Clarified a bunch of error messages

Originally committed to SVN as r1433.

aegisub/ass_dialogue.cpp

@@ -715,7 +715,7 @@ void AssDialogue::SetMarginString(const wxString origvalue,int which) {
 	if (value > 9999) value = 9999;
 
 	// Assign
-	if (which < 0 || which >= 4) throw _T("Invalid Margin");
+	if (which < 0 || which >= 4) throw _T("Invalid margin id");
 	Margin[which] = value;
 }
 
@@ -723,7 +723,7 @@ void AssDialogue::SetMarginString(const wxString origvalue,int which) {
 //////////////////////////
 // Gets string for margin
 wxString AssDialogue::GetMarginString(int which,bool pad) {
-	if (which < 0 || which >= 4) throw _T("Invalid margin");
+	if (which < 0 || which >= 4) throw _T("Invalid margin id");
 	int value = Margin[which];
 	if (pad) return wxString::Format(_T("%04i"),value);
 	else return wxString::Format(_T("%i"),value);

aegisub/ass_file.cpp

@@ -408,7 +408,7 @@ int AssFile::AddLine (wxString data,wxString group,int lasttime,int &version,wxS
 			if (versionString == _T("v4.00")) trueVersion = 0;
 			else if (versionString == _T("v4.00+")) trueVersion = 1;
 			else if (versionString == _T("v4.00++")) trueVersion = 2;
-			else throw _T("Unknown file version");
+			else throw _T("Unknown SSA file format version");
 			if (trueVersion != version) {
 				if (!(trueVersion == 2 && version == 1)) wxLogMessage(_T("Warning: File has the wrong extension."));
 				version = trueVersion;

aegisub/ass_style.cpp

@@ -437,7 +437,7 @@ void AssStyle::UpdateData() {
 /////////////////////////////
 // Sets margin from a string
 void AssStyle::SetMarginString(const wxString str,int which) {
-	if (which < 0 || which >= 4) throw _T("Invalid margin");
+	if (which < 0 || which >= 4) throw _T("Invalid margin id");
 	if (!str.IsNumber()) throw _T("Invalid margin value");
 	long value;
 	str.ToLong(&value);
@@ -451,7 +451,7 @@ void AssStyle::SetMarginString(const wxString str,int which) {
 //////////////////////////
 // Gets string for margin
 wxString AssStyle::GetMarginString(int which) {
-	if (which < 0 || which >= 4) throw _T("Invalid margin");
+	if (which < 0 || which >= 4) throw _T("Invalid margin id");
 	wxString result = wxString::Format(_T("%04i"),Margin[which]);
 	return result;
 }

aegisub/audio_karaoke.cpp

@@ -353,7 +353,7 @@ void AudioKaraoke::OnPaint(wxPaintEvent &event) {
 						dc.DrawLine(splitxpos, 0, splitxpos, h);
 					}
 				} else {
-					wxLogError(_T("WTF? Failed to GetPartialTextExtents"));
+					wxLogError(_T("Karaoke syllable display: Failed to GetPartialTextExtents. This should never happen, except on severely overloaded systems."));
 				}
 			}
 

aegisub/audio_player_alsa.cpp

@@ -148,7 +148,7 @@ void AlsaPlayer::OpenStream()
 
 	// Open device for blocking access
 	if (snd_pcm_open(&pcm_handle, device.mb_str(wxConvUTF8), stream, 0) < 0) { // supposedly we don't want SND_PCM_ASYNC even for async playback
-		throw _T("Error opening specified PCM device");
+		throw _T("ALSA player: Error opening specified PCM device");
 	}
 
 	SetUpHardware();
@@ -171,12 +171,12 @@ void AlsaPlayer::SetUpHardware()
 
 	// Get hardware params
 	if (snd_pcm_hw_params_any(pcm_handle, hwparams) < 0) {
-		throw _T("Error setting up default PCM device");
+		throw _T("ALSA player: Error setting up default PCM device");
 	}
 
 	// Set stream format
 	if (snd_pcm_hw_params_set_access(pcm_handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED) < 0) {
-		throw _T("Could not set interleaved stream format");
+		throw _T("ALSA player: Could not set interleaved stream format");
 	}
 
