Observed arrival · 2026-09-20
MediaScope: Playback Under a Microscope
A Chrome DevTools extension for tracing MP4, WebM, and live MSE playback from network requests to decoded frames.
○Open
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$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- Engineers debugging browser media playback
- Worth noticing
- It correlates network segments, MSE appends, DTS, PTS, samples, and decoded frames on one playback timeline.
Field notes
The extension organizes browser playback evidence into four broad stages: source and delivery, containers and samples, playback timing, and decoded output. Its examples expose details such as MP4 box offsets, codec configuration, NAL units, audio packet timing, and timed-text cues. The page also describes a 256 MiB rolling window for MSE capture and says audio and video SourceBuffers can be examined together on a synchronized media timeline.
Observed signals
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Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
ƒJavaScriptBrowser-side code central
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