Cap AVC profile level at 4.1 in stream master playlist (#41592)

* Cap AVC profile level at 4.1

* Use smaller multiplier in bandwidth calculation

homeassistant/components/stream/fmp4utils.py

@@ -70,7 +70,8 @@ def get_codec_string(segment: io.BytesIO) -> str:
         ):
             profile = stsd_box[111:112].hex()
             compatibility = stsd_box[112:113].hex()
-            level = stsd_box[113:114].hex()
+            # Cap level at 4.1 for compatibility with some Google Cast devices
+            level = hex(min(stsd_box[113], 41))[2:]
             codec += "." + profile + compatibility + level
 
         # Handle H265

homeassistant/components/stream/hls.py

@@ -32,10 +32,11 @@ class HlsMasterPlaylistView(StreamView):
     def render(track):
         """Render M3U8 file."""
         # Need to calculate max bandwidth as input_container.bit_rate doesn't seem to work
-        # Calculate file size / duration and use a multiplier to account for variation
+        # Calculate file size / duration and use a small multiplier to account for variation
+        # hls spec already allows for 25% variation
         segment = track.get_segment(track.segments[-1])
         bandwidth = round(
-            segment.segment.seek(0, io.SEEK_END) * 8 / segment.duration * 3
+            segment.segment.seek(0, io.SEEK_END) * 8 / segment.duration * 1.2
         )
         codecs = get_codec_string(segment.segment)
         lines = [