Class: FfmpegCommand

FfmpegCommand

new FfmpegCommand(input, options)

Create an ffmpeg command

Can be called with or without the 'new' operator, and the 'input' parameter may be specified as 'options.source' instead (or passed later with the addInput method).

Parameters:
Name Type Argument Description
input String | ReadableStream <optional>

input file path or readable stream
options Object <optional>

command options

Properties
Name Type Argument Default Description
logger Object <optional>
 <no logging>

logger object with 'error', 'warning', 'info' and 'debug' methods
niceness Number <optional>
 0

ffmpeg process niceness, ignored on Windows
priority Number <optional>
 0

alias for niceness
presets String <optional>
 "fluent-ffmpeg/lib/presets"

directory to load presets from
preset String <optional>
 "fluent-ffmpeg/lib/presets"

alias for presets
stdoutLines String <optional>
 100

maximum lines of ffmpeg output to keep in memory, use 0 for unlimited
timeout Number <optional>
 <no timeout>

ffmpeg processing timeout in seconds
source String | ReadableStream <optional>
 <no input>

alias for the input parameter
Source:

Audio methods

audioBitrate(bitrate)

Specify audio bitrate

Parameters:
Name Type Description
bitrate String | Number

audio bitrate in kbps (with an optional 'k' suffix)
Source:
Returns:

FfmpegCommand

Alias:
withAudioBitrate

audioChannels(channels)

Specify audio channel count

Parameters:
Name Type Description
channels Number

channel count
Source:
Returns:

FfmpegCommand

Alias:
withAudioChannels

audioCodec(codec)

Specify audio codec

Parameters:
Name Type Description
codec String

audio codec name
Source:
Returns:

FfmpegCommand

Alias:
withAudioCodec

audioFilter(filters)

Alias for FfmpegCommand#audioFilters

audioFilters(filters)

Specify custom audio filter(s)

Can be called both with one or many filters, or a filter array.

Parameters:
Name Type Description
filters String | Array.<String> | Array.<Object>

audio filter strings, string array or filter specification array, each with the following properties:

Properties
Name Type Argument Description
filter String

filter name
options String | Array.<String> | Object <optional>

filter option string, array, or object
Source:
Returns:

FfmpegCommand

Examples:
command.audioFilters('filter1');
command.audioFilters('filter1', 'filter2=param1=value1:param2=value2');
command.audioFilters(['filter1', 'filter2']);
command.audioFilters([
  {
    filter: 'filter1'
  },
  {
    filter: 'filter2',
    options: 'param=value:param=value'
  }
]);
command.audioFilters(
  {
    filter: 'filter1',
    options: ['value1', 'value2']
  },
  {
    filter: 'filter2',
    options: { param1: 'value1', param2: 'value2' }
  }
);
Aliases:
  • withAudioFilter
  • withAudioFilters
  • audioFilter

audioFrequency(freq)

Specify audio frequency

Parameters:
Name Type Description
freq Number

audio frequency in Hz
Source:
Returns:

FfmpegCommand

Alias:
withAudioFrequency

audioQuality(quality)

Specify audio quality

Parameters:
Name Type Description
quality Number

audio quality factor
Source:
Returns:

FfmpegCommand

Alias:
withAudioQuality

noAudio()

Disable audio in the output

Source:
Returns:

FfmpegCommand

Alias:
withNoAudio

withAudioBitrate(bitrate)

Alias for FfmpegCommand#audioBitrate

withAudioChannels(channels)

Alias for FfmpegCommand#audioChannels

withAudioCodec(codec)

Alias for FfmpegCommand#audioCodec

withAudioFilter(filters)

Alias for FfmpegCommand#audioFilters

withAudioFilters(filters)

Alias for FfmpegCommand#audioFilters

withAudioFrequency(freq)

Alias for FfmpegCommand#audioFrequency

withAudioQuality(quality)

Alias for FfmpegCommand#audioQuality

withNoAudio()

Alias for FfmpegCommand#noAudio

Capabilities methods

availableCodecs(callback)

Query ffmpeg for available codecs

Parameters:
Name Type Description
callback FfmpegCommand~codecCallback

callback function
Source:
Alias:
getAvailableCodecs

availableEncoders(callback)

Query ffmpeg for available encoders

Parameters:
Name Type Description
callback FfmpegCommand~encodersCallback

callback function
Source:
Alias:
getAvailableEncoders

availableFilters(callback)

