[chronojump] Webcam: Cannot playpreview if already capturing

[Xavier de Blas <xaviblas src gnome org>]

commit 66956046cd6c31da5bf7e28ead15e9e37543e750
Author: Xavier de Blas <xaviblas gmail com>
Date:   Tue Jul 16 16:37:25 2019 +0200

    Webcam: Cannot playpreview if already capturing

 src/webcam/webcamFfmpeg.cs | 8 ++++++++
 1 file changed, 8 insertions(+)
---
diff --git a/src/webcam/webcamFfmpeg.cs b/src/webcam/webcamFfmpeg.cs
index 3a842e92..e1e11cca 100644
--- a/src/webcam/webcamFfmpeg.cs
+++ b/src/webcam/webcamFfmpeg.cs
@@ -87,6 +87,10 @@ public class WebcamFfmpeg : Webcam
                if(process != null)
                        return new Result (false, "");
 
+               //cannot play preview with camera recording
+               if (ExecuteProcess.IsRunning3 (-1, GetExecutableCapture(os)))
+                       return new Result (false, "", "ffmpeg is already running");
+
                List<string> parameters = createParametersPlayPreview();
 
                process = new Process();
@@ -103,6 +107,10 @@ public class WebcamFfmpeg : Webcam
        }
        public override Result PlayPreviewNoBackground () //experimental
        {
+               //cannot play preview with camera recording
+               if (ExecuteProcess.IsRunning3 (-1, GetExecutableCapture(os)))
+                       return new Result (false, "", "ffmpeg is already running");
+
                List<string> parameters = createParametersPlayPreview();
 
                process = new Process();