Crate vtc

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A SMPTE Timecode Library for Rust

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PyPI version Documentation

Overview

vtc-rs is inspired by years of scripting workflow solutions in a Hollywood cutting room. It aims to capture all the ways in which timecode is used throughout the industry so users can spend more time on their workflow logic, and less time handling the corner-cases of parsing and calculating timecode.

Demo

Let’s take a quick high-level look at what you can do with vtc-rs:

use vtc::{Timecode, Framerate, Ntsc, rates, FilmFormat, FeetFramesStr};
use num::Rational64;

// It's easy to make a new 23.98 NTSC timecode. We use the with_frames constructor here since
// timecode is really a human-readable way to represent frame count.
let mut tc = Timecode::with_frames("17:23:13:02", rates::F23_98).unwrap();

// We can get all sorts of ways to represent the timecode.
assert_eq!(tc.timecode(), "17:23:13:02");
assert_eq!(tc.frames(), 1502234i64);
assert_eq!(tc.seconds(), Rational64::new(751868117, 12000));
assert_eq!(tc.runtime(3), "17:24:15.676");
assert_eq!(tc.premiere_ticks(), 15915544300656000i64);
assert_eq!(tc.feet_and_frames(FilmFormat::FF35mm4perf), "93889+10");
assert_eq!(tc.feet_and_frames(FilmFormat::FF16mm), "75111+14");

// We can inspect the framerate.
assert_eq!(tc.rate().playback(), Rational64::new(24000, 1001));
assert_eq!(tc.rate().timebase(), Rational64::new(24, 1));
assert_eq!(tc.rate().ntsc(), Ntsc::NonDropFrame);

// Parsing is flexible

// Partial timecode:
let parsed = Timecode::with_frames("3:12", rates::F23_98).unwrap();
assert_eq!(parsed.timecode(), "00:00:03:12");

// Frame count:
let parsed = Timecode::with_frames(24, rates::F23_98).unwrap();
assert_eq!(parsed.timecode(), "00:00:01:00");

// Seconds:
let parsed = Timecode::with_seconds(1.5, rates::F23_98).unwrap();
assert_eq!(parsed.timecode(), "00:00:01:12");

// Premiere Ticks:
let parsed = Timecode::with_premiere_ticks(254016000000i64, rates::F23_98).unwrap();
assert_eq!(parsed.timecode(), "00:00:01:00");

// Feet + Frames:
let parsed = Timecode::with_frames("1+08", rates::F23_98).unwrap();
assert_eq!(parsed.timecode(), "00:00:01:00");

// By default, Feet + Frames parsing infers 4-perf 35mm film, or
// 3-perf 35mm film if there is a final offset after a period:

let parsed = Timecode::with_frames("2+5.1", rates::F24).unwrap();
assert_eq!(parsed.timecode(), "00:00:01:23");

// If you want to do calculations with unusual footage formants,
// you can hint the Feet + Frames parser with a FeetFrames struct.

let feet_frames : FeetFramesStr = FeetFramesStr::new("22+1", FilmFormat::FF16mm);
let parsed = Timecode::with_frames(feet_frames, rates::F24).unwrap();
assert_eq!(parsed.timecode(), "00:00:18:09");

// And then these timecode objects can be turned back into footages.

let ff = parsed.feet_and_frames(FilmFormat::FF35mm4perf);
assert_eq!(ff, "27+09");

// We can add two timecodes
tc += Timecode::with_frames("01:00:00:00", rates::F23_98).unwrap();
assert_eq!(tc.timecode(), "18:23:13:02");

// We can subtract too.
tc -= Timecode::with_frames("01:00:00:00", rates::F23_98).unwrap();
assert_eq!(tc.timecode(), "17:23:13:02");

// It's easy to compare two timecodes:
assert!(tc > Timecode::with_frames("02:00:00:00", rates::F23_98).unwrap());

// And sort them:
let mut sorted = vec![tc, Timecode::with_frames("02:00:00:00", rates::F23_98).unwrap()];
sorted.sort();

assert_eq!(sorted[0].timecode(), "02:00:00:00");
assert_eq!(sorted[1].timecode(), "17:23:13:02");

// We can multiply:
tc *= 2;
assert_eq!(tc.timecode(), "34:46:26:04");

// ...divide... :
tc /= 2;
assert_eq!(tc.timecode(), "17:23:13:02");

// ... and even get the remainder of division!
let dividend = tc / 1.5;
let remainder = tc % 1.5;

assert_eq!(dividend.timecode(), "11:35:28:17");
assert_eq!(remainder.timecode(), "00:00:00:01");

// We can make a timecode negative:
tc = -tc;
assert_eq!(tc.timecode(), "-17:23:13:02");

// Or get it's absolute value.
tc = tc.abs();
assert_eq!(tc.timecode(), "17:23:13:02");