 	// Set sample format
@@ -188,65 +188,65 @@ void AlsaPlayer::SetUpHardware()
 			sample_format = SND_PCM_FORMAT_S16_LE;
 			break;
 		default:
-			throw _T("Can only handle 8 and 16 bit sound");
+			throw _T("ALSA player: Can only handle 8 and 16 bit sound");
 	}
 	if (snd_pcm_hw_params_set_format(pcm_handle, hwparams, sample_format) < 0) {
-		throw _T("Could not set sample format");
+		throw _T("ALSA player: Could not set sample format");
 	}
 
 	// Ask for resampling
 	if (snd_pcm_hw_params_set_rate_resample(pcm_handle, hwparams, 1) < 0) {
-		throw _T("Couldn't enable resampling");
+		throw _T("ALSA player: Couldn't enable resampling");
 	}
 
 	// Set sample rate
 	rate = provider->GetSampleRate();
 	real_rate = rate;
 	if (snd_pcm_hw_params_set_rate_near(pcm_handle, hwparams, &real_rate, 0) < 0) {
-		throw _T("Could not set sample rate");
+		throw _T("ALSA player: Could not set sample rate");
 	}
 	if (rate != real_rate) {
-		wxLogDebug(_T("Could not set ideal sample rate %d, using %d instead"), rate, real_rate);
+		wxLogDebug(_T("ALSA player: Could not set ideal sample rate %d, using %d instead"), rate, real_rate);
 	}
 
 	// Set number of channels
 	if (snd_pcm_hw_params_set_channels(pcm_handle, hwparams, provider->GetChannels()) < 0) {
-		throw _T("Could not set number of channels");
+		throw _T("ALSA player: Could not set number of channels");
 	}
-	printf("Set sample rate %u (wanted %u)\n", real_rate, rate);
+	printf("ALSA player: Set sample rate %u (wanted %u)\n", real_rate, rate);
 
 	// Set buffer size
 	unsigned int wanted_buflen = 1000000; // microseconds
 	buflen = wanted_buflen;
 	if (snd_pcm_hw_params_set_buffer_time_near(pcm_handle, hwparams, &buflen, &dir) < 0) {
-		throw _T("Couldn't set buffer length");
+		throw _T("ALSA player: Couldn't set buffer length");
 	}
 	if (buflen != wanted_buflen) {
-		wxLogDebug(_T("Couldn't get wanted buffer size of %u, got %u instead"), wanted_buflen, buflen);
+		wxLogDebug(_T("ALSA player: Couldn't get wanted buffer size of %u, got %u instead"), wanted_buflen, buflen);
 	}
 	if (snd_pcm_hw_params_get_buffer_size(hwparams, &bufsize) < 0) {
-		throw _T("Couldn't get buffer size");
+		throw _T("ALSA player: Couldn't get buffer size");
 	}
-	printf("Buffer size: %lu\n", bufsize);
+	printf("ALSA player: Buffer size: %lu\n", bufsize);
 
 	// Set period (number of frames ideally written at a time)
 	// Somewhat arbitrary for now
 	unsigned int wanted_period = bufsize / 4;
 	period_len = wanted_period; // microseconds
 	if (snd_pcm_hw_params_set_period_time_near(pcm_handle, hwparams, &period_len, &dir) < 0) {
-		throw _T("Couldn't set period length");
+		throw _T("ALSA player: Couldn't set period length");
 	}
 	if (period_len != wanted_period) {
-		wxLogDebug(_T("Couldn't get wanted period size of %d, got %d instead"), wanted_period, period_len);
+		wxLogDebug(_T("ALSA player: Couldn't get wanted period size of %d, got %d instead"), wanted_period, period_len);
 	}
 	if (snd_pcm_hw_params_get_period_size(hwparams, &period, &dir) < 0) {
-		throw _T("Couldn't get period size");
+		throw _T("ALSA player: Couldn't get period size");
 	}
-	printf("Period size: %lu\n", period);
+	printf("ALSA player: Period size: %lu\n", period);
 
 	// Apply parameters
 	if (snd_pcm_hw_params(pcm_handle, hwparams) < 0) {
-		throw _T("Failed applying sound hardware settings");
+		throw _T("ALSA player: Failed applying sound hardware settings");
 	}
 
 	// And free memory again
@@ -262,22 +262,22 @@ void AlsaPlayer::SetUpAsync()
 
