Analysis of technical principles of Exoplayer framework in the Java library

The Exoplayer framework is a powerful open source multimedia playback library, which is widely used in the development of Android applications.This article will analyze the technical principles of the EXOPLAYER framework in the Java class library, and explain the relevant concepts by providing the Java code example. Introduction to Exoplayer framework The Exoplayer framework is an alternative based on Android MediaPlayer API developed and released in 2014.Compared with the traditional MediaPlayer, EXOPLAYER provides higher -level functions and better performance, while facilitating developers to customize and expand. Second, the core category of Exoplayer 1. ExoPlayer: Exoplayer is the core class of the Exoplayer framework. It is responsible for coordinating all related subcutors and provided a unified interface to control and manage multimedia playback. 2. MediaSource: MediaSource is an important concept in the Exoplayer framework. It represents media resources and defines how to extract data from these resources.According to different media types, different MediaSource implementation classes, such as HLSMediasource, DashMediasource, etc. 3. TrackSelector: TrackSelector is responsible for selecting and processing tracks in media resources, such as audio orbiting, video rails, etc.Through the TrackSelector, you can flexibly select the required orbit and switch during playback. 4. Renderer: Renderer is a component to process media data. Each RENDERER is responsible for processing a specific type of media data.The EXOPLAYER framework provides multiple renderrs that have been implemented by default, such as MediaCodeCaudiorenderer, MediaCodeCVideorenderer, etc. Third, the workflow of Exoplayer 1. Create an Exoplayer instance: By calling the static method of ExopLayerFactory, you can create an Exoplayer instance. 2. Set the renderer: According to the need, use the defaultTrackSelector to create an Exoplayer object with the required renderer.Then use the setplayer method to associate the Exoplayer object with the SurfaceView or TextureView that needs to be rendered. 3. Prepare media resources: Create the required MediaSource object and use the Prepare method to pass it to Exoplayer instances.Exoplayer will start buffering data and prepare to start playing. 4. Start playback: Call the Start method of Exoplayer to start playing the media. 5. Surveillance and playback status: You can monitor the playback status of ExopLayer by adding a player.eventListener object and perform corresponding treatment when the state changes. Fourth, Exoplayer's example code Below is a simple example code that demonstrates how to play local video files with the Exoplayer framework. // Create an Exoplayer instance SimpleExoPlayer exoPlayer = ExoPlayerFactory.newSimpleInstance(context); // Create trackselector TrackSelector trackSelector = new DefaultTrackSelector(); // Re assievant to Exoplayer exoPlayer.setTrackSelector(trackSelector); // Set SurfaceView or TextureView to be rendered exoPlayer.setVideoSurfaceView(surfaceView); // Create media resources MediaSource mediaSource = new ExtractorMediaSource( Uri.fromFile(videoFile), new DefaultDataSourceFactory(context, "ExoPlayerDemo"), new DefaultExtractorsFactory(), null, null ); // Prepare media resources exoPlayer.prepare(mediaSource); // Start playing exoPlayer.setPlayWhenReady(true); In this code, a SimpleExoPlayer instance was first created and a defaultTrackselector object was created, and it was associated.Then specify the SurfaceView to be rendered and create a media resource MediaSource.Finally, prepare media resources through the Prepare method and call the SetplayWhenready method to start playing. Through the above examples, we can see the overall workflow of the Exoplayer framework and how to use the Exoplayer class library for multimedia playback operations. Summary: This article introduces the technical principles of the Exoplayer framework in the Java class library, including the core class, workflow and sample code of Exoplayer.Through the EXOPLAYER framework, developers can control and manage multimedia playback more flexibly to provide a better player experience for Android applications.