support music downloading

Dockerfile

@@ -23,7 +23,7 @@ RUN pnpm install --frozen-lockfile
 
 COPY src ./src
 
-RUN apk add python3
+RUN apk add python3 ffmpeg
 ADD https://github.com/yt-dlp/yt-dlp-nightly-builds/releases/latest/download/yt-dlp /bin/yt-dlp
 RUN chmod +x /bin/yt-dlp
 

src/botutil.ts

@@ -1,4 +1,7 @@
+import type { Thumbnail } from "@resync-tv/yt-dlp"
 import type { Chat, Message } from "grammy/types"
+
+import { InputFile } from "grammy/types"
 import { ADMIN_ID } from "./environment"
 import { bot } from "./setup"
 
@@ -84,3 +87,26 @@ export const link = (text: string, url: string) =>
 export const quote = (text: string) => `<blockquote>${text}</blockquote>`
 export const mention = (text: string, user_id: number) =>
 	`<a href="tg://user?id=${user_id}">${text}</a>`
+
+/**
+ * Gets a fitting thumbnail for the `sendAudio` method.
+ *
+ * https://core.telegram.org/bots/api#sendaudio
+ */
+export const getThumbnail = (thumbnails?: Thumbnail[]) => {
+	if (!thumbnails) return undefined
+
+	const MAX_SIZE = 320
+
+	// Thumbnail sizes go from smallest to largest
+	const reversed = [...thumbnails].reverse()
+
+	const match = reversed.find((thumbnail) => {
+		const { width, height } = thumbnail
+		if (!width || !height) return false
+
+		return width <= MAX_SIZE && height <= MAX_SIZE
+	})
+
+	if (match) return new InputFile({ url: match.url })
+}

src/index.ts

@@ -1,6 +1,6 @@
 import { getInfo, streamFromInfo } from "@resync-tv/yt-dlp"
 import { InputFile } from "grammy"
-import { deleteMessage, errorMessage } from "./botutil"
+import { deleteMessage, errorMessage, getThumbnail } from "./botutil"
 import { deniedMessage, tiktokArgs, tiktokMatcher } from "./constants"
 import { ADMIN_ID, WHITELISTED_IDS } from "./environment"
 import { Queue } from "./queue"
@@ -64,7 +64,7 @@ bot.on("message:text").on("::url", async (ctx, next) => {
 			const [download] = info.requested_downloads ?? []
 			if (!download || !download.url) throw new Error("No download available")
 
-			if (download.vcodec || download.ext === "mp4") {
+			if (download.vcodec !== "none") {
 				let video: InputFile | string
 
 				if (isTiktok) {
@@ -82,8 +82,22 @@ bot.on("message:text").on("::url", async (ctx, next) => {
 						allow_sending_without_reply: true,
 					},
 				})
+			} else if (download.acodec !== "none") {
+				const stream = streamFromInfo(info, ["-x", "--audio-format", "mp3"])
+				const audio = new InputFile(stream.stdout)
+
+				await ctx.replyWithAudio(audio, {
+					caption: removeHashtagsMentions(info.title),
+					performer: info.uploader,
+					title: info.title,
+					thumbnail: getThumbnail(info.thumbnails),
+					reply_parameters: {
+						message_id: ctx.message?.message_id,
+						allow_sending_without_reply: true,
+					},
+				})
 			} else {
-				throw new Error("No video available")
+				throw new Error("No download available")
 			}
 		} catch (error) {
 			return error instanceof Error