FFmkek

A basic wrapper around FFmpeg for node.js.

Installation

$ npm i ffmkek

Requirements

• FFmpeg (see FFmpeg instalation)

Examples

Options and inputs/outputs have to be added in the same order you would add them in your command line.

const FFmkek = require('ffmkek')

// ffmpeg -i some/video.mp4 -i some/audio.mp3 -shortest -vf "scale=300:-1, crop=150:150:0:0" out.mp4 -y
new FFmkek()
  .addInput('some/video.mp4')
  .addInput('some/audio.mp3')
  .addOption('-shortest')
  .addOption('-vf', 'scale=300:-1', 'crop=150:150:0:0')
  .write('out.mp4')

// ffmpeg -i pipe:0 -c copy out.mp4 -y
new FFmkek()
  .addInput(someReadableStream)
  .addOption('-c', 'copy')
  .write('out.mp4')

// ffmpeg -i pipe:0 -f h264 pipe:1 -y
new FFmkek()
  .addInput(someReadableStream)
  .addOption('-f', 'h264')
  .write(someWriteableStream)

FFmkek Documentation

FFmkek.prototype.addInput(input)

Adds a new input to the command.

Aliases: in, input

Params:

• input: string|Stream The path to the input file or a readable stream.

Returns: FFmkek The current command.

FFmkek.prototype.setOutput(output)

Adds a new output to the command.

Aliases: out, output, addOutput

Params:

• output: string|Stream The path to the ouput file or a writeable stream.

Returns: FFmkek The current command.

FFmkek.prototype.addOption(name, [value1[, ...[, valueN]]])

Calls addOption on the current Part. See Part.prototype.addOption().

Aliases: opt, option

Params:

• name: string
• valueN: string

Returns: FFmkek The current command.

FFmkek.prototype.setForce(flag)

Controls whether to add the -y option to the command or not. By default is set to true.

Params:

• flag: boolean

Returns: FFmkek The current command.

FFmkek.prototype.getArguments()

Formats the command arguments and returns them as an array.

Aliases: args, arguments

Returns: Array<string> The current command arguments.

FFmkek.prototype.run()

Executes the current command. If no output is set, creates a PassThrough stream.

Returns: Promise<string|Stream> The path of the file or the Stream that was written to.

FFmkek.prototype.write(output)

Shorthand for calling setOutput() and run().

Aliases: save

Params:

• output: string|Stream The path to the ouput file or a writeable stream.

Returns: Promise<string|Stream> The path of the file or the Stream that was written to.

FFmkek.prototype.setPath(path)

Changes the path to ffmpeg. If not called simply ffmpeg is used.

Params:

• path: string

Returns: FFmkek The current command.

Part Documentation

A FFmkek instance usually contains multiple Parts. Parts are abstractisations of an input or an output. Each part has:

• name: The file path or pipe number. (some/folder/input.mp4 or pipe:0)
• type: input or output
• options: The options that belong to this Part

Upon calling FFmkek.prototype.addInput() or FFmkek.prototype.setOutput(), the current part is "closed", along with the options added prior to it, and pushed to the parts array, which is a property of FFmkek instances. If you happen to need to modify a Part after calling those methods, you can just look them up in the parts array and modify them. Here's an example:

const command = new FFmkek()
  .addInput('some/file.mp4')
  .setOutput('other/file.mp4')

// Currently our command yields:
// ffmpeg -i some/file.mp4 other/file.mp4

command.parts.find(part => part.name === 'some/file.mp4').addOption('-r', 1)

// Now our command looks like:
// ffmpeg -r 1 -i some/file.mp4 other/file.mp4

Here's a real world usage for this.

Part.prototype.setName(name)

Sets the name of the part.

Params:

• name: string

Returns: Part self.

Part.prototype.setType(type)

Sets the type of the part. Can only be input or output. You can use the Part.INPUT and Part.OUTPUT constants instead.

Params:

• type: string

Returns: Part self.

Part.prototype.addOption(name, [value1[, ...[, valueN]]])

Adds an option to the Part. Values are concatenated automatically. Upon adding an option with the same name later on, the values are again concatenated, the option is not overwriten.

Params:

• name: string The name of the option. Does NOT prepend a hyphen automatically, you must add it yourself.
• valueN: string The set of values to set the option to.

Returns: Part self.

Part.prototype.apply(args)

Pushes all its options and name to an array.

new Part()
  .setName('some/file.mp4')
  .addOption('-c', 'copy')
  .addOption('-vf', 'scale=300:-2', 'crop=150:150:0:0')
  .apply([]) // => ['-c', 'copy', '-vf', 'scale=300:-2, crop=150:150:0:0', '-i', 'some/file.mp4']

Params:

• args: Array

Returns: Array The new array.

Part.prototype.remove()

Removes self from parent FFmkek command.

Returns: Part self.

Contributing

If there are things you don't agree with, or would like to have implemented, feel free to submit a pull request or file an issue.