Repository: mafintosh/mp4-stream
Branch: master
Commit: 2bdf2aad5fcc
Files: 10
Total size: 14.7 KB

Directory structure:
gitextract_vw7dh3fz/

├── .gitignore
├── .npmignore
├── .travis.yml
├── LICENSE
├── README.md
├── decode.js
├── encode.js
├── index.js
├── package.json
└── test.js

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FILE CONTENTS
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================================================
FILE: .gitignore
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node_modules
sandbox


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FILE: .npmignore
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test.js
.travis.yml


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FILE: .travis.yml
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language: node_js
node_js:
  - '6'
  - '8'
  - '10'
  - '12'


================================================
FILE: LICENSE
================================================
The MIT License (MIT)

Copyright (c) 2015 Mathias Buus

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.


================================================
FILE: README.md
================================================
# mp4-stream

Streaming mp4 encoder and decoder

```
npm install mp4-stream
```

[![build status](http://img.shields.io/travis/mafintosh/mp4-stream.svg?style=flat)](http://travis-ci.org/mafintosh/mp4-stream)

## Usage

``` js
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 end
* `stream.stream()` - get a readable stream of the box contents
* `stream.decode(callback)` - decode the box, including all childeren in the case of containers, and pass
the resulting box object to the callback

``` js
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 an `mdat` box. write the media content to this stream.
* `stream.finalize()` - finalizes the mp4 stream. call this when you're done.

``` js
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

``` js
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](https://github.com/jhiesey/mp4-box-encoding).

## License

MIT


================================================
FILE: decode.js
================================================
var stream = require('readable-stream')
var nextEvent = require('next-event')
var Box = require('mp4-box-encoding')

var EMPTY = Buffer.alloc(0)

class Decoder extends stream.Writable {
  constructor (opts) {
    super(opts)

    this.destroyed = false

    this._pending = 0
    this._missing = 0
    this._ignoreEmpty = false
    this._buf = null
    this._str = null
    this._cb = null
    this._ondrain = null
    this._writeBuffer = null
    this._writeCb = null

    this._ondrain = null
    this._kick()
  }

  destroy (err) {
    if (this.destroyed) return
    this.destroyed = true
    if (err) this.emit('error', err)
    this.emit('close')
  }

  _write (data, enc, next) {
    if (this.destroyed) return
    var drained = !this._str || !this._str._writableState.needDrain

    while (data.length && !this.destroyed) {
      if (!this._missing && !this._ignoreEmpty) {
        this._writeBuffer = data
        this._writeCb = next
        return
      }

      var consumed = data.length < this._missing ? data.length : this._missing
      if (this._buf) data.copy(this._buf, this._buf.length - this._missing)
      else if (this._str) drained = this._str.write(consumed === data.length ? data : data.slice(0, consumed))

      this._missing -= consumed

      if (!this._missing) {
        var buf = this._buf
        var cb = this._cb
        var stream = this._str

        this._buf = this._cb = this._str = this._ondrain = null
        drained = true

        this._ignoreEmpty = false
        if (stream) stream.end()
        if (cb) cb(buf)
      }

      data = consumed === data.length ? EMPTY : data.slice(consumed)
    }

    if (this._pending && !this._missing) {
      this._writeBuffer = data
      this._writeCb = next
      return
    }

    if (drained) next()
    else this._ondrain(next)
  }

  _buffer (size, cb) {
    this._missing = size
    this._buf = Buffer.alloc(size)
    this._cb = cb
  }

  _stream (size, cb) {
    this._missing = size
    this._str = new MediaData(this)
    this._ondrain = nextEvent(this._str, 'drain')
    this._pending++
    this._str.on('end', () => {
      this._pending--
      this._kick()
    })
    this._cb = cb
    return this._str
  }

