规范音频电平

理想情况下，你应该在录音界面使用音频响度计，以确保音频水平在各次录音中保持一致。

🌐 Ideally, you use the audio loudness meter in the Recording interface to ensure that the audio levels are consistent across recordings.

如果你需要在事后均衡音频音量，可以使用以下脚本：

🌐 If you need to do equalize the audio levels after the fact, you can use the following script:

note

这是一个破坏性操作——你的录音将被覆盖。
在运行此操作之前，请先提交你的更改。

normalize.ts
import { $ } from "bun";
import { renameSync } from "fs";
import { WEBCAM_PREFIX } from "./config/cameras";

type FfmpegVolumeOutput = {
  input_i: string;
  input_tp: string;
  input_lra: string;
  input_thresh: string;
  output_i: string;
  output_tp: string;
  output_lra: string;
  output_thresh: string;
  normalization_type: string;
  target_offset: string;
};

// Set your composition ID here
const id = "euro";

const files = await $`ls public/${id}`.quiet();
const webcamFiles = files.stdout
  .toString("utf8")
  .split("\n")
  .filter((f) => f.startsWith(WEBCAM_PREFIX));

const decibelValues: number[] = [];

for (const file of webcamFiles) {
  const path = `public/${id}/${file}`;
  const cmd =
    await $`ffmpeg -hide_banner -i ${path} -af loudnorm=I=-23:LRA=7:print_format=json -f null -`.quiet();
  const output = cmd.stderr.toString("utf8");
  const lines = output.split("\n");
  const indexOfLineBeforeStart = lines.findIndex((line) =>
    line.includes("[Parsed_loudnorm_0 @"),
  );
  const remaining = lines.slice(indexOfLineBeforeStart + 1);
  const indexOfOut = remaining.findIndex((i) => i.startsWith("[out#0"));
  const actual = indexOfOut === -1 ? remaining : remaining.slice(0, indexOfOut);
  const json = JSON.parse(actual.join("\n")) as FfmpegVolumeOutput;
  console.log(path, `${json.input_i}dB`);
  decibelValues.push(parseFloat(json.input_i));
}

const average = decibelValues.reduce((a, b) => a + b, 0) / decibelValues.length;
console.log("Average", `${average}dB`);
const toApply = Math.max(average, -20);
console.log("Applying", `${toApply}dB`);

for (const file of webcamFiles) {
  const path = `public/${id}/${file}`;
  const copiedPath = `public/${id}/normalized-${file}`;
  await $`ffmpeg -hide_banner -i ${path} -af loudnorm=I=${toApply}:LRA=7:TP=-2.0 -c:v copy ${copiedPath} -y`;
  renameSync(copiedPath, path);
}

这将计算所有录音的平均响度，并编辑每个文件，使其响度与平均值相同。

🌐 This will calculate the average loudness of all recordings and edit each file so it has the same loudness as the average.

使用以下方式执行：

🌐 Execute it using:

bun normalize.ts