Fix Low-Latency HLS VTT subtitle part loading #7626
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,5 +1,4 @@ | ||
| import BaseStreamController, { State } from './base-stream-controller'; | ||
| import { FragmentState } from './fragment-tracker'; | ||
| import { ErrorDetails, ErrorTypes } from '../errors'; | ||
| import { Events } from '../events'; | ||
|
|
@@ -48,7 +47,7 @@ export class SubtitleStreamController | |
| implements NetworkComponentAPI | ||
| { | ||
| private currentTrackId: number = -1; | ||
| private tracksBuffered: Array<TimeRange[] | undefined> = []; | ||
| private mainDetails: LevelDetails | null = null; | ||
|
|
||
| constructor( | ||
|
|
@@ -128,13 +127,7 @@ export class SubtitleStreamController | |
| event: Events.SUBTITLE_FRAG_PROCESSED, | ||
| data: SubtitleFragProcessed, | ||
| ) { | ||
| const { frag, part, success } = data; | ||
| if (!success) { | ||
| return; | ||
| } | ||
|
|
@@ -147,28 +140,32 @@ export class SubtitleStreamController | |
| // Create/update a buffered array matching the interface used by BufferHelper.bufferedInfo | ||
| // so we can re-use the logic used to detect how much has been buffered | ||
| let timeRange: TimeRange | undefined; | ||
| const start = (part || frag).start; | ||
| for (let i = 0; i < buffered.length; i++) { | ||
| if (start >= buffered[i].start && start <= buffered[i].end) { | ||
| timeRange = buffered[i]; | ||
| break; | ||
| } | ||
| } | ||
|
|
||
| const end = start + (part || frag).duration; | ||
| if (timeRange) { | ||
| timeRange.end = end; | ||
| } else { | ||
| timeRange = { start, end }; | ||
| buffered.push(timeRange); | ||
| } | ||
| if (!part || end >= frag.end) { | ||
| this.fragmentTracker.fragBuffered(frag as MediaFragment); | ||
| if (!this.fragContextChanged(frag)) { | ||
| if (isMediaFragment(frag)) { | ||
| this.fragPrevious = frag; | ||
| } | ||
| } | ||
| this.fragBufferedComplete(frag, part); | ||
| if (this.media) { | ||
| this.tickImmediate(); | ||
| } | ||
| } | ||
| } | ||
|
|
||
|
|
@@ -184,6 +181,7 @@ export class SubtitleStreamController | |
| } | ||
| data.endOffsetSubtitles = Math.max(0, endOffsetSubtitles); | ||
| this.tracksBuffered.forEach((buffered) => { | ||
| if (!buffered) return; | ||
| for (let i = 0; i < buffered.length; ) { | ||
| if (buffered[i].end <= endOffsetSubtitles) { | ||
| buffered.shift(); | ||
|
|
@@ -259,13 +257,13 @@ export class SubtitleStreamController | |
| } | ||
|
|
||
| // Check if track has the necessary details to load fragments | ||
| const currentTrack = this.levels[this.currentTrackId] as Level | undefined; | ||
| if (!currentTrack?.details) { | ||
| this.mediaBuffer = null; | ||
| return; | ||
| } | ||
| this.mediaBuffer = this.mediaBufferTimeRanges; | ||
| if (this.state !== State.STOPPED) { | ||
| this.setInterval(TICK_INTERVAL); | ||
| } | ||
| } | ||
|
|
@@ -281,7 +279,7 @@ export class SubtitleStreamController | |
| this.warn(`Subtitle tracks were reset while loading level ${trackId}`); | ||
| return; | ||
| } | ||
| const track = levels[trackId] as Level | undefined; | ||
| if (trackId >= levels.length || !track) { | ||
| return; | ||
| } | ||
|
|
@@ -346,26 +344,7 @@ export class SubtitleStreamController | |
| }); | ||
|
|
||
| // trigger handler right now | ||
|
Collaborator
There was a problem hiding this comment. The logic for streaming subtitles in LL-HLS has become much more lenient 👍
Collaborator
Author
There was a problem hiding this comment. Additional changes in #7482 will help to ensure proper playlist alignment. When combined with these changes, audio and subtitle segment loading will follow more of the same logic. |
||
| this.tickImmediate(); | ||
| } | ||
|
|
||
| _handleFragmentLoadComplete(fragLoadedData: FragLoadedData) { | ||
|
|
@@ -423,18 +402,23 @@ export class SubtitleStreamController | |
| } | ||
|
|
||
| doTick() { | ||
| if (this.state === State.IDLE) { | ||
| if ( | ||
| !this.media && | ||
| !this.primaryPrefetch && | ||
| (this.startFragRequested || !this.config.startFragPrefetch) | ||
| ) { | ||
| return; | ||
| } | ||
| const { currentTrackId, levels } = this; | ||
| const track = levels?.[currentTrackId]; | ||
|
Collaborator
There was a problem hiding this comment. Before there was a check to see if track is undefined, now it's removed here. I believe this may cause issues. We may need to keep what was here previously:
Collaborator
Author
There was a problem hiding this comment. We're covered by
Collaborator
There was a problem hiding this comment. Got it. that's true that the original code had that: |
||
| const trackDetails = track?.details; | ||
| if ( | ||
| !trackDetails || | ||
| this.waitForLive(track) || | ||
| this.waitForCdnTuneIn(trackDetails) | ||
| ) { | ||
| this.startFragRequested = false; | ||
| return; | ||
| } | ||
| const { config } = this; | ||
|
|
@@ -445,62 +429,32 @@ export class SubtitleStreamController | |
| config.maxBufferHole, | ||
| ); | ||
| const { end: targetBufferTime, len: bufferLen } = bufferedInfo; | ||
| const maxBufLen = | ||
| this.hls.maxBufferLength + trackDetails.levelTargetDuration; | ||
|
|
||
| if (bufferLen > maxBufLen || (bufferLen && !this.buffering)) { | ||
| return; | ||
| } | ||
| let frag = this.getNextFragment(currentTime, trackDetails); | ||
| if (!frag) { | ||
| return; | ||
| } | ||
| // Load earlier fragment in same discontinuity to make up for misaligned playlists and cues that extend beyond end of segment | ||
| if (isMediaFragment(frag)) { | ||
| const curSNIdx = frag.sn - trackDetails.startSN; | ||
| const prevFrag = trackDetails.fragments[curSNIdx - 1] as | ||
| | MediaFragment | ||
| | undefined; | ||
| if ( | ||
| prevFrag && | ||
| prevFrag.cc === frag.cc && | ||
| !trackDetails.partList?.length && | ||
| this.fragmentTracker.getState(prevFrag) === FragmentState.NOT_LOADED | ||
| ) { | ||
| frag = prevFrag; | ||
| } | ||
| } | ||
| this.loadFragment(frag, track, targetBufferTime); | ||
| } | ||
| } | ||
|
|
||
|
|
||
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
I don't see anywhere where we are appending an undefined object to tracksBuffered? Do we suspect we need this?
Uh oh!
There was an error while loading. Please reload this page.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
We don't append
undefinedvalues, but we do not usenoUncheckedIndexedAccesseither. When using (@typescript-eslint/)no-unnecessary-condition(I use this offline, but not in the project proper), typing this way helps by signaling that the result totracksBuffered[<missing-key-or-index>]may be undefined. Yes, it is bad typing, but simpler safety. I'm open to suggestions - short and long term.There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Got it, I think this is fine for now. And agree maybe something to look into in the future.