Reimar/video-compressor
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Calculate bitrate more accurately

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Reimar 2026-01-05 11:07:14 +01:00
parent 574478db84
commit b7dd6e752b
Signed by: Reimar
GPG Key ID: 93549FA07F0AE268
1 changed files with 7 additions and 7 deletions
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14
public/assets/scripts/main.js
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@ -11,8 +11,8 @@ async function compress() {
const videoLength = document.getElementById("uploaded-video").duration;
let targetFilesize; // Stored in kBit
switch (filesizeUnit) {
case "K": targetFilesize = filesize * 8.192; break;
case "M": targetFilesize = filesize * 8388.608; break;
case "K": targetFilesize = filesize * 8; break;
case "M": targetFilesize = filesize * 8000; break;
}
updateProgress(0);
@ -34,19 +34,19 @@ async function compress() {
// Use Two-Pass to create a video file with desired file size
// https://trac.ffmpeg.org/wiki/Encode/H.264#twopass
const bitrate = Math.round(targetFilesize / videoLength) - 128; // Subtract audio bitrate
const bitrate = Math.floor(targetFilesize / videoLength) - 128; // Subtract audio bitrate
console.debug("Target bitrate:", bitrate);
console.debug("Target bitrate:", bitrate, "Video length:", videoLength);
const options = ["-i", file.name, "-preset", "veryfast", "-c:v", "libx264", "-b:v", bitrate + "k"];
const options = ["-i", file.name, "-preset", "ultrafast", "-c:v", "libx264", "-b:v", bitrate + "k"];
pass = 1;
await ffmpeg.exec(["-y", ...options, "-pass", "1", "-vsync", "cfr", "-f", "null", "/dev/null"]);
await ffmpeg.exec([...options, "-pass", "1", "-vsync", "cfr", "-f", "null", "/dev/null"]);
pass = 2;
await ffmpeg.exec([...options, "-pass", "2", "-c:a", "aac", "-b:a", "128k", "compressed.mp4"]);
await ffmpeg.exec([...options, "-pass", "2", "-c:a", "copy", "-b:a", "128k", "compressed.mp4"]);
const video = await ffmpeg.readFile("compressed.mp4");