var fs = require("fs");
var path = require("path");
var GifCodec = require("gifwrap").GifCodec;

fs.readFile(path.join(__dirname, "./input.gif"), (err, buffer) => {
  if (err) throw err;
  var codec = new GifCodec();
  codec.decodeGif(buffer).then(gif => {
    codec
      .encodeGif(gif.frames, {
        loops: gif.loops,
        colorScope: gif.colorScope
      })
      .then(gif => {
        fs.writeFileSync(path.join(__dirname, "./output.gif"), gif.buffer);
      });
  });
});

var filePath = "pathtofile.gif"

await GifUtil.read(filePath)
.then(async inputGif => {
	//Loop through each frame
	for (var i=0; i<inputGif.frames.length; i++){
		//Modify the frame image buffer with jimp
		var newImgBuffer = await GifUtil.copyAsJimp(jimp, inputGif.frames[i])
		.resize(160, 160) // resize
		.getBufferAsync(jimp.AUTO)

		inputGif.frames[i].bitmap.height = 160
		inputGif.frames[i].bitmap.width = 160
		inputGif.frames[i].bitmap.data = newImgBuffer
	}
	
	//Pass inputGif to write() to preserve the original GIF's specs.
	return GifUtil.write(filePath, inputGif.frames, inputGif)
});

const bufferStream = new BufferStream();
await GifUtil.write(bufferStream, frames);
const gifBuffer = bufferStream.getBuffer();

    return GifUtil.read(downloadedFile)
        .then(inputGif =>
            // Pass inputGif to write() to preserve the original GIF's specs.
             GifUtil.write(outputFileName, inputGif.frames, inputGif))

(node:4428) UnhandledPromiseRejectionWarning: Error: marker was not found
    at decodeScan (gifier\node_modules\jpeg-js\lib\decoder.js:344:15)
    at constructor.parse (gifier\node_modules\jpeg-js\lib\decoder.js:804:29)
    at Object.decode [as image/jpeg] (gifier\node_modules\jpeg-js\lib\decoder.js:1096:11)
    at Jimp.parseBitmap (gifier\node_modules\@jimp\core\dist\utils\image-bitmap.js:196:53)
    at Jimp.parseBitmap (gifier\node_modules\@jimp\core\dist\index.js:431:32)
    at gifier\node_modules\@jimp\core\dist\index.js:373:15
    at FSReqCallback.readFileAfterClose [as oncomplete] (internal/fs/read_file_context.js:63:3)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:4428) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:4428) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

async function getFileBitmap(file){
    return new Promise((resolve)=>{
        Jimp.read(file)
        .then(image => {
            resolve(image.bitmap.data);
        })
    });
}

async function getGifFrames(file){
    return new Promise((resolve)=>{
        GifUtil.read(file).then(inputGif => {
            resolve(inputGif.frames);
        });         
    });
}

async function mergeThumbnail(baseImage, gifImage, outputImage){
    return new Promise( async (resolve, reject)=>{
        const res = sizeOf(baseImage);
        const width = res.width, height = res.height;
        const frames = [];
        let frame = new GifFrame(width, height, { delayCentisecs: 200 });
        frame.bitmap.data = await getFileBitmap(baseImage);
        frames.push(frame);
        let gif_frames = await getGifFrames(gifImage);
        gif_frames.forEach(frame => {
            frames.push(frame);
        });
        GifUtil.write(outputImage, frames);
        resolve();           
    });
}

function uploadFile(outputImage){
    let serverPath = "images/" + makeid(32) + ".gif";
    return new Promise((resolve, reject)=>{
        let uploader = new Upload();
        uploader.setup('clipdrop-prod', './secure/ClipDropAuth.json', 'clipdrop');
        uploader.logging(this.debug_mode);
        uploader.uploadFile(outputImage, serverPath, (uploaded_filename) => {
            resolve(uploaded_filename);
        });
    });
}

async function getFile(url, file){
    return new Promise((resolve, rject)=>{
        https.get(url, function(response) {
            if(debugMode)console.log("STARTED");
            response.pipe(file);
            if(debugMode)console.log("ENDED");
            resolve();
        });
    });
}


app.post('/merge', async (req, res) => {
    //vars: image, and gif are both localfiles, see provided file urls
    await mergeThumbnail(image, gif, outputImage);
    res.send(JSON.stringify({
        'url': uploaded_file
    }));
})

image: https://www.clipdrop.io/wp-content/assets/unsplash/1.jpg
gif: https://storage.googleapis.com/clipdrop/images/MncnmFkx3dF4CbK6q0iiwVD7H5MdQzDp.gif

var width  = 30;
var height = 1;
var images = [];

GifUtil.read(path.join(__dirname + "/../images/default.gif")).then(inputGif => {
	for (var frame = 0; frame<inputGif.frames.length; frame++){
		images[frame] = new Jimp(1, 1 ,0);
		images[frame].bitmap =  new BitmapImage(inputGif.frames[frame]);
		images[frame].resize(width, height); // ERROR INVALID RESIZE SETTINGS
	}
});

var width  = 30;
var height = 1;
var images = [];

