From 4a7144cd92d92faee6a11743cf7bdb960bf9b60a Mon Sep 17 00:00:00 2001
From: John Andrews <john@reven.co.nz>
Date: Wed, 26 Jul 2023 13:55:34 +1200
Subject: [PATCH] FF-1016 - fixing opus side by side

---
 .../Audio/FfmpegBuilderAudioAddTrack.cs       | 40 +++++++++++++++++--
 .../Audio/FfmpegBuilderAudioConvert.cs        | 16 +++++---
 2 files changed, 48 insertions(+), 8 deletions(-)

diff --git a/VideoNodes/FfmpegBuilderNodes/Audio/FfmpegBuilderAudioAddTrack.cs b/VideoNodes/FfmpegBuilderNodes/Audio/FfmpegBuilderAudioAddTrack.cs
index 10198708..8a8cb008 100644
--- a/VideoNodes/FfmpegBuilderNodes/Audio/FfmpegBuilderAudioAddTrack.cs
+++ b/VideoNodes/FfmpegBuilderNodes/Audio/FfmpegBuilderAudioAddTrack.cs
@@ -201,7 +201,7 @@ public class FfmpegBuilderAudioAddTrack : FfmpegBuilderNode
         else
         {
             int sampleRate = SampleRate == 1 ? audio.Stream.SampleRate : SampleRate;
-            audio.EncodingParameters.AddRange(GetNewAudioTrackParameters(Codec, Channels, Bitrate, sampleRate));
+            audio.EncodingParameters.AddRange(GetNewAudioTrackParameters(args, Codec, Channels, Bitrate, sampleRate));
             if (this.Channels > 0)
                 audio.Channels = this.Channels;
         }
@@ -285,14 +285,16 @@ public class FfmpegBuilderAudioAddTrack : FfmpegBuilderNode
     /// <summary>
     /// Gets hte new audio track parameters
     /// </summary>
+    /// <param name="args">the node parameters</param>
     /// <param name="codec">the codec of the new track</param>
     /// <param name="channels">the channels of the new track</param>
     /// <param name="bitrate">the bitrate of the new track</param>
     /// <param name="sampleRate">the sample rate</param>
     /// <returns>the new track parameters</returns>
-    internal static string[] GetNewAudioTrackParameters(string codec, float channels, int bitrate, int sampleRate)
+    internal static string[] GetNewAudioTrackParameters(NodeParameters args, string codec, float channels, int bitrate, int sampleRate)
     {
-        if (codec == "opus")
+        bool opus = codec == "opus"; 
+        if (opus)
             codec = "libopus";
         
         // Prepare the options list
@@ -309,6 +311,36 @@ public class FfmpegBuilderAudioAddTrack : FfmpegBuilderNode
             options.Add("-ac:a:{index}");
             options.Add(channels.ToString());
         }
+        else if (opus)
+        {
+            // FF-1016: Opus needs this for side by side channel layout
+            args.Logger?.ILog("OPUS Audio");
+            if (Math.Abs(channels - 61) < 1)
+            {
+                args.Logger?.ILog("Channels 61 detected setting to 8");
+                options.AddRange(new[] { "-ac:a:{index}", "8" });
+            }
+            else if (channels is > 5 and <= 6 || Math.Abs(channels - 51) < 1)
+            {
+                args.Logger?.ILog("Channels between 5 and 6 or 50/51 detected setting to 6");
+                options.AddRange(new[] { "-ac:a:{index}", "6" });
+            }
+            else if (channels is >= 4 and <= 5 || Math.Abs(channels - 40) < 2)
+            {
+                args.Logger?.ILog("Channels between 4 and 5 or 40/41 detected setting to 4");
+                options.AddRange(new[] { "-ac:a:{index}", "4" });
+            }
+            else if (channels == 0)
+            {
+                args.Logger?.ILog("No channels detected setting to 4");
+                options.AddRange(new[] { "-ac:a:{index}", "2" });
+            }
+            else if (Math.Abs(channels - 5) < 0.5)
+            {
+                args.Logger?.ILog("Channels 5 detected setting to 5");
+                options.AddRange(new[] { "-ac:a:{index}", "5" });
+            }
+        }
 
         // Handle bitrate
         if (bitrate > 0)
@@ -323,6 +355,8 @@ public class FfmpegBuilderAudioAddTrack : FfmpegBuilderNode
             options.Add("-ar:a:{index}");
             options.Add(sampleRate.ToString());
         }
+        
+        args.Logger.ILog("New Audo Arguments: " + string.Join(" ", options));
 
         return options.ToArray();
     }
diff --git a/VideoNodes/FfmpegBuilderNodes/Audio/FfmpegBuilderAudioConvert.cs b/VideoNodes/FfmpegBuilderNodes/Audio/FfmpegBuilderAudioConvert.cs
index fbcad09f..edd8ba08 100644
--- a/VideoNodes/FfmpegBuilderNodes/Audio/FfmpegBuilderAudioConvert.cs
+++ b/VideoNodes/FfmpegBuilderNodes/Audio/FfmpegBuilderAudioConvert.cs
@@ -104,7 +104,7 @@ public class FfmpegBuilderAudioConverter : FfmpegBuilderNode
 
             if (string.IsNullOrEmpty(this.Pattern))
             {
-                converting |= ConvertTrack(track);
+                converting |= ConvertTrack(args, track);
                 continue;
             }
 
@@ -120,14 +120,20 @@ public class FfmpegBuilderAudioConverter : FfmpegBuilderNode
                     matches = !matches;
                 if (matches)
                 {
-                    converting |= ConvertTrack(track);
+                    converting |= ConvertTrack(args, track);
                 }
             }
         }
         return converting ? 1: 2;
     }
-
-    private bool ConvertTrack(FfmpegAudioStream stream)
+    
+    /// <summary>
+    /// Converts and audio track
+    /// </summary>
+    /// <param name="args">the node arguments</param>
+    /// <param name="stream">teh stream to convert</param>
+    /// <returns>if the stream had to be converted or not</returns>
+    private bool ConvertTrack(NodeParameters args, FfmpegAudioStream stream)
     {
         bool codecSame = stream.Stream.Codec?.ToLower() == Codec?.ToLower();
         bool channelsSame = Channels == 0 || Channels == stream.Stream.Channels;
@@ -136,7 +142,7 @@ public class FfmpegBuilderAudioConverter : FfmpegBuilderNode
         if (codecSame && channelsSame && bitrateSame)
             return false;
 
-        stream.EncodingParameters.AddRange(FfmpegBuilderAudioAddTrack.GetNewAudioTrackParameters(Codec, Channels, Bitrate, 0));
+        stream.EncodingParameters.AddRange(FfmpegBuilderAudioAddTrack.GetNewAudioTrackParameters(args, Codec, Channels, Bitrate, 0));
         return true;
     }
 }