Support a free-form string argument passed from Avisynth to the Lua script.

Originally committed to SVN as r1476.

OverLua/avisynth.cpp

@@ -40,7 +40,7 @@ private:
 	double spf; // seconds per frame - for frame/timestamp conversion
 
 public:
-	OverLuaAvisynth(PClip _child, IScriptEnvironment *env, const char *file)
+	OverLuaAvisynth(PClip _child, IScriptEnvironment *env, const char *file, const char *datastring, const char *vfrfile)
 		: GenericVideoFilter(_child)
 	{
 		switch (vi.pixel_type) {
@@ -53,7 +53,7 @@ public:
 		}
 
 		try {
-			script = new OverLuaScript(file);
+			script = new OverLuaScript(file, datastring);
 			spf = (double)vi.fps_denominator / (double)vi.fps_numerator;
 		}
 		catch (const char *e) {
@@ -112,14 +112,14 @@ public:
 
 	static AVSValue __cdecl Create(AVSValue args, void* user_data, IScriptEnvironment* env)
 	{
-		return new OverLuaAvisynth(args[0].AsClip(), env, args[1].AsString());
+		return new OverLuaAvisynth(args[0].AsClip(), env, args[1].AsString(), args[2].AsString(0), args[3].AsString(0));
 	}
 };
 
 
 extern "C" __declspec(dllexport) const char* __stdcall AvisynthPluginInit2(IScriptEnvironment* env)
 {
-	env->AddFunction("OverLua", "cs", OverLuaAvisynth::Create, 0);
+	env->AddFunction("OverLua", "cs[data]s[vfr]s", OverLuaAvisynth::Create, 0);
 	return "OverLua";
 }
 

OverLua/docs/overlua.txt

@@ -2,6 +2,27 @@ OverLua provides a Lua 5.1 runtime environment with access to all
 standard libraries.
 
 
+The Avisynth filter
+-------------------
+
+The Avisynth filter version of OverLua exports one function:
+
+  OverLua(clip c, string scriptfile, string "datastring", string "vfrfile")
+
+The clip c argument is self-explanatory, the clip to render on.
+
+The scripfile is the path to the Lua script you want to load and run.
+
+datastring is a freeform string to pass to the Lua script. This will often
+be the path to a file with additional data for the script, such as timed
+subtitles/karaoke.
+
+vfrfile is the path to a timecode file Matroska format 1 or 2. If supplied,
+it will be used to translate frame numbers to timestamps instead of relying
+on the frame rate provided by Avisynth.
+VFR support is not implemented yet.
+
+
 API the Lua script must implement
 ---------------------------------
 
@@ -28,6 +49,11 @@ The render_frame function should not assume that frames are requested in
 any specific order.
 
 
+If a "datastring" argument is supplied to the OverLua Avisynth function, the
+argument value will be available through the global variable
+"overlua_datastring" in the Lua script environment.
+
+
 The frame object
 ----------------
 

OverLua/overlua.cpp

@@ -49,7 +49,7 @@ struct FileScriptReader {
 	}
 };
 
-OverLuaScript::OverLuaScript(const char *filename)
+OverLuaScript::OverLuaScript(const char *filename, const char *datastring)
 {
 	FileScriptReader reader;
 #ifdef WIN32
@@ -61,7 +61,7 @@ OverLuaScript::OverLuaScript(const char *filename)
 	reader.file = fopen(filename, "r");
 #endif
 
-	Create(reader, filename);
+	Create(reader, filename, datastring);
 
 	fclose(reader.file);
 }
@@ -84,36 +84,20 @@ int OverLuaScript::lua_debug_print(lua_State *L)
 {
 	const char *str = luaL_checkstring(L, 1);
 #ifdef WIN32
-	OutputDebugStringA(str);
+	OutputDebugStringA(str); // ought to be W version but conversion is such a hassle
 #else
 	printf(str);
 #endif
 	return 0;
 }
 
-OverLuaScript::OverLuaScript(const void *data, size_t length)
+OverLuaScript::OverLuaScript(const void *data, size_t length, const char *datastring)
 {
 	MemScriptReader reader;
 	reader.memdata = data;
 	reader.memdatasize = length;
 
-	Create(reader, "Memory script");
-
-	int err;
-
-	L = luaL_newstate();
-
-	err = lua_load(L, reader.reader, &reader, "Memory script");
-
-	// todo: better error handling
-	if (err == LUA_ERRSYNTAX) throw "Syntax error";
-	if (err = LUA_ERRMEM) throw "Memory error";
-
-	err = lua_pcall(L, 0, 0, 0);
-
-	if (err == LUA_ERRRUN) throw "Runtime error";
-	if (err == LUA_ERRMEM) throw "Memory error";
-	if (err == LUA_ERRERR) throw "Error-handler error";
+	Create(reader, "Memory script", datastring);
 }
 
 OverLuaScript::~OverLuaScript()
@@ -123,18 +107,12 @@ OverLuaScript::~OverLuaScript()
 
 void OverLuaScript::RenderFrameRGB(OverLuaFrameAggregate &frame, double time)
 {
-	OutputDebugStringW(L"RenderFrameRGB: get frame func\n");
 	lua_getglobal(L, "render_frame");
-	OutputDebugStringW(L"RenderFrameRGB: CreateLuaObject\n");
 	frame.CreateLuaObject(L);
 	lua_pushnumber(L, time);
-	OutputDebugStringW(L"RenderFrameRGB: call\n");
 	if (lua_pcall(L, 2, 0, 0)) {
 		const char *err = lua_tostring(L, -1);
-		//MessageBoxA(0, err, "OverLua", MB_ICONERROR);
 		throw err;
 	}
-	OutputDebugStringW(L"RenderFrameRGB: garbage collect\n");
 	lua_gc(L, LUA_GCCOLLECT, 0);
-	OutputDebugStringW(L"RenderFrameRGB: done rendering frame\n");
 }

OverLua/overlua.h

@@ -47,7 +47,7 @@ private:
 	OverLuaScript() { }
 
 	template <class ScriptReaderClass>
-	void Create(ScriptReaderClass &reader, const char *chunkname)
+	void Create(ScriptReaderClass &reader, const char *chunkname, const char *datastring)
 	{
 		int err;
 
@@ -62,6 +62,12 @@ private:
 		// Debug print
 		lua_pushcclosure(L, lua_debug_print, 0);
 		lua_setglobal(L, "dprint");
+		// Datastring
+		if (datastring)
+			lua_pushstring(L, datastring);
+		else
+			lua_pushnil(L);
+		lua_setglobal(L, "overlua_datastring");
 
 		err = lua_load(L, reader.reader, &reader, chunkname);
 
@@ -79,8 +85,8 @@ private:
 	static int lua_debug_print(lua_State *L);
 
 public:
-	OverLuaScript(const char *filename);
-	OverLuaScript(const void *data, size_t length);
+	OverLuaScript(const char *filename, const char *_datastring = 0);
+	OverLuaScript(const void *data, size_t length, const char *_datastring = 0);
 	virtual ~OverLuaScript();
 
 	void RenderFrameRGB(OverLuaFrameAggregate &frame, double time);