GifUtil.read(path.join(__dirname + "/../images/default.gif")).then(inputGif => {
	images = [];
	for (var frame = 0; frame<inputGif.frames.length; frame++){
		images[frame] = new Jimp(inputGif.frames[frame].bitmap.width, inputGif.frames[frame].bitmap.height ,0);
		images[frame].bitmap.data = inputGif.frames[frame].bitmap.data;
		images[frame].resize(width, height); // WORKS
	}
});

(node:3647) UnhandledPromiseRejectionWarning: Error: copy exceeds width of source bitmap
    at BitmapImage.blit (./node_modules/gifwrap/src/bitmapimage.js:91:19)
    at GifFrame.reframe (./node_modules/gifwrap/src/bitmapimage.js:227:15)
    at sourceGif.frames.forEach.frame (./server.js:9:27)
    at Array.forEach (<anonymous>)
    at GifUtil.read.then.sourceGif (./server.js:7:22)
    at <anonymous>
(node:3647) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:3647) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

The following code does 1 thing only, it loads an image, and a gif, then it merges the image to the start of the gif.
the image should be displayed for 2 seconds

Unknown gif block: 0x4

baseImage: https://www.clipdrop.io/wp-content/assets/unsplash/1.jpg
gifImage: https://storage.googleapis.com/clipdrop/images/MncnmFkx3dF4CbK6q0iiwVD7H5MdQzDp.gif

const { GifFrame, GifUtil, GifCodec } = require('gifwrap');
const Jimp = require('jimp');
const sizeOf = require('image-size');


async function getFileBitmap(file){
    return new Promise((resolve)=>{
        Jimp.read(file)
        .then(image => {
            resolve(image.bitmap.data);
        })
    });
}

async function getGifFrames(file){
    return new Promise((resolve)=>{
        GifUtil.read("fancy.gif").then(inputGif => {
            resolve(inputGif.frames);
        });         
    });
}


async function mergeThumbnail(baseImage, gifImage, outputImage){
    return new Promise( async (resolve, reject)=>{
        const res = sizeOf(baseImage);
        const width = res.width, height = res.height;
        const frames = [];
        let frame = new GifFrame(width, height, { delayCentisecs: 200 });
        frame.bitmap.data = await getFileBitmap(baseImage);
        frames.push(frame);
        let gif_frames = await getGifFrames(gifImage);
        gif_frames.forEach(frame => {
            frames.push(frame);
        });
        GifUtil.write(outputImage, frames);
        resolve();           
    });
}

app.post('/merge', async (req, res) => {
    let outputImage = "storage/" + makeid(12) + ".gif";
    if(debugMode)console.log(req.body.baseImage);
    if(debugMode)console.log(req.body.gifImage);

    let url = new URL(req.body.baseImage);
    let filename = path.basename(url.pathname);
    if(debugMode)console.log(filename);
    const file = fs.createWriteStream("storage/" + filename);
    const request = await getFile(req.body.baseImage, file);
    if(debugMode)console.log("File downloaded");

    let url2 = new URL(req.body.gifImage);
    let filename2 = path.basename(url.pathname);
    if(debugMode)console.log(filename2);
    const file2 = fs.createWriteStream("storage/" + filename2);
    const request2 = await getFile(req.body.gifImage, file2);
    if(debugMode)console.log("File downloaded");

    await mergeThumbnail("storage/" + filename, "storage/" + filename2, outputImage);
    if(debugMode)console.log("File converted");

    let uploaded_file = await uploadFile(outputImage);
    if(debugMode)console.log(uploaded_file);

    fs.unlinkSync("storage/" + filename);
    fs.unlinkSync("storage/" + filename2);
    fs.unlinkSync(outputImage);
    res.send(JSON.stringify({
        'url': uploaded_file
    }));
})

GifError: Invalid block size
at new GifReader (/var/www/gifier/node_modules/omggif/omggif.js:489:41)
at GifCodec.decodeGif (/var/www/gifier/node_modules/gifwrap/src/gifcodec.js:55:26)
at /var/www/gifier/node_modules/gifwrap/src/gifutil.js:222:24

GifUtil.read("org.gif").then(inputGif => {
    images = [];
    
	for (var frame = 0; frame<inputGif.frames.length; frame++){
		var j = new Jimp(inputGif.frames[frame].bitmap.width, inputGif.frames[frame].bitmap.height , 0);
        j.bitmap.data = inputGif.frames[frame].bitmap.data;
        j.resize(width, height);
       
        images[frame] = new GifFrame(j.bitmap);
    }

    inputGif.frames = images;
   

    return GifUtil.write("modified.gif", inputGif.frames, inputGif).then(outputGif => {
        console.log("modified");
    });
});

            let sourceGif=await codec.decodeGif(icon.data);
            for (let i in sourceGif.frames) {
                let frameImage = GifUtil.copyAsJimp(Jimp, sourceGif.frames[i]);
                //frameImage=await addMask(frameImage,icon); //function that resizes a frame and adds a mask to the frame 
                sourceGif.frames[i]=new GifFrame(frameImage.bitmap);
            }
            GifUtil.quantizeDekker(sourceGif.frames, 256);

            // The encoder determines GIF size from the frames, not the provided spec (sourceGif).
            outputBuffer=codec.encodeGif(sourceGif.frames, sourceGif);

Type: boolean
Default: false

imageminGiflossy({ unoptimize: true });