https://github.com/claus/flac-metadata

FLAC metadata processor for Node.js, implemented as Transform stream
https://github.com/claus/flac-metadata

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FLAC metadata processor for Node.js, implemented as Transform stream

• Host: GitHub
• URL: https://github.com/claus/flac-metadata
• Owner: claus
• Created: 2014-07-28T23:43:23.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2015-07-07T06:12:01.000Z (over 9 years ago)
• Last Synced: 2024-08-10T09:16:24.601Z (5 months ago)
• Language: JavaScript
• Size: 156 KB
• Stars: 14
• Watchers: 4
• Forks: 6
• Open Issues: 3
• Metadata Files:
  • Readme: README.md

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README

        
# flac-metadata

A FLAC metadata processor for Node.js, implemented as Transform stream.

## Installation

```npm install flac-metadata```

## Usage Examples

Some simple examples to get you started:

#### Noop

Does nothing, just pipes a source FLAC through the Processor into a target FLAC.

```js

var fs = require("fs");

var flac = require("flac-metadata");

var reader = fs.createReadStream("source.flac");

var writer = fs.createWriteStream("target.flac");

var processor = new flac.Processor();

reader.pipe(processor).pipe(writer);

```

#### Trace Metadata

Traces out the metadata from a FLAC file.

```js

var fs = require("fs");

var flac = require("flac-metadata");

var reader = fs.createReadStream("source.flac");

var processor = new flac.Processor({ parseMetaDataBlocks: true });

processor.on("postprocess", function(mdb) {

  console.log(mdb.toString());

});

reader.pipe(processor);

```

The output should be something like this:

```

[MetaDataBlockStreamInfo] type: 0, isLast: false

  minBlockSize: 4096

  maxBlockSize: 4096

  minFrameSize: 14

  maxFrameSize: 12389

  samples: 9750804

  sampleRate: 44100

  channels: 2

  bitsPerSample: 16

  duration: 3:41.107

  checksum: 1746dff27beb6d1875a88cfeed8a576b

[MetaDataBlockVorbisComment] type: 4, isLast: false

  vendor: reference libFLAC 1.2.1 20070917

  comments:

    ALBUM: Close to the Glass

    ARTIST: The Notwist

    GENRE: Rock

    DATE: 2014

    TITLE: Signals

[MetaDataBlockPicture] type: 6, isLast: true

  pictureType: 3

  mimeType: image/png

  description:

  width: 120

  height: 120

  bitsPerPixel: 32

  colors: 0

  pictureData: 391383

```

#### Strip All Metadata

Pipes a source FLAC through the Processor into a target FLAC, removing all metadata.

```js

var fs = require("fs");

var flac = require("flac-metadata");

var reader = fs.createReadStream("source.flac");

var writer = fs.createWriteStream("target.flac");

var processor = new flac.Processor();

processor.on("preprocess", function(mdb) {

  // STREAMINFO is always the first (and only mandatory) metadata block.

  if (mdb.type === flac.Processor.MDB_TYPE_STREAMINFO) {

    // When a metadata block's isLast flag is set to true in preprocess,

    // subsequent blocks are automatically discarded.

    mdb.isLast = true;

  }

});

reader.pipe(processor).pipe(writer);

```

#### Inject Metadata

Injects a VORBIS_COMMENT block (and removes the existing one, if any).

```js

var fs = require("fs");

var flac = require("flac-metadata");

var reader = fs.createReadStream("source.flac");

var writer = fs.createWriteStream("target.flac");

var processor = new flac.Processor();

var vendor = "reference libFLAC 1.2.1 20070917";

var comments = [

  "ARTIST=Boyracer",

  "TITLE=I've Got It And It's Not Worth Having",

  "ALBUM=B Is For Boyracer",

  "TRACKNUMBER=A1",

  "DATE=1993",

  "DISCOGS=22379"

];

processor.on("preprocess", function(mdb) {

  // Remove existing VORBIS_COMMENT block, if any.

  if (mdb.type === flac.Processor.MDB_TYPE_VORBIS_COMMENT) {

    mdb.remove();

  }

  // Inject new VORBIS_COMMENT block.

  if (mdb.removed || mdb.isLast) {

    var mdbVorbis = flac.data.MetaDataBlockVorbisComment.create(mdb.isLast, vendor, comments);

    this.push(mdbVorbis.publish());

  }

});

reader.pipe(processor).pipe(writer);

```

## License

MIT