diff --git a/app.py b/app.py
index 0ede270..daaedeb 100644
--- a/app.py
+++ b/app.py
@@ -14,7 +14,13 @@ from cisticola.scraper import (
     BitchuteScraper,
     RumbleScraper,
 )
-from cisticola.transformer import (ETLController, TelegramTelethonTransformer)
+from cisticola.transformer import (
+    ETLController, 
+    TelegramTelethonTransformer,
+    GettrTransformer, 
+    RumbleTransformer, 
+    BitchuteTransformer)
+
 from sync_with_gsheet import sync_channels
 
 def get_db_session():
@@ -49,7 +55,10 @@ def get_transformer_controller():
     controller = ETLController()
     controller.connect_to_db(engine)
 
-    transformers = [TelegramTelethonTransformer()]
+    transformers = [TelegramTelethonTransformer(), 
+        BitchuteTransformer(), 
+        GettrTransformer(), 
+        RumbleTransformer()]
 
     controller.register_transformers(transformers)
 
diff --git a/cisticola/base.py b/cisticola/base.py
index aad30b8..28ff9f8 100644
--- a/cisticola/base.py
+++ b/cisticola/base.py
@@ -256,6 +256,7 @@ class Post:
         # replace is here in order to prevent catastrophic backtracking
         urls = re.findall(URL_REGEX, self.content.replace("::::::::", ""))
         self.outlinks += urls
+        self.outlinks =  list(set(outlink for outlink in self.outlinks))
 
         HASHTAG_REGEX = r"(?:^|\s)[＃#]{1}(\w+)"
         
diff --git a/cisticola/transformer/bitchute.py b/cisticola/transformer/bitchute.py
index b14f756..c8dff36 100644
--- a/cisticola/transformer/bitchute.py
+++ b/cisticola/transformer/bitchute.py
@@ -69,7 +69,10 @@ class BitchuteTransformer(Transformer):
                 if raw['parent_id'] is not None:
                     # this block is for comments whose parent_ids correspond to deleted comments 
                     post = session.query(Post).filter_by(channel=data.channel, platform_id=raw['thread_id']).first()
-                    reply_to = post.id
+                    if post is None:
+                        reply_to = -1
+                    else:
+                        reply_to = post.id
                 else:
                     reply_to = -1
             else:
@@ -102,7 +105,7 @@ class BitchuteTransformer(Transformer):
             likes = raw['likes'],
             views = int(raw['views']) if raw.get('views') else None,
             video_title = raw['subject'],
-            video_duration = parse_duration_str(raw['length']))
+            video_duration = _parse_duration_str(raw['length']))
 
         transformed = insert(transformed)
         session.flush()
@@ -123,7 +126,9 @@ def parse_created(created: str, date_archived: datetime) -> datetime:
 
         return date_archived - relativedelta(**kwargs)
 
-def parse_duration_str(duration_str: str) -> int:
+def _parse_duration_str(duration_str: str) -> int:
+    """Convert duration string (e.g. '2:27:04') to the number of seconds (e.g. 8824).
+    """
     if not duration_str:
         return None
     else:
diff --git a/cisticola/transformer/gettr.py b/cisticola/transformer/gettr.py
index 275be48..0e0a4d0 100644
--- a/cisticola/transformer/gettr.py
+++ b/cisticola/transformer/gettr.py
@@ -3,6 +3,7 @@ from loguru import logger
 from typing import Generator, Union, Callable
 import dateutil.parser
 from datetime import datetime, timezone
+from sqlalchemy import func
 from gogettr import PublicClient
 from gogettr.api import GettrApiError
 
@@ -46,42 +47,55 @@ class GettrTransformer(Transformer):
 
         transformed = insert(transformed)
 
+    def _get_channel_id(self, username: str, category: str, insert: Callable, session):
+
+        channel = session.query(Channel).filter(func.lower(Channel.screenname)==func.lower(username), platform = 'Gettr').first()
+
+        if channel is None:
+            try:
+                client = PublicClient()
+                profile = client.user_info(username.lower())
+                screenname = profile.get('_id')
+                channel = Channel(
+                    name=profile.get('nickname'),
+                    platform_id=screenname,
+                    platform='Gettr',
+                    url="https://gettr.com/user/" + screenname,
+                    screenname=screenname,
+                    category=category,
+                    source=self.__version__,
+                    )
+            except GettrApiError:
+                channel = Channel(
+                    name = None,
+                    platform_id = None,
+                    platform = 'Gettr',
+                    url = None,
+                    screenname=username,
+                    category=category,
+                    source=self.__version__,
+                    notes='GettrApiError'
+                    )
+
+            channel = insert(channel)
+
+        return channel.id
 
     def transform(self, data: ScraperResult, insert: Callable, session) -> Generator[Union[Post, Channel, Media], None, None]:
         raw = json.loads(data.raw_data)
 
         if raw["activity"]["action"] == "shares_pst":
-            fwd_from = str(raw["activity"]["uid"])
-            channel = session.query(Channel).filter_by(platform_id=str(fwd_from)).first()
-            if channel is None:
-                try:
-                    client = PublicClient()
-                    profile = client.user_info(fwd_from.lower())
-                    screenname = profile.get('_id')
-                    channel = Channel(
-                        name=profile.get('nickname'),
-                        platform_id=screenname,
-                        platform=data.platform,
-                        url="https://gettr.com/user/" + screenname,
-                        screenname=screenname,
-                        category='forwarded',
-                        source=self.__version__,
-                        )
-                except GettrApiError:
-                     channel = Channel(
-                        name=None,
-                        platform_id=fwd_from,
-                        platform=data.platform,
-                        url="https://gettr.com/user/" + fwd_from,
-                        screenname=fwd_from,
-                        category='forwarded',
-                        source=self.__version__,
-                        )
-                channel = insert(channel)
-            forwarded_from = channel.id
+            forwarded_from = self._get_channel_id(
+                username = str(raw["activity"]["uid"]), category = 'forwarded', insert = insert, session = session)
         else:
             forwarded_from = None
 
