自学教程：C++ AVSValue类代码示例

                // utility functions                // Opens AVS file and sets some member variables.                void open(const char* avsfile) {                    DBGLOG("avsutil::impl::cavs_type::open(/"" << avsfile << "/")");                    try {                        // pack the filename as the argument of AviSynth filter                        AVSValue filename = avsfile;                        AVSValue args = AVSValue(&filename, 1);                        // load AviSynth script                        AVSValue imported = mv_se->Invoke("Import", args, 0);                        // get the clip and video informations                        mv_clip = imported.AsClip();                        // store filename                        mv_filepath = avsfile;                    }                    catch (AvisynthError& avserr) {                        mv_is_fine = false;                        mv_errmsg = avserr.msg;                    }                    catch (std::exception& ex) {                        mv_is_fine = false;                        mv_errmsg = ex.what();                    }                }

int main() {    try {        cout << "Creating script environment 1..." << endl;        IScriptEnvironment* env1 = CreateScriptEnvironment(3);        cout << "Creating script environment 2..." << endl;        IScriptEnvironment* env2 = CreateScriptEnvironment(3);        cout << "Deleting script environment 1..." << endl;        delete env1;        cout << "Invoking BlankClip on env 2..." << endl;        AVSValue ret = env2->Invoke("BlankClip", AVSValue(), 0);        PClip clp = ret.AsClip();        cout << "Reading frame 0 from env2..." << endl;        PVideoFrame frm = clp->GetFrame(0, env2);    } catch (AvisynthError &e) {        cerr << "AvisynthError: " << e.msg << endl;        return -1;    } catch (...) {        cerr << "unknown error" << endl;        return -1;    }    return 0;}

AVSValue ExpConditional::Evaluate(IScriptEnvironment* env) {  AVSValue cond = If->Evaluate(env);  if (!cond.IsBool())    env->ThrowError("Evaluate: left of `?' must be boolean (true/false)");  return (cond.AsBool() ? Then : Else)->Evaluate(env);}

int __stdcall dimzon_avs_getvariable_s(SafeStruct* pstr, const char* name, char* result, int len){	try	{		pstr->err[0] = 0;		try		{			AVSValue var = pstr->env->GetVar(name);			if(var.Defined())			{				if(!var.IsString())				{					strncpy_s(pstr->err, ERRMSG_LEN, "AviSynthWrapper: Requested variable is not String!", _TRUNCATE);					return AVS_VARWRNGTYPE;				}				strncpy_s(result, len, var.AsString(), len - 1);				return 0;			}			return AVS_VARNDEFINED;		}		catch(AvisynthError err)		{			strncpy_s(pstr->err, ERRMSG_LEN, err.msg, _TRUNCATE);			return AVS_GERROR;		}	}	catch(IScriptEnvironment::NotFound)	{		return AVS_VARNFOUND;	}}

bool Write::DoEval( IScriptEnvironment* env) {	bool keep_this_line = true;	int i;	AVSValue expr;	AVSValue result;	for (i=0; i<arrsize; i++) {		expr = arglist[i].expression;				if ( (linecheck==1) && (i==0)) {			try {				result = env->Invoke("Eval",expr);				if (!result.AsBool(true)) {					keep_this_line = false;					break;				}			} catch (AvisynthError) {//				env->ThrowError("Write: Can't eval linecheck expression!"); // results in KEEPING the line			}		} else {			try {				result = env->Invoke("Eval",expr);				result = env->Invoke("string",result);	//convert all results to a string				arglist[i].string = result.AsString(EMPTY);			} catch (AvisynthError error) {				arglist[i].string = env->SaveString(error.msg);			}		}	}	return keep_this_line;}

void ConditionalReader::SetRange(int start_frame, int stop_frame, AVSValue v) {    int i;    start_frame = std::max(std::min(start_frame, vi.num_frames-1), 0);    stop_frame = std::max(std::min(stop_frame, vi.num_frames-1), 0);    int p;    float q;    bool r;    switch (mode) {    case MODE_INT:        p = v.AsInt();        for (i = start_frame; i <= stop_frame; i++) {            intVal[i] = p;        }        break;    case MODE_FLOAT:        q = (float)v.AsFloat();        for (i = start_frame; i <= stop_frame; i++) {            floatVal[i] = q;        }        break;    case MODE_BOOL:        r = v.AsBool();        for (i = start_frame; i <= stop_frame; i++) {            boolVal[i] = r;        }        break;    }}

