diff --git a/annolid/utils/videos.py b/annolid/utils/videos.py
index 8a7bff4..184905b 100644
--- a/annolid/utils/videos.py
+++ b/annolid/utils/videos.py
@@ -2,7 +2,12 @@
 import subprocess
 
 
-def convert_mkv_to_mp4(input_folder, output_folder):
+def convert_mkv_to_mp4(input_folder, output_folder, scale_factor):
+    # Ensure the input folder exists
+    if not os.path.exists(input_folder):
+        print("Input folder does not exist.")
+        return
+
     # Ensure the output folder exists, create it if it doesn't
     if not os.path.exists(output_folder):
         os.makedirs(output_folder)
@@ -10,6 +15,10 @@ def convert_mkv_to_mp4(input_folder, output_folder):
     # Get a list of all .mkv files in the input folder
     mkv_files = [f for f in os.listdir(input_folder) if f.endswith('.mkv')]
 
+    if not mkv_files:
+        print("No .mkv files found in the input folder.")
+        return
+
     for mkv_file in mkv_files:
         input_path = os.path.join(input_folder, mkv_file)
         output_path = os.path.join(
@@ -18,7 +27,7 @@ def convert_mkv_to_mp4(input_folder, output_folder):
         # Run ffmpeg command to convert mkv to mp4 and resize
         cmd = [
             'ffmpeg', '-i', input_path,
-            '-vf', 'scale=iw/2:ih/2',
+            '-vf', f'scale=iw*{scale_factor}:ih*{scale_factor}',
             '-c:v', 'libx264', '-crf', '23',
             '-c:a', 'aac', '-b:a', '128k',
             output_path
@@ -35,4 +44,10 @@ def convert_mkv_to_mp4(input_folder, output_folder):
     input_folder = input("Enter the input folder path containing .mkv files: ")
     output_folder = input(
         "Enter the output folder path for converted .mp4 files: ")
-    convert_mkv_to_mp4(input_folder, output_folder)
+    scale_factor = float(
+        input("Enter the scale factor (e.g., 0.5 for half size): "))
+
+    if scale_factor <= 0:
+        print("Scale factor must be greater than 0.")
+    else:
+        convert_mkv_to_mp4(input_folder, output_folder, scale_factor)