select android 上的 hls 流上的高质量视频

select quality video on hls stream on android

HLS 协议基于 .m3u8 "Playlist" 文件的想法,其中包含以不同 video/audio 质量编码的相同内容的多个版本列表。

想法是让客户端播放器根据自定义规则(带宽、客户端视频大小等)自动切换质量。

使用 MediaPlayer class on android platform, I can stream hls content (for example this url).

如何以编程方式select在流式传输期间应用程序应使用哪个可用级别?

可能会迟到,但希望有人会发现它有用。

您可以使用 ExoPlayer 来执行此操作。

在你的 build.gradle:

implementation 'com.google.android.exoplayer:exoplayer:2.9.1'

在你的layout.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_height="match_parent"
            android:layout_width="match_parent">
    <com.google.android.exoplayer2.ui.PlayerView
        android:layout_width="match_parent"
        android:layout_height="400dp"
        android:id="@+id/video_player"/>
    <Button android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/quality_lo"
        android:text="@string/quality_lo"
        android:layout_below="@id/video_player"/>

    <Button android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/quality_mi"
        android:text="@string/quality_mi"
        android:layout_below="@id/video_player"
        android:layout_toEndOf="@id/quality_lo"/>

    <Button android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/quality_hi"
        android:text="@string/quality_hi"
        android:layout_below="@id/video_player"
        android:layout_toEndOf="@id/quality_mi"/>
</RelativeLayout>

在你的Activity

    int HI_BITRATE = 2097152;
    int MI_BITRATE = 1048576;
    int LO_BITRATE = 524288;

    PlayerView playerView = findViewById(R.id.video_player);

    DefaultTrackSelector trackSelector = new DefaultTrackSelector();
    DefaultTrackSelector.Parameters defaultTrackParam = trackSelector.buildUponParameters().build();
    trackSelector.setParameters(defaultTrackParam);

    SimpleExoPlayer player = ExoPlayerFactory.newSimpleInstance(this, trackSelector);

    playerView.setPlayer(player);

    DefaultDataSourceFactory fac = new DefaultDataSourceFactory(this,
            Util.getUserAgent(this, getString(R.string.app_name)));

    HlsMediaSource videoSource = new HlsMediaSource.Factory(fac).createMediaSource(
            Uri.parse("http://192.168.1.104:9999/statics/videos/oceans/master.m3u8")
    );

    player.prepare(videoSource);


    findViewById(R.id.quality_lo).setOnClickListener(v -> {
        DefaultTrackSelector.Parameters parameters = trackSelector.buildUponParameters()
                .setMaxVideoBitrate(LO_BITRATE)
                .setForceHighestSupportedBitrate(true)
                .build();
        trackSelector.setParameters(parameters);
    });

    findViewById(R.id.quality_mi).setOnClickListener(v -> {
        DefaultTrackSelector.Parameters parameters = trackSelector.buildUponParameters()
                .setMaxVideoBitrate(MI_BITRATE)
                .setForceHighestSupportedBitrate(true)
                .build();
        trackSelector.setParameters(parameters);
    });

    findViewById(R.id.quality_hi).setOnClickListener(v -> {
        DefaultTrackSelector.Parameters parameters = trackSelector.buildUponParameters()
                .setMaxVideoBitrate(HI_BITRATE)
                .setForceHighestSupportedBitrate(true)
                .build();
        trackSelector.setParameters(parameters);
    });

你掌握的m3u8文件应该是这样的:

#EXTM3U
#EXT-X-STREAM-INF:BANDWIDTH=2097152,RESOLUTION=1080x450,CODECS="avc1.4d001e,mp4a.40.2"
hi/hi.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=1048576,RESOLUTION=960x400,CODECS="avc1.4d001e,mp4a.40.2"
mi/mi.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=524288,RESOLUTION=720x300,CODECS="avc1.4d001e,mp4a.40.2"
lo/lo.m3u8

阅读 https://google.github.io/ExoPlayer/guide.html 了解更多信息。