code.delx.au - youtube-cgi/blob - youtube.cgi

   1 #!/usr/bin/env python3
   2
   3 import cgi
   4 import html.parser
   5 import http.cookiejar
   6 import json
   7 import os
   8 import re
   9 import shutil
  10 import subprocess
  11 import sys
  12 import time
  13 import urllib.error
  14 import urllib.parse
  15 import urllib.request
  16
  17
  18 USER_AGENT = "Mozilla/5.0 (X11; Linux x86_64; rv:67.0) Gecko/20100101 Firefox/67.0"
  19
  20 MIMETYPES = {
  21     "video/mp4": "mp4",
  22     "video/x-flv": "flv",
  23     "video/3gpp": "3gp",
  24 }
  25
  26 QUALITIES = {
  27     "hd1080": 5,
  28     "hd720": 4,
  29     "large": 3,
  30     "medium": 2,
  31     "small": 1,
  32 }
  33
  34
  35 class VideoUnavailable(Exception):
  36     pass
  37
  38 class NotYouTube(Exception):
  39     pass
  40
  41 def print_form(url="", msg=""):
  42     script_url = "https://%s%s" % (os.environ["HTTP_HOST"], os.environ["REQUEST_URI"])
  43     sys.stdout.write("Content-Type: text/html\r\n\r\n")
  44     sys.stdout.write("""
  45 <!DOCTYPE html>
  46 <html>
  47 <head>
  48     <title>delx.net.au - YouTube Scraper</title>
  49     <link rel="stylesheet" type="text/css" href="/style.css">
  50     <style type="text/css">
  51         input[type="text"] {
  52             width: 100%;
  53         }
  54         .error {
  55             color: red;
  56         }
  57     </style>
  58 </head>
  59 <body>
  60     <h1>delx.net.au - YouTube Scraper</h1>
  61     {0}
  62     <form action="" method="get">
  63     <p>This page will let you easily download YouTube videos to watch offline. It
  64     will automatically grab the highest quality version.</p>
  65     <div><input type="text" name="url" value="{1}"/></div>
  66     <div><input type="submit" value="Download!"/></div>
  67     </form>
  68     <p>Tip! Use this bookmarklet: <a href="javascript:(function(){window.location='{2}?url='+escape(location);})()">YouTube Download</a>
  69     to easily download videos. Right-click the link and add it to bookmarks,
  70     then when you're looking at a YouTube page select that bookmark from your
  71     browser's bookmarks menu to download the video straight away.</p>
  72 </body>
  73 </html>
  74 """.replace("{0}", msg).replace("{1}", url).replace("{2}", script_url))
  75
  76 cookiejar = http.cookiejar.CookieJar()
  77 urlopener = urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cookiejar))
  78 referrer = ""
  79
  80 def urlopen(url, offset=None):
  81     if url.startswith("//"):
  82         url = "https:" + url
  83     if not url.startswith("http://") and not url.startswith("https://"):
  84         url = "https://www.youtube.com" + url
  85
  86     global referrer
  87     req = urllib.request.Request(url)
  88     if not referrer:
  89         referrer = url
  90     else:
  91         req.add_header("Referer", referrer)
  92
  93     req.add_header("User-Agent", USER_AGENT)
  94
  95     if offset:
  96         req.add_header("Range", "bytes=%d-" % offset)
  97
  98     res = urlopener.open(req)
  99
 100     content_range = res.getheader("Content-Range")
 101     if content_range:
 102         tokens = content_range.split()
 103         assert tokens[0] == "bytes"
 104         start = int(tokens[1].split("-")[0])
 105         assert start == offset
 106     return res
 107
 108 def validate_url(url):
 109     parsed_url = urllib.parse.urlparse(url)
 110     scheme_ok = parsed_url.scheme == "https"
 111     host_ok = parsed_url.netloc.lstrip("www.") in ["youtube.com", "youtu.be"]
 112
 113     if scheme_ok and host_ok:
 114         return
 115     else:
 116         raise NotYouTube()
 117
 118 def parse_url(url, parser):
 119     f = urlopen(url)
 120     parser.feed(f.read().decode("utf-8"))
 121     parser.close()
 122     f.close()
 123
 124 def append_to_qs(url, params):
 125     r = list(urllib.parse.urlsplit(url))
