swift-iOS演示如何构建一个直播应用

This project is to demonstrate how to build a live broadcast app. It include these features: * Create a room to broadcast your live stream * Join a room to watch the live * Send likes, gifts, and comments    ## Introduction * RTMP server - Nginx RTMP module(https://github.com/arut/nginx-rtmp-module) * WebSocket server - Socket.io(http://socket.io/) * iOS client - LFLiveKit(https://github.com/LaiFengiOS/LFLiveKit) to push stream, IJKPlayer(https://github.com/Bilibili/ijkplayer) to play stream ## How to run #### 1. Nginx RTMP server You need to can set up your own rtmp server, the guidance can be found here: * https://github.com/arut/nginx-rtmp-module * https://www.atlantic.net/community/howto/install-rtmp-ubuntu-14-04/ #### 2. WebSocket server Just go to the `live-server` folder, run `npm install`, then start the server by `node app.js` #### 3. iOS client Go to the `live-ios` folder, run `pod install`(must use cocoapods 0.39.0) In Config.swift, update the server url: ``` struct Config { static var rtmpPushUrl = "rtmp://139.196.179.230/mytv/" static var rtmpPlayUrl = "rtmp://139.196.179.230/mytv/" static var serverUrl = "http://139.196.179.230:3000" } ``` The app can also run on a simulator, but to broadcast, you need to run it on a real device. ## Tutorial #### 1. Live streaming The basic live streaming flow is: ``` broadcaster -> rtmp -> media server -> cdn -> rtmp or hls -> audience ``` For the simplest case, we don't need a cdn server, then the flow will be: ``` broadcaster -> rtmp -> media server -> rtmp or hls -> audience ``` That is, the boadcaster push the live stream using the RTMP protocal to a media server, the audience pull the stream from the server using RTMP or HLS protocal. Some explaination for RTMP and HLS: * RTMP: RTMP is used to stream audio, video or data and is originally a proprietary protocol introduced by Macromedia (owned by Adobe). The protocol is TCP-based and offers therefore persistent connections. In short, RTMP encapsulates MP3/AAC audio and MP4/FLV video multimedia streams. * HLS: HTTP Live Streaming is known as HLS. As the name implies, it is the media streaming communications protocol based on HTTP; developed by Apple as part of their QuickTime, Safari, OS X, and iOS products. How does it work? It breaks the overall stream into a sequence of small HTTP-based files (.ts: Transport Stream). These transport stream files are indexed in the file .m3u8. It is required to download first the .m3u8 playlist to play a live stream. For the media server, there are serveral choices: * Adobe media server * Red5 * Nginx RTMP module * crtmpserver After setting up the server, you can test it using ffmpeg(install it by `brew install ffmpeg`). * push stream ``` ffmpeg -f avfoundation -framerate 30 -i "1:0" -f flv rtmp://server-url ``` * watch the stream: go to this site: https://www.hlsplayer.net/rtmp-player p.s. Lots of live stream cloud already covers the media server and cdn parts. You just need to push/pull the stream from it. #### 2. iOS RTMP libs There are serveral open source projects supporting RTMP, this project uses: * LFLiveKit(https://github.com/LaiFengiOS/LFLiveKit) to push rtmp stream * IJKPlayer(https://github.com/Bilibili/ijkplayer) to pull rtmp stream You can find the usage of these libs in their project pages. #### 3. Websocket server This project uses socket.io to handle the client-server communication, the logic is very simple, on the server side: ```js var rooms = {} io.on('connection', function(socket) { socket.on('create_room', function(room) { var roomKey = room.key rooms[roomKey] = room socket.roomKey = roomKey socket.join(roomKey) }) socket.on('close_room', function(roomKey) { delete rooms[roomKey] }) socket.on('disconnect', function() { if (socket.roomKey) { delete rooms[socket.roomKey] } }) socket.on('join_room', function(roomKey) { socket.join(roomKey) }) socket.on('upvote', function(roomKey) { io.to(roomKey).emit('upvote') }) socket.on('gift', function(data) { io.to(data.roomKey).emit('gift', data) }) }) ``` On the client side, it uses the socket.io swift client(https://github.com/socketio/socket.io-client-swift), the logic is also simple: create, join, or close a room: ```swift socket.on("connect") { data, ack in self.socket.emit("create_room", self.room) } socket.on("connect") { data, ack in self.socket.emit("join_room", self.room.key) } socket.disconnect() ``` publish likes and comments events: ```swift socket.emit("upvote", room.key) socket.emit("comment", [ "roomKey": room.key, "text": text ]) ``` listen likes and comments events: ```swift socket.on("upvote") { data, ack in self.emitterView.emitImage(R.image.heart()!) } socket.on("comment") { data, ack in let comment = Comment(dict: data[0] as! [String: AnyObject]) self.comments.append(comment) self.tableView.reloadData() } ```