fix: wait for endedtimeline event from transmuxer when reaching the e…

…nd of a timeline (#1058) Previously, when the end of a timeline was reached (i.e., the last segment in a given timeline was appended), `endTimeline` would be called, but the loader would not wait for the event to finish. This lead to issues where segment information came back after a segment is considered done with processing, and segment information could be dropped. This fix waits for the `endedtimeline` message from the transmuxer before it considers the transmux complete.
videojs · Feb 8, 2021 · b01ab72 · b01ab72
1 parent a34b4da
commit b01ab72
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Showing 4 changed files with 251 additions and 14 deletions.
diff --git a/src/media-segment-request.js b/src/media-segment-request.js
@@ -266,6 +266,8 @@ const transmuxAndNotify = ({
  audioSegmentTimingInfoFn,
  id3Fn,
  captionsFn,
+ isEndOfTimeline,
+ endedTimelineFn,
  dataFn,
  doneFn
 }) => {
@@ -360,6 +362,13 @@ const transmuxAndNotify = ({
  onCaptions: (captions) => {
  captionsFn(segment, [captions]);
  },
+ // if this is a partial transmux, the end of the timeline has not yet been reached
+ // until the last part of the segment is processed (at which point isPartial will
+ // be false)
+ isEndOfTimeline: isEndOfTimeline && !isPartial,
+ onEndedTimeline: () => {
+ endedTimelineFn();
+ },
  onDone: (result) => {
  // To handle partial appends, there won't be a done function passed in (since
  // there's still, potentially, more segment to process), so there's nothing to do.
@@ -382,6 +391,8 @@ const handleSegmentBytes = ({
  audioSegmentTimingInfoFn,
  id3Fn,
  captionsFn,
+ isEndOfTimeline,
+ endedTimelineFn,
  dataFn,
  doneFn
 }) => {
@@ -513,6 +524,8 @@ const handleSegmentBytes = ({
  audioSegmentTimingInfoFn,
  id3Fn,
  captionsFn,
+ isEndOfTimeline,
+ endedTimelineFn,
  dataFn,
  doneFn
  });
@@ -533,6 +546,11 @@ const handleSegmentBytes = ({
  * @param {Function} audioSegmentTimingInfoFn
  * a callback that receives audio timing info based on media times and
  * any adjustments made by the transmuxer
+ * @param {boolean} isEndOfTimeline
+ * true if this segment represents the last segment in a timeline
+ * @param {Function} endedTimelineFn
+ * a callback made when a timeline is ended, will only be called if
+ * isEndOfTimeline is true
  * @param {Function} dataFn - a callback that is executed when segment bytes are available
  * and ready to use
  * @param {Function} doneFn - a callback that is executed after decryption has completed
@@ -546,6 +564,8 @@ const decryptSegment = ({
  audioSegmentTimingInfoFn,
  id3Fn,
  captionsFn,
+ isEndOfTimeline,
+ endedTimelineFn,
  dataFn,
  doneFn
 }) => {
@@ -570,6 +590,8 @@ const decryptSegment = ({
  audioSegmentTimingInfoFn,
  id3Fn,
  captionsFn,
+ isEndOfTimeline,
+ endedTimelineFn,
  dataFn,
  doneFn
  });
@@ -618,6 +640,11 @@ const decryptSegment = ({
  * any adjustments made by the transmuxer
  * @param {Function} id3Fn - a callback that receives ID3 metadata
  * @param {Function} captionsFn - a callback that receives captions
+ * @param {boolean} isEndOfTimeline
