diff --git a/homeassistant/components/stream/fmp4utils.py b/homeassistant/components/stream/fmp4utils.py
index ed9dd6a9724..35d32d5b0e3 100644
--- a/homeassistant/components/stream/fmp4utils.py
+++ b/homeassistant/components/stream/fmp4utils.py
@@ -4,6 +4,8 @@ from __future__ import annotations
 from collections.abc import Generator
 from typing import TYPE_CHECKING
 
+from homeassistant.exceptions import HomeAssistantError
+
 if TYPE_CHECKING:
     from io import BufferedIOBase
 
@@ -11,7 +13,7 @@ if TYPE_CHECKING:
 def find_box(
     mp4_bytes: bytes, target_type: bytes, box_start: int = 0
 ) -> Generator[int, None, None]:
-    """Find location of first box (or sub_box if box_start provided) of given type."""
+    """Find location of first box (or sub box if box_start provided) of given type."""
     if box_start == 0:
         index = 0
         box_end = len(mp4_bytes)
@@ -141,12 +143,26 @@ def get_codec_string(mp4_bytes: bytes) -> str:
     return ",".join(codecs)
 
 
+def find_moov(mp4_io: BufferedIOBase) -> int:
+    """Find location of moov atom in a BufferedIOBase mp4."""
+    index = 0
+    while 1:
+        mp4_io.seek(index)
+        box_header = mp4_io.read(8)
+        if len(box_header) != 8:
+            raise HomeAssistantError("moov atom not found")
+        if box_header[4:8] == b"moov":
+            return index
+        index += int.from_bytes(box_header[0:4], byteorder="big")
+
+
 def read_init(bytes_io: BufferedIOBase) -> bytes:
     """Read the init from a mp4 file."""
-    bytes_io.seek(24)
+    moov_loc = find_moov(bytes_io)
+    bytes_io.seek(moov_loc)
     moov_len = int.from_bytes(bytes_io.read(4), byteorder="big")
     bytes_io.seek(0)
-    return bytes_io.read(24 + moov_len)
+    return bytes_io.read(moov_loc + moov_len)
 
 
 ZERO32 = b"\x00\x00\x00\x00"
diff --git a/tests/components/stream/test_hls.py b/tests/components/stream/test_hls.py
index 204b460b026..e9da793369f 100644
--- a/tests/components/stream/test_hls.py
+++ b/tests/components/stream/test_hls.py
@@ -29,7 +29,7 @@ from .common import (
 from tests.common import async_fire_time_changed
 
 STREAM_SOURCE = "some-stream-source"
-INIT_BYTES = b"init"
+INIT_BYTES = b"\x00\x00\x00\x08moov"
 FAKE_PAYLOAD = b"fake-payload"
 SEGMENT_DURATION = 10
 TEST_TIMEOUT = 5.0  # Lower than 9s home assistant timeout
diff --git a/tests/components/stream/test_ll_hls.py b/tests/components/stream/test_ll_hls.py
index 5755617f393..baad3043547 100644
--- a/tests/components/stream/test_ll_hls.py
+++ b/tests/components/stream/test_ll_hls.py
@@ -30,7 +30,7 @@ TEST_PART_DURATION = 0.75
 NUM_PART_SEGMENTS = int(-(-SEGMENT_DURATION // TEST_PART_DURATION))
 PART_INDEPENDENT_PERIOD = int(1 / TEST_PART_DURATION) or 1
 BYTERANGE_LENGTH = 1
-INIT_BYTES = b"init"
+INIT_BYTES = b"\x00\x00\x00\x08moov"
 SEQUENCE_BYTES = bytearray(range(NUM_PART_SEGMENTS * BYTERANGE_LENGTH))
 ALT_SEQUENCE_BYTES = bytearray(range(20, 20 + NUM_PART_SEGMENTS * BYTERANGE_LENGTH))
 VERY_LARGE_LAST_BYTE_POS = 9007199254740991
diff --git a/tests/components/stream/test_worker.py b/tests/components/stream/test_worker.py
index 00d735df74d..54400af65ab 100644
--- a/tests/components/stream/test_worker.py
+++ b/tests/components/stream/test_worker.py
@@ -242,7 +242,7 @@ class FakePyAvBuffer:
         # Forward to appropriate FakeStream
         packet.stream.mux(packet)
         # Make new init/part data available to the worker
-        self.memory_file.write(b"0")
+        self.memory_file.write(b"\x00\x00\x00\x00moov")
 
     def close(self):
         """Close the buffer."""