Dylan M. TaylorandNetterSilver
2f8f9ad8c9
* craft-timeline: exact media time, reports, media paths, ALE and CMX 3600 EDL New crate for editorial timeline interchange (#782), moved from FilmCraft at 4bec22bd: - time: filmcraft-time whole (Tick, FrameRate, TimeRange, SMPTE timecode, feet+frames, typed-timecode parsing) with its tests. - report: Report / Level / ReportEntry. - path: file URL and path conversion, relative references joined to a folder. - rate: timebase+ntsc and floating rates to exact rates, MAX_RATE. - ale: AleDoc, parse, write, standard heading and columns. - edl: the parser (events, lines, timecode fields, M2, AUD, comment extensions), the frame-rate guess, and the line layout of the writer, on frame counts. - Format, detect_text, decode_text. Each format module gives the document as the format writes it. Mapping onto an application's timeline stays in the application. * craft-timeline: strip a UTF-8 byte order mark when parsing ALE files An ALE saved with a BOM was refused as "not an ALE file": the mark made the first line something other than "Heading". Ported from storytold/filmcraft#4531. --------- Co-authored-by: NetterSilver <133535268+Silvertree2010@users.noreply.github.com>
craft-timeline
Editorial timeline interchange: the parts every reader and writer of an edit shares, and the text formats that are documents of their own.
| Module | What |
|---|---|
time |
Exact media time. A Tick is 1/254 016 000 000 s, which divides evenly into every broadcast frame duration and every common audio sample duration; FrameRate is an exact rational; SMPTE timecode (drop and non-drop), feet+frames and typed-timecode parsing are displays of ticks. Every conversion is total: a zero or negative rate gives zero, not a division by zero, and results saturate at the storage limits. |
rate |
Frame-rate conventions of documents: timebase + ntsc, floating rates snapped to exact ones, the highest rate an importer accepts (MAX_RATE). |
report |
Report: what an import or export could not represent exactly, identical messages merged with a count. |
path |
Media references: file:// URLs (localhost, drive letters, UNC hosts, percent-encoding) to and from paths, and relative references joined to a document's folder. Lexical only. |
ale |
Avid Log Exchange: AleDoc (heading, columns, rows), parse, write, the standard heading and columns. |
edl |
CMX 3600 edit decision lists: parse to the list as written (events, their lines and timecode fields, M2, AUD, clip-name, source-file, effect-name and locator comments), write for events the caller built, channel codes, reel names, the frame-rate guess. |
| crate root | Format (EDL, xmeml, FCPXML, OTIO, AAF, OMF), detect_text, decode_text. |
No file I/O. Each format module gives the document as the format writes it; mapping it onto an
application's timeline (which media a reel is, what a dissolve overlaps) stays in the application.
AAF and OMF are in craft-aaf.
Feature serde: Serialize / Deserialize for the time, report and Format types.
Specifications
Written from public descriptions only: SMPTE ST 12-1 (timecode); the CMX 3600 EDL format as
documented by its users (event lines, FCM, M2, and the common * FROM CLIP NAME:,
* SOURCE FILE:, * LOC: comment extensions); Avid's published description of ALE; RFC 8089
(file URIs).
Origin
Moved from FilmCraft's filmcraft-time (whole) and filmcraft-interchange (ale, the parser and
line layout of edl, the path and rate helpers of common, Report, Format).
Hostile input
Parsers are line-oriented over text the caller already holds, so memory is bounded by the input.
Timecode fields beyond i64 are refused; audio channels outside 1..=99 are refused and reported;
an FPS heading that is not a positive finite rate up to 100 000 is no rate. Tests cover each.