Query ffmpeg for available filters

Parameters:
Name Type Description
callback FfmpegCommand~filterCallback

callback function
Source:
Alias:
getAvailableFilters

availableFormats(callback)

Query ffmpeg for available formats

Parameters:
Name Type Description
callback FfmpegCommand~formatCallback

callback function
Source:
Alias:
getAvailableFormats

getAvailableCodecs(callback)

Alias for FfmpegCommand#availableCodecs

getAvailableEncoders(callback)

Alias for FfmpegCommand#availableEncoders

getAvailableFilters(callback)

Alias for FfmpegCommand#availableFilters

getAvailableFormats(callback)

Alias for FfmpegCommand#availableFormats

Custom options methods

addInputOption(options)

Alias for FfmpegCommand#inputOptions

addInputOptions(options)

Alias for FfmpegCommand#inputOptions

addOption(options)

Alias for FfmpegCommand#outputOptions

addOptions(options)

Alias for FfmpegCommand#outputOptions

addOutputOption(options)

Alias for FfmpegCommand#outputOptions

addOutputOptions(options)

Alias for FfmpegCommand#outputOptions

complexFilter(spec, map)

Specify a complex filtergraph

Calling this method will override any previously set filtergraph, but you can set as many filters as needed in one call.

Parameters:
Name Type Argument Description
spec String | Array

filtergraph string or array of filter specification objects, each having the following properties:

Properties
Name Type Argument Description
filter String

filter name
inputs String | Array <optional>

(array of) input stream specifier(s) for the filter, defaults to ffmpeg automatically choosing the first unused matching streams
outputs String | Array <optional>

(array of) output stream specifier(s) for the filter, defaults to ffmpeg automatically assigning the output to the output file
options Object | String | Array <optional>

filter options, can be omitted to not set any options
map Array <optional>

(array of) stream specifier(s) from the graph to include in ffmpeg output, defaults to ffmpeg automatically choosing the first matching streams.
Source:
Returns:

FfmpegCommand

Examples:

Overlay an image over a video (using a filtergraph string)

  ffmpeg()
    .input('video.avi')
    .input('image.png')
    .complexFilter('[0:v][1:v]overlay[out]', ['out']);

Overlay an image over a video (using a filter array)

  ffmpeg()
    .input('video.avi')
    .input('image.png')
    .complexFilter([{
      filter: 'overlay',
      inputs: ['0:v', '1:v'],
      outputs: ['out']
    }], ['out']);

Split video into RGB channels and output a 3x1 video with channels side to side

 ffmpeg()
   .input('video.avi')
   .complexFilter([
     // Duplicate video stream 3 times into streams a, b, and c
     { filter: 'split', options: '3', outputs: ['a', 'b', 'c'] },

     // Create stream 'red' by cancelling green and blue channels from stream 'a'
     { filter: 'lutrgb', options: { g: 0, b: 0 }, inputs: 'a', outputs: 'red' },

     // Create stream 'green' by cancelling red and blue channels from stream 'b'
     { filter: 'lutrgb', options: { r: 0, b: 0 }, inputs: 'b', outputs: 'green' },

     // Create stream 'blue' by cancelling red and green channels from stream 'c'
     { filter: 'lutrgb', options: { r: 0, g: 0 }, inputs: 'c', outputs: 'blue' },

     // Pad stream 'red' to 3x width, keeping the video on the left, and name output 'padded'
     { filter: 'pad', options: { w: 'iw*3', h: 'ih' }, inputs: 'red', outputs: 'padded' },

     // Overlay 'green' onto 'padded', moving it to the center, and name output 'redgreen'
     { filter: 'overlay', options: { x: 'w', y: 0 }, inputs: ['padded', 'green'], outputs: 'redgreen'},

     // Overlay 'blue' onto 'redgreen', moving it to the right
     { filter: 'overlay', options: { x: '2*w', y: 0 }, inputs: ['redgreen', 'blue']},
   ]);
Alias:
filterGraph

filterGraph(spec, map)

Alias for FfmpegCommand#complexFilter

inputOption(options)

Alias for FfmpegCommand#inputOptions

inputOptions(options)

Add custom input option(s)

When passing a single string or an array, each string containing two words is split (eg. inputOptions('-option value') is supported) for compatibility reasons. This is not the case when passing more than one argument.

