muvid.footage.media_views

What an editor draws: per-camera filmstrips and the song’s waveform peaks.

The studio’s Edit tab (the redesign in the plan of record’s Edit tab note, §5) draws every camera as a strip of thumbnails on the song’s timeline and the song as a waveform. Both are derived from media the project already holds, both are expensive to make and cheap to keep, so both are CACHED by content and parameters:

• filmstrips — one or more JPEG sprite sheets per clip (cols x rows frames each, frame_h pixels tall, width from the clip’s own aspect), sampled at fps frames per second of CLIP time: frame i of a clip is its picture at i / fps s. Cached at footage/filmstrips/<clip-hash>-<params>/ with an index.json, so a re-call is a file read and a re-uploaded clip with other bytes gets new sheets. Each sheet is registered in the host’s catalog (content-addressed) when the project is hosted, so the screen loads it by artifact_id.

• peaks — the song’s per-bucket peak absolute amplitude, mono, normalised to 0..1 over n equal buckets of the song. Cached at footage/peaks/<song-hash>-<n>.json.

Every file is written as a NEW file (temp + rename) — the catalog hardlinks them.

Module Attributes

FILMSTRIP_FPS

frames per second of clip time, frame height in pixels, frames per sheet (columns x rows), JPEG quality (ffmpeg's 2-31, lower is better).

Functions

clip_filmstrip(fp, clip_id, *[, fps, ...])	One clip's filmstrip record, generating (and caching) it when missing.
song_peaks(fp, *, n)	{duration_s, n, peaks} — n buckets of the song's peak |amplitude|, mono, normalised so the loudest bucket is 1.0 (all zeros for a silent song).
filmstrip_key(clip_hash, *, fps, height, ...)	The cache directory name: the clip's content and every parameter.
read_json(path)
write_json(path, record)

muvid.footage.media_views.FILMSTRIP_FPS = 2.0

frames per second of clip time, frame height in pixels, frames per sheet (columns x rows), JPEG quality (ffmpeg’s 2-31, lower is better). 2 fps x 90 px x 10x10 puts 50 s of a clip on one ~100-200 KB sheet.

Type:

Default sampling of a filmstrip

muvid.footage.media_views.clip_filmstrip(fp, clip_id, *, fps=2.0, height=90, cols=10, rows=10)

One clip’s filmstrip record, generating (and caching) it when missing.

Returns {duration_s, n_frames, frame_w, frame_h, sheets: [{artifact_id, cols, rows, first_frame, n_frames}]}.

Return type:

dict

muvid.footage.media_views.filmstrip_key(clip_hash, *, fps, height, cols, rows)

The cache directory name: the clip’s content and every parameter.

Return type:

str

>>> filmstrip_key("ab" * 32, fps=2.0, height=90, cols=10, rows=10)
'abababababababab-f2-h90-10x10-v2'

muvid.footage.media_views.song_peaks(fp, *, n)

{duration_s, n, peaks} — n buckets of the song’s peak |amplitude|, mono, normalised so the loudest bucket is 1.0 (all zeros for a silent song).

Return type:

dict