+ * true if this segment represents the last segment in a timeline
+ * @param {Function} endedTimelineFn
+ * a callback made when a timeline is ended, will only be called if
+ * isEndOfTimeline is true
  * @param {Function} dataFn - a callback that is executed when segment bytes are available
  * and ready to use
  * @param {Function} doneFn - a callback that is executed after all resources have been
@@ -632,6 +659,8 @@ const waitForCompletion = ({
  audioSegmentTimingInfoFn,
  id3Fn,
  captionsFn,
+ isEndOfTimeline,
+ endedTimelineFn,
  dataFn,
  doneFn
 }) => {
@@ -678,6 +707,8 @@ const waitForCompletion = ({
  audioSegmentTimingInfoFn,
  id3Fn,
  captionsFn,
+ isEndOfTimeline,
+ endedTimelineFn,
  dataFn,
  doneFn
  });
@@ -693,6 +724,8 @@ const waitForCompletion = ({
  audioSegmentTimingInfoFn,
  id3Fn,
  captionsFn,
+ isEndOfTimeline,
+ endedTimelineFn,
  dataFn,
  doneFn
  });
@@ -732,6 +765,11 @@ const handleLoadEnd = ({ loadendState, abortFn }) => (event) => {
  * @param {Function} audioSegmentTimingInfoFn
  * a callback that receives audio timing info based on media times and
  * any adjustments made by the transmuxer
+ * @param {boolean} isEndOfTimeline
+ * true if this segment represents the last segment in a timeline
+ * @param {Function} endedTimelineFn
+ * a callback made when a timeline is ended, will only be called if
+ * isEndOfTimeline is true
  * @param {Function} dataFn - a callback that is executed when segment bytes are available
  * and ready to use
  * @param {Event} event - the progress event object from XMLHttpRequest
@@ -745,6 +783,8 @@ const handleProgress = ({
  audioSegmentTimingInfoFn,
  id3Fn,
  captionsFn,
+ isEndOfTimeline,
+ endedTimelineFn,
  dataFn,
  handlePartialData
 }) => (event) => {
@@ -782,6 +822,8 @@ const handleProgress = ({
  audioSegmentTimingInfoFn,
  id3Fn,
  captionsFn,
+ isEndOfTimeline,
+ endedTimelineFn,
  dataFn
  });
  }
@@ -853,6 +895,11 @@ const handleProgress = ({
  * any adjustments made by the transmuxer
  * @param {Function} id3Fn - a callback that receives ID3 metadata
  * @param {Function} captionsFn - a callback that receives captions
+ * @param {boolean} isEndOfTimeline
+ * true if this segment represents the last segment in a timeline
+ * @param {Function} endedTimelineFn
+ * a callback made when a timeline is ended, will only be called if
+ * isEndOfTimeline is true
  * @param {Function} dataFn - a callback that receives data from the main segment's xhr
  * request, transmuxed if needed
  * @param {Function} doneFn - a callback that is executed only once all requests have
@@ -873,6 +920,8 @@ export const mediaSegmentRequest = ({
  audioSegmentTimingInfoFn,
  id3Fn,
  captionsFn,
+ isEndOfTimeline,
+ endedTimelineFn,
  dataFn,
  doneFn,
  handlePartialData
@@ -887,6 +936,8 @@ export const mediaSegmentRequest = ({
  audioSegmentTimingInfoFn,
  id3Fn,
  captionsFn,
+ isEndOfTimeline,
+ endedTimelineFn,
  dataFn,
  doneFn
  });
@@ -954,6 +1005,8 @@ export const mediaSegmentRequest = ({
  audioSegmentTimingInfoFn,
  id3Fn,
  captionsFn,
+ isEndOfTimeline,
+ endedTimelineFn,
  dataFn,
  handlePartialData
  })