// We can make dropframe timecode for 29.97 or 59.94 using one of the pre-set framerates.
// We can use an int to parse 15000 frames.
let drop_frame = Timecode::with_frames(15000, rates::F29_97_DF).unwrap();
assert_eq!(drop_frame.timecode(), "00:08:20;16");
assert_eq!(drop_frame.rate().ntsc(), Ntsc::DropFrame);

// We can make new timecodes with arbitrary framerates if we want:
let arbitrary = Timecode::with_frames(
    "01:00:00:00",
    Framerate::with_playback(48, Ntsc::None).unwrap(),
).unwrap();
assert_eq!(arbitrary.frames(), 172800);

// We can make NTSC values for timebases and playback speeds that do not ship with this
// crate:
let mut ntsc = Timecode::with_frames(
    "01:00:00:00",
    Framerate::with_timebase(120, Ntsc::NonDropFrame).unwrap(),
).unwrap();
assert_eq!(ntsc.rate().playback(), Rational64::new(120000, 1001));
assert_eq!(ntsc.rate().timebase(), Rational64::new(120, 1));
assert_eq!(ntsc.rate().ntsc(), Ntsc::NonDropFrame);

// We can also rebase them using another framerate:
ntsc = ntsc.rebase(rates::F59_94_NDF);
assert_eq!(ntsc.timecode(), "02:00:00:00");

Features

  • SMPTE Conventions:
    • NTSC
    • Drop-Frame
    • Interlaced timecode
  • Timecode Representations:
    • Timecode | ‘01:00:00:00’
    • Frames | 86400
    • Seconds | 3600.0
    • Runtime | ‘01:00:00.0’
    • Rational | 18018/5
    • Feet+Frames | ‘5400+00’
      • 35mm, 4-perf
      • 35mm, 3-perf
      • 35mm, 2-perf
      • 16mm
    • Premiere Ticks | 15240960000000
  • Operations:
    • Comparisons (==, <, <=, >, >=)
    • Add
    • Subtract
    • Scale (multiply and divide)
    • Div/Rem
    • Modulo
    • Negative
    • Absolute
    • Rebase (recalculate frame count at new framerate)
  • Flexible Parsing:
    • Partial timecodes | ‘1:12’
    • Partial runtimes | ‘1.5’
    • Negative string values | ‘-1:12’, ‘-3+00’
    • Poorly formatted tc | ‘1:13:4’
  • Built-in consts for common framerates.

Goals

  • Parse and fetch all Timecode representations.
  • A clean, rustic API.
  • Support all operations that make sense for timecode.

Non-Goals

  • Real-time timecode generators.

Timecode: A History

But first: what is timecode?

If you’re already familiar with timecode, it’s history, and it’s flavors, feel free to skip this section.

Back in the days of film, a running strip of numbers ran along the edge of the film stock to uniquely identify each frame, called keycode

Keycode was essential to the film editing process. The raw negative of a film is irreplaceable: you loose quality each time you make a copy. Editing film is necessarily a destructive process, and often required multiple iterations. It would be just a tad nerve-wracking to take a pair of scissors and some glue to the one-of-a-kind film reels straight out of the camera on set, then running it over and over through a flatbed.

To avoid potential disaster, editors made their cut of the film using copies of the raw negative, called a work print, allowing the editor to work without fear of sinking a project from slicing, dicing, and wearing at the film.

When the edit was complete, it was necessary to know exactly where the edits had been made, so it could be recreated with the raw negative for finishing. A cut list would be written out, with the exact reels and keycodes for every cut, and would be used to make an exact duplicate of the editor’s work print with the mint condition raw negative.

In video and digital filmmaking, the same approach is used. Massive RAW files from a RED, ARRI, Sony, or other cinema camera are rendered down to more manageable files an Editor’s machine won’t choke on. Once the edit is complete, the raw files are re-assembled using a digital cutlist on a powerful machine for finishing out the film.

In film, we referenced keycode to know exactly what frame was being displayed on screen at any given time. In digital video, we reference the timecode of a given frame.

For a technical deep-dive into the many flavors of timecode, check out Frame.io’s excellent blogpost on the subject. !

Modules

  • rates
    A collection of common framerates seen in the wild as constants.

Structs

  • FeetFramesStr
    A struct that bundles a str together with a format, to hint parsing.
  • Framerate
    The rate at which a video file frames are played back.
  • Timecode
    Timecode represents the frame at a particular time in a video.
  • TimecodeSections
    Holds the individual sections of a timecode for formatting / manipulation.

Enums

Traits

  • FramerateSource
    Implemented by any type that can be parsed into a rational playback frames-per-second value for a given an NTSC standard and whether the value represents a playback speed or a timecode timebase.
  • FramesSource
    Types implementing this trait can be converted into the number of frames that have elapsed since a timecode value of 00:00:00:00.
  • PremiereTicksSource
    Types implementing this trait can be converted into the number of Adobe Premiere Pro Ticks that have elapsed since a timecode value of 00:00:00:00.
  • SecondsSource
    Types implementing this trait can be converted into the number of real-world seconds that have elapsed since a timecode value of 00:00:00:00.

Type Definitions