Add camera presets snapshots and continuous recording playback

onvif.py

@@ -4,6 +4,7 @@ import datetime as dt
 import hashlib
 import secrets
 import urllib.request
+import urllib.error
 import urllib.parse
 import xml.etree.ElementTree as ET
 from xml.sax.saxutils import escape
@@ -39,8 +40,12 @@ def request(host, port, endpoint, namespace, operation, content, username, passw
     opener = urllib.request.build_opener(urllib.request.ProxyHandler({}), NoRedirect(), urllib.request.HTTPDigestAuthHandler(passwords))
     req = urllib.request.Request(target, data=envelope.encode(), headers={
         'Content-Type': 'application/soap+xml; charset=utf-8; action="' + namespace + '/' + operation + '"'})
-    with opener.open(req, timeout=5) as response:
-        root = ET.fromstring(response.read(1024 * 1024))
+    try:
+        with opener.open(req, timeout=5) as response:
+            root = ET.fromstring(response.read(1024 * 1024))
+    except urllib.error.HTTPError as exc:
+        exc.close()
+        raise
     if root.find('.//{http://www.w3.org/2003/05/soap-envelope}Fault') is not None:
         raise ValueError('ONVIF returned a fault; check device credentials and permissions')
     return root