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webrtc_sys/
video_track.rs

1// Copyright 2025 LiveKit, Inc.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use std::sync::Arc;
16
17use cxx::UniquePtr;
18
19use crate::{impl_thread_safety, video_frame::ffi::VideoFrame};
20
21#[cxx::bridge(namespace = "livekit_ffi")]
22pub mod ffi {
23    #[repr(i32)]
24    pub enum ContentHint {
25        None,
26        Fluid,
27        Detailed,
28        Text,
29    }
30
31    #[derive(Debug)]
32    pub struct VideoTrackSourceConstraints {
33        pub has_min_fps: bool,
34        pub min_fps: f64,
35        pub has_max_fps: bool,
36        pub max_fps: f64,
37    }
38
39    #[derive(Debug)]
40    pub struct VideoResolution {
41        pub width: u32,
42        pub height: u32,
43    }
44
45    #[derive(Debug)]
46    pub struct FrameMetadata {
47        pub has_packet_trailer: bool,
48        pub user_timestamp: u64,
49        pub frame_id: u32,
50    }
51
52    extern "C++" {
53        include!("livekit/video_frame.h");
54        include!("livekit/media_stream_track.h");
55
56        type VideoFrame = crate::video_frame::ffi::VideoFrame;
57        type MediaStreamTrack = crate::media_stream_track::ffi::MediaStreamTrack;
58    }
59
60    extern "C++" {
61        include!("livekit/packet_trailer.h");
62        include!("livekit/video_track.h");
63
64        type PacketTrailerHandler = crate::packet_trailer::ffi::PacketTrailerHandler;
65    }
66
67    unsafe extern "C++" {
68
69        type VideoTrack;
70        type NativeVideoSink;
71        type VideoTrackSource;
72
73        fn add_sink(self: &VideoTrack, sink: &SharedPtr<NativeVideoSink>);
74        fn remove_sink(self: &VideoTrack, sink: &SharedPtr<NativeVideoSink>);
75        fn set_should_receive(self: &VideoTrack, should_receive: bool);
76        fn should_receive(self: &VideoTrack) -> bool;
77        fn content_hint(self: &VideoTrack) -> ContentHint;
78        fn set_content_hint(self: &VideoTrack, hint: ContentHint);
79        fn new_native_video_sink(observer: Box<VideoSinkWrapper>) -> SharedPtr<NativeVideoSink>;
80
81        fn video_resolution(self: &VideoTrackSource) -> VideoResolution;
82        fn on_captured_frame(
83            self: &VideoTrackSource,
84            frame: &UniquePtr<VideoFrame>,
85            frame_metadata: &FrameMetadata,
86        ) -> bool;
87        fn set_packet_trailer_handler(
88            self: &VideoTrackSource,
89            handler: SharedPtr<PacketTrailerHandler>,
90        );
91        fn new_video_track_source(
92            resolution: &VideoResolution,
93            is_screencast: bool,
94        ) -> SharedPtr<VideoTrackSource>;
95        fn video_to_media(track: SharedPtr<VideoTrack>) -> SharedPtr<MediaStreamTrack>;
96        unsafe fn media_to_video(track: SharedPtr<MediaStreamTrack>) -> SharedPtr<VideoTrack>;
97        fn _shared_video_track() -> SharedPtr<VideoTrack>;
98    }
99
100    extern "Rust" {
101        type VideoSinkWrapper;
102
103        fn on_frame(self: &VideoSinkWrapper, frame: UniquePtr<VideoFrame>);
104        fn on_discarded_frame(self: &VideoSinkWrapper);
105        fn on_constraints_changed(
106            self: &VideoSinkWrapper,
107            constraints: VideoTrackSourceConstraints,
108        );
109    }
110}
111
112impl_thread_safety!(ffi::VideoTrack, Send + Sync);
113impl_thread_safety!(ffi::NativeVideoSink, Send + Sync);
114impl_thread_safety!(ffi::VideoTrackSource, Send + Sync);
115
116pub trait VideoSink: Send {
117    fn on_frame(&self, frame: UniquePtr<VideoFrame>);
118    fn on_discarded_frame(&self);
119    fn on_constraints_changed(&self, constraints: ffi::VideoTrackSourceConstraints);
120}
121
122pub struct VideoSinkWrapper {
123    observer: Arc<dyn VideoSink>,
124}
125
126impl VideoSinkWrapper {
127    pub fn new(observer: Arc<dyn VideoSink>) -> Self {
128        Self { observer }
129    }
130
131    fn on_frame(&self, frame: UniquePtr<VideoFrame>) {
132        self.observer.on_frame(frame);
133    }
134
135    fn on_discarded_frame(&self) {
136        self.observer.on_discarded_frame();
137    }
138
139    fn on_constraints_changed(&self, constraints: ffi::VideoTrackSourceConstraints) {
140        self.observer.on_constraints_changed(constraints);
141    }
142}