  _readBox () {
    const bufferHeaders = (len, buf) => {
      this._buffer(len, additionalBuf => {
        if (buf) {
          buf = Buffer.concat([buf, additionalBuf])
        } else {
          buf = additionalBuf
        }
        var headers = Box.readHeaders(buf)
        if (typeof headers === 'number') {
          bufferHeaders(headers - buf.length, buf)
        } else {
          this._pending++
          this._headers = headers
          this.emit('box', headers)
        }
      })
    }

    bufferHeaders(8)
  }

  stream () {
    if (!this._headers) throw new Error('this function can only be called once after \'box\' is emitted')
    var headers = this._headers
    this._headers = null

    return this._stream(headers.contentLen, () => {
      this._pending--
      this._kick()
    })
  }

  decode (cb) {
    if (!this._headers) throw new Error('this function can only be called once after \'box\' is emitted')
    var headers = this._headers
    this._headers = null

    this._buffer(headers.contentLen, buf => {
      var box = Box.decodeWithoutHeaders(headers, buf)
      cb(box)
      this._pending--
      this._kick()
    })
  }

  ignore () {
    if (!this._headers) throw new Error('this function can only be called once after \'box\' is emitted')
    var headers = this._headers
    this._headers = null

    this._missing = headers.contentLen
    if (this._missing === 0) {
      this._ignoreEmpty = true
    }
    this._cb = () => {
      this._pending--
      this._kick()
    }
  }

  _kick () {
    if (this._pending) return
    if (!this._buf && !this._str) this._readBox()
    if (this._writeBuffer) {
      var next = this._writeCb
      var buffer = this._writeBuffer
      this._writeBuffer = null
      this._writeCb = null
      this._write(buffer, null, next)
    }
  }
}

class MediaData extends stream.PassThrough {
  constructor (parent) {
    super()
    this._parent = parent
    this.destroyed = false
  }

  destroy (err) {
    if (this.destroyed) return
    this.destroyed = true
    this._parent.destroy(err)
    if (err) this.emit('error', err)
    this.emit('close')
  }
}

module.exports = Decoder


================================================
FILE: encode.js
================================================
var stream = require('readable-stream')
var Box = require('mp4-box-encoding')
var queueMicrotask = require('queue-microtask')

function noop () {}

class Encoder extends stream.Readable {
  constructor (opts) {
    super(opts)

    this.destroyed = false

    this._finalized = false
    this._reading = false
    this._stream = null
    this._drain = null
    this._want = false

    this._onreadable = () => {
      if (!this._want) return
      this._want = false
      this._read()
    }

    this._onend = () => {
      this._stream = null
    }
  }

  mdat (size, cb) {
    this.mediaData(size, cb)
  }

  mediaData (size, cb) {
    var stream = new MediaData(this)
    this.box({ type: 'mdat', contentLength: size, encodeBufferLen: 8, stream: stream }, cb)
    return stream
  }

  box (box, cb) {
    if (!cb) cb = noop
    if (this.destroyed) return cb(new Error('Encoder is destroyed'))

    var buf
    if (box.encodeBufferLen) {
      buf = Buffer.alloc(box.encodeBufferLen)
    }
    if (box.stream) {
      box.buffer = null
      buf = Box.encode(box, buf)
      this.push(buf)
      this._stream = box.stream
      this._stream.on('readable', this._onreadable)
      this._stream.on('end', this._onend)
      this._stream.on('end', cb)
      this._forward()
    } else {
      buf = Box.encode(box, buf)
      var drained = this.push(buf)
      if (drained) return queueMicrotask(cb)
      this._drain = cb
    }
  }

  destroy (err) {
    if (this.destroyed) return
    this.destroyed = true
    if (this._stream && this._stream.destroy) this._stream.destroy()
    this._stream = null
    if (this._drain) {
      var cb = this._drain
      this._drain = null
      cb(err)
    }
    if (err) this.emit('error', err)
    this.emit('close')
  }

  finalize () {
    this._finalized = true
    if (!this._stream && !this._drain) {
      this.push(null)
    }
  }

  _forward () {
    if (!this._stream) return

    while (!this.destroyed) {
      var buf = this._stream.read()

      if (!buf) {
        this._want = !!this._stream
        return
      }

      if (!this.push(buf)) return
    }
  }

  _read () {
    if (this._reading || this.destroyed) return
    this._reading = true

    if (this._stream) this._forward()
    if (this._drain) {
      var drain = this._drain
      this._drain = null
      drain()
    }

    this._reading = false
    if (this._finalized) {
      this.push(null)
    }
  }
}

class MediaData extends stream.PassThrough {
  constructor (parent) {
    super()
    this._parent = parent
    this.destroyed = false
  }

  destroy (err) {
    if (this.destroyed) return
    this.destroyed = true
    this._parent.destroy(err)
    if (err) this.emit('error', err)
    this.emit('close')
  }
}

module.exports = Encoder


================================================
FILE: index.js
================================================
const Decoder = require('./decode')
const Encoder = require('./encode')

exports.decode = opts => new Decoder(opts)
exports.encode = opts => new Encoder(opts)


