我正在寻找在 ExoPlayer 中实现缓存的任何示例。
ExoPlayer 在它的库中有不同的缓存类，谷歌在这个视频中解释说我们可以用 CacheDataSource 类来实现它，但谷歌没有提供任何关于它的演示。不幸的是，这似乎使用起来相当复杂，所以我目前正在寻找示例（在 Google 上没有成功）。
有没有人成功或有任何有用的信息？谢谢。
问问题
43960 次
10 回答
50
这是 ExoPlayer 2.+ 的解决方案
创建自定义缓存数据源工厂
public class CacheDataSourceFactory implements DataSource.Factory {
private final Context context;
private final DefaultDataSourceFactory defaultDatasourceFactory;
private final long maxFileSize, maxCacheSize;
public CacheDataSourceFactory(Context context, long maxCacheSize, long maxFileSize) {
super();
this.context = context;
this.maxCacheSize = maxCacheSize;
this.maxFileSize = maxFileSize;
String userAgent = Util.getUserAgent(context, context.getString(R.string.app_name));
DefaultBandwidthMeter bandwidthMeter = new DefaultBandwidthMeter();
defaultDatasourceFactory = new DefaultDataSourceFactory(this.context,
bandwidthMeter,
new DefaultHttpDataSourceFactory(userAgent, bandwidthMeter));
}
@Override
public DataSource createDataSource() {
LeastRecentlyUsedCacheEvictor evictor = new LeastRecentlyUsedCacheEvictor(maxCacheSize);
SimpleCache simpleCache = new SimpleCache(new File(context.getCacheDir(), "media"), evictor);
return new CacheDataSource(simpleCache, defaultDatasourceFactory.createDataSource(),
new FileDataSource(), new CacheDataSink(simpleCache, maxFileSize),
CacheDataSource.FLAG_BLOCK_ON_CACHE | CacheDataSource.FLAG_IGNORE_CACHE_ON_ERROR, null);
}
}
和播放器
BandwidthMeter bandwidthMeter = new DefaultBandwidthMeter();
TrackSelection.Factory videoTrackSelectionFactory =
new AdaptiveTrackSelection.Factory(bandwidthMeter);
TrackSelector trackSelector = new DefaultTrackSelector(videoTrackSelectionFactory);
SimpleExoPlayer exoPlayer = ExoPlayerFactory.newSimpleInstance(this, trackSelector);
MediaSource audioSource = new ExtractorMediaSource(Uri.parse(url),
new CacheDataSourceFactory(context, 100 * 1024 * 1024, 5 * 1024 * 1024), new DefaultExtractorsFactory(), null, null);
exoPlayer.setPlayWhenReady(true);
exoPlayer.prepare(audioSource);
它工作得很好。
于 2017-08-03T15:24:21.817 回答
36
默认情况下，ExoPlayer 不缓存媒体（视频、音频等）。例如，如果你想播放一个在线视频文件，每次 ExoPlayer 都会打开一个连接，读取数据然后播放它。
幸运的是，它为我们提供了一些接口和实现类来支持在我们的应用程序中缓存媒体。
你可以编写自己的缓存来实现 ExoPlayer 的给定接口。为简单起见，我将指导您如何使用实现类启用缓存。
第 1 步：指定一个包含您的媒体文件的文件夹，在 Android 中，对于较小的缓存文件夹（小于 1MB），您应该使用getCacheDir，否则您可以指定您喜欢的缓存文件夹，例如getFileDir。
第 2 步： 指定缓存文件夹的大小，以及达到该大小时的策略。有 2 个 API
- NoOpCacheEvictor永远不会驱逐/删除缓存文件。根据缓存文件夹的位置，如果它在内部存储中，当用户清除应用数据或卸载应用时，该文件夹将被删除。
- LeastRecentlyUsedCacheEvictor将首先驱逐/删除最近最少使用的缓存文件。例如，如果您的缓存大小为 10MB，当达到该大小时，它会自动查找并删除最近最少使用的文件。
把它放在一起
val renderersFactory = DefaultRenderersFactory(context.applicationContext)
val trackSelector = DefaultTrackSelector()
val loadControl = DefaultLoadControl()
val player = ExoPlayerFactory.newSimpleInstance(context, renderersFactory, trackSelector, loadControl)
player.addListener(this)
// Specify cache folder, my cache folder named media which is inside getCacheDir.
val cacheFolder = File(context.cacheDir, "media")
// Specify cache size and removing policies
val cacheEvictor = LeastRecentlyUsedCacheEvictor(1 * 1024 * 1024) // My cache size will be 1MB and it will automatically remove least recently used files if the size is reached out.
