From 901fc8d760cbcc237fbc21283614e271f22ec192 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafa=C5=82=20Dzi=C4=99giel?= <rafostar.github@gmail.com>
Date: Mon, 12 Apr 2021 17:41:42 +0200
Subject: [PATCH] YT: try harder to find suitable DASH streams

Instead of searching for 1080p only, accept also other H.264 formats for DASH streaming
---
 src/dash.js    |  31 +++------------
 src/youtube.js | 102 ++++++++++++++++++++++++++++++++++++++++---------
 2 files changed, 90 insertions(+), 43 deletions(-)

diff --git a/src/dash.js b/src/dash.js
index 01a34809..cb57b1d6 100644
--- a/src/dash.js
+++ b/src/dash.js
@@ -37,7 +37,9 @@ function generateDash(dashInfo)
 
 function _addAdaptationSet(streamsArr)
 {
-    const mimeInfo = _getMimeInfo(streamsArr[0].mimeType);
+    /* We just need it for adaptation type,
+     * so any stream will do */
+    const { mimeInfo } = streamsArr[0];
 
     const adaptArr = [
         `contentType="${mimeInfo.content}"`,
@@ -93,11 +95,9 @@ function _addAdaptationSet(streamsArr)
 
 function _getStreamRepresentation(stream)
 {
-    const mimeInfo = _getMimeInfo(stream.mimeType);
-
     const repOptsArr = [
         `id="${stream.itag}"`,
-        `codecs="${mimeInfo.codecs}"`,
+        `codecs="${stream.mimeInfo.codecs}"`,
         `bandwidth="${stream.bitrate}"`,
     ];
 
@@ -120,13 +120,8 @@ function _getStreamRepresentation(stream)
         repArr.push(`      <AudioChannelConfiguration ${audioConfArr.join(' ')}/>`);
     }
 
-    const encodedURL = Misc.encodeHTML(stream.url)
-        .replace('?', '/')
-        .replace(/&amp;/g, '/')
-        .replace(/=/g, '/');
-
     repArr.push(
-        `        <BaseURL>${encodedURL}</BaseURL>`
+        `        <BaseURL>${stream.url}</BaseURL>`
     );
 
     if(stream.indexRange) {
@@ -152,22 +147,6 @@ function _getStreamRepresentation(stream)
     return repArr.join('\n');
 }
 
-function _getMimeInfo(mimeType)
-{
-    const mimeArr = mimeType.split(';');
-
-    let codecs = mimeArr.find(info => info.includes('codecs')).split('=')[1];
-    codecs = codecs.substring(1, codecs.length - 1);
-
-    const mimeInfo = {
-        content: mimeArr[0].split('/')[0],
-        type: mimeArr[0],
-        codecs,
-    };
-
-    return mimeInfo;
-}
-
 function _getPar(width, height)
 {
     const gcd = _getGCD(width, height);
diff --git a/src/youtube.js b/src/youtube.js
index afc34a5d..c84b2010 100644
--- a/src/youtube.js
+++ b/src/youtube.js
@@ -357,27 +357,75 @@ var YouTubeClient = GObject.registerClass({
         )
             return null;
 
-        /* TODO: Options in prefs to set preferred video formats for adaptive streaming */
-        const videoStream = info.streamingData.adaptiveFormats.find(stream => {
-            return (stream.mimeType.startsWith('video/mp4') && stream.quality === 'hd1080');
-        });
-        const audioStream = info.streamingData.adaptiveFormats.find(stream => {
-            return (stream.mimeType.startsWith('audio/mp4'));
-        });
+        /* TODO: Options in prefs to set preferred video formats and adaptive streaming */
+        const isAdaptiveEnabled = false;
+        const allowedFormats = {
+            video: [
+                133,
+                134,
+                135,
+                136,
+                137,
+                298,
+                299,
+            ],
+            audio: [
+                140,
+            ]
+        };
 
-        if(!videoStream || !audioStream)
-            return null;
+        const filteredStreams = {
+            video: [],
+            audio: [],
+        };
+
+        for(let fmt of ['video', 'audio']) {
+            debug(`filtering ${fmt} streams`);
+            let index = allowedFormats[fmt].length;
+
+            while(index--) {
+                const itag = allowedFormats[fmt][index];
+                const foundStream = info.streamingData.adaptiveFormats.find(stream => (stream.itag == itag));
+                if(foundStream) {
+                    /* Parse and convert mimeType string into object */
+                    foundStream.mimeInfo = this._getMimeInfo(foundStream.mimeType);
+
+                    /* Sanity check */
+                    if(!foundStream.mimeInfo || foundStream.mimeInfo.content !== fmt) {
+                        debug(new Error(`mimeType parsing failed on stream: ${itag}`));
+                        continue;
+                    }
+
+                    /* Sort from worst to best */
+                    filteredStreams[fmt].unshift(foundStream);
+                    debug(`added ${fmt} itag: ${foundStream.itag}`);
+
+                    if(!isAdaptiveEnabled)
+                        break;
+                }
+            }
+            if(!filteredStreams[fmt].length) {
+                debug(`dash info ${fmt} streams list is empty`);
+                return null;
+            }
+        }
 
         debug('following redirects');
 
-        for(let stream of [videoStream, audioStream]) {
-            debug(`initial URL: ${stream.url}`);
+        for(let fmtArr of Object.values(filteredStreams)) {
+            for(let stream of fmtArr) {
+                debug(`initial URL: ${stream.url}`);
 
-            const result = await this._downloadDataPromise(stream.url, 'HEAD').catch(debug);
-            if(!result) return null;
+                const result = await this._downloadDataPromise(stream.url, 'HEAD').catch(debug);
+                if(!result) return null;
 
-            stream.url = result.uri;
-            debug(`resolved URL: ${stream.url}`);
+                stream.url = Misc.encodeHTML(result.uri)
+                    .replace('?', '/')
+                    .replace(/&amp;/g, '/')
+                    .replace(/=/g, '/');
+
+                debug(`resolved URL: ${stream.url}`);
+            }
         }
 
         debug('all redirects resolved');
@@ -385,8 +433,8 @@ var YouTubeClient = GObject.registerClass({
         return {
             duration: info.videoDetails.lengthSeconds,
             adaptations: [
-                [videoStream],
-                [audioStream],
+                filteredStreams.video,
+                filteredStreams.audio,
             ]
         };
     }
@@ -527,6 +575,26 @@ var YouTubeClient = GObject.registerClass({
         return reduced;
     }
 
+    _getMimeInfo(mimeType)
+    {
+        debug(`parsing mimeType: ${mimeType}`);
+
+        const mimeArr = mimeType.split(';');
+
+        let codecs = mimeArr.find(info => info.includes('codecs')).split('=')[1];
+        codecs = codecs.substring(1, codecs.length - 1);
+
+        const mimeInfo = {
+            content: mimeArr[0].split('/')[0],
+            type: mimeArr[0],
+            codecs,
+        };
+
+        debug(`parsed mimeType: ${JSON.stringify(mimeInfo)}`);
+
+        return mimeInfo;
+    }
+
     _getPlayerInfoPromise(videoId)
     {
         const data = this._getPlayerPostData(videoId);