Aegisub/aegisub/video_provider_avs.cpp

// Copyright (c) 2006, Fredrik Mellbin
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//   * Redistributions of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//   * Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//   * Neither the name of the Aegisub Group nor the names of its contributors
//     may be used to endorse or promote products derived from this software
//     without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// -----------------------------------------------------------------------------
//
// AEGISUB
//
// Website: http://aegisub.cellosoft.com
// Contact: mailto:zeratul@cellosoft.com
//


///////////
// Headers
#include <wx/wxprec.h>
#ifdef WITH_AVISYNTH
#include <wx/filename.h>
#include <wx/msw/registry.h>
#include <wx/filename.h>
#include "avisynth_wrap.h"
#include "video_provider.h"
#include "subtitles_provider.h"
#include "video_context.h"
#include "options.h"
#include "standard_paths.h"
#include "vfr.h"
#include "ass_file.h"
#include "gl_wrap.h"


////////////
// Provider
class AvisynthVideoProvider: public VideoProvider, SubtitlesProvider, AviSynthWrapper {
private:
	VideoInfo vi;
	AegiVideoFrame iframe;

	bool usedDirectShow;
	wxString rendererCallString;
	wxString decoderName;

	int num_frames;
	int last_fnum;

	double fps;
	wxArrayInt frameTime;
	bool byFrame;

	PClip RGB32Video;
	PClip SubtitledVideo;

	PClip OpenVideo(wxString _filename, bool mpeg2dec3_priority = true);
	PClip ApplySubtitles(wxString _filename, PClip videosource);

	void LoadVSFilter();
	void LoadASA();
	void LoadRenderer();

public:
	AvisynthVideoProvider(wxString _filename, double fps=0.0);
	~AvisynthVideoProvider();

	SubtitlesProvider *GetAsSubtitlesProvider();
	void LoadSubtitles(AssFile *subs);
	bool LockedToVideo() { return true; }

	const AegiVideoFrame DoGetFrame(int n);
	void GetFloatFrame(float* Buffer, int n);

	// properties
	int GetPosition() { return last_fnum; };
	int GetFrameCount() { return num_frames? num_frames: vi.num_frames; };
	double GetFPS() { return (double)vi.fps_numerator/(double)vi.fps_denominator; };
	int GetWidth() { return vi.width; };
	int GetHeight() { return vi.height; };

	void OverrideFrameTimeList(wxArrayInt list);
	bool IsNativelyByFrames() { return byFrame; }
	wxString GetWarning();
	wxString GetDecoderName() { return _T("Avisynth/") + decoderName; }
};


///////////
// Factory
class AvisynthVideoProviderFactory : public VideoProviderFactory {
public:
	VideoProvider *CreateProvider(wxString video,double fps=0.0) { return new AvisynthVideoProvider(video,fps); }
	AvisynthVideoProviderFactory() : VideoProviderFactory(_T("avisynth")) {}
} registerAVS;


///////////////
// Constructor
AvisynthVideoProvider::AvisynthVideoProvider(wxString _filename, double _fps) {
	AVSTRACE(wxString::Format(_T("AvisynthVideoProvider: Creating new AvisynthVideoProvider: \"%s\", \"%s\""), _filename, _subfilename));
	bool mpeg2dec3_priority = true;
	RGB32Video = NULL;
	SubtitledVideo = NULL;
	fps = _fps;
	num_frames = 0;
	last_fnum = -1;
	byFrame = false;

	AVSTRACE(_T("AvisynthVideoProvider: Loading Subtitles Renderer"));
	LoadRenderer();
	AVSTRACE(_T("AvisynthVideoProvider: Subtitles Renderer loaded"));

	AVSTRACE(_T("AvisynthVideoProvider: Opening video"));
	RGB32Video = OpenVideo(_filename,mpeg2dec3_priority);
	AVSTRACE(_T("AvisynthVideoProvider: Video opened"));

	SubtitledVideo = RGB32Video;
	AVSTRACE(_T("AvisynthVideoProvider: Applied subtitles"));

	vi = SubtitledVideo->GetVideoInfo();
	AVSTRACE(_T("AvisynthVideoProvider: Got video info"));
	AVSTRACE(_T("AvisynthVideoProvider: Done creating AvisynthVideoProvider"));
}


//////////////
// Destructor
AvisynthVideoProvider::~AvisynthVideoProvider() {
	AVSTRACE(_T("AvisynthVideoProvider: Destroying AvisynthVideoProvider"));
	RGB32Video = NULL;
	SubtitledVideo = NULL;
	AVSTRACE(_T("AvisynthVideoProvider: Destroying frame"));
	iframe.Clear();
	AVSTRACE(_T("AvisynthVideoProvider: AvisynthVideoProvider destroyed"));
}



