From 29a099cf03236edc6d46a262d64621dfcdac8989 Mon Sep 17 00:00:00 2001 From: Yannick RUI Date: Fri, 12 Jul 2019 13:28:41 +0200 Subject: [PATCH] Switch text track score from the score based logic to a comparison based logic similar to the one we use for audio track selection (see AudioTrackScore). --- .../trackselection/DefaultTrackSelector.java | 154 ++++++++++-------- 1 file changed, 84 insertions(+), 70 deletions(-) diff --git a/library/core/src/main/java/com/google/android/exoplayer2/trackselection/DefaultTrackSelector.java b/library/core/src/main/java/com/google/android/exoplayer2/trackselection/DefaultTrackSelector.java index 949bd178ea..511a974a0e 100644 --- a/library/core/src/main/java/com/google/android/exoplayer2/trackselection/DefaultTrackSelector.java +++ b/library/core/src/main/java/com/google/android/exoplayer2/trackselection/DefaultTrackSelector.java @@ -1552,38 +1552,30 @@ public class DefaultTrackSelector extends MappingTrackSelector { } } - int selectedTextTrackScore = Integer.MIN_VALUE; + TextTrackScore selectedTextTrackScore = null; int selectedTextRendererIndex = C.INDEX_UNSET; for (int i = 0; i < rendererCount; i++) { - int trackType = mappedTrackInfo.getRendererType(i); - switch (trackType) { - case C.TRACK_TYPE_VIDEO: - case C.TRACK_TYPE_AUDIO: - // Already done. Do nothing. - break; - case C.TRACK_TYPE_TEXT: - Pair textSelection = - selectTextTrack( - mappedTrackInfo.getTrackGroups(i), - rendererFormatSupports[i], - params, - selectedAudioLanguage); - if (textSelection != null && textSelection.second > selectedTextTrackScore) { - if (selectedTextRendererIndex != C.INDEX_UNSET) { - // We've already made a selection for another text renderer, but it had a lower score. - // Clear the selection for that renderer. - definitions[selectedTextRendererIndex] = null; - } - definitions[i] = textSelection.first; - selectedTextTrackScore = textSelection.second; - selectedTextRendererIndex = i; + // The below behaviour is different from video and audio track selection + // i.e. do not perform a text track pre selection if there are no preferredTextLanguage requested. + if (C.TRACK_TYPE_TEXT == mappedTrackInfo.getRendererType(i) && params.preferredTextLanguage != null) { + Pair textSelection = + selectTextTrack( + mappedTrackInfo.getTrackGroups(i), + rendererFormatSupports[i], + params); + if (textSelection != null + && (selectedTextTrackScore == null + || textSelection.second.compareTo(selectedTextTrackScore) > 0)) { + if (selectedTextRendererIndex != C.INDEX_UNSET) { + // We've already made a selection for another text renderer, but it had a lower + // score. Clear the selection for that renderer. + definitions[selectedTextRendererIndex] = null; } - break; - default: - definitions[i] = - selectOtherTrack( - trackType, mappedTrackInfo.getTrackGroups(i), rendererFormatSupports[i], params); - break; + TrackSelection.Definition definition = textSelection.first; + definitions[i] = definition; + selectedTextTrackScore = textSelection.second; + selectedTextRendererIndex = i; + } } } @@ -2051,22 +2043,20 @@ public class DefaultTrackSelector extends MappingTrackSelector { * @param formatSupport The result of {@link RendererCapabilities#supportsFormat} for each mapped * track, indexed by track group index and track index (in that order). * @param params The selector's current constraint parameters. - * @param selectedAudioLanguage The language of the selected audio track. May be null if the - * selected audio track declares no language or no audio track was selected. - * @return The {@link TrackSelection.Definition} and corresponding track score, or null if no + * selected text track declares no language or no text track was selected. + * @return The {@link TrackSelection.Definition} and corresponding {@link TextTrackScore}, or null if no * selection was made. * @throws ExoPlaybackException If an error occurs while selecting the tracks. */ @Nullable - protected Pair selectTextTrack( + protected Pair selectTextTrack( TrackGroupArray groups, int[][] formatSupport, - Parameters params, - @Nullable String selectedAudioLanguage) + Parameters params) throws ExoPlaybackException { TrackGroup selectedGroup = null; - int selectedTrackIndex = 0; - int selectedTrackScore = 0; + int selectedTrackIndex = C.INDEX_UNSET; + TextTrackScore