feat: conversion sample rate

messages/en.json

@@ -98,7 +98,8 @@
 			"quality_description": "This changes the default output quality of the converted files (in its category). Higher values may result in longer conversion times and file size.",
 			"quality_video": "This changes the default output quality of the converted video files. Higher values may result in longer conversion times and file size.",
 			"quality_audio": "Audio (kbps)",
-			"quality_images": "Image (%)"
+			"quality_images": "Image (%)",
+			"rate": "Sample rate (Hz)"
 		},
 		"vertd": {
 			"title": "Video conversion",

src/lib/components/functional/FancyInput.svelte

@@ -34,7 +34,8 @@
 		{disabled}
 		class="w-full p-3 rounded-lg bg-panel border-2 border-button
             {prefix ? 'pl-[2rem]' : 'pl-3'} 
-            {extension ? 'pr-[4rem]' : 'pr-3'}"
+            {extension ? 'pr-[4rem]' : 'pr-3'}
+			{disabled && 'opacity-50 cursor-not-allowed'}"
 	/>
 	{#if prefix}
 		<div class="absolute left-0 top-0 bottom-0 flex items-center px-2">

src/lib/converters/ffmpeg.svelte.ts

@@ -174,7 +174,7 @@ export class FFmpegConverter extends Converter {
 			const bitrateListener = (event: { message: string }) => {
 				if (bitrate !== null) return;
 				const n = parseInt(event.message.trim(), 10);
-				if (!n) return null;
+				if (!n) return;
 				bitrate = Math.round(n / 1000);
 				log(
 					["converters", this.name],
@@ -195,6 +195,48 @@ export class FFmpegConverter extends Converter {
 		}
 	}
 
+	private async detectAudioSampleRate(
+		ffmpeg: FFmpeg,
+	): Promise<number | null> {
+		const args = [
+			"-v",
+			"quiet",
+			"-select_streams",
+			"a:0",
+			"-show_entries",
+			"stream=sample_rate",
+			"-of",
+			"default=noprint_wrappers=1:nokey=1",
+			"input",
+		];
+
+		try {
+			let sampleRate: number | null = null;
+
+			const sampleRateListener = (event: { message: string }) => {
+				if (sampleRate !== null) return;
+				const n = parseInt(event.message.trim(), 10);
+				if (!n) return;
+				sampleRate = n;
+				log(
+					["converters", this.name],
+					`Detected stream audio sample rate: ${sampleRate} Hz`,
+				);
+			};
+
+			ffmpeg.on("log", sampleRateListener);
+
+			try {
+				await ffmpeg.ffprobe.call(ffmpeg, args);
+				return sampleRate;
+			} finally {
+				ffmpeg.off("log", sampleRateListener);
+			}
+		} catch {
+			return null;
+		}
+	}
+
 	private async buildConversionCommand(
 		ffmpeg: FFmpeg,
 		input: VertFile,
@@ -203,23 +245,74 @@ export class FFmpegConverter extends Converter {
 		const inputFormat = input.from.slice(1);
 		const outputFormat = to.slice(1);
 
-		const lossless = ["flac", "alac", "wav"];
+		const lossless = ["flac", "alac", "wav", "dsd", "dsf", "dff"];
 		const userSetting = Settings.instance.settings.ffmpegQuality;
-		log(["converters", this.name], `using user setting for audio bitrate: ${userSetting}`);
+		const userSampleRate = Settings.instance.settings.ffmpegSampleRate;
+		const customSampleRate =
+			Settings.instance.settings.ffmpegCustomSampleRate;
 		let audioBitrateArgs: string[] = [];
+		let sampleRateArgs: string[] = [];
 
+		const isLosslessToLossy =
+			lossless.includes(inputFormat) && !lossless.includes(outputFormat);
 		if (userSetting !== "auto") {
 			// user's setting
 			audioBitrateArgs = ["-b:a", `${userSetting}k`];
+			log(
+				["converters", this.name],
+				`using user setting for audio bitrate: ${userSetting}`,
+			);
 		} else {
 			// detect bitrate of original file and use
-			if (lossless.includes(inputFormat) && !lossless.includes(outputFormat)) {
+			if (isLosslessToLossy) {
-				audioBitrateArgs = ["-b:a", "320k"];
+				// use safe default
-				log(["converters", this.name], `using default audio bitrate: 320k`);
+				audioBitrateArgs = ["-b:a", "128k"];
+				log(
+					["converters", this.name],
+					`converting from lossless to lossy, using default audio bitrate: 128k`,
+				);
 			} else {
 				const inputBitrate = await this.detectAudioBitrate(ffmpeg);
-				audioBitrateArgs = inputBitrate ? ["-b:a", `${inputBitrate}k`] : [];
+				audioBitrateArgs = inputBitrate
-				log(["converters", this.name], `using detected audio bitrate: ${inputBitrate}k`);
+					? ["-b:a", `${inputBitrate}k`]
+					: [];
+				log(
+					["converters", this.name],
+					`using detected audio bitrate: ${inputBitrate}k`,
+				);
+			}
+		}
+
+		// sample rate setting
+		if (userSampleRate !== "auto") {
+			if (userSampleRate === "custom") {
+				sampleRateArgs = ["-ar", customSampleRate.toString()];
+			} else {
+				sampleRateArgs = ["-ar", userSampleRate];
+			}
+			log(
+				["converters", this.name],
+				`using user setting for sample rate: ${userSampleRate}`,
+			);
+		} else {
+			// detect sample rate of original file and use
+			if (isLosslessToLossy) {
+				// use safe default
+				sampleRateArgs = ["-ar", "44100"];
+				log(
+					["converters", this.name],
+					`converting from lossless to lossy, using default sample rate: 44100Hz`,
+				);
+			} else {
+				const inputSampleRate =
+					await this.detectAudioSampleRate(ffmpeg);
+				sampleRateArgs = inputSampleRate
+					? ["-ar", inputSampleRate.toString()]
+					: [];
+				log(
+					["converters", this.name],
+					`using detected audio sample rate: ${inputSampleRate}Hz`,
+				);
 			}
 		}
 
