Groundwork for playing youtube videos to voice

Geekbot.net/Commands/Voice.cs

@@ -1,4 +1,5 @@
 using System;
+using System.IO;
 using System.Threading.Tasks;
 using Discord;
 using Discord.Commands;
@@ -63,23 +64,32 @@ namespace Geekbot.net.Commands
             }
         }
 
-//        [Command("play")]
-//        public async Task play(IVoiceChannel channel = null)
-//        {
-//            try
-//            {
-//                var audioClient = _audioUtils.GetAudioClient(Context.Guild.Id);
-//                if (audioClient == null)
-//                {
-//                    await Context.Channel.SendMessageAsync("I'm not in a voice channel at the moment");
-//                    return;
-//                }
-//
-//            }
-//            catch (Exception e)
-//            {
-//                _errorHandler.HandleCommandException(e, Context);
-//            }
-//        }
+        [Command("ytplay")]
+        public async Task ytplay(string url)
+        {
+            try
+            {
+                if (!url.Contains("youtube"))
+                {
+                    await ReplyAsync("I can only play youtube videos");
+                    return;
+                }
+                var audioClient = _audioUtils.GetAudioClient(Context.Guild.Id);
+                if (audioClient == null)
+                {
+                    await ReplyAsync("I'm not in a voice channel at the moment");
+                    return;
+                }
+                var ffmpeg = _audioUtils.CreateStreamFromYoutube(url, Context.Guild.Id);
+                var output = ffmpeg.StandardOutput.BaseStream;
+                var discord = audioClient.CreatePCMStream(Discord.Audio.AudioApplication.Mixed);
+                await output.CopyToAsync(discord);
+                await discord.FlushAsync();
+            }
+            catch (Exception e)
+            {
+                _errorHandler.HandleCommandException(e, Context);
+            }
+        }
     }
 }

Geekbot.net/Lib/AudioClientCache.cs

@@ -1,17 +1,28 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Security.Cryptography;
 using Discord.Audio;
+using Discord.Net;
 
 namespace Geekbot.net.Lib
 {
     public class AudioUtils : IAudioUtils
     {
+        private string _tempFolderPath;
         private Dictionary<ulong, IAudioClient> _audioClients;
 
         public AudioUtils()
         {
             _audioClients = new Dictionary<ulong, IAudioClient>();
+            _tempFolderPath = Path.GetFullPath("./temp/");
+            if (!Directory.Exists(_tempFolderPath))
+            {
+                Directory.CreateDirectory(_tempFolderPath);
+            }
         }
-
+        
         public IAudioClient GetAudioClient(ulong guildId)
         {
             return _audioClients[guildId];
@@ -21,11 +32,62 @@ namespace Geekbot.net.Lib
         {
             _audioClients[guildId] = client;
         }
+        
+        public Process CreateStreamFromFile(string path)
+        {
+            var ffmpeg = new ProcessStartInfo
+            {
+                FileName = "ffmpeg",
+                Arguments = $"-i {path} -ac 2 -f s16le -ar 48000 pipe:1",
+                UseShellExecute = false,
+                RedirectStandardOutput = true,
+            };
+            return Process.Start(ffmpeg);
+        }
+
+        public Process CreateStreamFromYoutube(string url, ulong guildId)
+        {
+            var ytdlMediaUrl = GetYoutubeMediaUrl(url);
+            DownloadMediaUrl(ytdlMediaUrl, guildId);
+            return CreateStreamFromFile($"{_tempFolderPath}\\{guildId}.mp3");
+        }
+
+        private string GetYoutubeMediaUrl(string url)
+        {
+            var ytdl = new ProcessStartInfo()
+            {
+                FileName = "youtube-dl",
+                Arguments = $"-f bestaudio -g {url}",
+                UseShellExecute = false,
+                RedirectStandardOutput = true
+            };
+            var output = Process.Start(ytdl).StandardOutput.ReadToEnd();
+            if (string.IsNullOrWhiteSpace(output))
+            {
+                throw new System.Exception("Could not get Youtube Media URL");
+            }
+            return output;
+        }
+
+        private void DownloadMediaUrl(string url, ulong guildId)
+        {
+            var ffmpeg = new ProcessStartInfo
+            {
+                FileName = "ffmpeg",
+                Arguments = $"-re -i \"${url}\" -c:a mp3 -b:a 256k {_tempFolderPath}\\{guildId}.mp3",
+                UseShellExecute = false,
+                RedirectStandardOutput = true,
+            };
+            Process.Start(ffmpeg).WaitForExit();
+            return;
+        }
     }
 
     public interface IAudioUtils
     {
         IAudioClient GetAudioClient(ulong guildId);
         void StoreAudioClient(ulong guildId, IAudioClient client);
+        Process CreateStreamFromFile(string path);
+        Process CreateStreamFromYoutube(string url, ulong guildId);
     }
 }

readme.md

@@ -11,6 +11,7 @@ You can invite Geekbot to your server with [this link](https://discordapp.com/oa
 * DotNet Core 2
 * Redis
 * Discord.net
+* ffmpeg
 
 ## Running