defmodule Vtc.Timecode do
@moduledoc """
Represents a particular frame in a video clip.
New Timecode values are created with the `with_seconds/3` and `with_frames/2`, and
other function prefaced by `with_*`.
## Struct Fields
- `seconds`: The real-world seconds elapsed since 01:00:00:00 as a rational value.
(Note: The Ratio module automatically will coerce itself to an integer whenever
possible, so this value may be an integer when exactly a whole-second value).
- `rate`: the Framerate of the timecode.
## Sorting Support
[Timecode](`Vtc.Timecode`) implements `compare/2`, and as such, can be used wherever
the standard library calls for a `Sorter` module. Let's see it in action:
```elixir
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>
iex>
iex> Enum.sort([tc_02, tc_01], Timecode) |> inspect()
"[<01:00:00:00 <23.98 NTSC>>, <02:00:00:00 <23.98 NTSC>>]"
iex>
iex>
iex> Enum.sort([tc_01, tc_02], {:desc, Timecode}) |> inspect()
"[<02:00:00:00 <23.98 NTSC>>, <01:00:00:00 <23.98 NTSC>>]"
iex>
iex>
iex> Enum.max([tc_02, tc_01], Timecode) |> inspect()
"<02:00:00:00 <23.98 NTSC>>"
iex>
iex>
iex> Enum.min([tc_02, tc_01], Timecode) |> inspect()
"<01:00:00:00 <23.98 NTSC>>"
iex>
iex>
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>>}]"
```
## Arithmatic Autocasting
For operators that take two `timecode values`, likt `add/3` or `compare/2`, as long as
one argument is a [Timecode](`Vtc.Timecode`) value, `a` or `b` May be any value that
implements the [Frames](`Vtc.Source.Frames`) protocol, such as a timecode string, and
will be assumed to be the same framerate as the other. This is mostly to support quick
scripting.
If parsing the value fails during casting, the function raises a
`Vtc.Timecode.ParseError`.
"""
import Kernel, except: [div: 2, rem: 2, abs: 1]
alias Vtc.FilmFormat
alias Vtc.Framerate
alias Vtc.Source.Frames
alias Vtc.Source.Frames.FeetAndFrames
alias Vtc.Source.Frames.TimecodeStr
alias Vtc.Source.Seconds
alias Vtc.Source.Seconds.PremiereTicks
alias Vtc.Source.Seconds.RuntimeStr
alias Vtc.Timecode
alias Vtc.Timecode.Eval
alias Vtc.Timecode.ParseError
alias Vtc.Timecode.Sections
alias Vtc.Utils.Rational
@enforce_keys [:seconds, :rate]
defstruct [:seconds, :rate]
@typedoc """
[Timecode](`Vtc.Timecode`) type.
"""
@type t() :: %__MODULE__{
seconds: Ratio.t(),
rate: Framerate.t()
}
@typedoc """
Valid values for rounding options.
- `:closest`: Round the to the closet whole frame.
- `:floor`: Always round down to the closest whole-frame.
- `:ciel`: Always round up to the closest whole-frame.
"""
@type round() :: :closest | :floor | :ceil
@typedoc """
As `round/0`, but includes `:off` option to disable rounding entirely. Not all
functions exposed by this module make logical sense without some form of rouding, so
`:off` will not be accepted by all functions.
"""
@type maybe_round() :: round() | :off
@typedoc """
Type returned by `with_seconds/3` and `with_frames/3`.
"""
@type parse_result() :: {:ok, t()} | {:error, ParseError.t() | %ArgumentError{}}
@doc section: :parse
@doc """
Returns a new [Timecode](`Vtc.Timecode`) with a `:seconds` field value equal to the
`seconds` arg.
## Arguments
- `seconds`: A value which can be represented as a number of real-world seconds.
Must implement the [Seconds](`Vtc.Source.Seconds`) protocol.
- `rate`: Frame-per-second playback value of the timecode.
## Options
- `round`: How to round the result with regards to whole-frames.
## Examples
Accetps runtime strings...
```elixir
iex> Timecode.with_seconds("01:00:00.5", Rates.f23_98()) |> inspect()
"{:ok, <00:59:56:22 <23.98 NTSC>>}"
```
... floats...
```elixir
iex> Timecode.with_seconds(3600.5, Rates.f23_98()) |> inspect()
"{:ok, <00:59:56:22 <23.98 NTSC>>}"
```
... integers...
```elixir
iex> Timecode.with_seconds(3600, Rates.f23_98()) |> inspect()
"{:ok, <00:59:56:10 <23.98 NTSC>>}"
```
... integer Strings...
