fix(HLS): Only offset segment ref times when needed w/ EXT-X-MEDIA-SEQUENCE #6378
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JulianDomingo
added
component: HLS
|
Incremental code coverage: 100.00% |
avelad
requested changes
Mar 30, 2024
|
Looks simple enough. But please add tests, and please add more detail in the PR description to help others understand the problem and how this solves it. Thanks! |
…e to a warning instead.
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@JulianDomingo can you fix the build errors? Thanks! |
Done, I've updated the PR description and added unit tests. Fixed lint errors as well. |
avelad
added
type: bug
theodab
requested changes
Apr 5, 2024
|
@JulianDomingo Please, fix the tests |
…*before* the playlist update occurs.
Done; I mistakenly placed the initial assertion after the live playlist update occurs, which was not the intention. |
avelad
approved these changes
Apr 5, 2024
theodab
approved these changes
Apr 5, 2024
avelad
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Apr 8, 2024
…QUENCE (#6378) Fixes #6377 When choosing to synchronize HLS streams using `EXT-X-MEDIA-SEQUENCE` instead of `EXT-X-PROGRAM-DATE-TIME` during LIVE playlist variant switches, Shaka unnecessarily drops 'old' segments and offsets the segment references of the new playlist so that the earliest reference represents media time `0`: https://github.com/shaka-project/shaka-player/blob/ea740ba2468f3b035d463ea9933aa7eeccf5c748/lib/hls/hls_parser.js#L610-L613 This is problematic, as the `StreamingEngine`'s media time used to download new segments is based off the latest segment references: https://github.com/shaka-project/shaka-player/blob/ea740ba2468f3b035d463ea9933aa7eeccf5c748/lib/media/streaming_engine.js#L1248-L1250 https://github.com/shaka-project/shaka-player/blob/ea740ba2468f3b035d463ea9933aa7eeccf5c748/lib/media/streaming_engine.js#L1385 For example: ``` Playlist download #1 EXT-X-MEDIA-SEQUENCE Media Time 0 0 1 6 2 12 3 18 Playlist download #2 (what happens now) EXT-X-MEDIA-SEQUENCE Media Time 6 0 7 6 8 12 9 18 Playlist download #2 (desired behavior) EXT-X-MEDIA-SEQUENCE Media Time 6 36 7 42 8 48 9 54 ``` Without this fix, and given the above example, if Shaka tries to request the segment at `time=36`, it will fail because the media state only has segment references up to `time=18`. Until the manifests, 'catch up', the player freezes; this can be especially problematic when a large amount of time accumulates before a variant switch occurs. This has been confirmed by Pluto TV to fix their freezing issues.
avelad
pushed a commit
that referenced
this pull request
Apr 8, 2024
…QUENCE (#6378) Fixes #6377 When choosing to synchronize HLS streams using `EXT-X-MEDIA-SEQUENCE` instead of `EXT-X-PROGRAM-DATE-TIME` during LIVE playlist variant switches, Shaka unnecessarily drops 'old' segments and offsets the segment references of the new playlist so that the earliest reference represents media time `0`: https://github.com/shaka-project/shaka-player/blob/ea740ba2468f3b035d463ea9933aa7eeccf5c748/lib/hls/hls_parser.js#L610-L613 This is problematic, as the `StreamingEngine`'s media time used to download new segments is based off the latest segment references: https://github.com/shaka-project/shaka-player/blob/ea740ba2468f3b035d463ea9933aa7eeccf5c748/lib/media/streaming_engine.js#L1248-L1250 https://github.com/shaka-project/shaka-player/blob/ea740ba2468f3b035d463ea9933aa7eeccf5c748/lib/media/streaming_engine.js#L1385 For example: ``` Playlist download #1 EXT-X-MEDIA-SEQUENCE Media Time 0 0 1 6 2 12 3 18 Playlist download #2 (what happens now) EXT-X-MEDIA-SEQUENCE Media Time 6 0 7 6 8 12 9 18 Playlist download #2 (desired behavior) EXT-X-MEDIA-SEQUENCE Media Time 6 36 7 42 8 48 9 54 ``` Without this fix, and given the above example, if Shaka tries to request the segment at `time=36`, it will fail because the media state only has segment references up to `time=18`. Until the manifests, 'catch up', the player freezes; this can be especially problematic when a large amount of time accumulates before a variant switch occurs. This has been confirmed by Pluto TV to fix their freezing issues.
joeyparrish
pushed a commit
that referenced
this pull request
May 7, 2024
…QUENCE (#6378) Fixes #6377 When choosing to synchronize HLS streams using `EXT-X-MEDIA-SEQUENCE` instead of `EXT-X-PROGRAM-DATE-TIME` during LIVE playlist variant switches, Shaka unnecessarily drops 'old' segments and offsets the segment references of the new playlist so that the earliest reference represents media time `0`: https://github.com/shaka-project/shaka-player/blob/ea740ba2468f3b035d463ea9933aa7eeccf5c748/lib/hls/hls_parser.js#L610-L613 This is problematic, as the `StreamingEngine`'s media time used to download new segments is based off the latest segment references: https://github.com/shaka-project/shaka-player/blob/ea740ba2468f3b035d463ea9933aa7eeccf5c748/lib/media/streaming_engine.js#L1248-L1250 https://github.com/shaka-project/shaka-player/blob/ea740ba2468f3b035d463ea9933aa7eeccf5c748/lib/media/streaming_engine.js#L1385 For example: ``` Playlist download #1 EXT-X-MEDIA-SEQUENCE Media Time 0 0 1 6 2 12 3 18 Playlist download #2 (what happens now) EXT-X-MEDIA-SEQUENCE Media Time 6 0 7 6 8 12 9 18 Playlist download #2 (desired behavior) EXT-X-MEDIA-SEQUENCE Media Time 6 36 7 42 8 48 9 54 ``` Without this fix, and given the above example, if Shaka tries to request the segment at `time=36`, it will fail because the media state only has segment references up to `time=18`. Until the manifests, 'catch up', the player freezes; this can be especially problematic when a large amount of time accumulates before a variant switch occurs. This has been confirmed by Pluto TV to fix their freezing issues.
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Fixes #6377
When choosing to synchronize HLS streams using
EXT-X-MEDIA-SEQUENCEinstead ofEXT-X-PROGRAM-DATE-TIMEduring LIVE playlist variant switches, Shaka unnecessarily drops 'old' segments and offsets the segment references of the new playlist so that the earliest reference represents media time0:shaka-player/lib/hls/hls_parser.js
Lines 610 to 613 in ea740ba
This is problematic, as the
StreamingEngine's media time used to download new segments is based off the latest segment references:shaka-player/lib/media/streaming_engine.js
Lines 1248 to 1250 in ea740ba
shaka-player/lib/media/streaming_engine.js
Line 1385 in ea740ba
For example:
Without this fix, and given the above example, if Shaka tries to request the segment at
time=36, it will fail because the media state only has segment references up totime=18. Until the manifests, 'catch up', the player freezes; this can be especially problematic when a large amount of time accumulates before a variant switch occurs.This has been confirmed by Pluto TV to fix their freezing issues.