From e60fb71ff836e482915241309924e1b61f6b0802 Mon Sep 17 00:00:00 2001
From: Fedor Zhilkin <fzhilkin@mail.ru>
Date: Thu, 17 Sep 2020 20:50:38 +0300
Subject: [PATCH] -map filtering

Add map filtering to choose videostream
---
 .../FFMpeg/Arguments/MapStreamArgument.cs       | 17 +++++++++++++++++
 FFMpegCore/FFMpeg/FFMpegArguments.cs            |  3 ++-
 2 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 FFMpegCore/FFMpeg/Arguments/MapStreamArgument.cs

diff --git a/FFMpegCore/FFMpeg/Arguments/MapStreamArgument.cs b/FFMpegCore/FFMpeg/Arguments/MapStreamArgument.cs
new file mode 100644
index 0000000..f6d9977
--- /dev/null
+++ b/FFMpegCore/FFMpeg/Arguments/MapStreamArgument.cs
@@ -0,0 +1,17 @@
+namespace FFMpegCore.Arguments
+{
+    /// <summary>
+    /// Represents choice of video stream, works with one input file
+    /// </summary>
+    public class MapStreamArgument : IArgument
+    {
+        public readonly int VideoStream;
+
+        public MapStreamArgument(int videoStreamNum)
+        {
+            VideoStream = videoStreamNum;
+        }
+
+        public string Text => $"-map 0:{VideoStream}";
+    }
+}
\ No newline at end of file
diff --git a/FFMpegCore/FFMpeg/FFMpegArguments.cs b/FFMpegCore/FFMpeg/FFMpegArguments.cs
index b3285f6..db129ee 100644
--- a/FFMpegCore/FFMpeg/FFMpegArguments.cs
+++ b/FFMpegCore/FFMpeg/FFMpegArguments.cs
@@ -59,7 +59,8 @@ private FFMpegArguments(IInputArgument inputArgument)
         public FFMpegArguments WithDuration(TimeSpan? duration) => WithArgument(new DurationArgument(duration));
         public FFMpegArguments WithFastStart() => WithArgument(new FaststartArgument());
         public FFMpegArguments WithFrameOutputCount(int frames) => WithArgument(new FrameOutputCountArgument(frames));
-        
+        public FFMpegArguments WithVideoStream(int videoStreamNumber) => WithArgument(new MapStreamArgument(videoStreamNumber));
+
         public FFMpegArguments UsingShortest(bool shortest = true) => WithArgument(new ShortestArgument(shortest));
         public FFMpegArguments UsingMultithreading(bool multithread) => WithArgument(new ThreadsArgument(multithread));
         public FFMpegArguments UsingThreads(int threads) => WithArgument(new ThreadsArgument(threads));