```elixir
iex> Timecode.with_seconds("3600", Rates.f23_98()) |> inspect()
"{:ok, <00:59:56:10 <23.98 NTSC>>}"
```
... and float strings.
```elixir
iex> Timecode.with_seconds("3600.5", Rates.f23_98()) |> inspect()
"{:ok, <00:59:56:22 <23.98 NTSC>>}"
```
## Premiere Ticks
The `Vtc.Source.Seconds.PremiereTicks` struck implements the
[Seconds](`Vtc.Source.Seconds`) protocol and can be used to parse the format. This
struct is not a general-purpose Module for the unit, and only exists to hint to the
parsing function how it should be processed:
```elixir
iex> alias Vtc.Source.Seconds.PremiereTicks
iex>
iex> input = %PremiereTicks{in: 254_016_000_000}
iex> Timecode.with_seconds!(input, Rates.f23_98()) |> inspect()
"<00:00:01:00 <23.98 NTSC>>"
```
"""
@spec with_seconds(Seconds.t(), Framerate.t(), opts :: [round: maybe_round()]) :: parse_result()
def with_seconds(seconds, rate, opts \\ []) do
round = Keyword.get(opts, :round, :closest)
with {:ok, seconds} <- Seconds.seconds(seconds, rate) do
# If the vaue doesn't cleany divide into the framerate then we need to round to
# the nearest frame.
seconds = with_seconds_round_to_frame(seconds, rate, round)
{:ok, %__MODULE__{seconds: seconds, rate: rate}}
end
end
# Rounds seconds value to the nearest whole-frame.
@spec with_seconds_round_to_frame(Ratio.t(), Framerate.t(), maybe_round()) :: Ratio.t()
defp with_seconds_round_to_frame(seconds, _, :off), do: seconds
defp with_seconds_round_to_frame(seconds, rate, round) do
case Ratio.div(seconds, rate.playback) do
%Ratio{denominator: 1} ->
seconds
%Ratio{} ->
rate.playback
|> Ratio.mult(seconds)
|> Rational.round(round)
|> Ratio.new()
|> Ratio.div(rate.playback)
end
end
@doc section: :parse
@doc """
As `with_seconds/3`, but raises on error.
"""
@spec with_seconds!(Seconds.t(), Framerate.t(), opts :: [round: maybe_round()]) :: t()
def with_seconds!(seconds, rate, opts \\ []) do
seconds
|> with_seconds(rate, opts)
|> handle_raise_function()
end
@doc section: :parse
@doc """
Returns a new [Timecode](`Vtc.Timecode`) with a `frames/2` return value equal to the
`frames` arg.
## Arguments
- `frames`: A value which can be represented as a frame number / frame count. Must
implement the [Frames](`Vtc.Source.Frames`) protocol.
- `rate`: Frame-per-second playback value of the timecode.
## Options
- `round`: How to round the result with regards to whole-frames.
## Examples
Accepts timecode strings...
```elixir
iex> Timecode.with_frames("01:00:00:00", Rates.f23_98()) |> inspect()
"{:ok, <01:00:00:00 <23.98 NTSC>>}"
```
... feet+frames strings...
```elixir
iex> Timecode.with_frames("5400+00", Rates.f23_98()) |> inspect()
"{:ok, <01:00:00:00 <23.98 NTSC>>}"
```
By default, feet+frames is interpreted as 35mm, 4perf film. You can use the
[FeetAndFrames](`Vtc.Source.Frames.FeetAndFrames`) struct to parse other film formats:
```elixir
iex> alias Vtc.Source.Frames.FeetAndFrames
iex>
iex> {:ok, feet_and_frames} = FeetAndFrames.from_string("5400+00", film_format: :ff16mm)
iex> Timecode.with_frames(feet_and_frames, Rates.f23_98()) |> inspect()
"{:ok, <01:15:00:00 <23.98 NTSC>>}"
```
... integers...
```elixir
iex> Timecode.with_frames(86400, Rates.f23_98()) |> inspect()
"{:ok, <01:00:00:00 <23.98 NTSC>>}"
```
... and integer strings.
```elixir
iex> Timecode.with_frames("86400", Rates.f23_98()) |> inspect()
"{:ok, <01:00:00:00 <23.98 NTSC>>}"
```
"""
@spec with_frames(Frames.t(), Framerate.t()) :: parse_result()
def with_frames(frames, rate) do
with {:ok, frames} <- Frames.frames(frames, rate) do
frames
|> Ratio.new()
|> Ratio.div(rate.playback)
|> with_seconds(rate)
end
end
@doc section: :parse
@doc """
As `Timecode.with_frames/3`, but raises on error.