PVideoFrame __stdcall ConditionalSelect::GetFrame(int n, IScriptEnvironment* env) {  AVSValue prev_last = env->GetVarDef("last");  // Store previous last  AVSValue prev_current_frame = env->GetVarDef("current_frame");  // Store previous current_frame  env->SetVar("last", (AVSValue)child);      // Set implicit last  env->SetVar("current_frame", (AVSValue)n); // Set frame to be tested by the conditional filters.  AVSValue result;  try {    ScriptParser parser(env, expression, "[Conditional Select, Expression]");    PExpression exp = parser.Parse();    result = exp->Evaluate(env);    if (!result.IsInt())      env->ThrowError("Conditional Select: Expression must return an integer!");  }  catch (AvisynthError error) {        env->SetVar("last", prev_last);                   // Restore implicit last    env->SetVar("current_frame", prev_current_frame); // Restore current_frame    const int num_frames = child->GetVideoInfo().num_frames;    PVideoFrame dst = child->GetFrame(min(num_frames-1, n), env);    env->MakeWritable(&dst);    env->ApplyMessage(&dst, vi, error.msg, vi.width/W_DIVISOR, 0xa0a0a0, 0, 0);    return dst;  }  env->SetVar("last", prev_last);                   // Restore implicit last  env->SetVar("current_frame", prev_current_frame); // Restore current_frame  const int i = result.AsInt();    PVideoFrame dst;  if (i < 0 || i >= num_args) {    const int num_frames = child->GetVideoInfo().num_frames;    dst = child->GetFrame(min(num_frames-1, n), env);  }  else {    const int num_frames = child_array[i]->GetVideoInfo().num_frames;    dst = child_array[i]->GetFrame(min(num_frames-1, n), env);  }  if (show) {    char text[32];    _snprintf(text, sizeof(text)-1, "Expression Result:%i/n", result.AsInt());    text[sizeof(text)-1] = '/0';    env->MakeWritable(&dst);    env->ApplyMessage(&dst, vi, text, vi.width/4, 0xa0a0a0, 0, 0);  }  return dst;}

AVSValue __cdecl CSRIAviSynth::Create(AVSValue args, void* user_data,	IScriptEnvironment* env){	const char *rname = args.ArraySize() >= 2 ? args[2].AsString() : NULL,		*rver = args.ArraySize() >= 3 ? args[3].AsString() : NULL;	return new CSRIAviSynth(args[0].AsClip(), env, args[1].AsString(),		rname, rver);}

MVClipArray::MVClipArray(const AVSValue &vectors, int nSCD1, int nSCD2, IScriptEnvironment *env){   DebugPrintf("Constructing mvClipArray... : %i", vectors.ArraySize());   size_ = vectors.ArraySize();   pmvClips = new MVClip*[size_];   for ( int i = 0; i < size_; i++ )      pmvClips[i] = new MVClip(vectors[i].AsClip(), nSCD1, nSCD2, env);}

AVSValue ExpFunctionCall::Evaluate(IScriptEnvironment* env){  AVSValue result = Call(env);  if (result.IsClip()) {    return env->Invoke("Cache", result);  }  return result;}

AVSValue ExpAnd::Evaluate(IScriptEnvironment* env) {  AVSValue x = a->Evaluate(env);  if (!x.IsBool())    env->ThrowError("Evaluate: left operand of && must be boolean (true/false)");  if (!x.AsBool())    return x;  AVSValue y = b->Evaluate(env);  if (!y.IsBool())    env->ThrowError("Evaluate: right operand of && must be boolean (true/false)");  return y;}

  Echo( PClip _child, const AVSValue _clips, IScriptEnvironment* env )     : GenericVideoFilter(_child), ClipCount(_clips.ArraySize()) {    clips = new PClip[ClipCount];    for (int i=0; i < ClipCount; i++)      clips[i] = _clips[i].AsClip();  }

int AvxContext::OpenFile() {	try {		AVSValue ret = avx_library.env->Invoke("Import", scriptName);		if (!ret.IsClip()) {			AVXLOG_ERROR("%s", "Script did not return a clip");			return -1;		}		clip = ret.AsClip();		vi = clip->GetVideoInfo();	} catch (AvisynthError &e) {		AVXLOG_ERROR("AvisynthError: %s", e.msg);		return -1;	}	return 0;}

void ConditionalReader::SetFrame(int framenumber, AVSValue v) {    if (framenumber < 0 || framenumber > vi.num_frames-1 )        return;    switch (mode) {    case MODE_INT:        intVal[framenumber] = v.AsInt();        break;    case MODE_FLOAT:        floatVal[framenumber] = (float)v.AsFloat();        break;    case MODE_BOOL:        boolVal[framenumber] = v.AsBool();        break;    }}

int __stdcall dimzon_avs_isfuncexists(SafeStruct* pstr, const char *func){	pstr->err[0] = 0;	try	{		AVSValue var = pstr->env->FunctionExists(func);		if (var.IsBool())		{			return (var.AsBool()) ? 0 : AVS_VARNFOUND;		}		return AVS_VARWRNGTYPE;	}	catch(AvisynthError err)	{		strncpy_s(pstr->err, ERRMSG_LEN, err.msg, _TRUNCATE);		return AVS_GERROR;	}}

