短跑自适应回放与启动轨道，如何？
短跑自适应回放与启动轨道，如何？
提问于 2018-02-23 13:25:43
在我的应用程序中，我有三种播放自适应破折号视频的方法：
- 固定视音频音轨
- 自适应视音频音轨
- 自适应视频和音频音轨(带启动音轨)
前两种方法工作得很完美，但是第三种方法表现出了奇怪的。
我所做的是首先设置'onTracksChanged‘方法的起始轨道。当玩家调用方法onLoadingChanged(false)时，我希望删除对起始轨道的选择，让玩家选择最优的轨道。为了删除所选的内容，我调用了trackSelector.clearSelectionOverrides()，但这完全删除了缓冲区，视频停止并开始在最佳轨道上缓冲。
我想要实现的行为是以下
选择startingt (假设144 p)，->加载第一个块，->删除选择的144 p ->，继续在144 p中播放剩余的缓冲区，同时开始在最佳轨道加载。
我怎样才能做到这一点？
回答 2
Stack Overflow用户
回答已采纳
发布于 2018-03-02 19:12:48
你可以用一个AdaptiveTrackSelection和黑名单做所有的轨道，除了那些你想保留。要做到这一点，提供您自己的TrackSelection.Factory似乎是最容易的。
public class StartupTrackSelectionFactory implements TrackSelection.Factory {
// end blacklisting after ten seconds earliest
private static final long BLACKLIST_DURATION = 10 * 1000;
private final BandwidthMeter bandwidthMeter;
public StartupTrackSelectionFactory(BandwidthMeter bandwidthMeter) {
this.bandwidthMeter = bandwidthMeter;
}
@Override
public TrackSelection createTrackSelection(TrackGroup group, int... tracks) {
AdaptiveTrackSelection adaptiveTrackSelection = new AdaptiveTrackSelection(
group,
tracks,
bandwidthMeter,
AdaptiveTrackSelection.DEFAULT_MAX_INITIAL_BITRATE,
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);
int lowestBitrate = Integer.MAX_VALUE;
int lowestBitrateTrackIndex = C.INDEX_UNSET;
for (int i = 0; i < tracks.length; i++) {
Format format = group.getFormat(tracks[i]);
if (format.bitrate < lowestBitrate) {
lowestBitrateTrackIndex = i;
lowestBitrate = format.bitrate;
}
adaptiveTrackSelection.blacklist(tracks[i], BLACKLIST_DURATION);
}
if (lowestBitrateTrackIndex != C.INDEX_UNSET) {
adaptiveTrackSelection.blacklist(tracks[lowestBitrateTrackIndex], 0);
}
return adaptiveTrackSelection;
}
}现在，在创建DefaultTrackSelector时，您可以传递该StartupTrackSelectionFactory并使用它创建一个player实例。
TrackSelection.Factory trackSelectionFactory =
new StartupTrackSelectionFactory(BANDWIDTH_METER);
trackSelector = new DefaultTrackSelector(trackSelectionFactory);
player = ExoPlayerFactory.newSimpleInstance(renderersFactory, trackSelector);如果您希望保持侦听onLoadChange事件的方法，您可能首先希望将Long.MAX_VALUE作为黑名单持续时间，然后在调用onLoadChange时将所有索引的持续时间设置为0。
Stack Overflow用户
发布于 2021-06-10 14:51:14
由于从库中删除了createTrackSelection方法，我们现在可以直接实现AdaptiveTrackSelection.Factory()并覆盖它的createAdaptiveTrackSelection方法，并使用@marcbaechinger的代码。下面是它的kotlin版本。
class SmoothTrackSelectionFactory(bandwidthMeter: DefaultBandwidthMeter) : AdaptiveTrackSelection.Factory() {
// end blacklisting after ten seconds earliest
private val BLACKLIST_DURATION = (10 * 1000).toLong()
private var bandwidthMeter: BandwidthMeter = bandwidthMeter
override fun createAdaptiveTrackSelection(group: TrackGroup, bandwidthMeter: BandwidthMeter, tracks: IntArray, totalFixedTrackBandwidth: Int): AdaptiveTrackSelection {
val adaptiveTrackSelection = AdaptiveTrackSelection(
group,
tracks,
bandwidthMeter,
Integer.MAX_VALUE.toLong(),
AdaptiveTrackSelection.DEFAULT_MIN_DURATION_FOR_QUALITY_INCREASE_MS.toLong(),
AdaptiveTrackSelection.DEFAULT_MAX_DURATION_FOR_QUALITY_DECREASE_MS.toLong(),
AdaptiveTrackSelection.DEFAULT_MIN_DURATION_TO_RETAIN_AFTER_DISCARD_MS.toLong(),
AdaptiveTrackSelection.DEFAULT_BANDWIDTH_FRACTION,
AdaptiveTrackSelection.DEFAULT_BUFFERED_FRACTION_TO_LIVE_EDGE_FOR_QUALITY_INCREASE,
AdaptiveTrackSelection.DEFAULT_MIN_TIME_BETWEEN_BUFFER_REEVALUTATION_MS,
Clock.DEFAULT)
var lowestBitrate = Int.MAX_VALUE
var lowestBitrateTrackIndex = C.INDEX_UNSET
for (i in tracks.indices) {
val format: Format = group.getFormat(tracks[i])
if (format.bitrate < lowestBitrate) {
lowestBitrateTrackIndex = i
lowestBitrate = format.bitrate
}
adaptiveTrackSelection.blacklist(tracks[i], BLACKLIST_DURATION)
}
if (lowestBitrateTrackIndex != C.INDEX_UNSET) {
adaptiveTrackSelection.blacklist(tracks[lowestBitrateTrackIndex], 0)
}
return adaptiveTrackSelection
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/48948910
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