Parameters:
Name Type Argument Description
options String <repeatable>

option string(s) or string array
Source:
Returns:

FfmpegCommand

Examples:
command.inputOptions('option1');
command.inputOptions('option1', 'option2');
command.inputOptions(['option1', 'option2']);
Aliases:
  • addInputOption
  • addInputOptions
  • withInputOption
  • withInputOptions
  • inputOption

outputOption(options)

Alias for FfmpegCommand#outputOptions

outputOptions(options)

Add custom output option(s)

Parameters:
Name Type Argument Description
options String <repeatable>

option string(s) or string array
Source:
Returns:

FfmpegCommand

Examples:
command.outputOptions('option1');
command.outputOptions('option1', 'option2');
command.outputOptions(['option1', 'option2']);
Aliases:
  • addOutputOption
  • addOutputOptions
  • addOption
  • addOptions
  • withOutputOption
  • withOutputOptions
  • withOption
  • withOptions
  • outputOption

withInputOption(options)

Alias for FfmpegCommand#inputOptions

withInputOptions(options)

Alias for FfmpegCommand#inputOptions

withOption(options)

Alias for FfmpegCommand#outputOptions

withOptions(options)

Alias for FfmpegCommand#outputOptions

withOutputOption(options)

Alias for FfmpegCommand#outputOptions

withOutputOptions(options)

Alias for FfmpegCommand#outputOptions

Input methods

addInput(source)

Alias for FfmpegCommand#input

fpsInput(fps)

Alias for FfmpegCommand#inputFps

fromFormat(format)

Alias for FfmpegCommand#inputFormat

input(source)

Add an input to command

Also switches "current input", that is the input that will be affected by subsequent input-related methods.

Note: only one stream input is supported for now.

Parameters:
Name Type Description
source String | Readable

input file path or readable stream
Source:
Returns:

FfmpegCommand

Aliases:
  • mergeAdd
  • addInput

inputFormat(format)

Specify input format for the last specified input

Parameters:
Name Type Description
format String

input format
Source:
Returns:

FfmpegCommand

Aliases:
  • withInputFormat
  • fromFormat

inputFps(fps)

Specify input FPS for the last specified input (only valid for raw video formats)

Parameters:
Name Type Description
fps Number

input FPS
Source:
Returns:

FfmpegCommand

Aliases:
  • withInputFps
  • withInputFPS
  • withFpsInput
  • withFPSInput
  • inputFPS
  • inputFps
  • fpsInput

inputFPS(fps)

Alias for FfmpegCommand#inputFps

inputFps(fps)

Alias for FfmpegCommand#inputFps

loop(duration)

Loop over the last specified input

Parameters:
Name Type Argument Description
duration String | Number <optional>

loop duration in seconds or as a '[[hh:]mm:]ss[.xxx]' string
Source:
Returns:

FfmpegCommand

mergeAdd(source)

Alias for FfmpegCommand#input

native()

Use native framerate for the last specified input

Source:
Returns:

FfmmegCommand

Aliases:
  • nativeFramerate
  • withNativeFramerate

nativeFramerate()

Alias for FfmpegCommand#native

seek(seek)

Specify output seek time

Parameters:
Name Type Description
seek String | Number

seek time in seconds or as a '[hh:[mm:]]ss[.xxx]' string
Source:
Returns:

FfmpegCommand

Alias:
seekOutput

seekInput(seek)

Specify input seek time for the last specified input

Parameters:
Name Type Description
seek String | Number

seek time in seconds or as a '[hh:[mm:]]ss[.xxx]' string
Source:
Returns:

FfmpegCommand

Aliases:
  • setStartTime
  • seekTo

seekOutput(seek)

Alias for FfmpegCommand#seek

seekTo(seek)

Alias for FfmpegCommand#seekInput

setStartTime(seek)

Alias for FfmpegCommand#seekInput

withFpsInput(fps)

Alias for FfmpegCommand#inputFps

withFPSInput(fps)

Alias for FfmpegCommand#inputFps

withInputFormat(format)

Alias for FfmpegCommand#inputFormat

withInputFPS(fps)

Alias for FfmpegCommand#inputFps

withInputFps(fps)

Alias for FfmpegCommand#inputFps

withNativeFramerate()

Alias for FfmpegCommand#native

Metadata methods

ffprobe(index, options, callback)

Run ffprobe on last specified input

Parameters:
Name Type Argument Description
index Number <optional>
<nullable>

0-based index of input to probe (defaults to last input)
options Array.<String> <optional>
<nullable>

array of output options to return
callback FfmpegCommand~ffprobeCallback

callback function
Source:

Miscellaneous methods

preset(preset)

Use preset

Parameters:
Name Type Description
preset String | function

preset name or preset function
Source:
Alias:
usingPreset

usingPreset(preset)

Alias for FfmpegCommand#preset

Other methods

clone()

Clone an ffmpeg command

This method is useful when you want to process the same input multiple times. It returns a new FfmpegCommand instance with the exact same options.