////////////////////////////////////// VIDEO PROVIDER //////////////////////////////////////


/////////////////////////////////////////
// Actually open the video into Avisynth
PClip AvisynthVideoProvider::OpenVideo(wxString _filename, bool mpeg2dec3_priority) {
	AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Opening video"));
	wxMutexLocker lock(AviSynthMutex);
	AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Got AVS mutex"));
	AVSValue script;

	byFrame = false;
	usedDirectShow = false;
	decoderName = _("Unknown");

	wxString extension = _filename.Right(4);
	extension.LowerCase();

	try {
		// Prepare filename
		//char *videoFilename = env->SaveString(_filename.mb_str(wxConvLocal));
		wxFileName fname(_filename);
		char *videoFilename = env->SaveString(fname.GetShortPath().mb_str(wxConvLocal));

		// Avisynth file, just import it
		if (extension == _T(".avs")) { 
			AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Opening .avs file with Import"));
			script = env->Invoke("Import", videoFilename);
			AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Finished"));
			decoderName = _T("Import");
		}

		// Open avi file with AviSource
		else if (extension == _T(".avi")) {
			AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Opening .avi file with AviSource"));
			try {
				const char *argnames[2] = { 0, "audio" };
				AVSValue args[2] = { videoFilename, false };
				script = env->Invoke("AviSource", AVSValue(args,2), argnames);
				AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Successfully opened .avi file without audio"));
				byFrame = true;
				decoderName = _T("AviSource");
			}
			
			// On Failure, fallback to DSS
			catch (AvisynthError &) {
				AVSTRACE(_T("Failed to open .avi file with AviSource, switching to DirectShowSource"));
				goto directshowOpen;
			}
		}

		// Open d2v with mpeg2dec3
		else if (extension == _T(".d2v") && env->FunctionExists("Mpeg2Dec3_Mpeg2Source") && mpeg2dec3_priority) {
			AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Opening .d2v file with Mpeg2Dec3_Mpeg2Source"));
			script = env->Invoke("Mpeg2Dec3_Mpeg2Source", videoFilename);
			decoderName = _T("Mpeg2Dec3_Mpeg2Source");

            //if avisynth is 2.5.7 beta 2 or newer old mpeg2decs will crash without this
			if (env->FunctionExists("SetPlanarLegacyAlignment")) {
				AVSValue args[2] = { script, true };
        		script = env->Invoke("SetPlanarLegacyAlignment", AVSValue(args,2));
			}
		}

		// If that fails, try opening it with DGDecode
		else if (extension == _T(".d2v") && env->FunctionExists("DGDecode_Mpeg2Source")) {
			AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Opening .d2v file with DGDecode_Mpeg2Source"));
			script = env->Invoke("Mpeg2Source", videoFilename);
			decoderName = _T("DGDecode_Mpeg2Source");

            //note that DGDecode will also have issues like if the version is too ancient but no sane person
            //would use that anyway
		}

		else if (extension == _T(".d2v") && env->FunctionExists("Mpeg2Source")) {
			AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Opening .d2v file with other Mpeg2Source"));
			script = env->Invoke("Mpeg2Source", videoFilename);
			decoderName = _T("Mpeg2Source");

            //if avisynth is 2.5.7 beta 2 or newer old mpeg2decs will crash without this
        	if (env->FunctionExists("SetPlanarLegacyAlignment"))
        		script = env->Invoke("SetPlanarLegacyAlignment", script);
		}

		// Some other format, such as mkv, mp4, ogm... try FFMpegSource and DirectShowSource
		else {
			// Try loading FFMpegSource
			directshowOpen:
			bool ffsource = false;
			if (env->FunctionExists("ffmpegsource")) ffsource = true;
			if (!ffsource) {
				wxFileName ffsourcepath(StandardPaths::DecodePath(_T("?data/ffmpegsource.dll")));
				if (ffsourcepath.FileExists()) {
					AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Loading FFMpegSource"));
					env->Invoke("LoadPlugin",env->SaveString(ffsourcepath.GetFullPath().mb_str(wxConvLocal)));
					AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Loaded FFMpegSource"));
					byFrame = true;
				}
			}

			// If FFMpegSource loaded properly, try using it
			ffsource = false;
			if (env->FunctionExists("ffmpegsource")) {
				AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Invoking FFMpegSource"));
				const char *argnames[2] = { "source", "vcache" };
				AVSValue args[2] = { videoFilename, false };
				script = env->Invoke("ffmpegsource", AVSValue(args,2), argnames);
				//script = env->Invoke("ffmpegsource", videoFilename);
				AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Successfully opened file with FFMpegSource"));
				ffsource = true;
				decoderName = _T("FFmpegSource");
			}

