I am trying to setup canvas animation convertion to video with FFMPEG.wasm. The idea is to generate a bunch of images with canvas.toDataURL() then send them to a Node server to generate a video. Everything works perfectly with preuploaded images I am pulling from the public directory for testing, however when I try to send a bunch (or a single) of images created with canvas.toDataURL() I get the following error:

RuntimeError: abort(Error: ENAMETOOLONG: name too long, open 'data:image/png;base64, ...

I tried to replace canvas.toDataURL() with canvas.getContext('2d').getImageData(), however this didn't help either. Below is a cut code I am using:

front:

async function fetchData() {
  const response = await fetch('/api/record-canvas', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ image: here_goes_the_canvas_data }),
  });
}

backend:

await ffmpeg.load();
ffmpeg.FS('writeFile', `001.png`, await fetchFile(image));
await ffmpeg.run('-loop', '1', '-i', '001.png', '-c:v', 'libx264', '-t', '30', '-pix_fmt', 'yuv420p', 'out.mp4');
await fs.promises.writeFile('out.mp4', ffmpeg.FS('readFile', 'out.mp4'));

The code above is simplified to make a video of a single image looping it for 30 seconds. Again, works great with preuploaded image, however not with the canvas data.