"""
@spec with_frames!(Frames.t(), Framerate.t()) :: t()
def with_frames!(frames, rate) do
frames
|> with_frames(rate)
|> handle_raise_function()
end
@doc section: :manipulate
@doc """
Rebases `timecode` to a new framerate.
The real-world seconds are recalculated using the same frame count as if they were
being played back at `new_rate` instead of `timecode.rate`.
## Examples
```elixir
iex> timecode = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> {:ok, rebased} = Timecode.rebase(timecode, Rates.f47_95())
iex> inspect(rebased)
"<00:30:00:00 <47.95 NTSC>>"
```
"""
@spec rebase(t(), Framerate.t()) :: parse_result()
def rebase(%{rate: rate} = timecode, rate), do: {:ok, timecode}
def rebase(timecode, new_rate), do: timecode |> frames() |> with_frames(new_rate)
@doc section: :manipulate
@doc """
As `rebase/2`, but raises on error.
"""
@spec rebase!(t(), Framerate.t()) :: t()
def rebase!(timecode, new_rate), do: timecode |> rebase(new_rate) |> handle_raise_function()
@doc section: :compare
@doc """
Comapare the values of `a` and `b`.
Compatible with `Enum.sort/2`. For more on sorting non-builtin values, see
[the Elixir ducumentation](https://hexdocs.pm/elixir/1.13/Enum.html#sort/2-sorting-structs).
[auto-casts](#module-artithmatic-autocasting) [Frames](`Vtc.Source.Frames`) values.
See `eq?/2` for more information on how equality is determined.
## Examples
Using two timecodes, `01:00:00:00` NTSC is greater than `01:00:00:00` true because it
represents more real-world time.
```elixir
iex> a = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> b = Timecode.with_frames!("01:00:00:00", Rates.f24())
iex> :gt = Timecode.compare(a, b)
```
Using a timcode and a bare string:
```elixir
iex> timecode = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> :eq = Timecode.compare(timecode, "01:00:00:00")
```
"""
@spec compare(a :: t() | Frames.t(), b :: t() | Frames.t()) :: :lt | :eq | :gt
def compare(a, b) do
{a, b} = cast_op_args(a, b)
Ratio.compare(a.seconds, b.seconds)
end
@doc section: :compare
@doc """
Returns `true` if `a` is eqaul to `b`.
[auto-casts](#module-artithmatic-autocasting) [Frames](`Vtc.Source.Frames`) values.
## Examples
```elixir
iex> a = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> b = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> true = Timecode.eq?(a, b)
```
Timecodes with the *same* string representation, but *different* real-world seconds
values, are *not* equal:
```elixir
iex> a = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> b = Timecode.with_frames!("01:00:00:00", Rates.f24())
iex> false = Timecode.eq?(a, b)
```
But Timecodes with the *different* string representation, but the *same* real-world
seconds values, *are* equal:
```elixir
iex> a = Timecode.with_frames!("01:00:00:12", Rates.f23_98())
iex> b = Timecode.with_frames!("01:00:00:24", Rates.f47_95())
iex> true = Timecode.eq?(a, b)
```
"""
@spec eq?(a :: t() | Frames.t(), b :: t() | Frames.t()) :: boolean()
def eq?(a, b), do: compare(a, b) == :eq
@doc section: :compare
@doc """
Returns `true` if `a` is less than `b`.
[auto-casts](#module-artithmatic-autocasting) [Frames](`Vtc.Source.Frames`) values.
See `eq?/2` for more information on how equality is determined.
## Examples
```elixir
iex> a = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> b = Timecode.with_frames!("02:00:00:00", Rates.f23_98())
iex> true = Timecode.lt?(a, b)
iex> false = Timecode.lt?(b, a)
```
"""
@spec lt?(a :: t() | Frames.t(), b :: t() | Frames.t()) :: boolean()
def lt?(a, b), do: compare(a, b) == :lt
@doc section: :compare
@doc """
Returns `true` if `a` is less than or equal to `b`.
[auto-casts](#module-artithmatic-autocasting) [Frames](`Vtc.Source.Frames`) values.
See `eq?/2` for more information on how equality is determined.
"""
@spec lte?(a :: t() | Frames.t(), b :: t() | Frames.t()) :: boolean()
def lte?(a, b), do: compare(a, b) in [:lt, :eq]
@doc section: :compare
@doc """
Returns `true` if `a` is greater than `b`.
