d687ad1ed0
# Low Latency DASH - `availabilityTimeComplete=false` Low Latency DASH manifests generated by Packager were missing the attribute `availabilityTimeComplete`. As per the [DASH specs](https://dashif.org/docs/CR-Low-Latency-Live-r8.pdf): **_the AdaptationSet@availabilityTimeCompleteshould be present and be set to 'FALSE'_** ## The Issue The missing attribute caused ULL streams from Shaka Packager to no longer be compatible with DASH.js. Previous versions of DASH.js allowed users to specify ULL mode when initializing the player. However, the most recent releases of DASH.js automatically detect ULL by scanning the manifest for ULL specific attributes. Although there are many attributes only associated with ULL, [DASH.js only greps for `availabilityTimeComplete` in its detection logic](https://github.com/Dash-Industry-Forum/dash.js/blob/development/src/streaming/controllers/PlaybackController.js#L792-L805). Because of the missing attribute in Packager and the limited ULL verification criteria by DASH.js, Packager streams were not being treated as low latency streams by DASH.js. ## Testing ### Unit Testing `./mpd_unittest --gtest_filter="SegmentTemplateTest.OneSegmentLowLatency"` ` ./mpd_unittest --gtest_filter="LowLatencySegmentTest.LowLatencySegmentTemplate"` ### Manual Testing - Created a low latency stream with Shaka Packager - Observed the expected `availabilityTimeComplete=false` attribute in the generated DASH manifest. |
||
|---|---|---|
| .github | ||
| docs | ||
| npm | ||
| packager | ||
| .clang-format | ||
| .dockerignore | ||
| .gitignore | ||
| .gitmodules | ||
| AUTHORS | ||
| CHANGELOG.md | ||
| CONTRIBUTING.md | ||
| CONTRIBUTORS | ||
| DEPS | ||
| Dockerfile | ||
| LICENSE | ||
| README.md | ||
| chromium-LICENSE | ||
| gyp_packager.py | ||
README.md
Shaka Packager is a tool and a media packaging SDK for DASH and HLS packaging and encryption. It can prepare and package media content for online streaming.
Shaka Packager supports:
-
Both Video-On-Demand and Live.
-
Streaming formats:
-
Key systems:
-
Encryption standards:
-
Media Containers and codecs
Codecs ISO-BMFF WebM MPEG2-TS WVM Packed Audio² H264 (AVC) I / O - I / O I - H265 (HEVC) I / O - I - - VP8 I / O I / O - - - VP9 I / O I / O - - - AV1 I / O I / O - - - AAC I / O - I / O I O MP3 O - I / O - O Dolby AC3 I / O - I / O - O Dolby EAC3 I / O - O - O MPEG-H Audio I / O - - - - Dolby AC4 I / O - - - - DTS I / O - - - - FLAC I / O - - - - Opus I / O³ I / O - - - Vorbis - I / O - - - NOTES:
- I for input and O for output.
- ²: https://tools.ietf.org/html/draft-pantos-http-live-streaming-23#section-3.4
- ³: Opus support in ISO-BMFF is experimental.
-
Subtitles
Format Input Output Text WebVTT Y Y WebVTT in MP4 #405 Y Text TTML ⁴ Y TTML in MP4 - Y DVB-SUB Y - Teletext #272 - - ⁴: TTML input is only supported with TTML output (pass-through, DASH only), see also #584.
- Platforms
- Linux
- Mac
- Windows
- Cross compiling for ARM is also supported.
1: Limited support
Getting Shaka Packager
There are several ways you can get Shaka Packager.
- Using Docker. Instructions are available here.
- Get prebuilt binaries from release.
- Built from source, see Build Instructions for details.
Useful Links
- Announcement List (join for infrequent announcements and surveys)
- Subscribe to releases by following instructions from this blog- Documentation
- Tutorials
- Several open source players:
Contributing
If you have improvements or fixes, we would love to have your contributions. See https://github.com/shaka-project/shaka-packager/blob/main/CONTRIBUTING.md for details.