api: itunnel transplants (#1065)

api/src/core/api.js

@@ -313,7 +313,7 @@ export const runAPI = async (express, app, __dirname, isPrimary = true) => {
             ...Object.entries(req.headers)
         ]);
 
-        return stream(res, { type: 'internal', ...streamInfo });
+        return stream(res, { type: 'internal', data: streamInfo });
     };
 
     app.get('/itunnel', itunnelHandler);

api/src/misc/utils.js

@@ -37,3 +37,7 @@ export function splitFilenameExtension(filename) {
         return [ parts.join('.'), ext ]
     }
 }
+
+export function zip(a, b) {
+    return a.map((value, i) => [ value, b[i] ]);
+}

api/src/processing/match-action.js

@@ -15,7 +15,8 @@ export default function({ r, host, audioFormat, isAudioOnly, isAudioMuted, disab
             filename: r.filenameAttributes ?
                     createFilename(r.filenameAttributes, filenameStyle, isAudioOnly, isAudioMuted) : r.filename,
             fileMetadata: !disableMetadata ? r.fileMetadata : false,
-            requestIP
+            requestIP,
+            originalRequest: r.originalRequest
         },
         params = {};
 

api/src/processing/services/youtube.js

@@ -149,7 +149,7 @@ export default async function (o) {
         useHLS = false;
     }
 
-    let innertubeClient = "ANDROID";
+    let innertubeClient = o.innertubeClient || "ANDROID";
 
     if (cookie) {
         useHLS = false;
@@ -240,12 +240,12 @@ export default async function (o) {
     const quality = o.quality === "max" ? 9000 : Number(o.quality);
 
     const normalizeQuality = res => {
-        const shortestSide = res.height > res.width ? res.width : res.height;
+        const shortestSide = Math.min(res.height, res.width);
         return videoQualities.find(qual => qual >= shortestSide);
     }
 
     let video, audio, dubbedLanguage,
-        codec = o.format || "h264";
+        codec = o.format || "h264", itag = o.itag;
 
     if (useHLS) {
         const hlsManifest = info.streaming_data.hls_manifest_url;
@@ -351,17 +351,21 @@ export default async function (o) {
             Number(b.bitrate) - Number(a.bitrate)
         ).forEach(format => {
             Object.keys(codecList).forEach(yCodec => {
+                const matchingItag = slot => !itag || itag[slot] === format.itag;
                 const sorted = sorted_formats[yCodec];
                 const goodFormat = checkFormat(format, yCodec);
                 if (!goodFormat) return;
 
-                if (format.has_video) {
+                if (format.has_video && matchingItag('video')) {
                     sorted.video.push(format);
-                    if (!sorted.bestVideo) sorted.bestVideo = format;
+                    if (!sorted.bestVideo)
+                        sorted.bestVideo = format;
                 }
-                if (format.has_audio) {
+
+                if (format.has_audio && matchingItag('audio')) {
                     sorted.audio.push(format);
-                    if (!sorted.bestAudio) sorted.bestAudio = format;
+                    if (!sorted.bestAudio)
+                        sorted.bestAudio = format;
                 }
             })
         });
@@ -448,6 +452,18 @@ export default async function (o) {
         youtubeDubName: dubbedLanguage || false,
     }
 
+    itag = {
+        video: video.itag,
+        audio: audio.itag
+    };
+
+    const originalRequest = {
+        ...o,
+        dispatcher: undefined,
+        itag,
+        innertubeClient
+    };
+
     if (audio && o.isAudioOnly) {
         let bestAudio = codec === "h264" ? "m4a" : "opus";
         let urls = audio.url;
@@ -469,6 +485,7 @@ export default async function (o) {
             fileMetadata,
             bestAudio,
             isHLS: useHLS,
+            originalRequest
         }
     }
 
@@ -491,12 +508,12 @@ export default async function (o) {
             filenameAttributes.resolution = `${video.width}x${video.height}`;
             filenameAttributes.extension = codecList[codec].container;
 
-            video = video.url;
-            audio = audio.url;
-
             if (innertubeClient === "WEB" && innertube) {
                 video = video.decipher(innertube.session.player);
                 audio = audio.decipher(innertube.session.player);
+            } else {
+                video = video.url;
+                audio = audio.url;
             }
         }
 
@@ -512,6 +529,7 @@ export default async function (o) {
             filenameAttributes,
             fileMetadata,
             isHLS: useHLS,
+            originalRequest
         }
     }
 

api/src/stream/internal.js

@@ -7,7 +7,7 @@ const CHUNK_SIZE = BigInt(8e6); // 8 MB
 const min = (a, b) => a < b ? a : b;
 
 async function* readChunks(streamInfo, size) {
-    let read = 0n;
+    let read = 0n, chunksSinceTransplant = 0;
     while (read < size) {
         if (streamInfo.controller.signal.aborted) {
             throw new Error("controller aborted");
@@ -22,6 +22,16 @@ async function* readChunks(streamInfo, size) {
             signal: streamInfo.controller.signal
         });
 