			// DirectShowSource
			if (!ffsource) {
				AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Opening file with DirectShowSource"));

				// Try loading DirectShowSource2
				bool dss2 = false;
				if (env->FunctionExists("dss2")) dss2 = true;
				if (!dss2) {
					wxFileName dss2path(StandardPaths::DecodePath(_T("?data/avss.dll")));
					if (dss2path.FileExists()) {
						AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Loading DirectShowSource2"));
						env->Invoke("LoadPlugin",env->SaveString(dss2path.GetFullPath().mb_str(wxConvLocal)));
						AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Loaded DirectShowSource2"));
					}
				}

				// If DSS2 loaded properly, try using it
				dss2 = false;
				if (env->FunctionExists("dss2")) {
					AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Invoking DSS2"));
					if (fps == 0.0) script = env->Invoke("DSS2", videoFilename);
					else {
						const char *argnames[2] = { 0, "fps" };
						AVSValue args[2] = { videoFilename, fps };
						script = env->Invoke("DSS2", AVSValue(args,2), argnames);
					}
					AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Successfully opened file with DSS2"));
					dss2 = true;
					decoderName = _T("DSS2");
				}

				// Try DirectShowSource
				if (!dss2) {
					// Load DirectShowSource.dll from app dir if it exists
					wxFileName dsspath(StandardPaths::DecodePath(_T("?data/DirectShowSource.dll")));
					if (dsspath.FileExists()) {
						AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Loading DirectShowSource"));
						env->Invoke("LoadPlugin",env->SaveString(dsspath.GetFullPath().mb_str(wxConvLocal)));
						AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Loaded DirectShowSource"));
					}

					// Then try using DSS
					if (env->FunctionExists("DirectShowSource")) {
						if (fps == 0.0) {
							const char *argnames[3] = { 0, "video", "audio" };
							AVSValue args[3] = { videoFilename, true, false };
							script = env->Invoke("DirectShowSource", AVSValue(args,3), argnames);
						}
						else {
							const char *argnames[4] = { 0, "video", "audio" , "fps" };
							AVSValue args[4] = { videoFilename, true, false , fps };
							script = env->Invoke("DirectShowSource", AVSValue(args,4), argnames);
						}
						AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Successfully opened file with DSS without audio"));
						usedDirectShow = true;
						decoderName = _T("DirectShowSource");
					}

					// Failed to find a suitable function
					else {
						AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: DSS function not found"));
						throw AvisynthError("No function suitable for opening the video found");
					}
				}
			}
		}
	}
	
	// Catch errors
	catch (AvisynthError &err) {
		AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Avisynth error: ") + wxString(err.msg,wxConvLocal));
		throw _T("AviSynth error: ") + wxString(err.msg,wxConvLocal);
	}

	// Check if video was loaded properly
	if (!script.AsClip()->GetVideoInfo().HasVideo()) {
		AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: No suitable video found"));
		throw _T("Avisynth: No usable video found in ") + _filename;
	}

	// Convert to RGB32
	// If "Avisynth renders its own subs" is enabled, this should always be done,
	// regardless of shaders being enabled or not. (Since VSFilter will convert
	// to RGB32 and back again itself either way.)
	if (!OpenGLWrapper::UseShaders()) {
		script = env->Invoke("ConvertToRGB32", script);
		AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Converted to RGB32"));
	}

	// Cache
	AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: Finished opening video, AVS mutex will be released now"));
	return (env->Invoke("Cache", script)).AsClip();
}


////////////////////////
// Actually get a frame
const AegiVideoFrame AvisynthVideoProvider::DoGetFrame(int _n) {
	// Transform n if overriden
	int n = _n;
	if (frameTime.Count()) {
		if (n < 0) n = 0;
		if (n >= (signed) frameTime.Count()) n = frameTime.Count()-1;
		int time = frameTime[n];
		double curFps = (double)vi.fps_numerator/(double)vi.fps_denominator;
		n = time * curFps / 1000.0;
	}

	// Get avs frame
	AVSTRACE(_T("AvisynthVideoProvider::GetFrame"));
	wxMutexLocker lock(AviSynthMutex);
	PVideoFrame frame = SubtitledVideo->GetFrame(n,env);
	int Bpp = vi.BitsPerPixel() / 8;