[auto-casts](#module-artithmatic-autocasting) [Frames](`Vtc.Source.Frames`) values.
See `eq?/2` for more information on how equality is determined.
"""
@spec gt?(a :: t() | Frames.t(), b :: t() | Frames.t()) :: boolean()
def gt?(a, b), do: compare(a, b) == :gt
@doc section: :compare
@doc """
Returns `true` if `a` is greater than or eqaul to `b`.
[auto-casts](#module-artithmatic-autocasting) [Frames](`Vtc.Source.Frames`) values.
See `eq?/2` for more information on how equality is determined.
"""
@spec gte?(a :: t() | Frames.t(), b :: t() | Frames.t()) :: boolean()
def gte?(a, b), do: compare(a, b) in [:gt, :eq]
@doc section: :arithmatic
@doc """
Add two timecodes.
Uses the real-world seconds representation. When the rates of `a` and `b` are not
equal, the result will inheret the framerat of `a` and be rounded to the seconds
representation of the nearest whole-frame at that rate.
[auto-casts](#module-artithmatic-autocasting) [Frames](`Vtc.Source.Frames`) values.
## Options
- `round`: How to round the result with respect to whole-frames when mixing
framerates. Default: `:closest`.
## Examples
Two timecodes running at the same rate:
```elixir
iex> a = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> b = Timecode.with_frames!("01:30:21:17", Rates.f23_98())
iex> Timecode.add(a, b) |> inspect()
"<02:30:21:17 <23.98 NTSC>>"
```
Two timecodes running at different rates:
```elixir
iex> a = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> b = Timecode.with_frames!("00:00:00:02", Rates.f47_95())
iex> Timecode.add(a, b) |> inspect()
"<01:00:00:01 <23.98 NTSC>>"
```
Using a timcode and a bare string:
```elixir
iex> a = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.add(a, "01:30:21:17") |> inspect()
"<02:30:21:17 <23.98 NTSC>>"
```
"""
@spec add(a :: t() | Frames.t(), b :: t() | Frames.t(), opts :: [round: maybe_round()]) :: t()
def add(a, b, opts \\ []) do
{a, b} = cast_op_args(a, b)
a.seconds |> Ratio.add(b.seconds) |> with_seconds!(a.rate, opts)
end
@doc section: :arithmatic
@doc """
Subtract `b` from `a`.
Uses their real-world seconds representation. When the rates of `a` and `b` are not
equal, the result will inheret the framerat of `a` and be rounded to the seconds
representation of the nearest whole-frame at that rate.
[auto-casts](#module-artithmatic-autocasting) [Frames](`Vtc.Source.Frames`) values.
## Options
- `round`: How to round the result with respect to whole-frames when mixing
framerates. Default: `:closest`.
## Examples
Two timecodes running at the same rate:
```elixir
iex> a = Timecode.with_frames!("01:30:21:17", Rates.f23_98())
iex> b = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.sub(a, b) |> inspect()
"<00:30:21:17 <23.98 NTSC>>"
```
When `b` is greater than `a`, the result is negative:
```elixir
iex> a = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> b = Timecode.with_frames!("02:00:00:00", Rates.f23_98())
iex> Timecode.sub(a, b) |> inspect()
"<-01:00:00:00 <23.98 NTSC>>"
```
Two timecodes running at different rates:
```elixir
iex> a = Timecode.with_frames!("01:00:00:02", Rates.f23_98())
iex> b = Timecode.with_frames!("00:00:00:02", Rates.f47_95())
iex> Timecode.sub(a, b) |> inspect()
"<01:00:00:01 <23.98 NTSC>>"
```
Using a timcode and a bare string:
```elixir
iex> a = Timecode.with_frames!("01:30:21:17", Rates.f23_98())
iex> Timecode.sub(a, "01:00:00:00") |> inspect()
"<00:30:21:17 <23.98 NTSC>>"
```
"""
@spec sub(a :: t(), b :: t() | Frames.t(), opts :: [round: maybe_round()]) :: t()
def sub(a, b, opts \\ []) do
{a, b} = cast_op_args(a, b)
a.seconds |> Ratio.sub(b.seconds) |> with_seconds!(a.rate, opts)
end
# Casts args for ops with two timecodes as long as at least one argument is a
# timecode. The non-timecode argument inherents the framerate of the timecode
# argument.
@spec cast_op_args(t() | Frames.t(), t() | Frames.t()) :: {t(), t()}
defp cast_op_args(%__MODULE__{} = a, %__MODULE__{} = b), do: {a, b}
defp cast_op_args(%__MODULE__{} = a, b), do: {a, with_frames!(b, a.rate)}
defp cast_op_args(a, %__MODULE__{} = b), do: {with_frames!(a, b.rate), b}
@doc section: :arithmatic
@doc """
Scales `a` by `b`.
The result will inheret the framerat of `a` and be rounded to the seconds
representation of the nearest whole-frame based on the `:round` option.
## Options
- `round`: How to round the result with respect to whole-frame values. Defaults to
`:closest`.
## Examples
```elixir
iex> a = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.mult(a, 2) |> inspect()
"<02:00:00:00 <23.98 NTSC>>"
iex> a = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.mult(a, 0.5) |> inspect()
"<00:30:00:00 <23.98 NTSC>>"
```
"""
@spec mult(a :: t(), b :: Ratio.t() | number(), opts :: [round: maybe_round()]) :: t()
def mult(a, b, opts \\ []), do: a.seconds |> Ratio.mult(Ratio.new(b)) |> with_seconds!(a.rate, opts)
@doc section: :arithmatic
@doc """
Divides `dividend` by `divisor`.
The result will inherit the framerate of `dividend` and rounded to the nearest
whole-frame based on the `:round` option.
## Options
- `round`: How to round the result with respect to whole-frame values. Defaults to
`:floor` to match `divmod` and the expected meaning of `div` to mean integer
division in elixir.
## Examples
```elixir
iex> dividend = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.div(dividend, 2) |> inspect()
"<00:30:00:00 <23.98 NTSC>>"
iex> dividend = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.div(dividend, 0.5) |> inspect()
"<02:00:00:00 <23.98 NTSC>>"
```
"""
@spec div(
dividend :: t(),
divisor :: Ratio.t() | number(),
opts :: [round: maybe_round()]
) :: t()
def div(dividend, divisor, opts \\ []) do
opts = Keyword.put_new(opts, :round, :floor)
dividend.seconds |> Ratio.div(Ratio.new(divisor)) |> with_seconds!(dividend.rate, opts)
end
@doc section: :arithmatic
@doc """
Divides the total frame count of `dividend` by `divisor` and returns both a quotient
and a remainder.
The quotient returned is equivalent to `Timecode.div/3` with the `:round` option set
to `:floor`.
## Options
- `round_frames`: How to round the frame count before doing the divrem operation.
Default: `:closest`.
- `round_remainder`: How to round the remainder frames when a non-whole frame would
be the result. Default: `:closest`.
## Examples
```elixir
iex> dividend = Timecode.with_frames!("01:00:00:01", Rates.f23_98())
iex> Timecode.divrem(dividend, 4) |> inspect()
"{<00:15:00:00 <23.98 NTSC>>, <00:00:00:01 <23.98 NTSC>>}"
```
"""
@spec divrem(
dividend :: t(),
divisor :: Ratio.t() | number(),
opts :: [round_frames: round(), round_remainder: round()]
) :: {t(), t()}
def divrem(dividend, divisor, opts \\ []) do
round_frames = Keyword.get(opts, :round_frames, :closest)
round_remainder = Keyword.get(opts, :round_remainder, :closest)
with :ok <- ensure_round_enabled(round_frames, "round_frames"),
:ok <- ensure_round_enabled(round_remainder, "round_remainder") do
%{rate: rate} = dividend
{quotient, remainder} =
dividend
|> frames(round: round_frames)
|> Ratio.new()
|> Rational.divrem(Ratio.new(divisor))
remainder = Rational.round(remainder, round_remainder)
{with_frames!(quotient, rate), with_frames!(remainder, rate)}
end
end
@doc section: :arithmatic
@doc """
Devides the total frame count of `dividend` by `devisor`, and returns the remainder.
The quotient is floored before the remainder is calculated.
## Options
- `round_frames`: How to round the frame count before doing the rem operation.
Default: `:closest`.
- `round_remainder`: How to round the remainder frames when a non-whole frame would
be the result. Default: `:closest`.
## Examples
```elixir
iex> dividend = Timecode.with_frames!("01:00:00:01", Rates.f23_98())
iex> Timecode.rem(dividend, 4) |> inspect()
"<00:00:00:01 <23.98 NTSC>>"
```
"""
@spec rem(
dividend :: t(),
divisor :: Ratio.t() | number(),
opts :: [round_frames: round(), round_remainder: round()]
) :: t()
def rem(dividend, divisor, opts \\ []), do: dividend |> divrem(Ratio.new(divisor), opts) |> elem(1)
@doc section: :arithmatic
@doc """
As the kernel `-/1` function.
- Makes a positive `tc` value negative.
- Makes a negative `tc` value positive.
## Examples
```elixir
iex> tc = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.minus(tc) |> inspect()
"<-01:00:00:00 <23.98 NTSC>>"
```
```elixir
iex> tc = Timecode.with_frames!("-01:00:00:00", Rates.f23_98())
iex> Timecode.minus(tc) |> inspect()
"<01:00:00:00 <23.98 NTSC>>"
```
"""
@spec minus(t()) :: t()
def minus(tc), do: %{tc | seconds: Ratio.minus(tc.seconds)}
@doc section: :arithmatic
@doc """
Returns the absolute value of `tc`.
## Examples
```elixir
iex> tc = Timecode.with_frames!("-01:00:00:00", Rates.f23_98())
iex> Timecode.abs(tc) |> inspect()
"<01:00:00:00 <23.98 NTSC>>"
```
```elixir
iex> tc = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.abs(tc) |> inspect()
"<01:00:00:00 <23.98 NTSC>>"
```
"""
@spec abs(t()) :: t()
def abs(tc), do: %{tc | seconds: Ratio.abs(tc.seconds)}
@doc section: :arithmatic
@doc """
Evalutes timecode mathematical expressions in a `do` block.
Any code captured within this macro can use Kernel operators to work with timecode
values instead of module functions like `add/2`.
## Options
- `at`: The Framerate to cast non-timecode values to. If this value is not set, then
at least one value in each operation must be a [Timecode](`Vtc.Timecode`). This
value can be any value accepted by `Framerate.new/2`.
- `ntsc`: The `ntsc` value to use when creating a new Framerate with `at`. Not needed
if `at` is a [Framerate](`Vtc.Framerate`) value.
## Examples
Use eval to do some quick math. The block captures variables from the outer scope,
but contains the expression within its own scope, just like an `if` or `with`
statement.
```elixir
iex> require Timecode
iex>
iex> a = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> b = Timecode.with_frames!("00:30:00:00", Rates.f23_98())
iex> c = Timecode.with_frames!("00:15:00:00", Rates.f23_98())
iex>
iex> result = Timecode.eval do
iex> a + b * 2 - c
iex> end
iex>
iex> inspect(result)
"<01:45:00:00 <23.98 NTSC>>"
```
Or if you want to do it in one line:
```elixir
iex> require Timecode
iex>
iex> a = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> b = Timecode.with_frames!("00:30:00:00", Rates.f23_98())
iex> c = Timecode.with_frames!("00:15:00:00", Rates.f23_98())
iex>
iex> result = Timecode.eval(a + b * 2 - c)
iex>
iex> inspect(result)
"<01:45:00:00 <23.98 NTSC>>"
```
Just like the regular [Timecode](`Vtc.Timecode`) functions, only one value in an
arithmatic expression needs to be a [Timecode](`Vtc.Timecode`) value. In the case
above, since multiplication happens first, that's `b`:
```elixir
iex> b = Timecode.with_frames!("00:30:00:00", Rates.f23_98())
iex>
iex> result = Timecode.eval do
iex> "01:00:00:00" + b * 2 - "00:15:00:00"
iex> end
iex>
iex> inspect(result)
"<01:45:00:00 <23.98 NTSC>>"
```
You can supply a default framerate if you just want to do some quick calculations.
This framerate is inherited by every value that implements the
[Frames](`Vtc.Source.Frames`) protocol in the block, including integers:
```elixir
iex> result = Timecode.eval at: Rates.f23_98() do
iex> "01:00:00:00" + "00:30:00:00" * 2 - "00:15:00:00"
iex> end
iex>
iex> inspect(result)
"<01:45:00:00 <23.98 NTSC>>"
```
You can use any value that can be parsed by `Framerate.new/2`.
```elixir
iex> result = Timecode.eval at: 23.98 do
iex> "01:00:00:00" + "00:30:00:00" * 2 - "00:15:00:00"
iex> end
iex>
iex> inspect(result)
"<01:45:00:00 <23.98 NTSC>>"
```
`ntsc: :non_drop` is assumed by default, but you can set a different value with the
`:ntsc` option:
```elixir
iex> result = Timecode.eval at: 24, ntsc: nil do
iex> "01:00:00:00" + "00:30:00:00" * 2 - "00:15:00:00"
iex> end
iex>
iex> inspect(result)
"<01:45:00:00 <24.0 fps>>"
```
"""
@spec eval([at: Framerate.t() | number() | Ratio.t(), ntsc: Framerate.ntsc()], Macro.input()) :: Macro.t()
defmacro eval(opts \\ [], body), do: Eval.eval(opts, body)
@doc section: :convert
@doc """
Returns the number of frames that would have elapsed between 00:00:00:00 and
`timecode`.
## Options
- `round`: How to round the resulting frame number.
## What it is
Frame number / frames count is the number of a frame if the timecode started at
00:00:00:00 and had been running until the current value. A timecode of '00:00:00:10'
has a frame number of 10. A timecode of '01:00:00:00' has a frame number of 86400.
## Where you see it
- Frame-sequence files: 'my_vfx_shot.0086400.exr'
- FCP7XML cut lists:
```xml
<timecode>
<rate>
<timebase>24</timebase>
<ntsc>TRUE</ntsc>
</rate>
<string>01:00:00:00</string>
<frame>86400</frame> <!-- <====THIS LINE-->
<displayformat>NDF</displayformat>
</timecode>
```
## Examples
```elixir
iex> timecode = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.frames(timecode)
86400
```
"""
@spec frames(t(), opts :: [round: round()]) :: integer()
def frames(timecode, opts \\ []) do
round = Keyword.get(opts, :round, :closest)
with :ok <- ensure_round_enabled(round) do
timecode.seconds
|> Ratio.mult(timecode.rate.playback)
|> Rational.round(round)
end
end
@doc section: :convert
@doc """
The individual sections of a timecode string as i64 values.
## Examples
```elixir
iex> timecode = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.sections(timecode) |> inspect()
"%Vtc.Timecode.Sections{negative?: false, hours: 1, minutes: 0, seconds: 0, frames: 0}"
```
"""
@spec sections(t(), opts :: [round: round()]) :: Sections.t()
def sections(timecode, opts \\ []) do
round = Keyword.get(opts, :round, :closest)
with :ok <- ensure_round_enabled(round) do
Sections.from_timecode(timecode, opts)
end
end
@doc section: :convert
@doc """
Returns the the formatted SMPTE timecode
Ex: `01:00:00:00`. Drop frame timecode will be rendered with a ';' sperator before the
frames field.
## Options
- `round`: How to round the resulting frames field.
## What it is
Timecode is used as a human-readable way to represent the id of a given frame. It is
formatted to give a rough sense of where to find a frame:
`{HOURS}:{MINUTES}:{SECONDS}:{FRAME}`. For more on timecode, see Frame.io's
[excellent post](https://blog.frame.io/2017/07/17/timecode-and-frame-rates/) on the
subject.
## Where you see it
Timecode is ubiquitous in video editing, a small sample of places you might see
timecode:
- Source and Playback monitors in your favorite NLE.
- Burned into the footage for dailies.
- Cut lists like an EDL.
## Examples
```elixir
iex> timecode = Timecode.with_frames!(86400, Rates.f23_98())
iex> Timecode.timecode(timecode)
"01:00:00:00"
```
"""
@spec timecode(t(), opts :: [round: round()]) :: String.t()
def timecode(timecode, opts \\ []), do: timecode |> TimecodeStr.from_timecode(opts) |> then(& &1.in)
@doc section: :convert
@doc """
Runtime Returns the true, real-world runtime of `timecode` in HH:MM:SS.FFFFFFFFF
format.
Trailing zeroes are trimmed from the end of the return value. If the entire fractal
seconds value would be trimmed, '.0' is used.
## Options
- `precision`: The number of places to round to. Extra trailing 0's will still be
trimmed. Default: `9`.
- `trim_zeros?`: Whether to trim trailing zeroes. Default: `true`.
## What it is
The formatted version of seconds. It looks like timecode, but with a decimal seconds
value instead of a frame number place.
## Where you see it
• Anywhere real-world time is used.
• FFMPEG commands:
```shell
ffmpeg -ss 00:00:30.5 -i input.mov -t 00:00:10.25 output.mp4
```
## Note
The true runtime will often diverge from the hours, minutes, and seconds
value of the timecode representation when dealing with non-whole-frame
framerates. Even drop-frame timecode does not continuously adhere 1:1 to the
actual runtime. For instance, <01:00:00;00 <29.97 NTSC DF>> has a true runtime of
'00:59:59.9964', and <01:00:00:00 <23.98 NTSC>> has a true runtime of
'01:00:03.6'
## Examples
```elixir
iex> timecode = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.runtime(timecode)
"01:00:03.6"
```
"""
@spec runtime(t(), precision: non_neg_integer(), trim_zeros?: boolean()) :: String.t()
def runtime(timecode, opts \\ []), do: timecode |> RuntimeStr.from_timecode(opts) |> then(& &1.in)
@doc section: :convert
@doc """
Returns the number of elapsed ticks `timecode` represents in Adobe Premiere Pro.
