Introduce .NET bindings

.gitignore

@@ -41,9 +41,17 @@
 /base
 /build
 /buildtools
+/examples/unity/*
+!/examples/unity/Assets
+!/examples/unity/Packages
+!/examples/unity/ProjectSettings
 /ios
 /mojo
 /out
+/sdk/dotnet/unity/bin
+/sdk/dotnet/unity/obj
+/sdk/dotnet/webrtc/bin
+/sdk/dotnet/webrtc/obj
 /testing
 /third_party
 /tools

BUILD.gn

@@ -80,6 +80,9 @@ if (!build_with_chromium) {
         ]
       }
     }
+    if (rtc_enable_symbol_export && !is_android) {
+      deps += [ ":jingle_peerconnection_so" ]
+    }
   }
 }
 
@@ -389,8 +392,8 @@ config("common_objc") {
 if (!build_with_chromium) {
   # Target to build all the WebRTC production code.
   rtc_static_library("webrtc") {
-    # Only the root target should depend on this.
-    visibility = [ "//:default" ]
+    # Only the root target and "shared:webrtc" should depend on this.
+    visibility = [ "//:default", "shared:webrtc" ]
 
     sources = []
     complete_static_lib = true
@@ -669,6 +672,16 @@ if (rtc_include_tests) {
   }
 }
 
+if (!is_android) {
+  rtc_shared_library("jingle_peerconnection_so") {
+    deps = [
+      "sdk/c",
+      "pc:libjingle_peerconnection",
+      "rtc_base",
+    ]
+  }
+}
+
 # ---- Poisons ----
 #
 # Here is one empty dummy target for each poison type (needed because

README.pixiv.md

@@ -0,0 +1,144 @@
+This is a fork of WebRTC made by [pixiv Inc](https://www.pixiv.co.jp/).
+
+# Changes
+- `rtc_symbol_enable_export` is compatible with Windows build.
+- `tools_webrtc/libs/generate_licenses.py` is compatible with Windows build.
+- Partial C bindings are introduced at `sdk/c`
+- .NET bindings based on C bindings are introduced at `sdk/dotnet`
+  - `sdk/dotnet/unity` is a Unity package. Build with MSBuild.
+  - `example/unity` is an example to connect to
+    [WebRTC SFU Sora](https://sora.shiguredo.jp/) on Unity.
+- Native APIs are availble for Android library.
+- `webrtc::VideoBuffer`, a simple `webrtc::VideoSinkInterface` which allows you
+  to retrieve the last frame at an arbitrary time is introduced.
+
+# .NET bindings
+
+## Features
+
+There are a few .NET binding libraries for WebRTC. Such examples include:
+
+- [WebRTC for the Universal Windows Platform (webrtc-uwp)](https://webrtc-uwp.github.io/)
+- [MixedReality-WebRTC](https://github.com/microsoft/MixedReality-WebRTC), based on webrtc-uwp
+- [Unity Render Streaming](https://github.com/Unity-Technologies/UnityRenderStreaming)
+- The unity plugin located at `sdk/unityplugin`
+
+The bindings provided by this fork has following *unique* features:
+
+- Portable
+  - .NET Standard 2.0
+  - Satisfies additional requirements of [Mono's full AOT](https://www.mono-project.com/docs/advanced/aot/#full-aot)
+    and [IL2CPP](https://docs.unity3d.com/Manual/IL2CPP.html).
+  - No Unity or other runtime dependency.
+  - No operating system requirements other than WebRTC requirements.
+- Up-to-date
+  - [Unified Plan](https://webrtc.org/web-apis/chrome/unified-plan/)
+  - Available as a Unity [package](https://docs.unity3d.com/Manual/Packages.html),
+    whose format is an enhancement of traditional Unity asset packages.
+- Extensible
+  - Its interface-based API design allows to create bindings for C++ code using
+    native API.
+  - As low-level as native API.
+    - No assumption for inputs/outputs. Use [Unity's RenderTexture](https://docs.unity3d.com/Manual/class-RenderTexture.html)
+      or whatever.
+    - No assumption for signaling. You can use existing signaling server
+      implementations such as [Sora](https://sora.shiguredo.jp/) and SaaS such
+      as [ImageFlux Live Streaming](https://www.sakura.ad.jp/services/imageflux/livestreaming/).
+    - This also means you need more code to integrate it to an application.
+- Provides comprehensive license file
+  - Although it may sound ridiculous to say this as a *unique* feature, it is
+    almost impossible to create one without
+    `tools_webrtc/libs/generate_licenses.py`.
+
+## Tested platforms
+
+- Unity on Android
+- Unity on Linux/X11
+- Unity on Windows
+- Unity on iOS
+- Unity on macOS
+
+## Why fork instead of implementing C/.NET bindings completely out-of-tree?
+
+By forking and extending the build infrastructure for C/.NET bindings, the
+build system of those bindings are automatically aligned with the one of the
+library itself.
+
+The build system of WebRTC also contributes to the portability because it is of
+course capable to build for any platforms WebRTC supports.
+
+The changes made in existing code for the bindings are minimal, and it is
+expected to be easy to maintain them, comparing with possible tons of build
+scripts and their messes. (Note that it supports multiple platforms.)
+
+## Using the bindings
+
+The bindings are simple mappings for native APIs. See
+https://webrtc.org/native-code/native-apis/ for details of native APIs.
+
+You may also refer to `examples/unity` for .NET/Unity specifics.
+
+## Coding style
+
+C# coding style is conforming to
+[.NET Core coding style](https://github.com/dotnet/corefx/blob/master/Documentation/coding-guidelines/coding-style.md).
+
+## Release build procedure
+
+Currently unity package is built manually because of build system complications.
+The release build procedure is as follows:
+
+1. Prepare a computer with Linux installed for Android, Linux, and Windows
+   builds according to https://webrtc.org/native-code/development/.
+
+2. Check out this code base at `src`.
+
+3. Build `unity.msbuildproj` with:
+  * `src/sdk/dotnet/unity` as the working directory,
+  * `Android;LinuxX64;WinX64` as `Targets` property, and
+  * `Release` as `Configuration` property
+
+4. Prepare a computer with macOS installed for iOS and macOS builds according to
+   https://webrtc.org/native-code/development/.
+
+5. Check out this code base at `src`.
+
+6. Build `src/sdk/dotnet/unity/unity.msbuildproj` the following properties:
+  * `src/sdk/dotnet/unity` as the working directory,
+  * `Ios;MacX64` as `Targets` property, and
+  * `Release` as `Configuration` property
+
+7. Copy `Editor` and `Editor.meta` in `src/sdk/dotnet/unity/bin/Release`
+   produced by 6 to `src/sdk/dotnet/unity/bin/Release` produced by 3.
+
+8. Copy the contents of `src/sdk/dotnet/unity/bin/Release/Runtime`
+   produced by 6 to `src/sdk/dotnet/unity/bin/Release/Runtime` produced by 3.
+   Do not overwrite exist files.
+
+9. Add license notices included in `src/sdk/dotnet/unity/bin/Release/LICENSE.md`
+   produced by 6 to one produced by 3 if they are missing.
+
+9. Make a tarball containing `src/sdk/dotnet/unity/bin/Release/Runtime`
+   produced by 3 as `package` directory.
+
+10. Gzip the tarball produced by 9.
+
+# Further enhancements
+
+The following is something nice to have, but it is not currently planned to
+implement them:
+
+- Automated tests
+- Examples for .NET Core, .NET Framework/Mono and Xamarin
+- Examples independent of Sora
+- NuGet package
+
+# Additional copyright notice
+
+`examples/unity/Assets/aint_we_got_fun_billy_jones1921.mp3` is a recording of
+_Ain't We Got Fun_, performed by Billy Jones. It is distributed by Digital
+History.
+    Mintz, S., & McNeil, S. (2016). Digital History.
+    http://www.digitalhistory.uh.edu/music/music.cfm
+
+The copyrights of the recording has expired and it is in the public domain.