diff --git a/src/segment-loader.js b/src/segment-loader.js
@@ -2193,6 +2193,13 @@ export default class SegmentLoader extends videojs.EventTarget {
  }
 
  const simpleSegment = this.createSimplifiedSegmentObj_(segmentInfo);
+ const isEndOfStream = this.isEndOfStream_(segmentInfo.mediaIndex, segmentInfo.playlist);
+ const isWalkingForward = this.mediaIndex !== null;
+ const isDiscontinuity = segmentInfo.timeline !== this.currentTimeline_ &&
+ // currentTimeline starts at -1, so we shouldn't end the timeline switching to 0,
+ // the first timeline
+ segmentInfo.timeline > 0;
+ const isEndOfTimeline = isEndOfStream || (isWalkingForward && isDiscontinuity);
 
  segmentInfo.abortRequests = mediaSegmentRequest({
  xhr: this.vhs_.xhr,
@@ -2207,6 +2214,10 @@ export default class SegmentLoader extends videojs.EventTarget {
  videoSegmentTimingInfoFn: this.handleSegmentTimingInfo_.bind(this, 'video', segmentInfo.requestId),
  audioSegmentTimingInfoFn: this.handleSegmentTimingInfo_.bind(this, 'audio', segmentInfo.requestId),
  captionsFn: this.handleCaptions_.bind(this),
+ isEndOfTimeline,
+ endedTimelineFn: () => {
+ this.logger_('received endedtimeline callback');
+ },
  id3Fn: this.handleId3_.bind(this),
 
  dataFn: this.handleData_.bind(this),
@@ -2410,19 +2421,6 @@ export default class SegmentLoader extends videojs.EventTarget {
  // state away from loading until we are officially done loading the segment data.
  this.state = 'APPENDING';
 
- const isEndOfStream = this.isEndOfStream_(segmentInfo.mediaIndex, segmentInfo.playlist);
- const isWalkingForward = this.mediaIndex !== null;
- const isDiscontinuity = segmentInfo.timeline !== this.currentTimeline_ &&
- // TODO verify this behavior
- // currentTimeline starts at -1, but we shouldn't end the timeline switching to 0,
- // the first timeline
- segmentInfo.timeline > 0;
-
- if (!segmentInfo.isFmp4 &&
- (isEndOfStream || (isWalkingForward && isDiscontinuity))) {
- segmentTransmuxer.endTimeline(this.transmuxer_);
- }
-
  // used for testing
  this.trigger('appending');
 

diff --git a/src/segment-transmuxer.js b/src/segment-transmuxer.js
@@ -81,12 +81,15 @@ export const processTransmux = (options) => {
  onAudioSegmentTimingInfo,
  onId3,
  onCaptions,
- onDone
+ onDone,
+ onEndedTimeline,
+ isEndOfTimeline
  } = options;
  const transmuxedData = {
  isPartial,
  buffer: []
  };
+ let waitForEndedTimelineEvent = isEndOfTimeline;
 
  const handleMessage = (event) => {
  if (transmuxer.currentTransmux !== options) {
@@ -121,12 +124,24 @@ export const processTransmux = (options) => {
  if (event.data.action === 'caption') {
  onCaptions(event.data.caption);
  }
+ if (event.data.action === 'endedtimeline') {
+ waitForEndedTimelineEvent = false;
+ onEndedTimeline();
+ }
 
  // wait for the transmuxed event since we may have audio and video
  if (event.data.type !== 'transmuxed') {
  return;
  }
 
+ // If the "endedtimeline" event has not yet fired, and this segment represents the end
+ // of a timeline, that means there may still be data events before the segment
+ // processing can be considerred complete. In that case, the final event should be
+ // an "endedtimeline" event with the type "transmuxed."
+ if (waitForEndedTimelineEvent) {
+ return;
+ }
+
  transmuxer.onmessage = null;
  handleDone_({
  transmuxedData,
@@ -185,6 +200,10 @@ export const processTransmux = (options) => {
  // even if we didn't push any bytes, we have to make sure we flush in case we reached
  // the end of the segment
  transmuxer.postMessage({ action: isPartial ? 'partialFlush' : 'flush' });
+
+ if (isEndOfTimeline) {
+ transmuxer.postMessage({ action: 'endTimeline' });
+ }
 };
 
 export const dequeue = (transmuxer) => {