All options set after the clone() call will only be applied to the instance it has been called on.

Source:
Returns:

FfmpegCommand

Example:
var command = ffmpeg('/path/to/source.avi')
    .audioCodec('libfaac')
    .videoCodec('libx264')
    .format('mp4');

  command.clone()
    .size('320x200')
    .save('/path/to/output-small.mp4');

  command.clone()
    .size('640x400')
    .save('/path/to/output-medium.mp4');

  command.save('/path/to/output-original-size.mp4');

setFfmpegPath(ffmpegPath)

Manually define the ffmpeg binary full path.

Parameters:
Name Type Description
ffmpegPath String

The full path to the ffmpeg binary.
Source:
Returns:

FfmpegCommand

setFfprobePath(ffprobePath)

Manually define the ffprobe binary full path.

Parameters:
Name Type Description
ffprobePath String

The full path to the ffprobe binary.
Source:
Returns:

FfmpegCommand

setFlvtoolPath(flvtool)

Manually define the flvtool2/flvmeta binary full path.

Parameters:
Name Type Description
flvtool String

The full path to the flvtool2 or flvmeta binary.
Source:
Returns:

FfmpegCommand

Output methods

addOutput(target, pipeopts)

Alias for FfmpegCommand#output

duration(duration)

Set output duration

Parameters:
Name Type Description
duration String | Number

duration in seconds or as a '[[hh:]mm:]ss[.xxx]' string
Source:
Returns:

FfmpegCommand

Aliases:
  • withDuration
  • setDuration

flvmeta()

Run flvtool2/flvmeta on output

Source:
Returns:

FfmpegCommand

Alias:
updateFlvMetadata

format(format)

Set output format

Parameters:
Name Type Description
format String

output format name
Source:
Returns:

FfmpegCommand

Aliases:
  • toFormat
  • withOutputFormat
  • outputFormat

map(spec)

Add stream mapping to output

Parameters:
Name Type Description
spec String

stream specification string, with optional square brackets
Source:
Returns:

FfmpegCommand

output(target, pipeopts)

Add output

Parameters:
Name Type Argument Default Description
target String | Writable

target file path or writable stream
pipeopts Object <optional>
 {}

pipe options (only applies to streams)
Source:
Returns:

FfmpegCommand

Alias:
addOutput

outputFormat(format)

Alias for FfmpegCommand#format

setDuration(duration)

Alias for FfmpegCommand#duration

toFormat(format)

Alias for FfmpegCommand#format

updateFlvMetadata()

Alias for FfmpegCommand#flvmeta

withDuration(duration)

Alias for FfmpegCommand#duration

withOutputFormat(format)

Alias for FfmpegCommand#format

Processing methods

concat(target, options)

Merge (concatenate) inputs to a single file

Parameters:
Name Type Argument Description
target String | Writable

output file or writable stream
options Object <optional>

pipe options (only used when outputting to a writable stream)
Source:
Returns:

FfmpegCommand

Aliases:
  • concatenate
  • mergeToFile

concatenate(target, options)

Alias for FfmpegCommand#concat

exec()

Alias for FfmpegCommand#run

execute()

Alias for FfmpegCommand#run

kill(signal)

Kill current ffmpeg process, if any

Parameters:
Name Type Argument Default Description
signal String <optional>
 SIGKILL

signal name
Source:
Returns:

FfmpegCommand

mergeToFile(target, options)

Alias for FfmpegCommand#concat

pipe(stream, options)

Execute ffmpeg command and save output to a stream

If 'stream' is not specified, a PassThrough stream is created and returned. 'options' will be used when piping ffmpeg output to the output stream (@see http://nodejs.org/api/stream.html#stream_readable_pipe_destination_options)

Parameters:
Name Type Argument Default Description
stream stream.Writable <optional>

output stream
options Object <optional>
 {}

pipe options
Source:
Returns:

Output stream

Aliases:
  • stream
  • writeToStream

renice(niceness)

Renice current and/or future ffmpeg processes

Ignored on Windows platforms.

