mp4-stream
Streaming mp4 encoder and decoder
npm install mp4-stream
Usage
var mp4 = require('mp4-stream')
var fs = require('fs')
var decode = mp4.decode()
fs.createReadStream('video.mp4')
.pipe(decode)
.on('box', function (headers) {
console.log('found box (' + headers.type + ') (' + headers.length + ')')
if (headers.type === 'mdat') {
// you can get the contents as a stream
console.log('box has stream data (consume stream to continue)')
decode.stream().resume()
} else if (headers.type === 'moof') {
// you can ignore some boxes
decode.ignore()
} else {
// or you can fully decode them
decode.decode(function (box) {
console.log('box contents:', box)
})
}
}
})
All boxes have a type thats a 4 char string with a type name.
API
var stream = mp4.decode()
Create a new decoder.
The decoder is a writable stream you should write a mp4 file to. It emits the following additional events:
on('box', headers)- emitted when a new box is found.
Each time the box event fires, you must call one of these three functions:
stream.ignore()- ignore the entire box and continue parsing after its endstream.stream()- get a readable stream of the box contentsstream.decode(callback)- decode the box, including all childeren in the case of containers, and pass
the resulting box object to the callback
var fs = require('fs')
var stream = mp4.decode()
stream.on('box', function (headers) {
console.log('found new box:', headers)
})
fs.createReadStream('my-video.mp4').pipe(stream)
var stream = mp4.encode()
Create a new encoder.
The encoder is a readable stream you can use to generate a mp4 file. It has the following API:
stream.box(box, [callback])- adds a new mp4 box to the stream.var ws = stream.mediaData(size)- helper that adds anmdatbox. write the media content to this stream.stream.finalize()- finalizes the mp4 stream. call this when you're done.
var fs = require('fs')
var stream = mp4.encode()
stream.pipe(fs.createWriteStream('my-new-video.mp4'))
stream.box(anMP4Box, function (err) {
// box flushed
var content = stream.mediaData(lengthOfStream, function () {
// wrote media data
stream.finalize()
})
someContent.pipe(content)
})
Decode and encode a file
To decode and encode an mp4 file with this module do
var encoder = mp4.encode()
var decoder = mp4.decode()
decoder.on('box', function (headers) {
decoder.decode(function (box) {
encoder.box(box, next)
})
})
fs.createReadStream('my-movie.mp4').pipe(decoder)
encoder.pipe(fs.createWriteStream('my-movie-copy.mp4'))
Boxes
Mp4 supports a wide range of boxes, implemented in
mp4-box-encoding.
License
MIT