Close u2takey/ffmpeg-go#80

Discover CommandOption type and ffmpeg.GlobalCommandOptions array, that is processed before running ffmpeg or ffprobe commands.
Add tests.

ffmpeg_linux_test.go

@@ -9,6 +9,19 @@ import (
 func TestCompileWithOptions(t *testing.T) {
 	out := Input("dummy.mp4").Output("dummy2.mp4")
 	cmd := out.Compile(SeparateProcessGroup())
-	assert.Equal(t, cmd.SysProcAttr.Pgid, 0)
+	assert.Equal(t, 0, cmd.SysProcAttr.Pgid)
+	assert.True(t, cmd.SysProcAttr.Setpgid)
+}
+
+func TestGlobalCommandOptions(t *testing.T) {
+	out := Input("dummy.mp4").Output("dummy2.mp4")
+	GlobalCommandOptions = append(GlobalCommandOptions, func(cmd *exec.Cmd) {
+		cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true, Pgid: 0}
+	})
+	defer func() {
+		GlobalCommandOptions = GlobalCommandOptions[0 : len(GlobalCommandOptions)-1]
+	}()
+	cmd := out.Compile()
+	assert.Equal(t, 0, cmd.SysProcAttr.Pgid)
 	assert.True(t, cmd.SysProcAttr.Setpgid)
 }

ffmpeg_windows_test.go

@@ -18,3 +18,18 @@ func TestCompileWithOptions(t *testing.T) {
 	})
 	assert.Equal(t, true, cmd.SysProcAttr.HideWindow)
 }
+
+func TestGlobalCommandOptions(t *testing.T) {
+	out := Input("dummy.mp4").Output("dummy2.mp4")
+	GlobalCommandOptions = append(GlobalCommandOptions, func(cmd *exec.Cmd) {
+		if cmd.SysProcAttr == nil {
+			cmd.SysProcAttr = &syscall.SysProcAttr{}
+		}
+		cmd.SysProcAttr.HideWindow = true
+	})
+	defer func() {
+		GlobalCommandOptions = GlobalCommandOptions[0 : len(GlobalCommandOptions)-1]
+	}()
+	cmd := out.Compile()
+	assert.Equal(t, true, cmd.SysProcAttr.HideWindow)
+}

probe.go

@@ -34,6 +34,9 @@ func ProbeWithTimeoutExec(fileName string, timeOut time.Duration, kwargs KwArgs)
 	cmd := exec.CommandContext(ctx, "ffprobe", args...)
 	buf := bytes.NewBuffer(nil)
 	cmd.Stdout = buf
+	for _, option := range GlobalCommandOptions {
+		option(cmd)
+	}
 	err := cmd.Run()
 	if err != nil {
 		return "", err

run.go

@@ -236,6 +236,10 @@ func (s *Stream) ErrorToStdOut() *Stream {
 	return s.WithErrorOutput(os.Stdout)
 }
 
+type CommandOption func(cmd *exec.Cmd)
+
+var GlobalCommandOptions = make([]CommandOption, 0)
+
 type CompilationOption func(s *Stream, cmd *exec.Cmd)
 
 func (s *Stream) SetFfmpegPath(path string) *Stream {
@@ -259,6 +263,9 @@ func (s *Stream) Compile(options ...CompilationOption) *exec.Cmd {
 	for _, option := range options {
 		option(s, cmd)
 	}
+	for _, option := range GlobalCommandOptions {
+		option(cmd)
+	}
 	log.Printf("compiled command: ffmpeg %s\n", strings.Join(args, " "))
 	return cmd
 }