RtpTransceiver bindings & requirements for publishing tracks (#39)

- RtpSender
- RtpReceiver
- RtpTransceiver
- RtpParameters
- VideoFrameBuilder
- Interior mutability on c++ side
- Cleanup bindings ( Use #pragma once instead of include guards )
     - webrtc-sys/src/* headers are now used in only one place 
     - Avoid confusion between generated headers and our headers
- AdaptedVideoTrackSource
- Cleanup the workaround with unsupported Vec<Shared<T>>
    - Put everything inside one file

webrtc-sys/src/rtp_transceiver.rs

@@ -1,10 +1,62 @@
+use crate::impl_thread_safety;
+
 #[cxx::bridge(namespace = "livekit")]
 pub mod ffi {
+
+    #[derive(Debug)]
+    pub struct RtpTransceiverInit {
+        pub direction: RtpTransceiverDirection,
+        pub stream_ids: Vec<String>,
+        pub send_encodings: Vec<RtpEncodingParameters>,
+    }
+
+    extern "C++" {
+        include!("livekit/webrtc.h");
+        include!("livekit/rtp_parameters.h");
+        include!("livekit/rtp_sender.h");
+        include!("livekit/rtp_receiver.h");
+
+        type MediaType = crate::webrtc::ffi::MediaType;
+        type RtpTransceiverDirection = crate::webrtc::ffi::RtpTransceiverDirection;
+        type RtpEncodingParameters = crate::rtp_parameters::ffi::RtpEncodingParameters;
+        type RtpCodecCapability = crate::rtp_parameters::ffi::RtpCodecCapability;
+        type RtpHeaderExtensionCapability =
+            crate::rtp_parameters::ffi::RtpHeaderExtensionCapability;
+        type RtpSender = crate::rtp_sender::ffi::RtpSender;
+        type RtpReceiver = crate::rtp_receiver::ffi::RtpReceiver;
+    }
+
     unsafe extern "C++" {
         include!("livekit/rtp_transceiver.h");
 
         type RtpTransceiver;
 
-        fn _unique_rtp_transceiver() -> UniquePtr<RtpTransceiver>; // Ignore
+        fn media_type(self: &RtpTransceiver) -> MediaType;
+        fn mid(self: &RtpTransceiver) -> Result<String>;
+        fn sender(self: &RtpTransceiver) -> SharedPtr<RtpSender>;
+        fn receiver(self: &RtpTransceiver) -> SharedPtr<RtpReceiver>;
+        fn stopped(self: &RtpTransceiver) -> bool;
+        fn stopping(self: &RtpTransceiver) -> bool;
+        fn direction(self: &RtpTransceiver) -> RtpTransceiverDirection;
+        fn set_direction(self: &RtpTransceiver, direction: RtpTransceiverDirection) -> Result<()>;
+        fn current_direction(self: &RtpTransceiver) -> Result<RtpTransceiverDirection>;
+        fn fired_direction(self: &RtpTransceiver) -> Result<RtpTransceiverDirection>;
+        fn stop_standard(self: &RtpTransceiver) -> Result<()>;
+        fn set_codec_preferences(
+            self: &RtpTransceiver,
+            codecs: Vec<RtpCodecCapability>,
+        ) -> Result<()>;
+        fn codec_preferences(self: &RtpTransceiver) -> Vec<RtpCodecCapability>;
+        fn header_extensions_to_offer(self: &RtpTransceiver) -> Vec<RtpHeaderExtensionCapability>;
+        fn header_extensions_negotiated(self: &RtpTransceiver)
+            -> Vec<RtpHeaderExtensionCapability>;
+        fn set_offered_rtp_header_extensions(
+            self: &RtpTransceiver,
+            headers: Vec<RtpHeaderExtensionCapability>,
+        ) -> Result<()>;
+
+        fn _shared_rtp_transceiver() -> SharedPtr<RtpTransceiver>;
     }
 }
+
+impl_thread_safety!(ffi::RtpTransceiver, Send + Sync);