MediaScope

Inspect media metadata, MP4/WebM structures, packets, audio, subtitles, and MSE streams.

MediaScope adds a dedicated panel to Chrome DevTools for debugging file-based and Media Source Extensions (MSE) video and audio playback. Select a media element to explore it through these tabs: • Info — View the selected element’s source, playback state, resolution, duration, container, tracks, codecs, bitrate, and MSE SourceBuffers. • Structure — Browse MP4 box or WebM/Matroska element hierarchies with offsets, sizes, semantic fields, codec configuration, encryption metadata, and payload previews. • Network — Inspect media requests, byte ranges, response sizes, timing, cache status, headers, and their matches with captured MSE appends. • Timeline — Correlate network requests, SourceBuffer append operations, sample ranges, DTS, PTS, and keyframes on a unified timeline. • Manifest — Parse DASH MPD and HLS M3U8 manifests, including variants, representations, renditions, segments, timelines, and content-protection fields. • Samples — Inspect encoded samples and packets with real byte offsets, DTS, PTS, duration, size, track, and key-frame status. • GOP — View factual GOP boundaries, key-frame intervals, decode and presentation ranges, sample counts, byte sizes, and average bitrate. • Frame — Decode a frame at a selected timestamp and inspect its encoded NAL units with an optional codec-specific grid overlay. • Bitrate — Visualize encoded sample sizes and key frames over the currently loaded media time range. • Audio — Inspect audio codec details, sample rate, channels, language, packet timing, payload size, and bitrate. • Subtitles — Inspect DOM and container subtitle tracks and parse cues from WebVTT, TTML, and SubRip network responses. MediaScope supports MSE streams used by DASH and HLS players, as well as direct MP4 and WebM files, real blob/File sources, and MPEG-TS packets. Enable MSE capture and reload the inspected page to begin debugging the fragmented MP4 or WebM data passed to SourceBuffer. All inspection and parsing run locally inside your browser. MediaScope does not upload media, communicate with its own servers, or collect, store, or transmit personal data.