 	// Get current parameters
 	if (snd_pcm_sw_params_current(pcm_handle, sw_params) < 0) {
-		throw _T("Couldn't get current SW params");
+		throw _T("ALSA player: Couldn't get current SW params");
 	}
 
 	// How full the buffer must be before playback begins
 	if (snd_pcm_sw_params_set_start_threshold(pcm_handle, sw_params, bufsize - period) < 0) {
-		throw _T("Failed setting start threshold");
+		throw _T("ALSA player: Failed setting start threshold");
 	}
 
 	// The the largest write guaranteed never to block
 	if (snd_pcm_sw_params_set_avail_min(pcm_handle, sw_params, period) < 0) {
-		throw _T("Failed setting min available buffer");
+		throw _T("ALSA player: Failed setting min available buffer");
 	}
 
 	// Apply settings
 	if (snd_pcm_sw_params(pcm_handle, sw_params) < 0) {
-		throw _T("Failed applying SW params");
+		throw _T("ALSA player: Failed applying SW params");
 	}
 
 	// And free struct again
@@ -285,7 +285,7 @@ void AlsaPlayer::SetUpAsync()
 
 	// Attach async handler
 	if (snd_async_add_pcm_handler(&pcm_callback, pcm_handle, async_write_handler, this) < 0) {
-		throw _T("Failed attaching async handler");
+		throw _T("ALSA player: Failed attaching async handler");
 	}
 }
 

aegisub/audio_player_pulse.cpp

@@ -192,6 +192,7 @@ void PulseAudioPlayer::OpenStream()
 			pa_threaded_mainloop_stop(mainloop);
 			pa_threaded_mainloop_free(mainloop);
 			wxString s(pa_strerror(paerror), wxConvUTF8);
+			s.Prepend(_T("PulseAudio reported error: "));
 			throw s.c_str();
 		}
 		// otherwise loop once more
@@ -219,12 +220,13 @@ void PulseAudioPlayer::OpenStream()
 	pa_stream_set_state_callback(stream, (pa_stream_notify_cb_t)pa_stream_notify, this);
 	pa_stream_set_write_callback(stream, (pa_stream_request_cb_t)pa_stream_write, this);
 
-	// Connext stream
+	// Connect stream
 	//printf("Connecting playback stream\n");
 	paerror = pa_stream_connect_playback(stream, NULL, NULL, PA_STREAM_INTERPOLATE_TIMING|PA_STREAM_NOT_MONOTONOUS|PA_STREAM_AUTO_TIMING_UPDATE, NULL, NULL);
 	if (paerror) {
 		printf("PulseAudio reported error: %s (%d)\n", pa_strerror(paerror), paerror);
 		wxString s(pa_strerror(paerror), wxConvUTF8);
+		s.Prepend(_T("PulseAudio reported error: "));
 		throw s.c_str();
 	}
 	while (true) {
@@ -233,8 +235,8 @@ void PulseAudioPlayer::OpenStream()
 			break;
 		} else if (sstate == PA_STREAM_FAILED) {
 			paerror = pa_context_errno(context);
-			printf("Stream connection failed: %s (%d)\n", pa_strerror(paerror), paerror);
+			printf("PulseAudio player: Stream connection failed: %s (%d)\n", pa_strerror(paerror), paerror);
-			throw _T("Something went wrong connecting the stream");
+			throw _T("PulseAudio player: Something went wrong connecting the stream");
 		}
 	}
 	//printf("Connected playback stream, now playing\n\n");
@@ -285,7 +287,7 @@ void PulseAudioPlayer::Play(__int64 start,__int64 count)
 		pa_operation_unref(op);
 		if (!stream_success_val) {
 			paerror = pa_context_errno(context);
-			printf("Error flushing stream: %s (%d)\n", pa_strerror(paerror), paerror);
+			printf("PulseAudio player: Error flushing stream: %s (%d)\n", pa_strerror(paerror), paerror);
 		}
 	}
 
@@ -301,7 +303,7 @@ void PulseAudioPlayer::Play(__int64 start,__int64 count)
 	paerror = pa_stream_get_time(stream, &play_start_time);
 	pa_threaded_mainloop_unlock(mainloop);
 	if (paerror) {
-		printf("Error getting stream time: %s (%d)\n", pa_strerror(paerror), paerror);
+		printf("PulseAudio player: Error getting stream time: %s (%d)\n", pa_strerror(paerror), paerror);
 	}
 