@@ -235,6 +328,7 @@ export class FFmpegConverter extends Converter {
 				"-map",
 				"0:a:0",
 				...audioBitrateArgs,
+				...sampleRateArgs,
 				"output" + to,
 			];
 		}
@@ -270,6 +364,7 @@ export class FFmpegConverter extends Converter {
 					"1",
 					...codecArgs,
 					...audioBitrateArgs,
+					...sampleRateArgs,
 					"output" + to,
 				];
 			} else {
@@ -288,6 +383,7 @@ export class FFmpegConverter extends Converter {
 					"1",
 					...codecArgs,
 					...audioBitrateArgs,
+					...sampleRateArgs,
 					"output" + to,
 				];
 			}
@@ -305,6 +401,7 @@ export class FFmpegConverter extends Converter {
 			"-c:a",
 			audioCodec,
 			...audioBitrateArgs,
+			...sampleRateArgs,
 			"output" + to,
 		];
 	}
@@ -486,3 +583,16 @@ export const CONVERSION_BITRATES = [
 	32,
 ] as const;
 export type ConversionBitrate = (typeof CONVERSION_BITRATES)[number];
+
+export const SAMPLE_RATES = [
+	"auto",
+	"custom",
+	"48000",
+	"44100",
+	"32000",
+	"22050",
+	"16000",
+	"11025",
+	"8000",
+] as const;
+export type SampleRate = (typeof SAMPLE_RATES)[number];

src/lib/sections/settings/Conversion.svelte

@@ -6,6 +6,8 @@
 	import {
 		CONVERSION_BITRATES,
 		type ConversionBitrate,
+		SAMPLE_RATES,
+		type SampleRate,
 	} from "$lib/converters/ffmpeg.svelte";
 	import { m } from "$lib/paraglide/messages";
 	import Dropdown from "$lib/components/functional/Dropdown.svelte";
@@ -81,6 +83,34 @@
 						/>
 					</div>
 				</div>
+				<div class="grid grid-cols-2 gap-3">
+					<div class="flex flex-col gap-2">
+						<p class="text-sm font-bold">
+							{m["settings.conversion.rate"]()}
+						</p>
+						<Dropdown
+							options={SAMPLE_RATES.map((r) => r.toString())}
+							selected={settings.ffmpegSampleRate.toString()}
+							onselect={(option: string) => {
+								settings.ffmpegSampleRate =
+									option as SampleRate;
+							}}
+							settingsStyle
+						/>
+					</div>
+					<div class="flex flex-col gap-2">
+						<p class="text-sm font-bold select-none">&nbsp;&nbsp;</p>
+						<FancyInput
+							bind:value={
+								settings.ffmpegCustomSampleRate as unknown as string
+							}
+							type="number"
+							min={1}
+							extension={"Hz"}
+							disabled={settings.ffmpegSampleRate !== "custom"}
+						/>
+					</div>
+				</div>
 			</div>
 		</div>
 	</div></Panel

src/lib/sections/settings/index.svelte.ts

@@ -14,6 +14,8 @@ export interface ISettings {
 	vertdSpeed: ConversionSpeed; // videos
 	magickQuality: number; // images
 	ffmpegQuality: ConversionBitrate; // audio (or audio <-> video)
+	ffmpegSampleRate: string; // audio (or audio <-> video)
+	ffmpegCustomSampleRate: number; // audio (or audio <-> video) - only used when ffmpegSampleRate is "custom"
 }
 
 export class Settings {
@@ -26,6 +28,8 @@ export class Settings {
 		vertdSpeed: "slow",
 		magickQuality: 100,
 		ffmpegQuality: "auto",
+		ffmpegSampleRate: "auto",
+		ffmpegCustomSampleRate: 44100,
 	});
 
 	public save() {