 126     qs = urllib.parse.parse_qs(r[3])
 127     qs.update(params)
 128     r[3] = urllib.parse.urlencode(qs, True)
 129     url = urllib.parse.urlunsplit(r)
 130     return url
 131
 132 def get_player_config(scripts):
 133     player_config = None
 134     for script in scripts:
 135         for line in script.split("\n"):
 136             s = "ytplayer.config = {"
 137             if s in line:
 138                 p1 = line.find(s) + len(s) - 1
 139                 p2 = line.find("};", p1) + 1
 140                 if p1 >= 0 and p2 > 0:
 141                     return json.loads(line[p1:p2])
 142
 143 def extract_js(script):
 144     PREFIX = "var _yt_player={};(function(g){var window=this;"
 145     SUFFIX = ";})(_yt_player);\n"
 146     assert script.startswith(PREFIX)
 147     assert script.endswith(SUFFIX)
 148
 149     return script[len(PREFIX):-len(SUFFIX)]
 150
 151 def find_func_name(script):
 152     FUNC_NAME = R"([a-zA-Z0-9$]+)"
 153     DECODE_URI_COMPONENT = R"(\(decodeURIComponent)?"
 154     FUNC_PARAMS = R"(\([a-zA-Z,\.]+\.s\))"
 155     TERMINATOR = R"[,;\)]"
 156     PATTERN = FUNC_NAME + DECODE_URI_COMPONENT + FUNC_PARAMS + TERMINATOR
 157
 158     match = re.search(PATTERN, script)
 159     func_name = match.groups()[0]
 160     return func_name
 161
 162 def decode_signature(js_url, signature):
 163     f = urlopen(js_url)
 164     script = f.read().decode("utf-8")
 165     f.close()
 166
 167     func_name = find_func_name(script)
 168
 169     params = {
 170         "func_name": func_name,
 171         "signature": json.dumps(signature),
 172         "code": json.dumps(extract_js(script)),
 173     }
 174     p = subprocess.Popen(
 175         "node",
 176         shell=True,
 177         close_fds=True,
 178         stdin=subprocess.PIPE,
 179         stdout=subprocess.PIPE
 180     )
 181     js_decode_script = ("""
 182         const vm = require('vm');
 183
 184         const sandbox = {
 185             location: {
 186                 hash: '',
 187                 href: '',
 188                 protocol: 'http:'
 189             },
 190             history: {
 191                 pushState: function(){}
 192             },
 193             document: {},
 194             navigator: {
 195                 userAgent: ''
 196             },
 197             XMLHttpRequest: class XMLHttpRequest {},
 198             matchMedia: () => ({matches: () => {}, media: ''}),
 199             signature: %(signature)s,
 200             transformed_signature: null,
 201             g: function(){} // this is _yt_player
 202         };
 203         sandbox.window = sandbox;
 204
 205         const code_string = %(code)s + ';';
 206         const exec_string = 'transformed_signature = %(func_name)s(signature);';
 207         vm.runInNewContext(code_string + exec_string, sandbox);
 208
 209         console.log(sandbox.transformed_signature);
 210     """ % params)
 211
 212     p.stdin.write(js_decode_script.encode("utf-8"))
 213     p.stdin.close()
 214
 215     transformed_signature = p.stdout.read().decode("utf-8").strip()
 216     transformed_signature = urllib.parse.unquote(transformed_signature)
 217     if p.wait() != 0:
 218         raise Exception("js failed to execute: %d" % p.returncode)
 219
 220     return transformed_signature
 221
 222 def get_best_video(player_config):
 223     js_url = player_config["assets"]["js"]
 224
 225     player_args = player_config["args"]
 226     player_response = json.loads(player_args["player_response"])
 227     formats = player_response["streamingData"]["formats"]
 228
 229     best_url = None
 230     best_quality = None
 231     best_extension = None
 232     for format_data in formats:
 233         mimetype = format_data["mimeType"].split(";")[0]
 234         quality = format_data["quality"]
 235
 236         if quality not in QUALITIES:
