Alastor Wu
Staff Software Engineer at Mozilla
Portland, Oregon, United States
Summary
👤
Senior🎓
Top SchoolAlastor Wu is a Staff Software Engineer based in Portland with 11 years in software and over 8 years focused on media playback, codecs (H.264, VP9, AV1, HEVC) and web platform specs. He combines deep C++ and JavaScript expertise with cross-platform, multithreaded systems experience across Windows, macOS, Linux and Android, and a strong track record in automation testing and code review. At Mozilla he has driven performance and correctness improvements in Gecko’s media stack—implementing hardware decoding support, Media Source Extensions fixes, and Media Foundation DRM paths for high-resolution playback. He’s also contributed to web-platform-tests to tighten spec compliance for media elements and to frontline UI/audio features in legacy projects like Gaia. Pragmatic and detail-oriented, he pairs low-level engineering (profiler markers, pixel-aspect handling) with standards work such as editing Autoplay Policy Detection to align browser behavior with web specs.
11 years of coding experience
8 years of employment as a software developer
Bachelor's degree, Computer Science, Bachelor's degree, Computer Science at National Chiao Tung University
Stackoverflow
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Github Skills (22)
accessibility10
javascript10
ffmpeg10
decoding10
mse10
front-end-development10
html10
mediasource10
performance-monitor9
performance-analytics9
code-profiling9
ui-design9
performance-monitoring9
profiling9
performance-analysis9
Programming languages (10)
Github contributions (5)
mozilla/gecko-dev
Feb 2015 - Jan 2023
Read-only Git mirror of the Mercurial gecko repositories at https://hg.mozilla.org. How to contribute: https://firefox-source-docs.mozilla.org/contributing/contribution_quickref.html
Role in this project:
Back-end Developer
Back-end DeveloperContributions:2059 commits in 8 years
Contributions summary:Alastor contributed significantly to the media playback functionality, primarily focusing on improvements and fixes related to the Media Source Extensions (MSE) and hardware decoding. Their work involved adding profiler markers for detailed performance analysis, implementing support for HEVC video decoding, and resolving issues related to incorrect display sizes and handling of the pixel aspect ratio from metadata. They also addressed edge cases concerning stream ID changes and ensuring the proper initialization of the media engine for the Windows platform.
repositoriesfirefoxmercurialgit-mirrormozilla
web-platform-tests/wpt
Jun 2016 - Dec 2022
Test suites for Web platform specs — including WHATWG, W3C, and others
Role in this project:QA Engineer / Test Automation Engineer
QA Engineer / Test Automation EngineerContributions:46 commits, 1 comment, 3 issues in 6 years 6 months
Contributions summary:Alastor primarily contributed to the `web-platform-tests/wpt` repository by modifying and enabling existing web platform tests (WPT) related to media elements, specifically focusing on the `<track>` element and its associated events and functionalities. Their commits involved fixing test failures, correcting incorrect assertions, and adapting tests to align with the specifications. They also added new tests, addressing areas like text track cue lists and ensuring correct behavior across different scenarios and states within the media element.
microsoft-edgetest-runnerspecssafarifirefox
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