node-waveform


Input: any format audio or video file

Output: any or all of these:

* transcoded audio file
* waveform.js-compatible JSON representation of the audio file
* PNG rendering of the waveform

This is a Node.js module that wraps the waveform command
line interface. The C code is bundled
from that repository, so if you want to file an issue with or fork the C code,
go to the waveform repository.

Usage

At least one of the options transcode, waveformjs or png is required as
output destination.

``js
var waveform = require('waveform');

waveform(audiofile, {
// options
'scan': false, // whether to do a pass to detect duration

// transcoding options
transcode: "outputfile.mp3", // path to output-file, or - for stdout as a Buffer
bitrate: 320, // audio bitrate in kbps
format: "name", // e.g. mp3, ogg, mp4
codec: "name", // e.g. mp3, vorbis, flac, aac
mime: "mimetype", // e.g. audio/vorbis
'tag-artist': "artistname", // artist tag
'tag-title': "title", // title tag
'tag-year': 2000, // year tag
'tag-comment': "comment", // comment tag

// waveform.js options
waveformjs: "outputfile.json", // path to output-file, or - for stdout as a Buffer
'wjs-width': 800, // width in samples
'wjs-precision': 4, // how many digits of precision
'wjs-plain': false, // exclude metadata in output JSON (default off)

// png options
png: "outputfile.png", // path to output-file, or - for stdout as a Buffer
'png-width': 256, // width of the image
'png-height': 64, // height of the image
'png-color-bg': '00000000', // bg color, rrggbbaa
'png-color-center': '000000ff', // gradient center color, rrggbbaa
'png-color-outer': '000000ff', // gradient outer color, rrggbbaa
}, function(err, buf) {
// done
});
`

Installation

1. Install libgroove dev package.
Only the main library is needed. Packages are available for common
package managers.

2. Install libpng and zlib dev packages.

3. npm install waveform`