api/jsep.h

@@ -17,6 +17,8 @@
 // Though in the future, we're planning to provide an SDP parsing API, with a
 // structure more friendly than cricket::SessionDescription.
 
+#include "sdk/c/api/jsep.h"
+
 #ifndef API_JSEP_H_
 #define API_JSEP_H_
 
@@ -100,11 +102,15 @@ class IceCandidateCollection {
 // Corresponds to RTCSdpType in the WebRTC specification.
 // https://w3c.github.io/webrtc-pc/#dom-rtcsdptype
 enum class SdpType {
-  kOffer,     // Description must be treated as an SDP offer.
-  kPrAnswer,  // Description must be treated as an SDP answer, but not a final
-              // answer.
-  kAnswer  // Description must be treated as an SDP final answer, and the offer-
-           // answer exchange must be considered complete after receiving this.
+  // Description must be treated as an SDP offer.
+  kOffer = WEBRTC_SDP_TYPE_OFFER,
+
+  // Description must be treated as an SDP answer, but not a final answer.
+  kPrAnswer = WEBRTC_SDP_TYPE_PR_ANSWER,
+
+  // Description must be treated as an SDP final answer, and the offer-
+  // answer exchange must be considered complete after receiving this.
+  kAnswer = WEBRTC_SDP_TYPE_ANSER
 };
 
 // Returns the string form of the given SDP type. String forms are defined in

api/media_stream_interface.h

@@ -14,6 +14,8 @@
 // interfaces must be used only with PeerConnection. PeerConnectionManager
 // interface provides the factory methods to create MediaStream and MediaTracks.
 
+#include "sdk/c/api/media_stream_interface.h"
+
 #ifndef API_MEDIA_STREAM_INTERFACE_H_
 #define API_MEDIA_STREAM_INTERFACE_H_
 
@@ -56,7 +58,12 @@ class NotifierInterface {
 class RTC_EXPORT MediaSourceInterface : public rtc::RefCountInterface,
                                         public NotifierInterface {
  public:
-  enum SourceState { kInitializing, kLive, kEnded, kMuted };
+  enum SourceState {
+    kInitializing = WEBRTC_MEDIA_SOURCE_INTERFACE_SOURCE_STATE_INITIALIZING,
+    kLive = WEBRTC_MEDIA_SOURCE_INTERFACE_SOURCE_STATE_LIVE,
+    kEnded = WEBRTC_MEDIA_SOURCE_INTERFACE_SOURCE_STATE_ENDED,
+    kMuted = WEBRTC_MEDIA_SOURCE_INTERFACE_SOURCE_STATE_MUTED
+  };
 
   virtual SourceState state() const = 0;