CompletableFuture doesn't raise exceptions for runtime errors

Description

Errors happening after FFMpeg’s startup don’t raise exceptions. FFMpeg startup errors are raised correctly.

Steps to reproduce

1. Run an Nginx server with nginx-rtmp-module installed (such as the alfg/nginx-rtmp docker image)
2. Run an FFMpeg process with the following command ffmpeg -f lavfi -i testsrc=size=1920x1080:rate=25 -f lavfi -i sine=f=1:b=2000 -shortest -f flv rtmp://localhost:1935/proxy/source
3. Run the following test class

import com.github.kokorin.jaffree.StreamType;
import com.github.kokorin.jaffree.ffmpeg.FFmpeg;
import com.github.kokorin.jaffree.ffmpeg.UrlInput;
import com.github.kokorin.jaffree.ffmpeg.UrlOutput;

class TestClass {
    public static void main(String[] args) {
        FFmpeg.atPath()
              .addInput(UrlInput.fromUrl("rtmp://localhost:1935/hls/source"))
              .addOutput(UrlOutput.toUrl("rtmp://localhost:1935/hls/target")
                                  .setFormat("flv")
                                  .addMap(0, StreamType.AUDIO)
                                  .addMap(0, StreamType.VIDEO)
                                  .setCodec(StreamType.AUDIO, "copy")
                                  .setCodec(StreamType.VIDEO, "copy")
              )
              .executeAsync()
              .toCompletableFuture()
              .exceptionally(error -> {
                  System.err.println("An error has occured");
                  error.printStackTrace();

                  return null;
              })
              .join();
    }
}

1. Stop the Nginx server

This error message will come up but no exception will be raised.

c.g.k.jaffree.ffmpeg.FFmpegResultReader : [error] rtmp://localhost:1935/hls/source: Input/output error

Expected behavior

An exception should be raised because this issue causes FFMpeg to be stopped.

Logs

c.g.k.jaffree.ffmpeg.FFmpegResultReader : [error] rtmp://localhost:1935/hls/source: Input/output error

[kokorin]

You could create a branch from develop branch. Usually with GitHub one creates a branch in own fork project. When it’s done, PR could be created.

[k2r79]

Which branch must I start from ? I can see develop is behind master. Do I need specific rights to push my branch ?