================================================
FILE: package.json
================================================
{
  "name": "mp4-stream",
  "version": "3.1.3",
  "description": "Streaming mp4 encoder and decoder",
  "main": "index.js",
  "dependencies": {
    "mp4-box-encoding": "^1.3.0",
    "next-event": "^1.0.0",
    "queue-microtask": "^1.2.2",
    "readable-stream": "^3.0.6"
  },
  "devDependencies": {
    "standard": "^12.0.1",
    "tape": "^4.9.1"
  },
  "scripts": {
    "test": "standard && tape test.js"
  },
  "repository": {
    "type": "git",
    "url": "https://github.com/mafintosh/mp4-stream.git"
  },
  "author": "Mathias Buus (@mafintosh)",
  "license": "MIT",
  "bugs": {
    "url": "https://github.com/mafintosh/mp4-stream/issues"
  },
  "homepage": "https://github.com/mafintosh/mp4-stream"
}


================================================
FILE: test.js
================================================
var tape = require('tape')
var mp4 = require('./')

tape('all boxes are decoded', function (t) {
  var encode = mp4.encode()
  var decode = mp4.decode()

  var count = 0
  decode.on('box', function () {
    if (count === 0) {
      decode.decode(function () { })
    } else if (count === 1) {
      decode.stream().on('data', function () { })
    } else {
      decode.ignore()
    }
    count++
  })

  decode.on('finish', function () {
    t.same(count, 4)
    t.end()
  })

  for (let i = 0; i < 4; i++) {
    encode.box({
      type: 'ftyp',
      brand: 'mafi',
      brandVersion: 1
    })
  }

  encode.finalize()
  encode.pipe(decode)
})

tape('generates and parses', function (t) {
  var encode = mp4.encode()
  var decode = mp4.decode()

  decode.on('box', function (headers) {
    if (headers.type === 'ftyp') {
      decode.decode(function (box) {
        t.same(box.type, 'ftyp')
        t.same(box.brand, 'mafi')
        t.same(box.brandVersion, 1)
      })
    } else if (headers.type === 'mdat') {
      t.same(headers.type, 'mdat')
      t.same(headers.length, 8 + 11)
      var buffer = []
      var stream = decode.stream()
      stream.on('data', function (data) {
        buffer.push(data)
      })
      stream.on('end', function () {
        t.same(Buffer.concat(buffer).toString(), 'hello world')
        t.end()
      })
    } else {
      t.fail('unexpected box')
    }
  })

  encode.box({
    type: 'ftyp',
    brand: 'mafi',
    brandVersion: 1
  })

  var stream = encode.mediaData(11)
  stream.end('hello world')

  encode.finalize()
  encode.pipe(decode)
})

tape('generates and parses with decoder/encoder in between', function (t) {
  var encode = mp4.encode()
  var decode = mp4.decode()
  var encode2 = mp4.encode()
  var decode2 = mp4.decode()

  decode.on('box', function (headers) {
    if (headers.type === 'ftyp') {
      decode.decode(function (box) {
        t.same(box.type, 'ftyp')
        t.same(box.brand, 'mafi')
        t.same(box.brandVersion, 1)
      })
    } else if (headers.type === 'mdat') {
      t.same(headers.type, 'mdat')
      t.same(headers.length, 8 + 11)
      var buffer = []
      var stream = decode.stream()
      stream.on('data', function (data) {
        buffer.push(data)
      })
      stream.on('end', function () {
        t.same(Buffer.concat(buffer).toString(), 'hello world')
        t.end()
      })
    } else {
      t.fail('unexpected box')
    }
  })

  encode.box({
    type: 'ftyp',
    brand: 'mafi',
    brandVersion: 1
  })

  var stream = encode.mediaData(11)
  stream.end('hello world')

  encode.finalize()
  encode.pipe(decode2)
  decode2.on('box', function (headers) {
    decode2.decode(function (box) {
      encode2.box(box)
    })
  })
  decode2.on('end', function () {
    encode2.finalize()
  })
  encode2.pipe(decode)
})