diff --git a/homeassistant/components/media_source/__init__.py b/homeassistant/components/media_source/__init__.py
index 3be5bf040d7..d990b0b1f3d 100644
--- a/homeassistant/components/media_source/__init__.py
+++ b/homeassistant/components/media_source/__init__.py
@@ -2,6 +2,7 @@
 from __future__ import annotations
 
 from collections.abc import Callable
+import dataclasses
 from datetime import timedelta
 from typing import Any
 from urllib.parse import quote
@@ -165,15 +166,17 @@ async def websocket_resolve_media(
     """Resolve media."""
     try:
         media = await async_resolve_media(hass, msg["media_content_id"])
-        url = media.url
     except Unresolvable as err:
         connection.send_error(msg["id"], "resolve_media_failed", str(err))
-    else:
-        if url[0] == "/":
-            url = async_sign_path(
-                hass,
-                quote(url),
-                timedelta(seconds=msg["expires"]),
-            )
+        return
 
-        connection.send_result(msg["id"], {"url": url, "mime_type": media.mime_type})
+    data = dataclasses.asdict(media)
+
+    if data["url"][0] == "/":
+        data["url"] = async_sign_path(
+            hass,
+            quote(data["url"]),
+            timedelta(seconds=msg["expires"]),
+        )
+
+    connection.send_result(msg["id"], data)
diff --git a/homeassistant/components/media_source/local_source.py b/homeassistant/components/media_source/local_source.py
index 76598eac963..66baa0eaa8c 100644
--- a/homeassistant/components/media_source/local_source.py
+++ b/homeassistant/components/media_source/local_source.py
@@ -56,10 +56,6 @@ class LocalSource(MediaSource):
         if item.domain != DOMAIN:
             raise Unresolvable("Unknown domain.")
 
-        if not item.identifier:
-            # Empty source_dir_id and location
-            return "", ""
-
         source_dir_id, _, location = item.identifier.partition("/")
         if source_dir_id not in self.hass.config.media_dirs:
             raise Unresolvable("Unknown source directory.")
@@ -74,36 +70,39 @@ class LocalSource(MediaSource):
     async def async_resolve_media(self, item: MediaSourceItem) -> PlayMedia:
         """Resolve media to a url."""
         source_dir_id, location = self.async_parse_identifier(item)
-        if source_dir_id == "" or source_dir_id not in self.hass.config.media_dirs:
-            raise Unresolvable("Unknown source directory.")
-
-        mime_type, _ = mimetypes.guess_type(
-            str(self.async_full_path(source_dir_id, location))
-        )
+        path = self.async_full_path(source_dir_id, location)
+        mime_type, _ = mimetypes.guess_type(str(path))
         assert isinstance(mime_type, str)
         return PlayMedia(f"/media/{item.identifier}", mime_type)
 
     async def async_browse_media(self, item: MediaSourceItem) -> BrowseMediaSource:
         """Return media."""
-        try:
-            source_dir_id, location = self.async_parse_identifier(item)
-        except Unresolvable as err:
-            raise BrowseError(str(err)) from err
+        if item.identifier:
+            try:
+                source_dir_id, location = self.async_parse_identifier(item)
+            except Unresolvable as err:
+                raise BrowseError(str(err)) from err
+
+        else:
+            source_dir_id, location = None, ""
 
         result = await self.hass.async_add_executor_job(
             self._browse_media, source_dir_id, location
         )
+
         return result
 
-    def _browse_media(self, source_dir_id: str, location: str) -> BrowseMediaSource:
+    def _browse_media(
+        self, source_dir_id: str | None, location: str
+    ) -> BrowseMediaSource:
         """Browse media."""
 
         # If only one media dir is configured, use that as the local media root
-        if source_dir_id == "" and len(self.hass.config.media_dirs) == 1:
+        if source_dir_id is None and len(self.hass.config.media_dirs) == 1:
             source_dir_id = list(self.hass.config.media_dirs)[0]
 
         # Multiple folder, root is requested
-        if source_dir_id == "":
+        if source_dir_id is None:
             if location:
                 raise BrowseError("Folder not found.")
 
diff --git a/tests/components/media_source/test_init.py b/tests/components/media_source/test_init.py
index 7aae72475cb..a32535a5657 100644
--- a/tests/components/media_source/test_init.py
+++ b/tests/components/media_source/test_init.py
@@ -1,8 +1,8 @@
 """Test Media Source initialization."""
 from unittest.mock import Mock, patch
-from urllib.parse import quote
 
 import pytest
+import yarl
 
 from homeassistant.components import media_source
 from homeassistant.components.media_player import MEDIA_CLASS_DIRECTORY, BrowseError
@@ -159,7 +159,10 @@ async def test_websocket_resolve_media(hass, hass_ws_client, filename):
 
     client = await hass_ws_client(hass)
 
-    media = media_source.models.PlayMedia(f"/media/local/{filename}", "audio/mpeg")
+    media = media_source.models.PlayMedia(
+        f"/media/local/{filename}",
+        "audio/mpeg",
+    )
 
     with patch(
         "homeassistant.components.media_source.async_resolve_media",
@@ -177,9 +180,13 @@ async def test_websocket_resolve_media(hass, hass_ws_client, filename):
 
     assert msg["success"]
     assert msg["id"] == 1
-    assert msg["result"]["url"].startswith(quote(media.url))
     assert msg["result"]["mime_type"] == media.mime_type
 
+    # Validate url is signed.
+    parsed = yarl.URL(msg["result"]["url"])
+    assert parsed.path == getattr(media, "url")
+    assert "authSig" in parsed.query
+
     with patch(
         "homeassistant.components.media_source.async_resolve_media",
         side_effect=media_source.Unresolvable("test"),