我试图用 ExoPlayer2.x 制作一个流媒体应用程序。现在我陷入了一个问题。我正在尝试制作一个Bitrate Changer. 我不想使用TrackSelector. 我只想使用一种方法来更改Bitrate单个视频以在低速连接时使用。
用户可以
bitrate从对话框中手动选择
我的竞争对手已经做到了这一点。所以请大家有什么想法和我分享。示例代码赞赏
我已经尝试过使用它，但问题是这在2.x 版本中不起作用
player.prepare(mediaSource, !haveResumePosition, false);
trackSelector.setParameters(trackSelector.getParameters()
.withMaxVideoBitrate(bitrate)
.withMaxVideoSize(width, height));
提前致谢 ！
要将所需的比特率设置为 exoplayer，您需要实现自定义 TrackSelector检查此以获取更多详细信息
你可以覆盖BaseTrackSelection，有功能determineIdealSelectedIndex，这是你需要的。
这是我为我的项目制作的方法：
public enum HLSQuality {
Auto, Quality1080, Quality720, Quality480, NoValue
}
public class ClassAdaptiveTrackSelection extends BaseTrackSelection {
public static final class Factory implements TrackSelection.Factory {
private final BandwidthMeter bandwidthMeter;
private final int maxInitialBitrate = 2000000;
private final int minDurationForQualityIncreaseMs = 10000;
private final int maxDurationForQualityDecreaseMs = 25000;
private final int minDurationToRetainAfterDiscardMs = 25000;
private final float bandwidthFraction = 0.75f;
private final float bufferedFractionToLiveEdgeForQualityIncrease = 0.75f;
public Factory(BandwidthMeter bandwidthMeter) {
this.bandwidthMeter = bandwidthMeter;
}
@Override
public ClassAdaptiveTrackSelection createTrackSelection(TrackGroup group, int... tracks) {
Log.d(ClassAdaptiveTrackSelection.class.getSimpleName(), " Video player quality reset to Auto");
sHLSQuality = HLSQuality.Auto;
return new ClassAdaptiveTrackSelection(
group,
tracks,
bandwidthMeter,
maxInitialBitrate,
minDurationForQualityIncreaseMs,
maxDurationForQualityDecreaseMs,
minDurationToRetainAfterDiscardMs,
bandwidthFraction,
bufferedFractionToLiveEdgeForQualityIncrease
);
}
}
private static HLSQuality sHLSQuality = HLSQuality.Auto;
private final BandwidthMeter bandwidthMeter;
private final int maxInitialBitrate;
private final long minDurationForQualityIncreaseUs;
private final long maxDurationForQualityDecreaseUs;
private final long minDurationToRetainAfterDiscardUs;
private final float bandwidthFraction;
private final float bufferedFractionToLiveEdgeForQualityIncrease;
private int selectedIndex;
private int reason;
private ClassAdaptiveTrackSelection(TrackGroup group,
int[] tracks,
BandwidthMeter bandwidthMeter,
int maxInitialBitrate,
long minDurationForQualityIncreaseMs,
long maxDurationForQualityDecreaseMs,
long minDurationToRetainAfterDiscardMs,
float bandwidthFraction,
float bufferedFractionToLiveEdgeForQualityIncrease) {
super(group, tracks);
this.bandwidthMeter = bandwidthMeter;
this.maxInitialBitrate = maxInitialBitrate;
this.minDurationForQualityIncreaseUs = minDurationForQualityIncreaseMs * 1000L;
this.maxDurationForQualityDecreaseUs = maxDurationForQualityDecreaseMs * 1000L;
this.minDurationToRetainAfterDiscardUs = minDurationToRetainAfterDiscardMs * 1000L;
this.bandwidthFraction = bandwidthFraction;
this.bufferedFractionToLiveEdgeForQualityIncrease = bufferedFractionToLiveEdgeForQualityIncrease;
selectedIndex = determineIdealSelectedIndex(Long.MIN_VALUE);
reason = C.SELECTION_REASON_INITIAL;
}
@Override
public void updateSelectedTrack(long playbackPositionUs, long bufferedDurationUs, long availableDurationUs) {
long nowMs = SystemClock.elapsedRealtime();
// Stash the current selection, then make a new one.
int currentSelectedIndex = selectedIndex;
selectedIndex = determineIdealSelectedIndex(nowMs);
if (selectedIndex == currentSelectedIndex) {
return;
}
if (!isBlacklisted(currentSelectedIndex, nowMs)) {
// Revert back to the current selection if conditions are not suitable for switching.
