diff --git a/render.py b/render.py
index b08de77..57925ef 100644
--- a/render.py
+++ b/render.py
@@ -84,7 +84,7 @@ def compose(clips, fragment, target=150, base=1024, voice_over=None, options=Non
     selected_clips = []
 
     tags = []
-    while selected_clips_length < target:
+    while selected_clips_length < target * 1.1:
         if not tags:
             tags = fragment["tags"].copy()
         tag = random_choice(seq, tags, pop=True)
@@ -132,18 +132,18 @@ def compose(clips, fragment, target=150, base=1024, voice_over=None, options=Non
         next_length = length + clip['duration'] 
         if target - next_length < -target*0.1:
             break
-        length += int(clip['duration'] * fps) / fps
+        clip_duration = int(clip['duration'] * fps) / fps
+        length += clip_duration
 
         # 50/50 source or ai
         src = clip['source']
         audio = clip['source']
         # select ai if we have one
-        if 'ai' in clip:
-            if clip["use_ai"]:
-                src = random_choice(seq, list(clip['ai'].values()), False)
+        if 'ai' in clip and clip.get("use_ai"):
+            src = random_choice(seq, list(clip['ai'].values()), False)
 
         print('%07.3f-%07.3f %07.3f %s (%s)' % (
-            length-clip['duration'],
+            length-clip_duration,
             length,
             clip['duration'],
             os.path.basename(clip['source']),
@@ -196,6 +196,9 @@ def compose(clips, fragment, target=150, base=1024, voice_over=None, options=Non
             if not clips:
                 print("not enough clips, also consider last clip")
                 clips = all_clips.copy()
+            for clip in clips:
+                if "ai" in clip:
+                    clip["use_ai"] = True
 
     scene_duration = int(get_scene_duration(scene) * fps)
     voice_overs = []