 237             continue
 238         if mimetype not in MIMETYPES:
 239             continue
 240
 241         extension = MIMETYPES[mimetype]
 242         quality = QUALITIES.get(quality, -1)
 243
 244         if best_quality is not None and quality < best_quality:
 245             continue
 246
 247         if "cipher" in format_data:
 248             cipher = urllib.parse.parse_qs(format_data["cipher"])
 249             video_url = cipher["url"][0]
 250             if "sig" in cipher:
 251                 signature = cipher["sig"][0]
 252             elif "s" in cipher:
 253                 signature = decode_signature(js_url, cipher["s"][0])
 254             sp = cipher.get("sp", ["signature"])[0]
 255             video_url = append_to_qs(video_url, {sp: signature})
 256         else:
 257             video_url = format_data["url"]
 258
 259         best_url = video_url
 260         best_quality = quality
 261         best_extension = extension
 262
 263     return best_url, best_extension
 264
 265 def sanitize_filename(filename):
 266     return (
 267         re.sub("\s+", " ", filename.strip())
 268         .replace("\\", "-")
 269         .replace("/", "-")
 270         .replace("\0", " ")
 271     )
 272
 273 def get_video_url(page):
 274     player_config = get_player_config(page.scripts)
 275     if not player_config:
 276         raise VideoUnavailable(page.unavailable_message or "Could not find video URL")
 277
 278     video_url, extension = get_best_video(player_config)
 279     if not video_url:
 280         return None, None
 281
 282     title = player_config["args"].get("title", None)
 283     if not title:
 284         title = json.loads(player_config["args"]["player_response"])["videoDetails"]["title"]
 285     if not title:
 286         title = "Unknown title"
 287
 288     filename = sanitize_filename(title) + "." + extension
 289
 290     return video_url, filename
 291
 292 class YouTubeVideoPageParser(html.parser.HTMLParser):
 293     def __init__(self):
 294         super().__init__()
 295         self.unavailable_message = None
 296         self.scripts = []
 297
 298     def handle_starttag(self, tag, attrs):
 299         attrs = dict(attrs)
 300         self._handle_unavailable_message(tag, attrs)
 301         self._handle_script(tag, attrs)
 302
 303     def handle_endtag(self, tag):
 304         self.handle_data = self._ignore_data
 305
 306     def _ignore_data(self, _):
 307         pass
 308
 309     def _handle_unavailable_message(self, tag, attrs):
 310         if attrs.get("id", None) == "unavailable-message":
 311             self.handle_data = self._handle_unavailable_message_data
 312
 313     def _handle_unavailable_message_data(self, data):
 314         self.unavailable_message = data.strip()
 315
 316     def _handle_script(self, tag, attrs):
 317         if tag == "script":
 318             self.handle_data = self._handle_script_data
 319
 320     def _handle_script_data(self, data):
 321         if data:
 322             self.scripts.append(data)
 323
 324 def write_video(filename, video_data):
 325     quoted_filename = urllib.parse.quote(filename.encode("utf-8"))
 326     sys.stdout.buffer.write(
 327         b"Content-Disposition: attachment; filename*=UTF-8''{0}\r\n"
 328         .replace(b"{0}", quoted_filename.encode("utf-8"))
 329     )
 330     sys.stdout.buffer.write(
 331         b"Content-Length: {0}\r\n"
 332         .replace(b"{0}", video_data.getheader("Content-Length").encode("utf-8"))
 333     )
 334     sys.stdout.buffer.write(b"\r\n")
 335     shutil.copyfileobj(video_data, sys.stdout.buffer)
 336     video_data.close()
 337
 338 def cgimain():
 339     args = cgi.parse()
 340     try:
 341         url = args["url"][0]
 342     except:
 343         print_form(url="https://www.youtube.com/watch?v=FOOBAR")
 344         return
 345
 346     try:
 347         page = YouTubeVideoPageParser()