Format currentFormat = getFormat(currentSelectedIndex);
Format selectedFormat = getFormat(selectedIndex);
if (selectedFormat.bitrate > currentFormat.bitrate
&& bufferedDurationUs < minDurationForQualityIncreaseUs(availableDurationUs)) {
// The selected track is a higher quality, but we have insufficient buffer to safely switch
// up. Defer switching up for now.
selectedIndex = currentSelectedIndex;
} else if (selectedFormat.bitrate < currentFormat.bitrate
&& bufferedDurationUs >= maxDurationForQualityDecreaseUs) {
// The selected track is a lower quality, but we have sufficient buffer to defer switching
// down for now.
selectedIndex = currentSelectedIndex;
}
}
// If we adapted, update the trigger.
if (selectedIndex != currentSelectedIndex) {
reason = C.SELECTION_REASON_ADAPTIVE;
}
}
@Override
public int getSelectedIndex() {
return selectedIndex;
}
@Override
public int getSelectionReason() {
return reason;
}
@Override
public Object getSelectionData() {
return null;
}
@Override
public int evaluateQueueSize(long playbackPositionUs, List<? extends MediaChunk> queue) {
if (queue.isEmpty()) {
return 0;
}
int queueSize = queue.size();
long bufferedDurationUs = queue.get(queueSize - 1).endTimeUs - playbackPositionUs;
if (bufferedDurationUs < minDurationToRetainAfterDiscardUs) {
return queueSize;
}
int idealSelectedIndex = determineIdealSelectedIndex(SystemClock.elapsedRealtime());
Format idealFormat = getFormat(idealSelectedIndex);
// If the chunks contain video, discard from the first SD chunk beyond
// minDurationToRetainAfterDiscardUs whose resolution and bitrate are both lower than the ideal
// track.
for (int i = 0; i < queueSize; i++) {
MediaChunk chunk = queue.get(i);
Format format = chunk.trackFormat;
long durationBeforeThisChunkUs = chunk.startTimeUs - playbackPositionUs;
if (durationBeforeThisChunkUs >= minDurationToRetainAfterDiscardUs
&& format.bitrate < idealFormat.bitrate
&& format.height != Format.NO_VALUE && format.height < 720
&& format.width != Format.NO_VALUE && format.width < 1280
&& format.height < idealFormat.height) {
return i;
}
}
return queueSize;
}
private int determineIdealSelectedIndex(long nowMs) {
if (sHLSQuality != HLSQuality.Auto) {
Log.d(ClassAdaptiveTrackSelection.class.getSimpleName(), " Video player quality seeking for " + String.valueOf(sHLSQuality));
for (int i = 0; i < length; i++) {
Format format = getFormat(i);
if (HLSUtil.getQuality(format) == sHLSQuality) {
Log.d(ClassAdaptiveTrackSelection.class.getSimpleName(), " Video player quality set to " + String.valueOf(sHLSQuality));
return i;
}
}
}
Log.d(ClassAdaptiveTrackSelection.class.getSimpleName(), " Video player quality seeking for auto quality " + String.valueOf(sHLSQuality));
long bitrateEstimate = bandwidthMeter.getBitrateEstimate();
long effectiveBitrate = bitrateEstimate == BandwidthMeter.NO_ESTIMATE
? maxInitialBitrate : (long) (bitrateEstimate * bandwidthFraction);
int lowestBitrateNonBlacklistedIndex = 0;
for (int i = 0; i < length; i++) {
if (nowMs == Long.MIN_VALUE || !isBlacklisted(i, nowMs)) {
Format format = getFormat(i);
if (format.bitrate <= effectiveBitrate && HLSUtil.isQualityPlayable(format)) {
Log.d(ClassAdaptiveTrackSelection.class.getSimpleName(), " Video player quality auto quality found " + String.valueOf(sHLSQuality));
return i;
} else {
lowestBitrateNonBlacklistedIndex = i;
}
}
}
return lowestBitrateNonBlacklistedIndex;
}
private long minDurationForQualityIncreaseUs(long availableDurationUs) {
boolean isAvailableDurationTooShort = availableDurationUs != C.TIME_UNSET
&& availableDurationUs <= minDurationForQualityIncreaseUs;
return isAvailableDurationTooShort
? (long) (availableDurationUs * bufferedFractionToLiveEdgeForQualityIncrease)
: minDurationForQualityIncreaseUs;
}
static void setHLSQuality(HLSQuality HLSQuality) {
sHLSQuality = HLSQuality;
}
}
//this part goes as initialization of your exo player
mDefaultTrackSelector = new DefaultTrackSelector(new ClassAdaptiveTrackSelection.Factory(mDefaultBandwidthMeter));
//when you want to set max speed rate just use
ClassAdaptiveTrackSelection.setHLSQuality(HLSQuality.Quality480);