Out of memory when running stream

[Dmitry Vakhnin]

I have a command running stream via ffmpeg
libcamera-vid --framerate 24 --nopreview --inline -t 0 --width 1920 --height 1080 --listen -o - | ffmpeg -f lavfi -i anullsrc -i - -profile:v high -pix_fmt yuvj420p -level:v 4.1 -preset ultrafast -framerate 24 -g 48 -tune zerolatency -vcodec libx264 -r 10 -s 1920x1080 -b:v 2M -f flv rtmp://a.rtmp.youtube.com/live2/YOUR_KEY

And after some time - I'm having out of memory error

Error

  Exhausted heap space, trying to allocate 8589934608 bytes.
Unhandled exception:
Out of Memory
#0      List._grow (dart:core-patch/growable_array.dart:376:19)
#1      List.addAll (dart:core-patch/growable_array.dart:304:9)
#2      runExecutableArguments.streamToResult (package:process_run/src/process_run.dart:132:12)
#3      _FutureListener.handleValue (dart:async/future_impl.dart:162:18)
#4      Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:846:45)
#5      Future._propagateToListeners (dart:async/future_impl.dart:875:13)
#6      Future._complete (dart:async/future_impl.dart:638:7)
#7      _StreamIterator._onData (dart:async/stream_impl.dart:1034:20)
#8      _RootZone.runUnaryGuarded (dart:async/zone.dart:1594:10)
#9      _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339:11)
#10     _StreamController.add (dart:async/stream_controller.dart:606:5)
#11     runExecutableArguments.<anonymous closure> (package:process_run/src/process_run.dart:147:13)
#12     _RootZone.runUnaryGuarded (dart:async/zone.dart:1594:10)
#13     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339:11)
#14     _StreamController.add (dart:async/stream_controller.dart:606:5)
#15     _Socket._onData (dart:io-patch/socket_patch.dart:2447:41)
#16     _RootZone.runUnaryGuarded (dart:async/zone.dart:1594:10)
#17     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339:11)
#18     _StreamController.add (dart:async/stream_controller.dart:606:5)
#19     new _RawSocket.<anonymous closure> (dart:io-patch/socket_patch.dart:1936:33)
#20     _NativeSocket.issueReadEvent.issue (dart:io-patch/socket_patch.dart:1379:14)
#21     _startMicrotaskLoop (dart:async/schedule_microtask.dart:49:5)
#22     _RawReceivePort._handleMessage (dart:isolate-patch/isolate_patch.dart:185:5)

[Alexandre Roux]

Thanks for the report, indeed it seems that putting all the resulting output in memory is causing the error. I'll look into it.

[Alexandre Roux]

To handle such case (i.e. it is trying to add 10GB of output here). I have added a way to discard putting the output in the resulting ProcessResult.stdout. I have added options noStdoutResult and noStderrResult to ShellOptions and runExecutableArguments. In this case the resulting ProcessResult will have a null stdout (or stderr). You can still stream the output as desired but the overall result is discarded and it should solve your issue. Let me know

usage example:

var shell = Shell(options: ShellOptions(noStdoutResult: true));
await shell.run('xxxx');