Fix finding body start

Author: lpastusz

src/elevenlabs/music_custom.py

@@ -16,6 +16,19 @@
 logger = logging.getLogger(__name__)
 
 
+def _find_body_start(data: bytes, start: int) -> int:
+    """Find the blank line separating headers from body, returning the index of the body start."""
+    crlf_pos = data.find(b"\r\n\r\n", start)
+    if crlf_pos != -1:
+        return crlf_pos + 4
+
+    lf_pos = data.find(b"\n\n", start)
+    if lf_pos != -1:
+        return lf_pos + 2
+
+    raise ValueError("Could not find header/body separator in audio part")
+
+
 @dataclass
 class SongMetadata:
     title: str
@@ -145,16 +158,7 @@ def _parse_multipart(self, stream: typing.Iterator[bytes]) -> MultipartResponse:
             raise ValueError('Could not find audio part boundary')
 
         # Find the start of audio data (after headers and empty line)
-        audio_start = second_boundary + len(boundary_bytes)
-
-        # Skip past the headers to find the empty line (\n\n)
-        while audio_start < len(response_bytes) - 1:
-            if (response_bytes[audio_start] == 0x0A and
-                response_bytes[audio_start + 1] == 0x0A):
-                # Found \n\n - audio starts after this
-                audio_start += 2
-                break
-            audio_start += 1
+        audio_start = _find_body_start(response_bytes, second_boundary + len(boundary_bytes))
 
         # Audio goes until the end (or until we find another boundary)
         audio_buffer = response_bytes[audio_start:]
@@ -281,16 +285,7 @@ async def _parse_multipart_async(self, stream: typing.AsyncIterator[bytes]) -> M
             raise ValueError('Could not find audio part boundary')
 
         # Find the start of audio data (after headers and empty line)
-        audio_start = second_boundary + len(boundary_bytes)
-
-        # Skip past the headers to find the empty line (\n\n)
-        while audio_start < len(response_bytes) - 1:
-            if (response_bytes[audio_start] == 0x0A and
-                response_bytes[audio_start + 1] == 0x0A):
-                # Found \n\n - audio starts after this
-                audio_start += 2
-                break
-            audio_start += 1
+        audio_start = _find_body_start(response_bytes, second_boundary + len(boundary_bytes))
 
         # Audio goes until the end (or until we find another boundary)
         audio_buffer = response_bytes[audio_start:]