Class: Timecode
Overview
Timecode is a convenience object for calculating SMPTE timecode natively. The promise is that you only have to store two values to know the timecode - the amount of frames and the framerate. An additional perk might be to save the dropframeness, but we avoid that at this point.
You can calculate in timecode objects ass well as with conventional integers and floats. Timecode is immutable and can be used as a value object. Timecode objects are sortable.
Here’s how to use it with ActiveRecord (your column names will be source_tc_frames_total and tape_fps)
composed_of :source_tc, :class_name => 'Timecode',
:mapping => [%w(source_tc_frames total), %w(tape_fps fps)]
Defined Under Namespace
Classes: CannotParse, Error, RangeError, WrongFramerate
Constant Summary collapse
- VERSION =
'0.1.8'
- DEFAULT_FPS =
25.0
- NTSC_FPS =
:stopdoc:
(30.0 * 1000 / 1001).freeze
- ALLOWED_FPS_DELTA =
(0.001).freeze
- COMPLETE_TC_RE =
/^(\d{2}):(\d{2}):(\d{2}):(\d{2})$/
- DF_TC_RE =
/^(\d{1,2}):(\d{1,2}):(\d{1,2});(\d{2})$/
- FRACTIONAL_TC_RE =
/^(\d{2}):(\d{2}):(\d{2}).(\d{1,8})$/
- WITH_FRACTIONS_OF_SECOND =
"%02d:%02d:%02d.%02d"
- WITH_FRAMES =
"%02d:%02d:%02d:%02d"
Class Method Summary collapse
-
.at(hrs, mins, secs, frames, with_fps = DEFAULT_FPS) ⇒ Object
Initialize a Timecode object at this specfic timecode.
-
.from_seconds(seconds_float, the_fps = DEFAULT_FPS) ⇒ Object
create a timecode from the number of seconds.
-
.from_uint(uint, fps = DEFAULT_FPS) ⇒ Object
Some systems (like SGIs) and DPX format store timecode as unsigned integer, bit-packed.
-
.new(from, fps = DEFAULT_FPS) ⇒ Object
Use initialize for integers and parsing for strings.
-
.parse(input, with_fps = DEFAULT_FPS) ⇒ Object
Parse timecode entered by the user.
-
.parse_with_fractional_seconds(tc_with_fractions_of_second, fps = DEFAULT_FPS) ⇒ Object
Parse a timecode with fractional seconds instead of frames.
-
.soft_parse(input, with_fps = DEFAULT_FPS) ⇒ Object
Parse timecode and return zero if none matched.
-
.validate_atoms!(hrs, mins, secs, frames, with_fps) ⇒ Object
Validate the passed atoms for the concrete framerate.
Instance Method Summary collapse
-
#*(arg) ⇒ Object
Multiply the timecode by a number.
-
#+(arg) ⇒ Object
add number of frames (or another timecode) to this one.
-
#-(arg) ⇒ Object
Subtract a number of frames.
-
#/(arg) ⇒ Object
Get the number of times a passed timecode fits into this time span (if performed with Timecode) or a Timecode that multiplied by arg will give this one.
-
#<=>(other_tc) ⇒ Object
Timecodes can be compared to each other.
-
#convert(new_fps) ⇒ Object
Convert to different framerate based on the total frames.
-
#fps ⇒ Object
get FPS.
-
#frame_interval ⇒ Object
get frame interval in fractions of a second.
-
#framerate_in_delta(one, two) ⇒ Object
Validate that framerates are within a small delta deviation considerable for floats.
-
#frames ⇒ Object
get the number of frames.
-
#hours ⇒ Object
get the number of hours.
-
#initialize(total = 0, fps = DEFAULT_FPS) ⇒ Timecode
constructor
Initialize a new Timecode object with a certain amount of frames and a framerate will be interpreted as the total number of frames.
-
#inspect ⇒ Object
:nodoc:.
-
#minutes ⇒ Object
get the number of minutes.
-
#seconds ⇒ Object
get the number of seconds.
-
#succ ⇒ Object
Get the next frame.
-
#to_f ⇒ Object
get total frames as float.
-
#to_i ⇒ Object
get total frames as integer.
-
#to_s ⇒ Object
get formatted SMPTE timecode.
-
#to_seconds ⇒ Object
get the timecode as a floating-point number of seconds (used in Quicktime).
-
#to_uint ⇒ Object
get the timecode as bit-packed unsigned 32 bit int (suitable for DPX and SGI).
-
#total ⇒ Object
get total frame count.
-
#with_frames_as_fraction ⇒ Object
(also: #with_fractional_seconds)
FFmpeg expects a fraction of a second as the last element instead of number of frames.
-
#zero? ⇒ Boolean
is the timecode at 00:00:00:00.
Constructor Details
#initialize(total = 0, fps = DEFAULT_FPS) ⇒ Timecode
Initialize a new Timecode object with a certain amount of frames and a framerate will be interpreted as the total number of frames
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# File 'lib/timecode.rb', line 47 def initialize(total = 0, fps = DEFAULT_FPS) raise WrongFramerate, "FPS cannot be zero" if fps.zero? # If total is a string, use parse raise RangeError, "Timecode cannot be negative" if total.to_i < 0 # Always cast framerate to float, and num of rames to integer @total, @fps = total.to_i, fps.to_f @value = validate! freeze end |
Class Method Details
.at(hrs, mins, secs, frames, with_fps = DEFAULT_FPS) ⇒ Object
Initialize a Timecode object at this specfic timecode
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# File 'lib/timecode.rb', line 123 def at(hrs, mins, secs, frames, with_fps = DEFAULT_FPS) validate_atoms!(hrs, mins, secs, frames, with_fps) total = (hrs*(60*60*with_fps) + mins*(60*with_fps) + secs*with_fps + frames).round new(total, with_fps) end |
.from_seconds(seconds_float, the_fps = DEFAULT_FPS) ⇒ Object
create a timecode from the number of seconds. This is how current time is supplied by QuickTime and other systems which have non-frame-based timescales
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# File 'lib/timecode.rb', line 159 def from_seconds(seconds_float, the_fps = DEFAULT_FPS) total_frames = (seconds_float.to_f * the_fps.to_f).ceil new(total_frames, the_fps) end |
.from_uint(uint, fps = DEFAULT_FPS) ⇒ Object
Some systems (like SGIs) and DPX format store timecode as unsigned integer, bit-packed. This method unpacks such an integer into a timecode.
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# File 'lib/timecode.rb', line 166 def from_uint(uint, fps = DEFAULT_FPS) tc_elements = (0..7).to_a.reverse.map do | multiplier | ((uint >> (multiplier * 4)) & 0x0F) end.join.scan(/(\d{2})/).flatten.map{|e| e.to_i} tc_elements << fps at(*tc_elements) end |
.new(from, fps = DEFAULT_FPS) ⇒ Object
Use initialize for integers and parsing for strings
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# File 'lib/timecode.rb', line 65 def new(from, fps = DEFAULT_FPS) from.is_a?(String) ? parse(from, fps) : super(from, fps) end |
.parse(input, with_fps = DEFAULT_FPS) ⇒ Object
Parse timecode entered by the user. Will raise if the string cannot be parsed. The following formats are supported:
-
10h 20m 10s 1f (or any combination thereof) - will be disassembled to hours, frames, seconds and so on automatically
-
123 - will be parsed as 00:00:01:23
-
00:00:00:00 - will be parsed as zero TC
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# File 'lib/timecode.rb', line 79 def parse(input, with_fps = DEFAULT_FPS) # Drop frame goodbye if (input =~ DF_TC_RE) raise Error, "We do not support drop-frame TC" # No empty values elsif (input =~ /A(\s+)Z/) raise CannotParse, "Empty timecode" # 00:00:00:00 elsif (input =~ COMPLETE_TC_RE) atoms_and_fps = input.scan(COMPLETE_TC_RE).to_a.flatten.map{|e| Integer(e)} + [with_fps] return at(*atoms_and_fps) # 00:00:00.0 elsif input =~ FRACTIONAL_TC_RE parse_with_fractional_seconds(input, with_fps) # 10h 20m 10s 1f 00:00:00:01 - space separated is a sum of parts elsif input =~ /\s/ parts = input.gsub(/\s/, ' ').split.reject{|e| e.strip.empty? } raise CannotParse, "No atoms" if parts.empty? parts.map{|part| parse(part, with_fps) }.inject{|sum, p| sum + p.total } # 10s elsif input =~ /^(\d+)s$/ return new(input.to_i * with_fps, with_fps) # 10h elsif input =~ /^(\d+)h$/i return new(input.to_i * 60 * 60 * with_fps, with_fps) # 20m elsif input =~ /^(\d+)m$/i return new(input.to_i * 60 * with_fps, with_fps) # 60f - 60 frames, or 2 seconds and 10 frames elsif input =~ /^(\d+)f$/i return new(input.to_i, with_fps) # Only a bunch of digits, treat 12345 as 00:01:23:45 elsif (input =~ /^(\d+)$/) atoms_len = 2 * 4 # left-pad input AND truncate if needed padded = input[0..atoms_len].rjust(8, "0") atoms = padded.scan(/(\d{2})/).flatten.map{|e| e.to_i } + [with_fps] return at(*atoms) else raise CannotParse, "Cannot parse #{input} into timecode, unknown format" end end |
.parse_with_fractional_seconds(tc_with_fractions_of_second, fps = DEFAULT_FPS) ⇒ Object
Parse a timecode with fractional seconds instead of frames. This is how ffmpeg reports a timecode
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# File 'lib/timecode.rb', line 145 def parse_with_fractional_seconds(tc_with_fractions_of_second, fps = DEFAULT_FPS) fraction_expr = /\.(\d+)$/ fraction_part = ('.' + tc_with_fractions_of_second.scan(fraction_expr)[0][0]).to_f seconds_per_frame = 1.0 / fps.to_f frame_idx = (fraction_part / seconds_per_frame).floor tc_with_frameno = tc_with_fractions_of_second.gsub(fraction_expr, ":%02d" % frame_idx) parse(tc_with_frameno, fps) end |
.soft_parse(input, with_fps = DEFAULT_FPS) ⇒ Object
Parse timecode and return zero if none matched
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# File 'lib/timecode.rb', line 70 def soft_parse(input, with_fps = DEFAULT_FPS) parse(input) rescue new(0, with_fps) end |
.validate_atoms!(hrs, mins, secs, frames, with_fps) ⇒ Object
Validate the passed atoms for the concrete framerate
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# File 'lib/timecode.rb', line 130 def validate_atoms!(hrs, mins, secs, frames, with_fps) case true when hrs > 99 raise RangeError, "There can be no more than 99 hours, got #{hrs}" when mins > 59 raise RangeError, "There can be no more than 59 minutes, got #{mins}" when secs > 59 raise RangeError, "There can be no more than 59 seconds, got #{secs}" when frames > (with_fps -1) raise RangeError, "There can be no more than #{with_fps -1} frames @#{with_fps}, got #{frames}" end end |
Instance Method Details
#*(arg) ⇒ Object
Multiply the timecode by a number
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# File 'lib/timecode.rb', line 276 def *(arg) raise RangeError, "Timecode multiplier cannot be negative" if (arg < 0) self.class.new(@total*arg.to_i, @fps) end |
#+(arg) ⇒ Object
add number of frames (or another timecode) to this one
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# File 'lib/timecode.rb', line 254 def +(arg) if (arg.is_a?(Timecode) && framerate_in_delta(arg.fps, @fps)) self.class.new(@total+arg.total, @fps) elsif (arg.is_a?(Timecode)) raise WrongFramerate, "You are calculating timecodes with different framerates" else self.class.new(@total + arg, @fps) end end |
#-(arg) ⇒ Object
Subtract a number of frames
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# File 'lib/timecode.rb', line 265 def -(arg) if (arg.is_a?(Timecode) && framerate_in_delta(arg.fps, @fps)) self.class.new(@total-arg.total, @fps) elsif (arg.is_a?(Timecode)) raise WrongFramerate, "You are calculating timecodes with different framerates" else self.class.new(@total-arg, @fps) end end |
#/(arg) ⇒ Object
Get the number of times a passed timecode fits into this time span (if performed with Timecode) or a Timecode that multiplied by arg will give this one
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# File 'lib/timecode.rb', line 288 def /(arg) arg.is_a?(Timecode) ? (@total / arg.total) : self.class.new(@total /arg, @fps) end |
#<=>(other_tc) ⇒ Object
Timecodes can be compared to each other
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# File 'lib/timecode.rb', line 293 def <=>(other_tc) if framerate_in_delta(fps, other_tc.fps) self.total <=> other_tc.total else raise WrongFramerate, "Cannot compare timecodes with different framerates" end end |
#convert(new_fps) ⇒ Object
Convert to different framerate based on the total frames. Therefore, 1 second of PAL video will convert to 25 frames of NTSC (this is suitable for PAL to film TC conversions and back).