selectedTrackScore = null; for (int groupIndex = 0; groupIndex < groups.length; groupIndex++) { TrackGroup trackGroup = groups.get(groupIndex); int[] trackFormatSupport = formatSupport[groupIndex]; @@ -2074,39 +2064,8 @@ public class DefaultTrackSelector extends MappingTrackSelector { if (isSupported(trackFormatSupport[trackIndex], params.exceedRendererCapabilitiesIfNecessary)) { Format format = trackGroup.getFormat(trackIndex); - int maskedSelectionFlags = - format.selectionFlags & ~params.disabledTextTrackSelectionFlags; - boolean isDefault = (maskedSelectionFlags & C.SELECTION_FLAG_DEFAULT) != 0; - boolean isForced = (maskedSelectionFlags & C.SELECTION_FLAG_FORCED) != 0; - int trackScore; - int languageScore = getFormatLanguageScore(format, params.preferredTextLanguage); - boolean trackHasNoLanguage = formatHasNoLanguage(format); - if (languageScore > 0 || (params.selectUndeterminedTextLanguage && trackHasNoLanguage)) { - if (isDefault) { - trackScore = 11; - } else if (!isForced) { - // Prefer non-forced to forced if a preferred text language has been specified. Where - // both are provided the non-forced track will usually contain the forced subtitles as - // a subset. - trackScore = 7; - } else { - trackScore = 3; - } - trackScore += languageScore; - } else if (isDefault) { - trackScore = 2; - } else if (isForced - && (getFormatLanguageScore(format, selectedAudioLanguage) > 0 - || (trackHasNoLanguage && stringDefinesNoLanguage(selectedAudioLanguage)))) { - trackScore = 1; - } else { - // Track should not be selected. - continue; - } - if (isSupported(trackFormatSupport[trackIndex], false)) { - trackScore += WITHIN_RENDERER_CAPABILITIES_BONUS; - } - if (trackScore > selectedTrackScore) { + TextTrackScore trackScore = new TextTrackScore(format, params, trackFormatSupport[trackIndex]); + if ((selectedTrackScore == null) || trackScore.compareTo(selectedTrackScore) > 0) { selectedGroup = trackGroup; selectedTrackIndex = trackIndex; selectedTrackScore = trackScore; @@ -2535,4 +2494,59 @@ public class DefaultTrackSelector extends MappingTrackSelector { } + /** Represents how well an text track matches the selection {@link Parameters}. */ + protected static final class TextTrackScore implements Comparable { + + private final boolean isWithinRendererCapabilities; + private final int preferredLanguageScore; + private final int localeLanguageMatchIndex; + private final int localeLanguageScore; + private final boolean isDefaultSelectionFlag; + + public TextTrackScore(Format format, Parameters parameters, int formatSupport) { + isWithinRendererCapabilities = isSupported(formatSupport, false); + preferredLanguageScore = getFormatLanguageScore(format, parameters.preferredTextLanguage); + isDefaultSelectionFlag = (format.selectionFlags & C.SELECTION_FLAG_DEFAULT) != 0; + String[] localeLanguages = Util.getSystemLanguageCodes(); + int bestMatchIndex = Integer.MAX_VALUE; + int bestMatchScore = 0; + for (int i = 0; i < localeLanguages.length; i++) { + int score = getFormatLanguageScore(format, localeLanguages[i]); + if (score > 0) { + bestMatchIndex = i; + bestMatchScore = score; + break; + } + } + localeLanguageMatchIndex = bestMatchIndex; + localeLanguageScore = bestMatchScore; + } + + /** + * Compares this score with another. + * + * @param other The other score to compare to. + * @return A positive integer if this score is better than the other. Zero if they are equal. A + * negative integer if this score is worse than the other. + */ + @Override + public int compareTo(@NonNull TextTrackScore other) { + if (this.isWithinRendererCapabilities != other.isWithinRendererCapabilities) { + return this.isWithinRendererCapabilities ? 1 : -1; + } + if (this.preferredLanguageScore != other.preferredLanguageScore) { + return compareInts(this.preferredLanguageScore, other.preferredLanguageScore); + } + if (this.isDefaultSelectionFlag != other.isDefaultSelectionFlag) { + return this.isDefaultSelectionFlag ? 1 : -1; + } + if (this.localeLanguageMatchIndex != other.localeLanguageMatchIndex) { + return -compareInts(this.localeLanguageMatchIndex, other.localeLanguageMatchIndex); + } + if (this.localeLanguageScore != other.localeLanguageScore) { + return compareInts(this.localeLanguageScore, other.localeLanguageScore); + } + return 0; + } + } }