2

我有这个简单的 .m3u8 文件

#EXTM3U
#EXT-X-VERSION:5

#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio",NAME="English stereo",LANGUAGE="en"

#EXT-X-STREAM-INF:BANDWIDTH=1728000,CODECS="avc1.42c00d,mp4a.40.2",RESOLUTION=640x360,AUDIO="audio"
https://bitdash-a.akamaihd.net/content/MI201109210084_1/m3u8s/f08e80da-bf1d-4e3d-8899-f0f6155f6efa_video_360_800000.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=628000,CODECS="avc1.42c00d,mp4a.40.2",RESOLUTION=320x180,AUDIO="audio"
https://bitdash-a.akamaihd.net/content/MI201109210084_1/m3u8s/f08e80da-bf1d-4e3d-8899-f0f6155f6efa_video_180_250000.m3u8

使用 simpleExoplayer 我像这样加载这个流:

// 1. Create a default TrackSelector
Handler mainHandler = new Handler();
BandwidthMeter bandwidthMeter = new DefaultBandwidthMeter();
TrackSelection.Factory videoTrackSelectionFactory =
    new AdaptiveTrackSelection.Factory(bandwidthMeter);
TrackSelector trackSelector =
    new DefaultTrackSelector(videoTrackSelectionFactory);

// 2. Create the player
SimpleExoPlayer player =
    ExoPlayerFactory.newSimpleInstance(context, trackSelector);

// Produces DataSource instances through which media data is loaded.
DataSource.Factory dataSourceFactory = new DefaultDataSourceFactory(context,
    Util.getUserAgent(context, "yourApplicationName"), bandwidthMeter);
// This is the MediaSource representing the media to be played.
MediaSource videoSource = new HlsMediaSource.Factory(dataSourceFactory)
    .createMediaSource(mp4VideoUri);
// Prepare the player with the source.
player.prepare(videoSource);
player.setPlayWhenReady(true);

但即使在高 WIFI 互联网上,它也将始终选择分辨率为 320x180 的第二轨道,并且永远不会切换到分辨率为 640x360 的更高轨道。

如果我用 maxInt 替换 DEFAULT_MAX_INITIAL_BITRATE 那么它将正确选择第一个轨道(640x360)但是如果在播放中间我切断了 wifi 让手机只使用低 3G 连接,那么它永远不会切换到第二个轨道(320x180),每次播放都会卡住

也是检查MediaCodecUtil.getDecoderInfo("video/avc", false).adaptive,它返回 TRUE

我做错了什么?hls 在 simpleExoPlayer 中是否正常工作?

4

2 回答 2

7

DefaultBandwidthMeter是计量网络容量的组件。DefaultBandwidthMeter实现和接口BandwidthMeterTransferListener

您应该只使用一个 DefaultBandwidthMeter 实例并将其传递给AdaptiveTrackSelection.Factory(作为 BandwidthMeter)和DefaultDataSourceFactory(作为 TransferListener)。这样,在数据源中完成的计量将在轨道选择器中生效。

使用您传递给 AdaptiveTrackSelection.Factory 的实例上方的代码,您不知道计量的是什么,根据您的描述,这显然不起作用。

另请注意,如果您创建一个新DefaultBandwidthMeter实例,那么到目前为止完成的计量将会丢失。因此,您可能希望使用DefaultBandwidthMeteras 静态变量等来保留早期播放的计量。

TrackSelection.Factory videoTrackSelectionFactory =
    new AdaptiveTrackSelection.Factory(DEFAULT_BANDWIDTH_METER);
TrackSelector trackSelector =
    new DefaultTrackSelector(videoTrackSelectionFactory);

DataSource.Factory dataSourceFactory = new DefaultDataSourceFactory(context,
    Util.getUserAgent(context, "yourApplicationName"), DEFAULT_BANDWIDTH_METER);

另请参阅演示应用程序的 PlayerActivity 是如何做到的

于 2018-01-30T19:44:31.680 回答
2

就我而言,带宽变化时它没有切换轨道,所以我替换了DefaultHttpDataSourceFactorytoOkHttpDataSourceFactory并添加了依赖项:

这是代码片段:

implementation 'com.google.android.exoplayer:extension-okhttp:2.12.1'

val httpCallFactory = OkHttpClient.Builder()
            .writeTimeout(httpWriteTimeout, TimeUnit.MILLISECONDS)
            .readTimeout(httpReadTimeout, TimeUnit.MILLISECONDS)
            .connectTimeout(httpConnectTimeout, TimeUnit.MILLISECONDS)
            .build()
        val dataSourceFactory = OkHttpDataSourceFactory(
            httpCallFactory,
            userAgent,
            transferListener
        )

        /* val dataSourceFactory = DefaultHttpDataSourceFactory(
             userAgent,
             transferListener,
             DefaultHttpDataSource.DEFAULT_CONNECT_TIMEOUT_MILLIS,
             DefaultHttpDataSource.DEFAULT_READ_TIMEOUT_MILLIS,
             true
         )*/
        val mediaSource: MediaSource = buildMediaSource(Uri.parse(url), dataSourceFactory)
        exoPlayer.setMediaSource(mediaSource, resetPosition)
        exoPlayer.prepare()
于 2020-12-09T07:54:16.410 回答