static AVSValue __cdeclcreate_iscombed(AVSValue args, void*, ise_t* env){    enum { CLIP, CTHRESH, MTHRESH, MI, BLOCKX, BLOCKY, METRIC, OPT };    CombMask* cm = nullptr;    try {        AVSValue cf = env->GetVar("current_frame");        validate(!cf.IsInt(),                 "This filter can only be used within ConditionalFilter.");        int n = cf.AsInt();        PClip clip = args[CLIP].AsClip();        int metric = args[METRIC].AsInt(0);        int cth = args[CTHRESH].AsInt(metric == 0 ? 6 : 10);        int mth = args[MTHRESH].AsInt(9);        int mi = args[MI].AsInt(80);        int blockx = args[BLOCKX].AsInt(16);        int blocky = args[BLOCKY].AsInt(16);        bool is_avsplus = env->FunctionExists("SetFilterMTMode");        arch_t arch = get_arch(args[OPT].AsInt(-1), is_avsplus);        validate(mi < 0 || mi > 128, "MI must be between 0 and 128.");        validate(blockx != 8 && blockx != 16 && blockx != 32,                 "blockx must be set to 8, 16 or 32.");        validate(blocky != 8 && blocky != 16 && blocky != 32,                 "blocky must be set to 8, 16 or 32.");        cm = new CombMask(clip, cth, mth, false, arch, false, metric, is_avsplus);        bool is_combed = (get_check_combed(arch))(            cm->GetFrame(n, env), mi, blockx, blocky, is_avsplus, env);        delete cm;        return AVSValue(is_combed);    } catch (std::runtime_error& e) {        if (cm) delete cm;        env->ThrowError("IsCombed: %s", e.what());    }    return 0;}

void ConditionalReader::SetFrame(int framenumber, AVSValue v) {  if ((framenumber+offset) < 0 || (framenumber+offset) > vi.num_frames-1 )    return;  switch (mode) {    case MODE_INT:      intVal[framenumber+offset] = v.AsInt();      break;    case MODE_FLOAT:      floatVal[framenumber+offset] = v.AsFloatf();      break;    case MODE_BOOL:      boolVal[framenumber+offset] = v.AsBool();      break;    case MODE_STRING:      stringVal[framenumber+offset] = v.AsString("");      break;  }}

/// @brief Read from environment/// @param _clip///void AvisynthAudioProvider::LoadFromClip(AVSValue _clip) {	AVSValue script;	// Check if it has audio	VideoInfo vi = _clip.AsClip()->GetVideoInfo();	if (!vi.HasAudio()) throw agi::AudioDataNotFoundError("No audio found.", 0);	IScriptEnvironment *env = avs_wrapper.GetEnv();	// Convert to one channel	char buffer[1024];	strcpy(buffer,lagi_wxString(OPT_GET("Audio/Downmixer")->GetString()).mb_str(csConvLocal));	script = env->Invoke(buffer, _clip);	// Convert to 16 bits per sample	script = env->Invoke("ConvertAudioTo16bit", script);	vi = script.AsClip()->GetVideoInfo();	// Convert sample rate	int setsample = OPT_GET("Provider/Audio/AVS/Sample Rate")->GetInt();	if (vi.SamplesPerSecond() < 32000) setsample = 44100;	if (setsample != 0) {		AVSValue args[2] = { script, setsample };		script = env->Invoke("ResampleAudio", AVSValue(args,2));	}	// Set clip	PClip tempclip = script.AsClip();	vi = tempclip->GetVideoInfo();	// Read properties	channels = vi.AudioChannels();	num_samples = vi.num_audio_samples;	sample_rate = vi.SamplesPerSecond();	bytes_per_sample = vi.BytesPerAudioSample();	float_samples = false;	clip = tempclip;}

void ConditionalReader::SetRange(int start_frame, int stop_frame, AVSValue v) {  int i;  start_frame = max(start_frame+offset, 0);  stop_frame = min(stop_frame+offset, vi.num_frames-1);  int p;  float q;  bool r;  const char* s;  switch (mode) {    case MODE_INT:      p = v.AsInt();      for (i = start_frame; i <= stop_frame; i++) {        intVal[i] = p;      }      break;    case MODE_FLOAT:      q = v.AsFloatf();      for (i = start_frame; i <= stop_frame; i++) {        floatVal[i] = q;      }      break;    case MODE_BOOL:      r = v.AsBool();      for (i = start_frame; i <= stop_frame; i++) {        boolVal[i] = r;      }      break;    case MODE_STRING:      s = v.AsString("");      for (i = start_frame; i <= stop_frame; i++) {        stringVal[i] = s;      }      break;  }}

AVSValue LoadPlugin(AVSValue args, void* user_data, IScriptEnvironment* env) {  bool quiet = (user_data != 0);  args = args[0];  const char* result=0;  for (int i=0; i<args.ArraySize(); ++i) {    HMODULE plugin;    const char* plugin_name = args[i].AsString();    if (MyLoadLibrary(plugin_name, &plugin, quiet, env)) {      typedef const char* (__stdcall *AvisynthPluginInitFunc)(IScriptEnvironment* env);      AvisynthPluginInitFunc AvisynthPluginInit = (AvisynthPluginInitFunc)dlsym(plugin, "AvisynthPluginInit2");      if (!AvisynthPluginInit) {        AvisynthPluginInit = (AvisynthPluginInitFunc)dlsym(plugin, "[email
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