diff --git a/hydrus/core/HydrusVideoHandling.py b/hydrus/core/HydrusVideoHandling.py
index 820eb393..160268cf 100644
--- a/hydrus/core/HydrusVideoHandling.py
+++ b/hydrus/core/HydrusVideoHandling.py
@@ -1,8 +1,10 @@
 import numpy
+import numpy.typing
 import os
 import re
 import struct
 import subprocess
+from typing import Optional
 
 from hydrus.core import HydrusAudioHandling
 from hydrus.core import HydrusConstants as HC
@@ -43,7 +45,7 @@ def CheckFFMPEGError( lines ):
         raise HydrusExceptions.DamagedOrUnusualFileException( 'FFMPEG could not parse.' )
         
     
-def GetAPNGChunks( file_header_bytes: bytes ):
+def GetAPNGChunks( file_header_bytes: bytes ) ->list:
     
     # https://wiki.mozilla.org/APNG_Specification
     # a chunk is:
@@ -72,7 +74,7 @@ def GetAPNGChunks( file_header_bytes: bytes ):
     
     return chunks
     
-def GetAPNGACTLChunkData( file_header_bytes: bytes ):
+def GetAPNGACTLChunkData( file_header_bytes: bytes ) -> Optional[bytes]:
     
     # the acTL chunk can be in different places, but it has to be near the top
     # although it is almost always in fixed position (I think byte 29), we have seen both pHYs and sRGB chunks appear before it
@@ -92,7 +94,7 @@ def GetAPNGACTLChunkData( file_header_bytes: bytes ):
         return None
         
     
-def GetAPNGDuration( apng_bytes: bytes ):
+def GetAPNGDuration( apng_bytes: bytes ) -> float:
     
     frame_control_chunk_name = b'fcTL'
     
@@ -122,7 +124,7 @@ def GetAPNGDuration( apng_bytes: bytes ):
     
     return total_duration
     
-def GetAPNGNumFrames( apng_actl_bytes: bytes ):
+def GetAPNGNumFrames( apng_actl_bytes: bytes ) -> int:
     
     ( num_frames, ) = struct.unpack( '>I', apng_actl_bytes[ : 4 ] )
     
@@ -565,7 +567,7 @@ def GetMime( path ):
     
     return HC.APPLICATION_UNKNOWN
     
-def HasVideoStream( path ):
+def HasVideoStream( path ) -> bool:
     
     lines = GetFFMPEGInfoLines( path )
     
@@ -823,7 +825,7 @@ def ParseFFMPEGFPSPossibleResults( video_line ):
     
     return ( possible_results, confident )
     
-def ParseFFMPEGHasVideo( lines ):
+def ParseFFMPEGHasVideo( lines ) -> bool:
     
     try:
         
@@ -893,7 +895,7 @@ def ParseFFMPEGMimeText( lines ):
         raise HydrusExceptions.DamagedOrUnusualFileException( 'Error reading file type!' )
         
     
-def ParseFFMPEGNumFramesManually( lines ):
+def ParseFFMPEGNumFramesManually( lines ) -> int:
     
     frame_lines = [ line for line in lines if line.startswith( 'frame=' ) ]
     
@@ -950,7 +952,7 @@ def ParseFFMPEGVideoFormat( lines ):
     
     return ( True, video_format )
     
-def ParseFFMPEGVideoLine( lines, png_ok = False ):
+def ParseFFMPEGVideoLine( lines, png_ok = False ) -> str:
     
     if png_ok:
         
@@ -974,7 +976,7 @@ def ParseFFMPEGVideoLine( lines, png_ok = False ):
     
     return line
     
-def ParseFFMPEGVideoResolution( lines, png_ok = False ):
+def ParseFFMPEGVideoResolution( lines, png_ok = False ) -> tuple[int,int]:
     
     try:
         
@@ -1023,7 +1025,7 @@ def ParseFFMPEGVideoResolution( lines, png_ok = False ):
         raise HydrusExceptions.DamagedOrUnusualFileException( 'Error parsing resolution!' )
         
     
-def VideoHasAudio( path, info_lines ):
+def VideoHasAudio( path, info_lines ) -> bool:
     
     ( audio_found, audio_format ) = HydrusAudioHandling.ParseFFMPEGAudio( info_lines )
     
@@ -1127,7 +1129,7 @@ class VideoRendererFFMPEG( object ):
         self.initialize()
         
     
-    def close( self ):
+    def close( self ) -> None:
         
         if self.process is not None:
             
@@ -1224,7 +1226,7 @@ class VideoRendererFFMPEG( object ):
             
         
     
-    def skip_frames( self, n ):
+    def skip_frames( self, n ) -> None:
         
         n = int( n )
         
@@ -1243,7 +1245,7 @@ class VideoRendererFFMPEG( object ):
             
         
     
-    def read_frame( self ):
+    def read_frame( self ) -> numpy.typing.ArrayLike:
         
         if self.pos == self._num_frames:
             
@@ -1300,7 +1302,7 @@ class VideoRendererFFMPEG( object ):
         return result
         
     
-    def set_position( self, pos ):
+    def set_position( self, pos ) -> None:
         
         rewind = pos < self.pos
         jump_a_long_way_ahead = pos > self.pos + 60
@@ -1315,7 +1317,7 @@ class VideoRendererFFMPEG( object ):
             
         
     
-    def Stop( self ):
+    def Stop( self ) -> None:
         
         self.close()