	// Aegisub's video frame
	AegiVideoFrame &final = iframe;
	final.flipped = false;
	final.cppAlloc = true;
	final.invertChannels = false;

	// Format
	if (vi.IsRGB32()) {
		final.format = FORMAT_RGB32;
		final.flipped = true;
		final.invertChannels = true;
	}
	else if (vi.IsRGB24()) {
		final.format = FORMAT_RGB24;
		final.flipped = true;
		final.invertChannels = true;
	}
	else if (vi.IsYV12()) final.format = FORMAT_YV12;
	else if (vi.IsYUY2()) final.format = FORMAT_YUY2;

	// Set size properties
	int uvpitch = 0;
	if (final.format == FORMAT_YV12) uvpitch = frame->GetPitch(PLANAR_U);
	final.pitch[0] = frame->GetPitch();
	final.pitch[1] = uvpitch;
	final.pitch[2] = uvpitch;
	final.w = frame->GetRowSize() / Bpp;
	final.h = frame->GetHeight();

	// Allocate
	final.Allocate();

	// Copy
	memcpy(final.data[0],frame->GetReadPtr(),final.pitch[0] * final.h);

	// Copy second and third planes for YV12
	if (final.format == FORMAT_YV12) {
		int uvh = frame->GetHeight(PLANAR_U);
		memcpy(final.data[1],frame->GetReadPtr(PLANAR_U),uvpitch * uvh);
		memcpy(final.data[2],frame->GetReadPtr(PLANAR_V),uvpitch * uvh);
	}

	// Set last number
	last_fnum = n;
	return final;
}


////////////////////////////////////////////////////////
// Apply VSFilter subtitles, or whatever is appropriate
PClip AvisynthVideoProvider::ApplySubtitles(wxString _filename, PClip videosource) {
	AVSTRACE(_T("AvisynthVideoProvider::ApplySutitles: Applying subtitles"));
	wxMutexLocker lock(AviSynthMutex);
	AVSTRACE(_T("AvisynthVideoProvider::ApplySutitles: Got AVS mutex"));

	// Insert subs
	AVSValue script;
	char temp[512];
	wxFileName fname(_filename);
	strcpy(temp,fname.GetShortPath().mb_str(wxConvLocal));
	AVSValue args[2] = { videosource, temp };

	try {
		AVSTRACE(_T("AvisynthVideoProvider::ApplySutitles: Now invoking ") + rendererCallString);
		script = env->Invoke(rendererCallString.mb_str(wxConvUTF8), AVSValue(args,2));
		AVSTRACE(_T("AvisynthVideoProvider::ApplySutitles: Invoked successfully"));
	}
	catch (AvisynthError &err) {
		AVSTRACE(_T("AvisynthVideoProvider::ApplySutitles: Avisynth error: ") + wxString(err.msg,wxConvLocal));
		throw _T("AviSynth error: ") + wxString(err.msg,wxConvLocal);
	}

	// Cache
	AVSTRACE(_T("AvisynthVideoProvider::ApplySutitles: Subtitles applied, AVS mutex will be released now"));
	return (env->Invoke("Cache", script)).AsClip();
}



////////////////////////////////////// SUBTITLES PROVIDER //////////////////////////////////////


/////////////////////////////
// Get as subtitles provider
SubtitlesProvider *AvisynthVideoProvider::GetAsSubtitlesProvider() {
	if (Options.AsBool(_T("Avisynth render own subs"))) return this;
	return NULL;
}


/////////////////////
// Refresh subtitles
void AvisynthVideoProvider::LoadSubtitles(AssFile *subs) {
	// Reset
	AVSTRACE(_T("AvisynthVideoProvider::RefreshSubtitles: Refreshing subtitles"));
	SubtitledVideo = NULL;

	// Dump subs to disk
	wxString subfilename = VideoContext::Get()->GetTempWorkFile();
	subs->Save(subfilename,false,false,_T("UTF-8"));
	delete subs;

	// Load subtitles
	SubtitledVideo = ApplySubtitles(subfilename, RGB32Video);
	AVSTRACE(_T("AvisynthVideoProvider::RefreshSubtitles: Subtitles refreshed"));
	vi = SubtitledVideo->GetVideoInfo();
	AVSTRACE(_T("AvisynthVideoProvider: Got video info"));
}


/////////////////////////////
// Load appropriate renderer
void AvisynthVideoProvider::LoadRenderer() {
	// Get prefferred
	wxString prefferred = Options.AsText(_T("Avisynth subs renderer"));