Parameters:
Name Type Argument Default Description
niceness Number <optional>
 0

niceness value between -20 (highest priority) and 20 (lowest priority)
Source:
Returns:

FfmpegCommand

run()

Run ffmpeg command

Source:
Aliases:
  • exec
  • execute

save(output)

Execute ffmpeg command and save output to a file

Parameters:
Name Type Description
output String

file path
Source:
Returns:

FfmpegCommand

Alias:
saveToFile

saveToFile(output)

Alias for FfmpegCommand#save

screenshot(config, folder)

Alias for FfmpegCommand#screenshots

screenshots(config, folder)

Generate images from a video

Note: this method makes the command emit a 'filenames' event with an array of the generated image filenames.

Parameters:
Name Type Argument Default Description
config Number | Object <optional>
 1

screenshot count or configuration object with the following keys:

Properties
Name Type Argument Default Description
count Number <optional>

number of screenshots to take; using this option takes screenshots at regular intervals (eg. count=4 would take screens at 20%, 40%, 60% and 80% of the video length).
folder String <optional>
 '.'

output folder
filename String <optional>
 'tn.png'

output filename pattern, may contain the following tokens:

  • '%s': offset in seconds
  • '%w': screenshot width
  • '%h': screenshot height
  • '%r': screenshot resolution (same as '%wx%h')
  • '%f': input filename
  • '%b': input basename (filename w/o extension)
  • '%i': index of screenshot in timemark array (can be zero-padded by using it like %000i)
timemarks Array.<Number> | Array.<String> <optional>

array of timemarks to take screenshots at; each timemark may be a number of seconds, a '[[hh:]mm:]ss[.xxx]' string or a 'XX%' string. Overrides 'count' if present.
timestamps Array.<Number> | Array.<String> <optional>

alias for 'timemarks'
fastSeek Boolean <optional>

use fast seek (less accurate)
size String <optional>

screenshot size, with the same syntax as FfmpegCommand#size
folder String <optional>

output folder (legacy alias for 'config.folder')
Source:
Returns:

FfmpegCommand

Aliases:
  • takeScreenshots
  • thumbnail
  • thumbnails
  • screenshot

stream(stream, options)

Alias for FfmpegCommand#pipe

takeScreenshots(config, folder)

Alias for FfmpegCommand#screenshots

thumbnail(config, folder)

Alias for FfmpegCommand#screenshots

thumbnails(config, folder)

Alias for FfmpegCommand#screenshots

writeToStream(stream, options)

Alias for FfmpegCommand#pipe

Video methods

fps(fps)

Specify output FPS

Parameters:
Name Type Description
fps Number

output FPS
Source:
Returns:

FfmpegCommand

Aliases:
  • withOutputFps
  • withOutputFPS
  • withFpsOutput
  • withFPSOutput
  • withFps
  • withFPS
  • outputFPS
  • outputFps
  • fpsOutput
  • FPSOutput
  • FPS

FPS(fps)

Alias for FfmpegCommand#fps

fpsOutput(fps)

Alias for FfmpegCommand#fps

FPSOutput(fps)

Alias for FfmpegCommand#fps

frames(frames)

Only transcode a certain number of frames

Parameters:
Name Type Description
frames Number

frame count
Source:
Returns:

FfmpegCommand

Aliases:
  • takeFrames
  • withFrames

noVideo()

Disable video in the output

Source:
Returns:

FfmpegCommand

Alias:
withNoVideo

outputFps(fps)

Alias for FfmpegCommand#fps

outputFPS(fps)

Alias for FfmpegCommand#fps

takeFrames(frames)

Alias for FfmpegCommand#frames

videoBitrate(bitrate, constant)

Specify video bitrate

Parameters:
Name Type Argument Default Description
bitrate String | Number

video bitrate in kbps (with an optional 'k' suffix)
constant Boolean <optional>
 false

enforce constant bitrate
Source:
Returns:

FfmpegCommand

Alias:
withVideoBitrate

videoCodec(codec)

Specify video codec

Parameters:
Name Type Description
codec String

video codec name
Source:
Returns:

FfmpegCommand

Alias:
withVideoCodec

videoFilter(filters)

Alias for FfmpegCommand#videoFilters

videoFilters(filters)

Specify custom video filter(s)

Can be called both with one or many filters, or a filter array.