+        mentions = []
+        for mentioned_user in raw.get("utgs", []):
+            mentioned_id = self._get_channel_id(
+                username = mentioned_user, category = 'mentioned', insert = insert, session = session)
+            mentions.append(mentioned_id)
+            
         transformed = Post(
             raw_id=data.id,
             platform_id=raw["_id"],
@@ -99,6 +113,7 @@ class GettrTransformer(Transformer):
             hashtags=raw.get("htgs", []),
             outlinks = list(filter(None, [raw.get("prevsrc")])),
             forwarded_from = forwarded_from,
+            mentions = mentions,
             likes = raw.get('lkbpst'),
             forwards = raw.get("shbpst"),
             views = raw.get('vfpst')
diff --git a/cisticola/transformer/rumble.py b/cisticola/transformer/rumble.py
index f9671c9..79289f5 100644
--- a/cisticola/transformer/rumble.py
+++ b/cisticola/transformer/rumble.py
@@ -3,6 +3,7 @@ from loguru import logger
 from typing import Generator, Union, Callable
 import dateutil.parser
 from datetime import datetime, timezone
+from sqlalchemy import func, JSON, String, cast, text
 
 from cisticola.transformer.base import Transformer 
 from cisticola.base import RawChannelInfo, ChannelInfo, ScraperResult, Post, Image, Video, Media, Channel
@@ -22,19 +23,30 @@ class RumbleTransformer(Transformer):
     def transform_info(self, data: RawChannelInfo, insert: Callable, session) -> Generator[Union[Post, Channel, Media], None, None]:
         raw = json.loads(data.raw_data)
 
+        if 'id' not in raw:
+            # The first version of the Rumble ChannelInfo scraper didn't return
+            # the platform_id, so this is a workaround.
+            channel = session.query(RawChannelInfo).filter(text("raw_channel_info.raw_data::jsonb ->> 'name'=:name"), RawChannelInfo.platform == 'Rumble').params(name=raw['name']).order_by(RawChannelInfo.date_archived.desc()).first()
+            if channel is None:
+                platform_id = None
+            else:
+                platform_id = json.loads(channel.raw_data)['id']
+        else:
+            platform_id = raw['id']
+
         transformed = ChannelInfo(
             raw_channel_info_id=data.id,
             channel=data.channel,
-            platform_id=raw['id'],
+            platform_id=platform_id,
             platform=data.platform,
             scraper=data.scraper,
             transformer=self.__version__,
-            screenname=raw['id'],
+            screenname=platform_id,
             name=raw['name'],
             description='', # does not exist for Rumble
             description_url='', # does not exist for Rumble
             description_location='', # does not exist for Rumble
-            followers=raw['subscribers'],
+            followers=_process_number(raw['subscribers']),
             following=-1, # does not exist for Rumble
             verified=raw['verified'],
             date_created=None, # does not exist for Rumble
@@ -63,7 +75,9 @@ class RumbleTransformer(Transformer):
             author_id=raw['author_id'],
             author_username=raw['author_name'],
             views = _process_number(raw.get('views')),
-            likes = _process_number(raw.get('rumbles')))
+            likes = _process_number(raw.get('rumbles')),
+            video_title = raw['title'],
+            video_duration=_parse_duration_str(raw['duration']))
 
         insert(transformed)
 
@@ -76,4 +90,18 @@ def _process_number(s):
     if s is None:
         return None
     else:
-        return int(s.replace(',', ''))
\ No newline at end of file
+        s = s.replace(' ', '')
+        if s.endswith('M'):
+            return int(float(s[:-1]) * 1e6)
+        elif s.endswith('K'):
+            return int(float(s[:-1]) * 1000)
+        return int(s)
+
+def _parse_duration_str(duration_str: str) -> int:
+    """Convert duration string (e.g. '2:27:04') to the number of seconds (e.g. 8824).
+    """
+    if not duration_str:
+        return None
+    else:
+        duration_list = duration_str.split(':')
+        return sum([int(s) * int(g) for s, g in zip([1, 60, 3600], reversed(duration_list))])
\ No newline at end of file
diff --git a/cisticola/transformer/telegram_telethon.py b/cisticola/transformer/telegram_telethon.py
index 3f9ac02..eb48d06 100644
--- a/cisticola/transformer/telegram_telethon.py
+++ b/cisticola/transformer/telegram_telethon.py
@@ -131,7 +131,7 @@ class TelegramTelethonTransformer(Transformer):
         fwd_from = None
 
         if raw['fwd_from'] and raw['fwd_from']['from_id'] and 'channel_id' in raw['fwd_from']['from_id']:
-            channel = session.query(Channel).filter_by(platform_id=str(raw['fwd_from']['from_id']['channel_id'])).first()
+            channel = session.query(Channel).filter_by(platform_id=str(raw['fwd_from']['from_id']['channel_id']), platform = 'Telegram').first()
 
             if channel is None:
                 (screenname, name, notes) = self.get_screenname_from_id(raw['fwd_from']['from_id']['channel_id'])