GIF流编码器和解码器：gif-stream
jopen
10年前
gif-stream是一个用于Node和浏览器的GIF流编码器和解码器。
Decoding 示例
This example uses the concat-frames module to collect the output of the GIF decoder into an array of frame objects.
var GIFDecoder = require('gif-stream/decoder'); var concat = require('concat-frames'); // decode a GIF file to RGB pixels fs.createReadStream('in.gif') .pipe(new GIFDecoder) .pipe(concat(function(frames) { // frames is an array of frame objects // each one has a `pixels` property containing // the raw RGB pixel data for that frame, as // well as the width, height, etc. })); Encoding 示例
You can encode a GIF by writing or piping indexed/quantized data to a GIFEncoder stream. If you write data to it manually, you need to first quantize the pixel data to produce a color palette and a buffer of indexed pixels. You can use the neuquant module to do this.
Alternatively, if you have a stream of RGB data already, you can pipe it first to a neuquant stream, and then to a GIF encoder, which will do the hard work of quantizing and writing indexed data for you.
var GIFEncoder = require('gif-stream/encoder'); var neuquant = require('neuquant'); // encode an animated GIF file by writing pixels to it. // you need to manually quantize the data to produce a palette and indexed pixels. var q = neuquant.quantize(pixels); var enc = new GIFEncoder(width, height, { palette: q.palette }); enc.pipe(fs.createWriteStream('out.gif')); // write indexed data enc.end(q.indexed); // or, pipe data from another RGB stream // boom: streaming image transcoding! fs.createReadStream('rgb.png') .pipe(new PNGDecoder) .pipe(new neuquant.Stream) .pipe(new GIFEncoder) .pipe(fs.createWriteStream('out.gif'));