From ca8275436b82d3335724c260a2660d09d8633071 Mon Sep 17 00:00:00 2001
From: Sky Z <qe201020335@sina.com>
Date: Thu, 14 Jul 2022 02:23:38 -0400
Subject: [PATCH] Add other stream types to Channel (V,s,d,t)

---
 FFMpegCore/FFMpeg/Arguments/CopyArgument.cs   |  5 ++-
 .../FFMpeg/Arguments/MapStreamArgument.cs     | 17 ++++++---
 FFMpegCore/FFMpeg/Enums/Enums.cs              | 35 ++++++++++++++++++-
 FFMpegCore/FFMpeg/FFMpegArgumentOptions.cs    |  7 ++--
 4 files changed, 53 insertions(+), 11 deletions(-)

diff --git a/FFMpegCore/FFMpeg/Arguments/CopyArgument.cs b/FFMpegCore/FFMpeg/Arguments/CopyArgument.cs
index 91419d5..eeac4c8 100644
--- a/FFMpegCore/FFMpeg/Arguments/CopyArgument.cs
+++ b/FFMpegCore/FFMpeg/Arguments/CopyArgument.cs
@@ -16,9 +16,8 @@ public CopyArgument(Channel channel = Channel.Both)
 
         public string Text => Channel switch
         {
-            Channel.Audio => "-c:a copy",
-            Channel.Video => "-c:v copy",
-            _ => "-c copy"
+            Channel.Both => "-c:a copy -c:v copy",
+            _ => $"-c{Channel.StreamType()} copy"
         };
     }
 }
diff --git a/FFMpegCore/FFMpeg/Arguments/MapStreamArgument.cs b/FFMpegCore/FFMpeg/Arguments/MapStreamArgument.cs
index b904be5..66087b6 100644
--- a/FFMpegCore/FFMpeg/Arguments/MapStreamArgument.cs
+++ b/FFMpegCore/FFMpeg/Arguments/MapStreamArgument.cs
@@ -1,19 +1,28 @@
-namespace FFMpegCore.Arguments
+using FFMpegCore.Enums;
+
+namespace FFMpegCore.Arguments
 {
     /// <summary>
-    /// Represents choice of video stream
+    /// Represents choice of stream by the stream specifier 
     /// </summary>
     public class MapStreamArgument : IArgument
     {
         private readonly int _inputFileIndex;
         private readonly int _streamIndex;
+        private readonly Channel _channel;
 
-        public MapStreamArgument(int streamIndex, int inputFileIndex)
+        public MapStreamArgument(int streamIndex, int inputFileIndex, Channel channel = Channel.All)
         {
+            if (channel == Channel.Both)
+            {
+                // "Both" is not valid in this case and probably means all stream types
+                channel = Channel.All;
+            }
             _inputFileIndex = inputFileIndex;
             _streamIndex = streamIndex;
+            _channel = channel;
         }
 
-        public string Text => $"-map {_inputFileIndex}:{_streamIndex}";
+        public string Text => $"-map {_inputFileIndex}{_channel.StreamType()}:{_streamIndex}";
     }
 }
\ No newline at end of file
diff --git a/FFMpegCore/FFMpeg/Enums/Enums.cs b/FFMpegCore/FFMpeg/Enums/Enums.cs
index 7520fea..a6eb413 100644
--- a/FFMpegCore/FFMpeg/Enums/Enums.cs
+++ b/FFMpegCore/FFMpeg/Enums/Enums.cs
@@ -46,10 +46,43 @@ public enum Filter
         Aac_AdtstoAsc
     }
 
+    /// <summary>
+    /// https://ffmpeg.org/ffmpeg.html#Stream-specifiers-1
+    /// ’v’ or ’V’ for video, ’a’ for audio, ’s’ for subtitle, ’d’ for data, and ’t’ for attachments
+    /// ’V’ only matches video streams which are not attached pictures, video thumbnails or cover arts.
+    /// Both for audio + video
+    /// All for all types
+    /// </summary>
     public enum Channel
     {
         Audio,
         Video,
-        Both
+        Both,
+        VideoNoAttachedPic,
+        Subtitle,
+        Data,
+        Attachments,
+        All
     }
+    internal static class ChannelMethods
+    {
+        /// <summary>
+        /// <see cref="Channel.Both"/> is left as empty because it cannot be in a single stream specifier
+        /// </summary>
+        /// <returns>The stream_type used in stream specifiers</returns>
+        public static string StreamType(this Channel channel)
+        {
+            return channel switch
+            {
+                Channel.Audio => ":a",
+                Channel.Video => ":v",
+                Channel.VideoNoAttachedPic => ":V",
+                Channel.Subtitle => ":s",
+                Channel.Data => ":d",
+                Channel.Attachments => ":t",
+                _ => string.Empty
+            };
+        }
+    }
+
 }
\ No newline at end of file
diff --git a/FFMpegCore/FFMpeg/FFMpegArgumentOptions.cs b/FFMpegCore/FFMpeg/FFMpegArgumentOptions.cs
index 171264e..a84c86e 100644
--- a/FFMpegCore/FFMpeg/FFMpegArgumentOptions.cs
+++ b/FFMpegCore/FFMpeg/FFMpegArgumentOptions.cs
@@ -61,9 +61,10 @@ public FFMpegArgumentOptions WithAudioFilters(Action<AudioFilterOptions> audioFi
         public FFMpegArgumentOptions Seek(TimeSpan? seekTo) => WithArgument(new SeekArgument(seekTo));
         public FFMpegArgumentOptions Loop(int times) => WithArgument(new LoopArgument(times));
         public FFMpegArgumentOptions OverwriteExisting() => WithArgument(new OverwriteArgument());
-        public FFMpegArgumentOptions SelectStream(int streamIndex, int inputFileIndex = 0) => WithArgument(new MapStreamArgument(streamIndex, inputFileIndex));
-        public FFMpegArgumentOptions SelectStreams(IEnumerable<int> streamIndices, int inputFileIndex = 0) =>
-            streamIndices.Aggregate(this, (options, streamIndex) => options.SelectStream(streamIndex, inputFileIndex));
+        public FFMpegArgumentOptions SelectStream(int streamIndex, int inputFileIndex = 0,
+            Channel channel = Channel.All) => WithArgument(new MapStreamArgument(streamIndex, inputFileIndex, channel));
+        public FFMpegArgumentOptions SelectStreams(IEnumerable<int> streamIndices, int inputFileIndex = 0, Channel channel = Channel.All) =>
+            streamIndices.Aggregate(this, (options, streamIndex) => options.SelectStream(streamIndex, inputFileIndex, channel));
 
         public FFMpegArgumentOptions ForceFormat(ContainerFormat format) => WithArgument(new ForceFormatArgument(format));
         public FFMpegArgumentOptions ForceFormat(string format) => WithArgument(new ForceFormatArgument(format));