcoder( 5243): 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
E/Transcoder( 5243): 	at java.lang.Thread.run(Thread.java:764)
E/flutter ( 5243): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: NoSuchMethodError: The getter 'length' was called on null.
E/flutter ( 5243): Receiver: null
E/flutter ( 5243): Tried calling: length
E/flutter ( 5243): #0      Object.noSuchMethod (dart:core-patch/object_patch.dart:53:5)
E/flutter ( 5243): #1      _parseJson (dart:convert-patch/convert_patch.dart:30:28)
E/flutter ( 5243): #2      JsonDecoder.convert (dart:convert/json.dart:505:36)
E/flutter ( 5243): #3      JsonCodec.decode (dart:convert/json.dart:153:41)
E/flutter ( 5243): #4      VideoCompress.compressVideo (package:video_compress/src/video_compressor.dart:159:26)
E/flutter ( 5243): <asynchronous suspension>
E/flutter ( 5243): #5      _MyHomePageState.build.<anonymous closure> (package:video_compress_example/main.dart:101:44)
E/flutter ( 5243): <asynchronous suspension>
E/flutter ( 5243): #6      _MyHomePageState.build.<anonymous closure> (package:video_compress_example/main.dart)
E/flutter ( 5243): #7      _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:779:19)
E/flutter ( 5243): #8      _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:862:36)
E/flutter ( 5243): #9      GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:182:24)
E/flutter ( 5243): #10     TapGestureRecognizer.handleTapUp (package:flutter/src/gestures/tap.dart:504:11)
E/flutter ( 5243): #11     BaseTapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:282:5)
E/flutter ( 5243): #12     BaseTapGestureRecognizer.acceptGesture (package:flutter/src/gestures/tap.dart:254:7)
E/flutter ( 5243): #13     GestureArenaManager.sweep (package:flutter/src/gestures/arena.dart:156:27)
E/flutter ( 5243): #14     GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:222:20)
E/flutter ( 5243): #15     GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:198:22)
E/flutter ( 5243): #16     GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:156:7)
E/flutter ( 5243): #17     GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:102:7)
E/flutter ( 5243): #18     GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:86:7)
E/flutter ( 5243): #19     _rootRunUnary (dart:async/zone.dart:1159:13)
E/flutter ( 5243): #20     _CustomZone.runUnary (dart:async/zone.dart:1048:19)
E/flutter ( 5243): #21     _CustomZone.runUnaryGuarded (dart:async/zone.dart:950:7)
E/flutter ( 5243): #22     _invoke1 (dart:ui/hooks.dart:275:10)
E/flutter ( 5243): #23     _dispatchPointerDataPacket (dart:ui/hooks.dart:184:5)
E/flutter ( 5243): 

[jonataslaw]

This happens when you are trying to decode a smaller file for higher quality.
Are you using DefaultQuality? I recommend that before converting, you do some logic using MediaInfo so if the file is smaller than 480p, use LowQuality Rather Default.

[trey-rosius]

thanks a lot. It works now

[jigarfumakiya]

Hey @jonataslaw , can you tell me how can I check if my file is lower then 480p using mediaInfo?