api: add audio bitrate functionality

api/src/config.js

@@ -1,12 +1,5 @@
 const genericUserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36";
 const supportedAudio = ["mp3", "ogg", "wav", "opus"];
-const ffmpegArgs = {
-    webm: ["-c:v", "copy", "-c:a", "copy"],
-    mp4: ["-c:v", "copy", "-c:a", "copy", "-movflags", "faststart+frag_keyframe+empty_moov"],
-    audio: ["-ar", "48000", "-ac", "2", "-b:a", "320k"],
-    m4a: ["-movflags", "frag_keyframe+empty_moov"],
-    gif: ["-vf", "scale=-1:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse", "-loop", "0"]
-}
 
 const env = {
     apiURL: process.env.API_URL || '',
@@ -42,5 +35,4 @@ export {
 
     genericUserAgent,
     supportedAudio,
-    ffmpegArgs,
 }

api/src/processing/match-action.js

@@ -5,7 +5,7 @@ import { createResponse } from "./request.js";
 import { createStream } from "../stream/manage.js";
 import { audioIgnore, services } from "./service-config.js";
 
-export default function({ r, host, audioFormat, isAudioOnly, isAudioMuted, disableMetadata, filenameStyle, twitterGif, requestIP }) {
+export default function({ r, host, audioFormat, isAudioOnly, isAudioMuted, disableMetadata, filenameStyle, twitterGif, requestIP, audioBitrate }) {
     let action,
         responseType = "stream",
         defaultParams = {
@@ -193,8 +193,10 @@ export default function({ r, host, audioFormat, isAudioOnly, isAudioMuted, disab
             params = {
                 type: processType,
                 u: Array.isArray(r.urls) ? r.urls[1] : r.urls,
-                audioFormat: audioFormat,
-                copy: copy
+
+                audioBitrate,
+                audioCopy: copy,
+                audioFormat,
             }
             break;
     }

api/src/processing/match.js

@@ -261,7 +261,8 @@ export default async function(host, patternMatch, obj) {
             disableMetadata,
             filenameStyle: obj.filenameStyle,
             twitterGif: obj.twitterGif,
-            requestIP
+            requestIP,
+            audioBitrate: obj.audioBitrate,
         })
     } catch {
         return createResponse("error", {

api/src/processing/schema.js

@@ -8,6 +8,10 @@ export const apiSchema = z.object({
           .min(1)
           .transform((url) => normalizeURL(decodeURIComponent(url))),
 
+    audioBitrate: z.enum(
+        ["320", "256", "128", "96", "64"]
+    ).default("256"),
+
     audioFormat: z.enum(
         ["best", "mp3", "ogg", "wav", "opus"]
     ).default("mp3"),

api/src/stream/manage.js

@@ -37,11 +37,15 @@ export function createStream(obj) {
             urls: obj.u,
             service: obj.service,
             filename: obj.filename,
-            audioFormat: obj.audioFormat,
+
+            requestIP: obj.requestIP,
             headers: obj.headers,
-            copy: !!obj.copy,
+
             metadata: obj.fileMetadata || false,
-            requestIP: obj.requestIP
+
+            audioBitrate: obj.audioBitrate,
+            audioCopy: !!obj.audioCopy,
+            audioFormat: obj.audioFormat,
         };
 
     streamCache.set(

api/src/stream/types.js

@@ -3,12 +3,19 @@ import ffmpeg from "ffmpeg-static";
 import { spawn } from "child_process";
 import { create as contentDisposition } from "content-disposition-header";
 
-import { env, ffmpegArgs } from "../config.js";
+import { env } from "../config.js";
 import { metadataManager } from "../misc/utils.js";
 import { destroyInternalStream } from "./manage.js";
 import { hlsExceptions } from "../processing/service-config.js";
 import { getHeaders, closeRequest, closeResponse, pipe } from "./shared.js";
 
+const ffmpegArgs = {
+    webm: ["-c:v", "copy", "-c:a", "copy"],
+    mp4: ["-c:v", "copy", "-c:a", "copy", "-movflags", "faststart+frag_keyframe+empty_moov"],
+    m4a: ["-movflags", "frag_keyframe+empty_moov"],
+    gif: ["-vf", "scale=-1:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse", "-loop", "0"]
+}
+
 const toRawHeaders = (headers) => {
     return Object.entries(headers)
                  .map(([key, value]) => `${key}: ${value}\r\n`)
@@ -209,18 +216,24 @@ const convertAudio = (streamInfo, res) => {
             '-vn'
         )
 
-        if (streamInfo.metadata) {
-            args = args.concat(metadataManager(streamInfo.metadata))
+        if (streamInfo.audioCopy) {
+            args.push("-c:a", "copy")
+        } else {
+            args.push("-b:a", `${streamInfo.audioBitrate}k`)
         }
 
-        args = args.concat(
-            streamInfo.copy ? ["-c:a", "copy"] : ffmpegArgs.audio
-        );
+        if (streamInfo.audioFormat === "opus") {
+            args.push("-vbr", "off")
+        }
 
         if (ffmpegArgs[streamInfo.audioFormat]) {
             args = args.concat(ffmpegArgs[streamInfo.audioFormat])
         }
 
+        if (streamInfo.metadata) {
+            args = args.concat(metadataManager(streamInfo.metadata))
+        }
+
         args.push('-f', streamInfo.audioFormat === "m4a" ? "ipod" : streamInfo.audioFormat, 'pipe:3');
 
         process = spawn(...getCommand(args), {
@@ -257,7 +270,7 @@ const convertGif = (streamInfo, res) => {
         }
 
         args.push('-i', streamInfo.urls);
-        args = args.concat(ffmpegArgs["gif"]);
+        args = args.concat(ffmpegArgs.gif);
         args.push('-f', "gif", 'pipe:3');
 
         process = spawn(...getCommand(args), {