implemented option to set playback volume

Author: munzili

DemoHarness/Program.cs

@@ -46,6 +46,12 @@ private static void Main(string[] args)
                             fileName = Console.ReadLine();
                             ShowInstruction();
                             break;
+                        case "volume":
+                            Console.WriteLine("Enter new volume in percent");
+                            byte volume = Convert.ToByte(Console.ReadLine());
+                            player.SetVolume(volume).Wait();
+                            ShowInstruction();
+                            break;
                         case "exit":
                             break;
                         default:
@@ -75,6 +81,7 @@ private static void ShowInstruction()
             Console.WriteLine("resume - Resume the playback");
             Console.WriteLine("stop - Stop the playback");
             Console.WriteLine("change - Change the file name");
+            Console.WriteLine("volume - Set the volume");
             Console.WriteLine("exit - Exit the app");
         }
 

NetCoreAudio/Interfaces/IPlayer.cs

@@ -14,5 +14,6 @@ public interface IPlayer
         Task Pause();
         Task Resume();
         Task Stop();
+        Task SetVolume(byte percent);
     }
 }

NetCoreAudio/Player.cs

@@ -80,5 +80,14 @@ private void OnPlaybackFinished(object sender, EventArgs e)
         {
             PlaybackFinished?.Invoke(this, e);
         }
+
+        /// <summary>
+        /// Sets the playing volume as percent
+        /// </summary>
+        /// <returns></returns>
+        public async Task SetVolume(byte percent)
+        {
+            await _internalPlayer.SetVolume(percent);
+        }
     }
-}
+}

NetCoreAudio/Players/LinuxPlayer.cs

@@ -1,5 +1,7 @@
 using NetCoreAudio.Interfaces;
+using System;
 using System.IO;
+using System.Threading.Tasks;
 
 namespace NetCoreAudio.Players
 {
@@ -16,5 +18,16 @@ protected override string GetBashCommand(string fileName)
                 return "aplay -q";
             }
         }
+
+        public override Task SetVolume(byte percent)
+        {
+            if (percent > 100)
+                throw new ArgumentOutOfRangeException(nameof(percent), "Percent can't exceed 100");
+
+            var tempProcess = StartBashProcess($"amixer -M set Headphone {percent}%");
+            tempProcess.WaitForExit();
+
+            return Task.CompletedTask;
+        }
     }
 }

NetCoreAudio/Players/MacPlayer.cs

@@ -1,4 +1,6 @@
 using NetCoreAudio.Interfaces;
+using System;
+using System.Threading.Tasks;
 
 namespace NetCoreAudio.Players
 {
@@ -8,5 +10,16 @@ protected override string GetBashCommand(string fileName)
         {
             return "afplay";
         }
+
+        public override Task SetVolume(byte percent)
+        {
+            if (percent > 100)
+                throw new ArgumentOutOfRangeException(nameof(percent), "Percent can't exceed 100");
+
+            var tempProcess = StartBashProcess($"osascript -e \"set volume output volume {percent}\"");
+            tempProcess.WaitForExit();
+
+            return Task.CompletedTask;
+        }
     }
 }

NetCoreAudio/Players/UnixPlayerBase.cs

@@ -99,5 +99,7 @@ internal void HandlePlaybackFinished(object sender, EventArgs e)
                 PlaybackFinished?.Invoke(this, e);
             }
         }
+
+        public abstract Task SetVolume(byte percent);
     }
 }

NetCoreAudio/Players/WindowsPlayer.cs

@@ -17,7 +17,10 @@ internal class WindowsPlayer : IPlayer
 		[DllImport("winmm.dll")]
 		private static extern int mciGetErrorString(int errorCode, StringBuilder errorText, int errorTextSize);
 
-		private Timer _playbackTimer;
+        [DllImport("winmm.dll")]
+        public static extern int waveOutSetVolume(IntPtr hwo, uint dwVolume);
+
+        private Timer _playbackTimer;
         private Stopwatch _playStopwatch;
 
 		private string _fileName;
@@ -119,5 +122,17 @@ private Task ExecuteMsiCommand(string commandString)
 
             return Task.CompletedTask;
         }
-	}
+
+        public Task SetVolume(byte percent)
+        {
+            // Calculate the volume that's being set
+            int NewVolume = ushort.MaxValue / 100 * percent;
+            // Set the same volume for both the left and the right channels
+            uint NewVolumeAllChannels = ((uint)NewVolume & 0x0000ffff) | ((uint)NewVolume << 16);
+            // Set the volume
+            waveOutSetVolume(IntPtr.Zero, NewVolumeAllChannels);
+
+            return Task.CompletedTask;
+        }
+    }
 }