更改外挂机HLS质量

Question

我正试图在ExoPlayer中设置视频比特率。我已经这样设置了：

trackSelector = new DefaultTrackSelector(factory);
DefaultTrackSelector.Parameters parameters = trackSelector.getParameters();
parameters.withMaxVideoBitrate(maxBitrate);
parameters.withExceedRendererCapabilitiesIfNecessary(false);
parameters.withExceedVideoConstraintsIfNecessary(false);
trackSelector.setParameters(parameters);

但不管用。在我发现的任何地方，我都发现人们在使用HlsChunk源代码，这在ExoPlayer2.6中是私有的。有人能帮我吗？

Answer 1

DataSource.Factory dataSourceFactory = new DefaultDataSourceFactory(Objects.requireNonNull(getContext()),
                Util.getUserAgent(this.getContext(), getResources().getString(R.string.app_name)));
trackSelector = new CustomTrackSelector();
            videoSource = new HlsMediaSource.Factory(dataSourceFactory).createMediaSource(mp4VideoUri);
    player = ExoPlayerFactory.newSimpleInstance(this.getContext(), trackSelector);

public class CustomTrackSelector extends DefaultTrackSelector
{
    public CustomTrackSelector()
    {
        super();
    }
    protected @Nullable
    TrackSelection selectVideoTrack(
            TrackGroupArray groups,
            int[][] formatSupports,
            int mixedMimeTypeAdaptationSupports,
            Parameters params,
            @Nullable TrackSelection.Factory adaptiveTrackSelectionFactory)
            throws ExoPlaybackException
    {
        AdaptiveTrackSelection adaptiveTrackSelection = null;
        if (groups.length > 0)
        {
            for (int groupIndex = 0; groupIndex < groups.length; groupIndex++)
            {
                TrackGroup trackGroup = groups.get(groupIndex);
                int[] tracks = new int[trackGroup.length];
                //creation of indexes array
                for (int i = 0; i < trackGroup.length; i++)
                {
                    tracks[i] = i;
                }

                adaptiveTrackSelection = new AdaptiveTrackSelection(
                        trackGroup,
                        tracks,
                        new DefaultBandwidthMeter(),
                        AdaptiveTrackSelection.DEFAULT_MIN_DURATION_FOR_QUALITY_INCREASE_MS,
                        AdaptiveTrackSelection.DEFAULT_MAX_DURATION_FOR_QUALITY_DECREASE_MS,
                        AdaptiveTrackSelection.DEFAULT_MIN_DURATION_TO_RETAIN_AFTER_DISCARD_MS,
                        AdaptiveTrackSelection.DEFAULT_BANDWIDTH_FRACTION,
                        AdaptiveTrackSelection.DEFAULT_BUFFERED_FRACTION_TO_LIVE_EDGE_FOR_QUALITY_INCREASE,
                        AdaptiveTrackSelection.DEFAULT_MIN_TIME_BETWEEN_BUFFER_REEVALUTATION_MS,
                        Clock.DEFAULT);

                for (int i = 0; i < tracks.length; i++)
                {
                    Format format = trackGroup.getFormat(tracks[i]);
                    if (format.width < MIN_WIDTH)
                    {
                        Logger.log(this, "Video track blacklisted with width = " + format.width);
                        adaptiveTrackSelection.blacklist(tracks[i], BLACKLIST_DURATION);
                    } else
                    {
                        Logger.log(this, "Video track NOT blacklisted with width = " + format.width);
                    }
                }
            }
        }

        return adaptiveTrackSelection;
    }
}

上面的方法只是将你不想选择的曲目列入黑名单，允许玩家在那些没有列入黑名单的曲目之间进行选择。

我们有黑名单的轨道根据宽度参数，但显然你可以过滤他们使用比特率。

通过这种行为，玩家将开始使用你允许它使用的轨道，在一段时间后（黑名单时间），它可以切换回使用所有的轨道在需要的情况下。如果希望始终排除一个音轨，只需使用integer.max_value作为黑名单时间。