	// Load
	if (prefferred.Lower() == _T("asa")) LoadASA();
	else LoadVSFilter();
}


/////////////////
// Load VSFilter
void AvisynthVideoProvider::LoadVSFilter() {
	AVSTRACE(_T("AvisynthVideoProvider::LoadVSFilter: Loading VSFilter"));
	// Loading an avisynth plugin multiple times does almost nothing

	wxFileName vsfilterPath(StandardPaths::DecodePath(_T("?data/csri/vsfilter.dll")));
	if (!vsfilterPath.FileExists())
		vsfilterPath = wxFileName(StandardPaths::DecodePath(_T("?data/vsfilter.dll")));
	rendererCallString = _T("TextSub");

	if (vsfilterPath.FileExists()) {
		AVSTRACE(_T("AvisynthVideoProvider::LoadVSFilter: Invoking LoadPlugin"));
		env->Invoke("LoadPlugin",env->SaveString(vsfilterPath.GetFullPath().mb_str(wxConvLocal)));
		AVSTRACE(_T("AvisynthVideoProvider::LoadVSFilter: Loaded"));
	}
	else {
		AVSTRACE(_T("AvisynthVideoProvider::LoadVSFilter: VSFilter.dll not found in Aegisub dir, trying to locate registered DShow filter"));
		wxRegKey reg(_T("HKEY_CLASSES_ROOT\\CLSID\\{9852A670-F845-491B-9BE6-EBD841B8A613}\\InprocServer32"));
		if (reg.Exists()) {
			wxString fn;
			reg.QueryValue(_T(""),fn);
			
			vsfilterPath = fn;

			if (vsfilterPath.FileExists()) {
				AVSTRACE(_T("AvisynthVideoProvider::LoadVSFilter: Found as DShow filter, loading"));
				env->Invoke("LoadPlugin",env->SaveString(vsfilterPath.GetFullPath().mb_str(wxConvLocal)));
				AVSTRACE(_T("AvisynthVideoProvider::LoadVSFilter: Loaded"));
				return;
			}
			
			vsfilterPath = _T("vsfilter.dll");
		}
		else if (vsfilterPath.FileExists()) {
			AVSTRACE(_T("AvisynthVideoProvider::LoadVSFilter: Found on system path, loading"));
			env->Invoke("LoadPlugin",env->SaveString(vsfilterPath.GetFullPath().mb_str(wxConvLocal)));
			AVSTRACE(_T("AvisynthVideoProvider::LoadVSFilter: Loaded"));
		}
		else if (!env->FunctionExists("TextSub")) {
			AVSTRACE(_T("AvisynthVideoProvider::LoadVSFilter: Couldn't locate VSFilter"));
			throw _T("Couldn't locate VSFilter for Avisynth internal subtitle rendering");
		}
	}
}


////////////
// Load asa
void AvisynthVideoProvider::LoadASA() {
	AVSTRACE(_T("AvisynthVideoProvider::LoadASA: Loading asa"));
	// Loading an avisynth plugin multiple times does almost nothing

	wxFileName asaPath(StandardPaths::DecodePath(_T("?data/asa.dll")));
	rendererCallString = _T("asa");

	if (asaPath.FileExists()) {
		AVSTRACE(_T("AvisynthVideoProvider::LoadASA: Invoking LoadPlugin"));
		env->Invoke("LoadPlugin",env->SaveString(asaPath.GetFullPath().mb_str(wxConvLocal)));
		AVSTRACE(_T("AvisynthVideoProvider::LoadASA: Loaded"));
	}
	else {
		asaPath = _T("asa.dll");
		if (asaPath.FileExists()) {
			AVSTRACE(_T("AvisynthVideoProvider::LoadASA: Invoking LoadPlugin"));
			env->Invoke("LoadPlugin",env->SaveString(asaPath.GetFullPath().mb_str(wxConvLocal)));
			AVSTRACE(_T("AvisynthVideoProvider::LoadASA: Loaded"));
		}
		else if (!env->FunctionExists("asa")) {
			AVSTRACE(_T("AvisynthVideoProvider::LoadASA: Couldn't locate asa"));
			throw _T("Couldn't locate asa for Avisynth internal subtitle rendering");
		}
	}
}


////////////////////////
// Override frame times
void AvisynthVideoProvider::OverrideFrameTimeList(wxArrayInt list) {
	frameTime = list;
	num_frames = frameTime.Count();
}


///////////////
// Get warning
wxString AvisynthVideoProvider::GetWarning() {
	if (usedDirectShow) return _("Warning! The file is being opened using Avisynth's DirectShowSource, which has unreliable seeking. Frame numbers might not match the real number. PROCEED AT YOUR OWN RISK!");
	else return _T("");
}

#endif