+        if (chunk.statusCode === 403 && chunksSinceTransplant >= 3 && streamInfo.transplant) {
+            chunksSinceTransplant = 0;
+            try {
+                await streamInfo.transplant(streamInfo.dispatcher);
+                continue;
+            } catch {}
+        }
+
+        chunksSinceTransplant++;
+
         const expected = min(CHUNK_SIZE, size - read);
         const received = BigInt(chunk.headers['content-length']);
 

api/src/stream/manage.js

@@ -9,6 +9,7 @@ import { env } from "../config.js";
 import { closeRequest } from "./shared.js";
 import { decryptStream, encryptStream } from "../misc/crypto.js";
 import { hashHmac } from "../security/secrets.js";
+import { zip } from "../misc/utils.js";
 
 // optional dependency
 const freebind = env.freebindCIDR && await import('freebind').catch(() => {});
@@ -40,6 +41,7 @@ export function createStream(obj) {
             audioFormat: obj.audioFormat,
 
             isHLS: obj.isHLS || false,
+            originalRequest: obj.originalRequest
         };
 
     // FIXME: this is now a Promise, but it is not awaited
@@ -100,6 +102,7 @@ export function createInternalStream(url, obj = {}) {
         controller,
         dispatcher,
         isHLS: obj.isHLS,
+        transplant: obj.transplant
     });
 
     let streamLink = new URL('/itunnel', `http://127.0.0.1:${env.tunnelPort}`);
@@ -115,13 +118,17 @@ export function createInternalStream(url, obj = {}) {
     return streamLink.toString();
 }
 
-export function destroyInternalStream(url) {
+function getInternalTunnelId(url) {
     url = new URL(url);
     if (url.hostname !== '127.0.0.1') {
         return;
     }
 
-    const id = url.searchParams.get('id');
+    return url.searchParams.get('id');
+}
+
+export function destroyInternalStream(url) {
+    const id = getInternalTunnelId(url);
 
     if (internalStreamCache.has(id)) {
         closeRequest(getInternalStream(id)?.controller);
@@ -129,9 +136,68 @@ export function destroyInternalStream(url) {
     }
 }
 
+const transplantInternalTunnels = function(tunnelUrls, transplantUrls) {
+    if (tunnelUrls.length !== transplantUrls.length) {
+        return;
+    }
+
+    for (const [ tun, url ] of zip(tunnelUrls, transplantUrls)) {
+        const id = getInternalTunnelId(tun);
+        const itunnel = getInternalStream(id);
+
+        if (!itunnel) continue;
+        itunnel.url = url;
+    }
+}
+
+const transplantTunnel = async function (dispatcher) {
+    if (this.pendingTransplant) {
+        await this.pendingTransplant;
+        return;
+    }
+
+    let finished;
+    this.pendingTransplant = new Promise(r => finished = r);
+
+    try {
+        const handler = await import(`../processing/services/${this.service}.js`);
+        const response = await handler.default({
+            ...this.originalRequest,
+            dispatcher
+        });
+
+        if (!response.urls) {
+            return;
+        }
+
+        response.urls = [response.urls].flat();
+        if (this.originalRequest.isAudioOnly && response.urls.length > 1) {
+            response.urls = [response.urls[1]];
+        } else if (this.originalRequest.isAudioMuted) {
+            response.urls = [response.urls[0]];
+        }
+
+        const tunnels = [this.urls].flat();
+        if (tunnels.length !== response.urls.length) {
+            return;
+        }
+
+        transplantInternalTunnels(tunnels, response.urls);
+    }
+    catch {}
+    finally {
+        finished();
+        delete this.pendingTransplant;
+    }
+}
+
 function wrapStream(streamInfo) {
     const url = streamInfo.urls;
 
+    if (streamInfo.originalRequest) {
+        streamInfo.transplant = transplantTunnel.bind(streamInfo);
+    }
+
     if (typeof url === 'string') {
         streamInfo.urls = createInternalStream(url, streamInfo);
     } else if (Array.isArray(url)) {

api/src/stream/stream.js

@@ -10,7 +10,7 @@ export default async function(res, streamInfo) {
                 return await stream.proxy(streamInfo, res);
 
             case "internal":
-                return internalStream(streamInfo, res);
+                return internalStream(streamInfo.data, res);
 
             case "merge":
                 return stream.merge(streamInfo, res);