Module media

Media decoding: a small trait layer over two backends.

• mf — Windows Media Foundation (native software decode, no external deps, instant seeks). Primary.
• ffpipe — ffmpeg.exe / ffprobe.exe child processes. Universal fallback, images, probing, export. Everything produces top-down RGBA8 frames and interleaved stereo f32 audio at SAMPLE_RATE.

Modules

ffpipe

ffmpeg.exe / ffprobe.exe child-process backend. Universal fallback decoder, image loader, prober, and the process launcher used by export.

mf

Windows Media Foundation backend (IMFSourceReader). Native software decode, no external deps, instant seeks.

proxy

Proxy media: background all-intra low-res transcodes of imported video, played instead of the originals in the preview. Every proxy frame is a keyframe (-g 1), so seeks, reverse scrubs and clip-boundary cold opens decode without reference chains — the reason big NLEs feel instant. Proxies live in the cache dir, named by a hash of (source path, mtime, height): a re-exported source gets a fresh proxy automatically and stale files are just never referenced again. Export and full-quality one-shot renders never see proxies (their DecoderPools carry no map).

thumbs

Thumbnail cache for timeline filmstrips and library previews. Non-blocking: get/texture return immediately; misses are queued to ONE worker thread (newest request first, so scrubbing/zooming stays responsive) that owns a DecoderPool (backend from settings) and decodes h-pixel-tall RGBA thumbnails (aspect kept; images ignore t; Sequence clips are not handled here — the timeline draws a label). Results are kept in an LRU bounded by both entry count (≤512) and decoded bytes (≤48 MB) and uploaded lazily as egui textures (texture) so panels can paint them directly. ctx.request_repaint() when a thumbnail lands. Key = (path, t rounded to 0.5 s buckets, h rounded up to 16 px); clear() forgets everything (e.g. after save-over-original).

waveform

Audio waveform peaks per (file, audio stream): computed once on a background thread (decoding the whole stream through an AudioSource), cached in memory and on disk under Settings::cache_dir() (key = hash of path + file size + mtime + stream). PEAKS_PER_SEC buckets of mono (min, max).

ytdlp

URL import: download media from a link with yt-dlp.exe, the same child-process pattern ffpipe.rs uses for ffmpeg. Entirely optional — exe() returns None when yt-dlp is not installed and the Library then hides its “Import URL…” button.

Structs

DecoderPool

Lazily opened decoders, one per (path) / (path, audio stream). Failed opens are remembered (None) so a missing file doesn’t re-spawn work every frame.

Frame

Top-down RGBA8 image. rgba.len() == width*height*4.

Enums

Backend

Constants

CHANNELS

POOL_AUDIOS 🔒

POOL_VIDEOS 🔒

Live decoders kept per pool (LRU past this). Failed opens (None) are cheap and never counted.

SAMPLE_RATE

Traits

AudioSource

VideoSource

Functions

ext

Lower-case file extension (“” when none).

is_image_path

open_audio

open_video

probe

Probe a media file into an Asset (id = 0). ffprobe gives the richest stream metadata, so it is preferred when present; Media Foundation otherwise.