Add brotli content-encoding support (#2433)

Authored by: coletdjnz

yt_dlp/utils.py

@@ -47,6 +47,7 @@ from .compat import (
     compat_HTMLParser,
     compat_HTTPError,
     compat_basestring,
+    compat_brotli,
     compat_chr,
     compat_cookiejar,
     compat_ctypes_WINFUNCTYPE,
@@ -143,10 +144,16 @@ def random_user_agent():
     return _USER_AGENT_TPL % random.choice(_CHROME_VERSIONS)
 
 
+SUPPORTED_ENCODINGS = [
+    'gzip', 'deflate'
+]
+if compat_brotli:
+    SUPPORTED_ENCODINGS.append('br')
+
 std_headers = {
     'User-Agent': random_user_agent(),
     'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
-    'Accept-Encoding': 'gzip, deflate',
+    'Accept-Encoding': ', '.join(SUPPORTED_ENCODINGS),
     'Accept-Language': 'en-us,en;q=0.5',
     'Sec-Fetch-Mode': 'navigate',
 }
@@ -1357,6 +1364,12 @@ class YoutubeDLHandler(compat_urllib_request.HTTPHandler):
         except zlib.error:
             return zlib.decompress(data)
 
+    @staticmethod
+    def brotli(data):
+        if not data:
+            return data
+        return compat_brotli.decompress(data)
+
     def http_request(self, req):
         # According to RFC 3986, URLs can not contain non-ASCII characters, however this is not
         # always respected by websites, some tend to give out URLs with non percent-encoded
@@ -1417,6 +1430,12 @@ class YoutubeDLHandler(compat_urllib_request.HTTPHandler):
             resp = compat_urllib_request.addinfourl(gz, old_resp.headers, old_resp.url, old_resp.code)
             resp.msg = old_resp.msg
             del resp.headers['Content-encoding']
+        # brotli
+        if resp.headers.get('Content-encoding', '') == 'br':
+            resp = compat_urllib_request.addinfourl(
+                io.BytesIO(self.brotli(resp.read())), old_resp.headers, old_resp.url, old_resp.code)
+            resp.msg = old_resp.msg
+            del resp.headers['Content-encoding']
         # Percent-encode redirect URL of Location HTTP header to satisfy RFC 3986 (see
         # https://github.com/ytdl-org/youtube-dl/issues/6457).
         if 300 <= resp.code < 400: