diff --git a/src/lua_baselib.c b/src/lua_baselib.c
index bc9c7b43e..47d685b1c 100644
--- a/src/lua_baselib.c
+++ b/src/lua_baselib.c
@@ -2586,10 +2586,36 @@ static int lib_rGetNameByColor(lua_State *L)
 
 // S_SOUND
 ////////////
+static int GetValidSoundOrigin(lua_State *L, void **origin)
+{
+	const char *type;
+
+	lua_settop(L, 1);
+	type = GetUserdataUType(L);
+
+	if (fasticmp(type, "mobj_t"))
+	{
+		*origin = *((mobj_t **)luaL_checkudata(L, 1, META_MOBJ));
+		if (!(*origin))
+			return LUA_ErrInvalid(L, "mobj_t");
+		return 1;
+	}
+	else if (fasticmp(type, "sector_t"))
+	{
+		*origin = *((sector_t **)luaL_checkudata(L, 1, META_SECTOR));
+		if (!(*origin))
+			return LUA_ErrInvalid(L, "sector_t");
+
+		*origin = &((sector_t *)(*origin))->soundorg;
+		return 1;
+	}
+
+	return LUA_ErrInvalid(L, "mobj_t/sector_t");
+}
+
 static int lib_sStartSound(lua_State *L)
 {
 	void *origin = NULL;
-	const char *origtype;
 	sfxenum_t sound_id = luaL_checkinteger(L, 2);
 	player_t *player = NULL;
 	//NOHUD
@@ -2604,28 +2630,8 @@ static int lib_sStartSound(lua_State *L)
 			return LUA_ErrInvalid(L, "player_t");
 	}
 	if (!lua_isnil(L, 1))
-	{
-		lua_settop(L, 1);
-
-		origtype = GetUserdataUType(L);
-
-		if (fasticmp(origtype, "mobj_t"))
-		{
-			origin = *((mobj_t **)luaL_checkudata(L, 1, META_MOBJ));
-			if (!origin)
-				return LUA_ErrInvalid(L, "mobj_t");
-		}
-		else if (fasticmp(origtype, "sector_t"))
-		{
-			origin = *((sector_t **)luaL_checkudata(L, 1, META_SECTOR));
-			if (!origin)
-				return LUA_ErrInvalid(L, "sector_t");
-
-			origin = &((sector_t *)origin)->soundorg;
-		}
-		else
-			return LUA_ErrInvalid(L, "mobj_t/sector_t");
-	}
+		if (!GetValidSoundOrigin(L, &origin))
+			return 0;
 	if (!player || P_IsLocalPlayer(player))
 	{
 		if (hud_running)
@@ -2639,7 +2645,6 @@ static int lib_sStartSound(lua_State *L)
 static int lib_sStartSoundAtVolume(lua_State *L)
 {
 	void *origin = NULL;
-	const char *origtype;
 	sfxenum_t sound_id = luaL_checkinteger(L, 2);
 	INT32 volume = (INT32)luaL_checkinteger(L, 3);
 	player_t *player = NULL;
@@ -2654,56 +2659,19 @@ static int lib_sStartSoundAtVolume(lua_State *L)
 			return LUA_ErrInvalid(L, "player_t");
 	}
 	if (!lua_isnil(L, 1))
-	{
-		lua_settop(L, 1);
-
-		origtype = GetUserdataUType(L);
-
-		if (fasticmp(origtype, "mobj_t"))
-		{
-			origin = *((mobj_t **)luaL_checkudata(L, 1, META_MOBJ));
-			if (!origin)
-				return LUA_ErrInvalid(L, "mobj_t");
-		}
-		else if (fasticmp(origtype, "sector_t"))
-		{
-			origin = *((sector_t **)luaL_checkudata(L, 1, META_SECTOR));
-			if (!origin)
-				return LUA_ErrInvalid(L, "sector_t");
-
-			origin = &((sector_t *)origin)->soundorg;
-		}
-		else
+		if (!GetValidSoundOrigin(L, &origin))
 			return LUA_ErrInvalid(L, "mobj_t/sector_t");
-	}
+
 	if (!player || P_IsLocalPlayer(player))
-	S_StartSoundAtVolume(origin, sound_id, volume);
+		S_StartSoundAtVolume(origin, sound_id, volume);
 	return 0;
 }
 
 static int lib_sStopSound(lua_State *L)
 {
 	void *origin = NULL;
-	const char *origtype;
 	//NOHUD
-	lua_settop(L, 1);
-	origtype = GetUserdataUType(L);
-
-	if (fasticmp(origtype, "mobj_t"))
-	{
-		origin = *((mobj_t **)luaL_checkudata(L, 1, META_MOBJ));
-		if (!origin)
-			return LUA_ErrInvalid(L, "mobj_t");
-	}
-	else if (fasticmp(origtype, "sector_t"))
-	{
-		origin = *((sector_t **)luaL_checkudata(L, 1, META_SECTOR));
-		if (!origin)
-			return LUA_ErrInvalid(L, "sector_t");
-
-		origin = &((sector_t *)origin)->soundorg;
-	}
-	else
+	if (!GetValidSoundOrigin(L, &origin))
 		return LUA_ErrInvalid(L, "mobj_t/sector_t");
 