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# File 'lib/timecode.rb', line 234 def convert(new_fps) self.class.new(@total, new_fps) end |
#fps ⇒ Object
get FPS
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# File 'lib/timecode.rb', line 187 def fps @fps end |
#frame_interval ⇒ Object
get frame interval in fractions of a second
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# File 'lib/timecode.rb', line 212 def frame_interval 1.0/@fps end |
#framerate_in_delta(one, two) ⇒ Object
Validate that framerates are within a small delta deviation considerable for floats
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# File 'lib/timecode.rb', line 313 def framerate_in_delta(one, two) (one.to_f - two.to_f).abs <= ALLOWED_FPS_DELTA end |
#frames ⇒ Object
get the number of frames
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# File 'lib/timecode.rb', line 192 def frames value_parts[3] end |
#hours ⇒ Object
get the number of hours
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# File 'lib/timecode.rb', line 207 def hours value_parts[0] end |
#inspect ⇒ Object
:nodoc:
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# File 'lib/timecode.rb', line 58 def inspect # :nodoc: "#<Timecode:%s (%dF@%.2f)>" % [to_s, total, fps] end |
#minutes ⇒ Object
get the number of minutes
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# File 'lib/timecode.rb', line 202 def minutes value_parts[1] end |
#seconds ⇒ Object
get the number of seconds
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# File 'lib/timecode.rb', line 197 def seconds value_parts[2] end |
#succ ⇒ Object
Get the next frame
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# File 'lib/timecode.rb', line 282 def succ self.class.new(@total + 1, @fps) end |
#to_f ⇒ Object
get total frames as float
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# File 'lib/timecode.rb', line 244 def to_f @total end |
#to_i ⇒ Object
get total frames as integer
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# File 'lib/timecode.rb', line 249 def to_i @total end |
#to_s ⇒ Object
get formatted SMPTE timecode
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# File 'lib/timecode.rb', line 239 def to_s WITH_FRAMES % value_parts end |
#to_seconds ⇒ Object
get the timecode as a floating-point number of seconds (used in Quicktime)
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# File 'lib/timecode.rb', line 227 def to_seconds (@total / @fps) end |
#to_uint ⇒ Object
get the timecode as bit-packed unsigned 32 bit int (suitable for DPX and SGI)
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# File 'lib/timecode.rb', line 217 def to_uint elements = (("%02d" * 4) % [hours,minutes,seconds,frames]).split(//).map{|e| e.to_i } uint = 0 elements.reverse.each_with_index do | p, i | uint |= p << 4 * i end uint end |
#total ⇒ Object
get total frame count
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# File 'lib/timecode.rb', line 182 def total to_f end |
#with_frames_as_fraction ⇒ Object Also known as: with_fractional_seconds
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# File 'lib/timecode.rb', line 305 def with_frames_as_fraction vp = value_parts.dup vp[-1] = (100.0 / @fps) * vp[-1] WITH_FRACTIONS_OF_SECOND % vp end |
#zero? ⇒ Boolean
is the timecode at 00:00:00:00
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# File 'lib/timecode.rb', line 177 def zero? @total.zero? end |