 348         validate_url(url)
 349         parse_url(url, page)
 350         video_url, filename = get_video_url(page)
 351         video_data = urlopen(video_url)
 352     except VideoUnavailable as e:
 353         print_form(
 354             url=url,
 355             msg="<p class='error'>Sorry, there was an error: %s</p>" % cgi.escape(e.args[0])
 356         )
 357     except NotYouTube:
 358         print_form(
 359             url=url,
 360             msg="<p class='error'>Sorry, that does not look like a YouTube page!</p>"
 361         )
 362     except Exception as e:
 363         print_form(
 364             url=url,
 365             msg="<p class='error'>Sorry, there was an unknown error.</p>"
 366         )
 367         return
 368
 369     write_video(filename, video_data)
 370
 371 def pp_size(size):
 372     suffixes = ["", "KiB", "MiB", "GiB"]
 373     for i, suffix in enumerate(suffixes):
 374         if size < 1024:
 375             break
 376         size /= 1024
 377     return "%.2f %s" % (size, suffix)
 378
 379 def copy_with_progress(content_length, infile, outfile):
 380     def print_status():
 381         rate = 0
 382         if now != last_ts:
 383             rate = last_bytes_read / (now - last_ts)
 384         sys.stdout.write("\33[2K\r")
 385         sys.stdout.write("%s / %s (%s/sec)" % (
 386             pp_size(bytes_read),
 387             pp_size(content_length),
 388             pp_size(rate),
 389         ))
 390         sys.stdout.flush()
 391
 392     last_ts = 0
 393     last_bytes_read = 0
 394     bytes_read = 0
 395     while True:
 396         now = time.time()
 397         if now - last_ts > 0.5:
 398             print_status()
 399             last_ts = now
 400             last_bytes_read = 0
 401
 402         buf = infile.read(32768)
 403         if not buf:
 404             break
 405         outfile.write(buf)
 406         last_bytes_read += len(buf)
 407         bytes_read += len(buf)
 408
 409     # Newline at the end
 410     print_status()
 411     print()
 412
 413 def main():
 414     try:
 415         url = sys.argv[1]
 416     except:
 417         print("Usage: %s https://youtube.com/watch?v=FOOBAR" % sys.argv[0], file=sys.stderr)
 418         sys.exit(1)
 419
 420     page = YouTubeVideoPageParser()
 421     parse_url(url, page)
 422     video_url, filename = get_video_url(page)
 423     print("Downloading", filename)
 424
 425     outfile = open(filename, "ab")
 426     offset = outfile.tell()
 427     if offset > 0:
 428         print("Resuming download from", pp_size(offset))
 429     total_size = None
 430
 431     while True:
 432         try:
 433             video_data = urlopen(video_url, offset)
 434         except urllib.error.HTTPError as e:
 435             if e.code == 416:
 436                 print("File is complete!")
 437                 break
 438             else:
 439                 raise
 440
 441         content_length = int(video_data.getheader("Content-Length"))
 442         if total_size is None:
 443             total_size = content_length
 444
 445         try:
 446             copy_with_progress(content_length, video_data, outfile)
 447         except IOError as e:
 448             print()
 449
 450         video_data.close()
 451         if outfile.tell() != total_size:
 452             old_offset = offset
 453             offset = outfile.tell()
 454             if old_offset == offset:
 455                 time.sleep(1)
 456             print("Restarting download from", pp_size(offset))
 457         else:
 458             break
 459
 460     outfile.close()
 461
 462
 463 if __name__ == "__main__":
 464     if "SCRIPT_NAME" in os.environ:
 465         cgimain()
 466     else:
 467         try:
 468             main()
 469         except KeyboardInterrupt:
 470             print("\nExiting...")
 471             sys.exit(1)
 472