Parameters:
Name Type Description
filters String | Array.<String> | Array.<Object>

video filter strings, string array or filter specification array, each with the following properties:

Properties
Name Type Argument Description
filter String

filter name
options String | Array.<String> | Object <optional>

filter option string, array, or object
Source:
Returns:

FfmpegCommand

Examples:
command.videoFilters('filter1');
command.videoFilters('filter1', 'filter2=param1=value1:param2=value2');
command.videoFilters(['filter1', 'filter2']);
command.videoFilters([
  {
    filter: 'filter1'
  },
  {
    filter: 'filter2',
    options: 'param=value:param=value'
  }
]);
command.videoFilters(
  {
    filter: 'filter1',
    options: ['value1', 'value2']
  },
  {
    filter: 'filter2',
    options: { param1: 'value1', param2: 'value2' }
  }
);
Aliases:
  • withVideoFilter
  • withVideoFilters
  • videoFilter

withFPS(fps)

Alias for FfmpegCommand#fps

withFps(fps)

Alias for FfmpegCommand#fps

withFPSOutput(fps)

Alias for FfmpegCommand#fps

withFpsOutput(fps)

Alias for FfmpegCommand#fps

withFrames(frames)

Alias for FfmpegCommand#frames

withNoVideo()

Alias for FfmpegCommand#noVideo

withOutputFps(fps)

Alias for FfmpegCommand#fps

withOutputFPS(fps)

Alias for FfmpegCommand#fps

withVideoBitrate(bitrate, constant)

Alias for FfmpegCommand#videoBitrate

withVideoCodec(codec)

Alias for FfmpegCommand#videoCodec

withVideoFilter(filters)

Alias for FfmpegCommand#videoFilters

withVideoFilters(filters)

Alias for FfmpegCommand#videoFilters

Video size methods

applyAutoPad(pad, color)

Alias for FfmpegCommand#autopad

applyAutopad(pad, color)

Alias for FfmpegCommand#autopad

applyAutoPadding(pad, color)

Alias for FfmpegCommand#autopad

applyAutopadding(pad, color)

Alias for FfmpegCommand#autopad

aspect(aspect)

Set output aspect ratio

Parameters:
Name Type Description
aspect String | Number

aspect ratio (number or 'X:Y' string)
Source:
Returns:

FfmpegCommand

Aliases:
  • withAspect
  • withAspectRatio
  • setAspect
  • setAspectRatio
  • aspectRatio

aspectRatio(aspect)

Alias for FfmpegCommand#aspect

autopad(pad, color)

Enable auto-padding the output

Parameters:
Name Type Argument Default Description
pad Boolean <optional>
 true

enable/disable auto-padding
color String <optional>
 'black'

pad color
Source:
Aliases:
  • applyAutopadding
  • applyAutoPadding
  • applyAutopad
  • applyAutoPad
  • withAutopadding
  • withAutoPadding
  • withAutopad
  • withAutoPad
  • autoPad

autoPad(pad, color)

Alias for FfmpegCommand#autopad

keepDAR()

Keep display aspect ratio

This method is useful when converting an input with non-square pixels to an output format that does not support non-square pixels. It rescales the input so that the display aspect ratio is the same.

Source:
Returns:

FfmpegCommand

Aliases:
  • keepPixelAspect
  • keepDisplayAspect
  • keepDisplayAspectRatio

keepDisplayAspect()

Alias for FfmpegCommand#keepDAR

keepDisplayAspectRatio()

Alias for FfmpegCommand#keepDAR

keepPixelAspect()

Alias for FfmpegCommand#keepDAR

setAspect(aspect)

Alias for FfmpegCommand#aspect

setAspectRatio(aspect)

Alias for FfmpegCommand#aspect

setSize(size)

Alias for FfmpegCommand#size

size(size)

Set output size

The 'size' parameter can have one of 4 forms:

  • 'X%': rescale to xx % of the original size
  • 'WxH': specify width and height
  • 'Wx?': specify width and compute height from input aspect ratio
  • '?xH': specify height and compute width from input aspect ratio

Note: both dimensions will be truncated to multiples of 2.

