Haydn: Part 1 (#2007)

* Haydn: Part 1

Based on my reverse of audio 11.0.0.

As always, core implementation under LGPLv3 for the same reasons as for Amadeus.

This place the bases of a more flexible audio system while making audout & audin accurate.

This have the following improvements:
- Complete reimplementation of audout and audin.
- Audin currently only have a dummy backend.
- Dramatically reduce CPU usage by up to 50% in common cases (SoundIO and OpenAL).
- Audio Renderer now can output to 5.1 devices when supported.
- Audio Renderer init its backend on demand instead of keeping two up all the time.
- All backends implementation are now in their own project.
- Ryujinx.Audio.Renderer was renamed Ryujinx.Audio and was refactored because of this.

As a note, games having issues with OpenAL haven't improved and will not
because of OpenAL design (stopping when buffers finish playing causing
possible audio "pops" when buffers are very small).

* Update for latest hexkyz's edits on Switchbrew

* audren: Rollback channel configuration changes

* Address gdkchan's comments

* Fix typo in OpenAL backend driver

* Address last comments

* Fix a nit

* Address gdkchan's comments

Ryujinx.Audio.Renderer/Integration/HardwareDevice.cs

@@ -1,60 +0,0 @@
-//
-// Copyright (c) 2019-2021 Ryujinx
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with this program.  If not, see <https://www.gnu.org/licenses/>.
-//
-
-using System;
-using System.Diagnostics;
-
-namespace Ryujinx.Audio.Renderer.Integration
-{
-    /// <summary>
-    /// Represent an hardware device used in <see cref="Dsp.Command.DeviceSinkCommand"/>
-    /// </summary>
-    public interface HardwareDevice : IDisposable
-    {
-        /// <summary>
-        /// Get the supported sample rate of this device.
-        /// </summary>
-        /// <returns>The supported sample rate of this device.</returns>
-        uint GetSampleRate();
-
-        /// <summary>
-        /// Get the channel count supported by this device.
-        /// </summary>
-        /// <returns>The channel count supported by this device.</returns>
-        uint GetChannelCount();
-
-        /// <summary>
-        /// Appends new PCM16 samples to the device.
-        /// </summary>
-        /// <param name="data">The new PCM16 samples.</param>
-        /// <param name="channelCount">The number of channels.</param>
-        void AppendBuffer(ReadOnlySpan<short> data, uint channelCount);
-
-        /// <summary>
-        /// Check if the audio renderer needs to perform downmixing.
-        /// </summary>
-        /// <returns>True if downmixing is needed.</returns>
-        public bool NeedDownmixing()
-        {
-            uint channelCount = GetChannelCount();
-
-            Debug.Assert(channelCount > 0 && channelCount <= RendererConstants.ChannelCountMax);
-
-            return channelCount != RendererConstants.ChannelCountMax;
-        }
-    }
-}