<h1 align="center">vtc-ex</h1>
<p align="center">
<img height=150 class="heightSet" align="center" src="https://raw.githubusercontent.com/opencinemac/vtc-py/master/zdocs/source/_static/logo1.svg"/>
</p>
<p align="center">A SMPTE Timecode Library for Elixir</p>
<p align="center">
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</p>
<p align="center">
<a href="https://hex.pm/packages/vtc"><img src="https://img.shields.io/hexpm/v/vtc.svg" alt="PyPI version" height="18"></a>
<a href="https://hexdocs.pm/vtc/readme.html"><img src="https://img.shields.io/badge/docs-hexdocs.pm-blue" alt="Documentation"></a>
</p>
## Demo
A small preview of what `Vtc` has to offer. Note that printing statements like
`inspect/1` have been elided from the examples below.
`Vtc` can [parse](https://hexdocs.pm/vtc/Vtc.Timecode.html#parse) a number of different
formats, from timecodes, to frame counts, to film length measured in feet and frames:
```elixir
iex> Timecode.with_seconds!(1.5, Rates.f23_98())
"<00:05:23:04 <23.98 NTSC>>"
iex>
iex> tc = Timecode.with_frames!("17:23:13:02", Rates.f23_98())
"<17:23:00:02 <23.98 NTSC>>"
```
Once in a [Timecode](https://hexdocs.pm/vtc/Vtc.Timecode.html) struct, you
[convert](https://hexdocs.pm/vtc/Vtc.Timecode.html#convert) to any of the supported
formats:
```elixir
iex> Timecode.frames(tc)
1501922
iex>
iex> Timecode.feet_and_frames(tc)
"<93889+10 :ff35mm_4perf>"
```
[Comparisons](https://hexdocs.pm/vtc/Vtc.Timecode.html#compare) and
[kernel sorting](https://hexdocs.pm/vtc/Vtc.Timecode.html#module-sorting-support) are
supported, with many helper functions for specific comparisons:
```elixir
iex> Timecode.compare(tc, "02:00:00:00")
:gt
iex>
iex> Timecode.gt?(tc, "02:00:00:00")
true
iex>
iex> tc_01 = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> tc_02 = Timecode.with_frames!("02:00:00:00", Rates.f23_98())
iex> data_01 = %{id: 2, tc: tc_01}
iex> data_02 = %{id: 1, tc: tc_02}
iex> Enum.sort_by([data_02, data_01], &(&1.tc), Timecode) |> inspect()
"[%{id: 2, tc: <01:00:00:00 <23.98 NTSC>>}, %{id: 1, tc: <02:00:00:00 <23.98 NTSC>>}]"
```
All sensible [arithmatic](https://hexdocs.pm/vtc/Vtc.Timecode.html#arithmatic)
operations are provided, such as addition, subtraction, and multiplication:
```elixir
iex> tc = Timecode.add(tc, "01:00:00:00")
"<18:23:13:02 <23.98 NTSC>>"
```
You can even use native operators within special
[eval/2](https://hexdocs.pm/vtc/Vtc.Timecode.html#eval/2) blocks:
```elixir
iex> Timecode.eval at: 23.98 do
iex> tc + "00:30:00:00" * 2 - "00:15:00:00"
iex> end
"<19:08:13:02 <23.98 NTSC>>"
```
[Ranges](https://hexdocs.pm/vtc/Vtc.Range.html) let you operate on in/out points, such
as finding the overlapping area between two ranges:
```elixir
iex> a_in = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> a = Range.new!(a_in, "02:00:00:00")
"<01:00:00:00 - 02:00:00:00 :exclusive <23.98 NTSC>>"
iex>
iex> b_in = Timecode.with_frames!("01:45:00:00", Rates.f23_98())
iex> b = Range.new!(b_in, "02:30:00:00")
"<01:45:00:00 - 02:30:00:00 :exclusive <23.98 NTSC>>"
iex>
iex> Range.intersection!(a, b)
"<01:45:00:00 - 02:00:00:00 :exclusive <23.98 NTSC>>"
```
## Further Reading
Check out the [Quickstart Guide](https://hexdocs.pm/vtc/quickstart.html) for a more in
depth walkthrough of what `Vtc` can do, or dive straight into the
[API reference](https://hexdocs.pm/vtc/api-reference.html).
## Goals
- Offer a comprehensive set of tools for parsing, manipulating and rendering timecode
in with all it's quirks and incarnations.
- Define an intuitive, idiomatic Elixir API.
- Do all calculations in Rational representation, so there is both no drift or rounding
errors when manipulating NTSC timecode, and we can represent time as finely as
possible rather than being limited to the granularity of frame numbers.
- Be approachable for newcomers to the timecode problem space. Each function and concept
in the [API reference](https://hexdocs.pm/vtc/api-reference.html) includes a primer on
what it is and where it is used in Film and Television workflow.
- Offer a flexible set of tools that support both rigorous, production-quality code and
quick scratch scripts.
## Features
- SMPTE Conventions:
- [X] NTSC
- [X] Drop-Frame
- [ ] Interlaced timecode
- Timecode Representations:
- [X] Timecode | '01:00:00:00'
- [X] Frames | 86400
- [X] Seconds | 3600.0
- [X] Runtime | '01:00:00.0'
- [X] Rational | 18018/5
- [X] Feet+Frames | '5400+00'
- [X] 35mm, 4-perf
- [ ] 35mm, 3-perf
- [X] 35mm, 2-perf
- [X] 16mm
- [X] Premiere Ticks | 15240960000000
- Operations:
- [X] Comparisons (==, <, <=, >, >=)
- [X] Add
- [X] Subtract
- [X] Scale (multiply and divide)
- [X] Divmod
- [X] Modulo
- [X] Negative
- [X] Absolute
- [X] Rebase (recalculate frame count at new framerate)
- [X] Native Operator Evaluation
- Flexible Parsing:
- [X] Partial timecodes | '1:12'
- [X] Partial runtimes | '1.5'
- [X] Negative string values | '-1:12', '-3+00'
- [X] Poorly formatted tc | '1:13:4'
- [X] Built-in consts for common framerates.
- [X] Configurable rounding options.
- [X] Support for standard library sorting behavior.
- [X] Range type for working with and comparing frame ranges.
- [X] Overlap between ranges
- [X] Distance between ranges
- [X] Inclusive and exclusive ranges
## Attributions
Drop-frame calculations adapted from
[David Heidelberger's blog](https://www.davidheidelberger.com/2010/06/10/drop-frame-timecode/).
35mm, 2perf and 16mm format support based on
[Jamie Hardt's work for vtc-rs](https://github.com/opencinemac/vtc-rs/pull/8).
Logo made by Freepik from [www.flaticon.com](https://www.flaticon.com/).
## Installation
If [available in Hex](https://hex.pm/docs/publish), the package can be installed
by adding `vtc` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[
{:vtc, "~> 0.7"}
]
end
```