Parameters:
Name Type Description
size String

size string, eg. '33%', '320x240', '320x?', '?x240'
Source:
Returns:

FfmpegCommand

Aliases:
  • withSize
  • setSize

withAspect(aspect)

Alias for FfmpegCommand#aspect

withAspectRatio(aspect)

Alias for FfmpegCommand#aspect

withAutoPad(pad, color)

Alias for FfmpegCommand#autopad

withAutopad(pad, color)

Alias for FfmpegCommand#autopad

withAutopadding(pad, color)

Alias for FfmpegCommand#autopad

withAutoPadding(pad, color)

Alias for FfmpegCommand#autopad

withSize(size)

Alias for FfmpegCommand#size

Type Definitions

codecCallback(err, codecs)

A callback passed to FfmpegCommand#availableCodecs.

Parameters:
Name Type Description
err Error | null

error object or null if no error happened
codecs Object

codec object with codec names as keys and the following properties for each codec (more properties may be available depending on the ffmpeg version used):

Properties
Name Type Description
description String

codec description
canDecode Boolean

whether the codec is able to decode streams
canEncode Boolean

whether the codec is able to encode streams
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encodersCallback(err, encoders)

A callback passed to FfmpegCommand#availableEncoders.

Parameters:
Name Type Description
err Error | null

error object or null if no error happened
encoders Object

encoders object with encoder names as keys and the following properties for each encoder:

Properties
Name Type Description
description String

codec description
type Boolean

"audio", "video" or "subtitle"
frameMT Boolean

whether the encoder is able to do frame-level multithreading
sliceMT Boolean

whether the encoder is able to do slice-level multithreading
experimental Boolean

whether the encoder is experimental
drawHorizBand Boolean

whether the encoder supports draw_horiz_band
directRendering Boolean

whether the encoder supports direct encoding method 1
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ffprobeCallback(err, ffprobeData)

A callback passed to the FfmpegCommand#ffprobe method.

Parameters:
Name Type Description
err Error | null

error object or null if no error happened
ffprobeData Object

ffprobe output data; this object has the same format as what the following command returns:

`ffprobe -print_format json -show_streams -show_format INPUTFILE`
Properties
Name Type Description
streams Array

stream information
format Object

format information
Source:

filterCallback(err, filters)

A callback passed to FfmpegCommand#availableFilters.

Parameters:
Name Type Description
err Error | null

error object or null if no error happened
filters Object

filter object with filter names as keys and the following properties for each filter:

Properties
Name Type Description
description String

filter description
input String

input type, one of 'audio', 'video' and 'none'
multipleInputs Boolean

whether the filter supports multiple inputs
output String

output type, one of 'audio', 'video' and 'none'
multipleOutputs Boolean

whether the filter supports multiple outputs
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formatCallback(err, formats)

A callback passed to FfmpegCommand#availableFormats.

Parameters:
Name Type Description
err Error | null

error object or null if no error happened
formats Object

format object with format names as keys and the following properties for each format:

Properties
Name Type Description
description String

format description
canDemux Boolean

whether the format is able to demux streams from an input file
canMux Boolean

whether the format is able to mux streams into an output file
Source:

Events

codecData

Emitted when ffmpeg reports input codec data

Parameters:
Name Type Description
codecData Object

codec data object

Properties
Name Type Description
format String

input format name
audio String

input audio codec name
audio_details String

input audio codec parameters
video String

input video codec name
video_details String

input video codec parameters
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end

Emitted when a command finishes processing

Parameters:
Name Type Argument Description
filenames|stdout Array | String | null <optional>

generated filenames when taking screenshots, ffmpeg stdout when not outputting to a stream, null otherwise
stderr String | null

ffmpeg stderr
Source:

error

Emitted when an error happens when preparing or running a command

Parameters:
Name Type Description
error Error

error object
stdout String | null

ffmpeg stdout, unless outputting to a stream
stderr String | null

ffmpeg stderr
Source:

progress

Emitted when ffmpeg reports progress information

Parameters:
Name Type Description
progress Object

progress object

Properties
Name Type Argument Description
frames Number

number of frames transcoded
currentFps Number

current processing speed in frames per second
currentKbps Number

current output generation speed in kilobytes per second
targetSize Number

current output file size
timemark String

current video timemark
percent Number <optional>

processing progress (may not be available depending on input)
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start

Emitted just after ffmpeg has been spawned.

Parameters:
Name Type Description
command String

ffmpeg command line
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stderr

Emitted when ffmpeg outputs to stderr

Parameters:
Name Type Description
line String

stderr output line
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