Refactor streams playback start #3308
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Thanks to this PR, use cases as described in issue #3146 are correctly handled |
| let startTime = streamSeekTime; | ||
| if (isNaN(startTime)) { | ||
| startTime = isDynamic ? e.liveStartTime : e.streamInfo.start; | ||
| startTime = Math.max(startTime, getStartTimeFromUri()); |
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Following up the discussion we had on Slack and using #t during startup: Using #t for live will not work with dynamic manifests as the live edge will always have a higher value than the #t. I think it should be Math.min but we need to consider the DVR window at this point. If #t is out of the DVR window we can either ignore it or adjust its value.
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Addition: For Math.min for live, Math.max for VoD
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getStartTimeFromUri() should return NaN instead of -1
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No, getStartTimeFromUri() should not return NaN
Math.max and Math.min are expecting each parameter to ba a valid number
Math.max(x, NaN) and Math.min(x, NaN) return NaN
But I do modify acording your remarks and take advantage of this PR to make code conformed to MPD anchors spec
- always use seeking process from PlaybackController to seek controllers - adjust seek time in BufferController according to effective appended ranges - ScheduleController: do not stop scheduler when updating data (at manifest updates)
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As discussed on Slack, tested: VoD
Live
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| it('should start static stream at period start if #t is beyond period end', function (done) { | ||
| doneFn = done; | ||
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| let uriStartTime = 700; |
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Suggest to define this as staticStreamInfo.duration + 100 in case we ever change the value in staticStreamInfo.duration
* Refactor stream playback starting process: - always use seeking process from PlaybackController to seek controllers - adjust seek time in BufferController according to effective appended ranges - ScheduleController: do not stop scheduler when updating data (at manifest updates) * revert gap/discontinuity limit for buffer range tolerance (to do in another PR) * update code comments * BufferController: optimise effective range seeking if seek target * avoid seeking at NaN * remove commented code * remove commented code * Add processing of MPD time anchor (#t) according to Annex C of MPEG DASH spec * StreamProcessor: update DVR info metrics also if SEGMENTS_UPDATE_FAILED_ERROR_CODE * rename getStartTimeFromUriParameters() parameter to 'rangeStart' * Start at DVR window start if #t is before DVR window range * Ignore #t=posix: notation for static streams * #t=<time> shall be relative to period start for dynamic streams * update unit tests
This PR intends to refactor and simplify streams playback start process:
The changes are illustrated in following sequence diagram: https://sketchboard.me/nCcqJmksDzlb#/