 	S_StopSound(origin);
@@ -2713,35 +2681,14 @@ static int lib_sStopSound(lua_State *L)
 static int lib_sStopSoundByID(lua_State *L)
 {
 	void *origin = NULL;
-	const char *origtype;
 	sfxenum_t sound_id = luaL_checkinteger(L, 2);
 	//NOHUD
 
 	if (sound_id >= NUMSFX)
 		return luaL_error(L, "sfx %d out of range (0 - %d)", sound_id, NUMSFX-1);
 	if (!lua_isnil(L, 1))
-	{
-		lua_settop(L, 1);
-
-		origtype = GetUserdataUType(L);
-
-		if (fasticmp(origtype, "mobj_t"))
-		{
-			origin = *((mobj_t **)luaL_checkudata(L, 1, META_MOBJ));
-			if (!origin)
-				return LUA_ErrInvalid(L, "mobj_t");
-		}
-		else if (fasticmp(origtype, "sector_t"))
-		{
-			origin = *((sector_t **)luaL_checkudata(L, 1, META_SECTOR));
-			if (!origin)
-				return LUA_ErrInvalid(L, "sector_t");
-
-			origin = &((sector_t *)origin)->soundorg;
-		}
-		else
+		if (!GetValidSoundOrigin(L, &origin))
 			return LUA_ErrInvalid(L, "mobj_t/sector_t");
-	}
 
 	S_StopSoundByID(origin, sound_id);
 	return 0;
@@ -2968,27 +2915,9 @@ static int lib_sSetMusicPosition(lua_State *L)
 static int lib_sOriginPlaying(lua_State *L)
 {
 	void *origin = NULL;
-	const char *origtype;
 	//NOHUD
 	INLEVEL
-	lua_settop(L, 1);
-	origtype = GetUserdataUType(L);
-
-	if (fasticmp(origtype, "mobj_t"))
-	{
-		origin = *((mobj_t **)luaL_checkudata(L, 1, META_MOBJ));
-		if (!origin)
-			return LUA_ErrInvalid(L, "mobj_t");
-	}
-	else if (fasticmp(origtype, "sector_t"))
-	{
-		origin = *((sector_t **)luaL_checkudata(L, 1, META_SECTOR));
-		if (!origin)
-			return LUA_ErrInvalid(L, "sector_t");
-
-		origin = &((sector_t *)origin)->soundorg;
-	}
-	else
+	if (!GetValidSoundOrigin(L, &origin))
 		return LUA_ErrInvalid(L, "mobj_t/sector_t");
 
 	lua_pushboolean(L, S_OriginPlaying(origin));
@@ -3008,35 +2937,13 @@ static int lib_sIdPlaying(lua_State *L)
 static int lib_sSoundPlaying(lua_State *L)
 {
 	void *origin = NULL;
-	const char *origtype;
 	sfxenum_t id = luaL_checkinteger(L, 2);
 	//NOHUD
 	INLEVEL
 	if (id >= NUMSFX)
 		return luaL_error(L, "sfx %d out of range (0 - %d)", id, NUMSFX-1);
-	if (!lua_isnil(L, 1))
-	{
-		lua_settop(L, 1);
-
-		origtype = GetUserdataUType(L);
-
-		if (fasticmp(origtype, "mobj_t"))
-		{
-			origin = *((mobj_t **)luaL_checkudata(L, 1, META_MOBJ));
-			if (!origin)
-				return LUA_ErrInvalid(L, "mobj_t");
-		}
-		else if (fasticmp(origtype, "sector_t"))
-		{
-			origin = *((sector_t **)luaL_checkudata(L, 1, META_SECTOR));
-			if (!origin)
-				return LUA_ErrInvalid(L, "sector_t");
-
-			origin = &((sector_t *)origin)->soundorg;
-		}
-		else
-			return LUA_ErrInvalid(L, "mobj_t/sector_t");
-	}
+	if (!GetValidSoundOrigin(L, &origin))
+		return LUA_ErrInvalid(L, "mobj_t/sector_t");
 
 	lua_pushboolean(L, S_SoundPlaying(origin, id));
 	return 1;