// Build cache
val cache = SimpleCache(cacheFolder, cacheEvictor)
// Build data source factory with cache enabled, if data is available in cache it will return immediately, otherwise it will open a new connection to get the data.
val cacheDataSourceFactory = CacheDataSourceFactory(cache, DefaultHttpDataSourceFactory("ExoplayerDemo"))
val uri = Uri.parse("Put your media url here")
val mediaSource = ExtractorMediaSource.Factory(cacheDataSourceFactory).createMediaSource(uri)
player.prepare(mediaSource)
于 2018-10-23T12:01:20.700 回答
10
我在这里回答了这个类似的问题：https ://stackoverflow.com/a/58678192/2029134
基本上，我使用这个库：https ://github.com/danikula/AndroidVideoCache 从 URL 缓存文件然后将其放入 ExoPlayer。
这是示例代码：
String mediaURL = "https://my_cool_vid.com/vi.mp4";
SimpleExoPlayer exoPlayer = ExoPlayerFactory.newSimpleInstance(getContext());
HttpProxyCacheServer proxyServer = HttpProxyCacheServer.Builder(getContext()).maxCacheSize(1024 * 1024 * 1024).build();
String proxyURL = proxyServer.getProxyUrl(mediaURL);
DataSource.Factory dataSourceFactory = new DefaultDataSourceFactory(getContext(),
Util.getUserAgent(getContext(), getActivity().getApplicationContext().getPackageName()));
exoPlayer.prepare(new ProgressiveMediaSource.Factory(dataSourceFactory)
.createMediaSource(Uri.parse(proxyURL)););
希望有帮助。
于 2019-11-03T07:26:50.570 回答
8
要解决多个视频或进程尝试访问同一个缓存的问题，您需要一个真正的 Singleton。一种可靠的方法是这样做：
object VideoCache {
private var sDownloadCache: SimpleCache? = null
private const val maxCacheSize: Long = 100 * 1024 * 1024
fun getInstance(context: Context): SimpleCache {
val evictor = LeastRecentlyUsedCacheEvictor(maxCacheSize)
if (sDownloadCache == null) sDownloadCache = SimpleCache(File(context.cacheDir, "koko-media"), evictor)
return sDownloadCache as SimpleCache
}
}
您现在可以使用：
private val simpleCache: SimpleCache by lazy {
VideoCache.getInstance(context)
}
于 2019-03-15T07:04:43.563 回答
6
这是一个用 OkHttp 替换演示数据源的示例，默认为无缓存 https://github.com/b95505017/ExoPlayer/commit/ebfdda8e7848a2e2e275f5c0525f614b56ef43a6 https://github.com/b95505017/ExoPlayer/tree/okhttp_http_data_source 所以，你只是需要正确配置 OkHttp 缓存并且请求应该被缓存。
于 2015-12-11T14:51:48.327 回答
2
我已经在渲染器构建器中这样实现了
private static final int BUFFER_SEGMENT_SIZE = 64 * 1024;
private static final int BUFFER_SEGMENT_COUNT = 160;
final String userAgent = Util.getUserAgent(mContext, appName);
final DefaultBandwidthMeter bandwidthMeter = new DefaultBandwidthMeter();
final Allocator allocator = new DefaultAllocator(BUFFER_SEGMENT_SIZE);*
Cache cache = new SimpleCache(context.getCacheDir(), new LeastRecentlyUsedCacheEvictor(1024 * 1024 * 10));
DataSource dataSource = new DefaultUriDataSource(context, bandwidthMeter, userAgent);
CacheDataSource cacheDataSource = new CacheDataSource(cache, dataSource, false, false);
ExtractorSampleSource sampleSource = new ExtractorSampleSource(uri
, cacheDataSource
, allocator
, BUFFER_SEGMENT_COUNT * BUFFER_SEGMENT_SIZE
, new Mp4Extractor());
于 2015-08-10T07:09:36.603 回答
2
除了宝乐的回答，这里准备使用CacheDataSourceFactory保留一个实例的Kotlin版本SimpleCache来解决多个Cache对象写入同一个目录的问题。
class CacheDataSourceFactory(private val context: Context,
private val maxCacheSize: Long,
private val maxFileSize: Long) : DataSource.Factory {
private val defaultDatasourceFactory: DefaultDataSourceFactory
private val simpleCache: SimpleCache by lazy {
val evictor = LeastRecentlyUsedCacheEvictor(maxCacheSize)
SimpleCache(File(context.cacheDir, "media"), evictor)
}
init {
val userAgent = Util.getUserAgent(context, context.packageName)
