Cause: the browser build kept the desktop's cache budgets (1 GB layer
cache, 1 GB footage frame cache) inside the page's memory, which wasm32
caps at 4 GiB. FilmCraft's decoders keep up to 384 MB of decoded frames
per open movie beside them, so a comp of eight stacked 1080p H.264 clips
grew the page by about 55 MB/s while playing and ran it out of memory
after about 50 s ("unreachable": a failed allocation).
Fix: in the browser Prefs::cache_budgets keeps the Layer Cache within
512 MB and the Footage Frame Cache within 256 MB (WEB_LAYER_CACHE,
WEB_MEDIA_CACHE); smaller settings and the desktop are unchanged, and
the RAM preview keeps its budget. Docs (web, preferences) say so.
Tests: tests_m145::web_cache_budgets_leave_room_for_the_decoders: with
4 GB settings the web budgets are the caps, the desktop's are the
settings, and smaller settings stay as they are.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
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