With MEM1-MEM3 twelve clips on a timeline still took 5.1 GB, only 2.5 GB of
it live: each decoded picture allocated three planes, each eviction freed
them, and the system allocator kept the freed pages.
filmcraft_frame::pool keeps the planes of frames the GOP caches evict (up to
192 MiB per sample type; a frame something else still holds is left alone).
The H.264 decoder, through a plane allocator hook that keeps the crate free
of dependencies, and the VideoToolbox path take their output planes from it.
perf.stats reports decode.planePoolMB and decode.planesReused.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>