video-compressor/public/assets/scripts/main.js

109 lines
3.1 KiB
JavaScript

const ffmpeg = new FFmpegWASM.FFmpeg();
async function compress() {
document.getElementById("uploaded-video").pause();
showSection("loading");
const filesize = document.getElementById("filesize").value;
const filesizeUnit = document.getElementById("filesize-unit").value;
const file = document.getElementById("file-input").files[0];
const videoLength = document.getElementById("uploaded-video").duration;
let targetFilesize; // Stored in kBit
switch (filesizeUnit) {
case "K": targetFilesize = filesize * 8; break;
case "M": targetFilesize = filesize * 8000; break;
}
updateProgress(0);
ffmpeg.on("log", event => {
console.log("[ffmpeg]", event.type, event.message);
});
let pass;
ffmpeg.on("progress", event => {
updateProgress(event.progress, pass);
});
await ffmpeg.load({ coreURL: "/assets/scripts/core/package/dist/umd/ffmpeg-core.js" });
await ffmpeg.writeFile(file.name, await readFromBlob(file));
// Use Two-Pass to create a video file with desired file size
// https://trac.ffmpeg.org/wiki/Encode/H.264#twopass
const bitrate = Math.floor(targetFilesize / videoLength) - 128; // Subtract audio bitrate
console.debug("Target bitrate:", bitrate, "Video length:", videoLength);
const options = ["-i", file.name, "-preset", "ultrafast", "-c:v", "libx264", "-b:v", bitrate + "k"];
pass = 1;
await ffmpeg.exec([...options, "-pass", "1", "-vsync", "cfr", "-f", "null", "/dev/null"]);
pass = 2;
await ffmpeg.exec([...options, "-pass", "2", "-c:a", "copy", "-b:a", "128k", "compressed.mp4"]);
const video = await ffmpeg.readFile("compressed.mp4");
location.href = URL.createObjectURL(new Blob([video.buffer], { type: "video/mp4" }));
}
function cancel() {
ffmpeg.terminate();
showSection("file-picker");
}
function updateProgress(progress, pass) {
const percent = (progress * 100).toFixed(1) + "%";
document.getElementById("progress-step-value").innerText = pass;
document.getElementById("progress-percentage").innerText = percent;
document.getElementById("progress-indicator").style.clipPath = `rect(0 ${percent} 100% 0)`;
}
function openFileSelector() {
document.getElementById("file-input").click();
}
function selectFile() {
setTimeout(() => {
const file = document.getElementById("file-input").files[0];
document.getElementById("uploaded-video").src = URL.createObjectURL(file);
document.getElementById("uploaded-video").load();
hideElements("#file-drop-area", "#file-input-spacing");
showElements("#uploaded-video", "#change-file");
}, 200);
}
// https://github.com/ffmpegwasm/ffmpeg.wasm/blob/main/packages/util/src/index.ts
function readFromBlob(blob) {
return new Promise((resolve, reject) => {
const fileReader = new FileReader();
fileReader.onload = () => {
const { result } = fileReader;
if (result instanceof ArrayBuffer) {
resolve(new Uint8Array(result));
} else {
resolve(new Uint8Array());
}
};
fileReader.onerror = (event) => {
reject(
Error(
`File could not be read! Code=${event?.target?.error?.code || -1}`
)
);
};
fileReader.readAsArrayBuffer(blob);
});
}