val bandwidthMeter = DefaultBandwidthMeter()
defaultDatasourceFactory = DefaultDataSourceFactory(context,
bandwidthMeter,
DefaultHttpDataSourceFactory(userAgent, bandwidthMeter))
}
override fun createDataSource(): DataSource {
return CacheDataSource(simpleCache,
defaultDatasourceFactory.createDataSource(),
FileDataSource(),
CacheDataSink(simpleCache, maxFileSize),
CacheDataSource.FLAG_BLOCK_ON_CACHE or CacheDataSource.FLAG_IGNORE_CACHE_ON_ERROR,
null)
}
}
于 2018-11-14T13:46:45.697 回答
1
这是我在 Kotlin 中的示例（项目可在此处获得）：
class MainActivity : AppCompatActivity() {
private var player: SimpleExoPlayer? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
if (cache == null) {
cache = SimpleCache(File(cacheDir, "media"), LeastRecentlyUsedCacheEvictor(MAX_PREVIEW_CACHE_SIZE_IN_BYTES))
}
setContentView(R.layout.activity_main)
}
override fun onStart() {
super.onStart()
playVideo()
}
private fun playVideo() {
player = ExoPlayerFactory.newSimpleInstance(this@MainActivity, DefaultTrackSelector())
playerView.player = player
player!!.volume = 1f
player!!.playWhenReady = true
player!!.repeatMode = Player.REPEAT_MODE_ALL
player!!.playVideoFromUrl(this, "https://sample-videos.com/video123/mkv/240/big_buck_bunny_240p_20mb.mkv", cache!!)
// player!!.playVideoFromUrl(this, "https://sample-videos.com/video123/mkv/720/big_buck_bunny_720p_1mb.mkv", cache!!)
// player!!.playVideoFromUrl(this, "https://sample-videos.com/video123/mkv/720/big_buck_bunny_720p_1mb.mkv")
// player!!.playRawVideo(this,R.raw.videoplayback)
}
override fun onStop() {
super.onStop()
playerView.player = null
player!!.release()
player = null
}
companion object {
const val MAX_PREVIEW_CACHE_SIZE_IN_BYTES = 20L * 1024L * 1024L
var cache: com.google.android.exoplayer2.upstream.cache.Cache? = null
@JvmStatic
fun getUserAgent(context: Context): String {
val packageManager = context.packageManager
val info = packageManager.getPackageInfo(context.packageName, 0)
val appName = info.applicationInfo.loadLabel(packageManager).toString()
return Util.getUserAgent(context, appName)
}
}
fun SimpleExoPlayer.playRawVideo(context: Context, @RawRes rawVideoRes: Int) {
val dataSpec = DataSpec(RawResourceDataSource.buildRawResourceUri(rawVideoRes))
val rawResourceDataSource = RawResourceDataSource(context)
rawResourceDataSource.open(dataSpec)
val factory: DataSource.Factory = DataSource.Factory { rawResourceDataSource }
prepare(LoopingMediaSource(ExtractorMediaSource.Factory(factory).createMediaSource(rawResourceDataSource.uri)))
}
fun SimpleExoPlayer.playVideoFromUrl(context: Context, url: String, cache: Cache? = null) = playVideoFromUri(context, Uri.parse(url), cache)
fun SimpleExoPlayer.playVideoFile(context: Context, file: File) = playVideoFromUri(context, Uri.fromFile(file))
fun SimpleExoPlayer.playVideoFromUri(context: Context, uri: Uri, cache: Cache? = null) {
val factory = if (cache != null)
CacheDataSourceFactory(cache, DefaultHttpDataSourceFactory(getUserAgent(context)))
else
DefaultDataSourceFactory(context, MainActivity.getUserAgent(context))
val mediaSource = ExtractorMediaSource.Factory(factory).createMediaSource(uri)
prepare(mediaSource)
}
}
于 2019-01-07T11:45:52.723 回答
-1
SimpleCache simpleCache = new SimpleCache(new File(context.getCacheDir(), "media/"+id), evictor);
在这里，id一定是独一无二的。
于 2020-04-01T04:33:20.913 回答
-1
Exoplayer 的文档列表是DashDownloader 类，并有一些用于该类型源的示例代码。（单击 [Frames] 以返回文档的导航。我必须将其删除才能获得深层链接。）
于 2018-06-26T06:44:22.850 回答