## Options
- `round`: How to round the resulting ticks.
## What it is
Internally, Adobe Premiere Pro uses ticks to divide up a second, and keep track of how
far into that second we are. There are 254016000000 ticks in a second, regardless of
framerate in Premiere.
## Where you see it
- Premiere Pro Panel functions and scripts.
- FCP7XML cutlists generated from Premiere:
```xml
<clipitem id="clipitem-1">
...
<in>158</in>
<out>1102</out>
<pproTicksIn>1673944272000</pproTicksIn>
<pproTicksOut>11675231568000</pproTicksOut>
...
</clipitem>
```
## Examples
```elixir
iex> timecode = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.premiere_ticks(timecode)
915372057600000
```
"""
@spec premiere_ticks(t(), opts :: [round: round()]) :: integer()
def premiere_ticks(timecode, opts \\ []) do
round = Keyword.get(opts, :round, :closest)
with :ok <- ensure_round_enabled(round) do
timecode |> PremiereTicks.from_timecode(opts) |> then(& &1.in)
end
end
@doc section: :convert
@doc """
Returns the number of physical film feet and frames `timecode` represents if shot
on film.
Ex: '5400+13'.
## Options
- `round`: How to round the internal frame count before conversion. Default: `:closest`.
- `fiim_format`: The film format to use when doing the calculation. For more on film
formats, see `Vtc.FilmFormat`. Default: `:ff35mm_4perf`, by far the most common
format used to shoot Hollywood movies.
## What it is
On physical film, each foot contains a certain number of frames. For 35mm, 4-perf film
(the most common type on Hollywood movies), this number is 16 frames per foot.
Feet-And-Frames was often used in place of Keycode to quickly reference a frame in the
edit.
## Where you see it
For the most part, feet + frames has died out as a reference, because digital media is
not measured in feet. The most common place it is still used is Studio Sound
Departments. Many Sound Mixers and Designers intuitively think in feet + frames, and
it is often burned into the reference picture for them.
- Telecine.
- Sound turnover reference picture.
- Sound turnover change lists.
For more information on individual film formats, see the `Vtc.FilmFormat` module.
## Examples
Defaults to 35mm, 4perf:
```elixir
iex> timecode = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.feet_and_frames(timecode) |> inspect()
"<5400+00 :ff35mm_4perf>"
```
Use `String.Chars` to convert the resulting struct to a traditional F=F string:
```elixir
iex> alias Vtc.Source.Frames.FeetAndFrames
iex>
iex> timecode = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.feet_and_frames(timecode) |> String.Chars.to_string()
"5400+00"
```
Outputting as a different film format:
## Examples
```elixir
iex> timecode = Timecode.with_frames!("01:00:00:00", Rates.f23_98())
iex> Timecode.feet_and_frames(timecode, film_format: :ff16mm) |> inspect()
"<4320+00 :ff16mm>"
```
"""
@spec feet_and_frames(t(), opts :: [fiim_format: FilmFormat.t(), round: round()]) :: FeetAndFrames.t()
def feet_and_frames(timecode, opts \\ []), do: FeetAndFrames.from_timecode(timecode, opts)
# Ensures that rounding is enabled for functions that cannot meaningfully turn
# rounding off, such as those that must return an integer.
@spec ensure_round_enabled(maybe_round(), String.t()) :: :ok
defp ensure_round_enabled(round, arg_name \\ "round")
defp ensure_round_enabled(:off, arg_name), do: raise(ArgumentError.exception("`#{arg_name}` cannot be `:off`"))
defp ensure_round_enabled(_, _), do: :ok
@spec handle_raise_function({:ok, t()} | {:error, Exception.t()}) :: t()
defp handle_raise_function({:ok, result}), do: result
defp handle_raise_function({:error, error}), do: raise(error)
end
defimpl Inspect, for: Vtc.Timecode do
alias Vtc.Timecode
@spec inspect(Timecode.t(), Elixir.Inspect.Opts.t()) :: String.t()
def inspect(timecode, _opts) do
"<#{Timecode.timecode(timecode)} #{inspect(timecode.rate)}>"
end
end
defimpl String.Chars, for: Vtc.Timecode do
alias Vtc.Timecode
@spec to_string(Timecode.t()) :: String.t()
def to_string(timecode), do: inspect(timecode)
end
