Bound outer export batches by actual renderer-pool capacity before nested Rayon work can steal a sibling frame. Cover image sequences, GIF, stepped export and overlapping audio with the original one-renderer regression.
Addresses #1956.
Full original GPU contribution preserved at `preserve/861-gpu-export-original` (674e8cd68d).
Co-authored-by: Codex <noreply@openai.com>
pool::trim() from Pipeline::drop flushed the whole process-wide pool after every
render-preview segment and proxy, and threw away playback's U8/U16 planes too.
Now Pipeline::drop calls pool::trim_f32() only when !settings.part_of_batch.
PoolStats gains f32_idle_bytes so the tests can check the float shelf alone.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The export pipeline hands the float image of every frame it converts back to
`filmcraft_frame::pool` (#184), which keeps up to 320 MiB of them, and the decoders' plane shelves
hold up to 192 MiB of each type. An export's images are the size of its frames, which nothing else
asks for, so a finished export left them idle until the next one.
`pool::trim()` frees every idle buffer. `Pipeline` calls it when it is dropped, one place for every
way an export ends (done, failed, cancelled, dropped half way by a host that steps it, as the web
build does) and for every caller of `export` / `Exporter` (previews, proxies and AAF/OMF mixdowns
share the pipeline). A job still rendering at that moment allocates a few images again: the pool is
only a cache.
Measured with a synthetic 3 s 1080p24 matte exported as PNG frames three times in one process
(Apple M1, `footprint`, 10 s after the last export): 575 MB without the trim, the pool holding
332 MB idle, and 258 MB with it. macOS returns the freed pages over a few seconds, not at once.
Tests: `crates/frame/tests/pool_trim.rs` (every shelf emptied, the pool works afterwards) and
`crates/export/tests/pool_trim.rs` (an image sequence, a finished and a cancelled video, an export
that could not start and a stepped export dropped half way each leave nothing idle; without the
trim they fail).
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