 	PulseAudioPlayer::pa_stream_write(stream, pa_stream_writable_size(stream), this);
@@ -313,7 +315,7 @@ void PulseAudioPlayer::Play(__int64 start,__int64 count)
 	pa_operation_unref(op);
 	if (!stream_success_val) {
 		paerror = pa_context_errno(context);
-		printf("Error triggering stream: %s (%d)\n", pa_strerror(paerror), paerror);
+		printf("PulseAudio player: Error triggering stream: %s (%d)\n", pa_strerror(paerror), paerror);
 	}
 
 	// Update timer
@@ -343,7 +345,7 @@ void PulseAudioPlayer::Stop(bool timerToo)
 	pa_operation_unref(op);
 	if (!stream_success_val) {
 		paerror = pa_context_errno(context);
-		printf("Error flushing stream: %s (%d)\n", pa_strerror(paerror), paerror);
+		printf("PulseAudio player: Error flushing stream: %s (%d)\n", pa_strerror(paerror), paerror);
 	}
 
 	// And unref it

aegisub/audio_provider_hd.cpp

@@ -60,7 +60,7 @@ HDAudioProvider::HDAudioProvider(AudioProvider *source) {
 	wxLongLong freespace;
 	if (wxGetDiskSpace(DiskCachePath(), NULL, &freespace)) {
 		if (num_samples * channels * bytes_per_sample > freespace) {
-			throw wxString(_T("Not enough free diskspace in "))+DiskCachePath()+wxString(_T(" to cache the audio"));
+			throw wxString(_T("Not enough free disk space in "))+DiskCachePath()+wxString(_T(" to cache the audio"));
 		}
 	}
 
@@ -68,7 +68,7 @@ HDAudioProvider::HDAudioProvider(AudioProvider *source) {
 	diskCacheFilename = DiskCacheName();
 	file_cache.Create(diskCacheFilename,true,wxS_DEFAULT);
 	file_cache.Open(diskCacheFilename,wxFile::read_write);
-	if (!file_cache.IsOpened()) throw _T("Unable to write to disk cache.");
+	if (!file_cache.IsOpened()) throw _T("Unable to write to audio disk cache.");
 
 	// Start progress
 	volatile bool canceled = false;

aegisub/dialog_style_editor.cpp

@@ -588,7 +588,7 @@ void DialogStyleEditor::OnSetColor (int n) {
 		case 2: modify = &work->secondary; break;
 		case 3: modify = &work->outline; break;
 		case 4: modify = &work->shadow; break;
-		default: throw _T("Never gets here");
+		default: throw _T("Internal error in style editor, attempted setting colour id outside range");
 	}
 	modify->SetWXColor(colorButton[n-1]->GetColour());
 	if (SubsPreview) SubsPreview->SetStyle(work);

aegisub/dialog_style_manager.cpp

@@ -235,7 +235,7 @@ void DialogStyleManager::LoadCatalog () {
 	wxString dirname = StandardPaths::DecodePath(_T("?user/catalog/"));
 	if (!wxDirExists(dirname)) {
 		if (!wxMkdir(dirname)) {
-			throw _T("Error creating directory!");
+			throw _T("Failed creating directory for style catalogues");
 		}
 		else {
 			// Create default style
@@ -441,7 +441,7 @@ void DialogStyleManager::OnCatalogNew (wxCommandEvent &event) {
 		wxString dirname = StandardPaths::DecodePath(_T("?user/catalog/"));
 		if (!wxDirExists(dirname)) {
 			if (!wxMkdir(dirname)) {
-				throw _T("Error creating directory!");
+				throw _T("Failed creating directory for style catalogues");
 			}
 		}
 		Store.Save(name);

aegisub/frame_main.cpp

@@ -561,7 +561,7 @@ void FrameMain::LoadSubtitles (wxString filename,wxString charset) {
 		// File exists?
 		if (isFile) {
 			wxFileName fileCheck(filename);
-			if (!fileCheck.FileExists()) throw _T("File does not exist.");
+			if (!fileCheck.FileExists()) throw _T("Selected file does not exist.");
 
 			// Make sure that file isn't actually a timecode file
 			TextFileReader testSubs(filename);
@@ -1074,9 +1074,9 @@ void FrameMain::LoadKeyframes(wxString filename) {
 
 		// Read header
 		wxString cur = file.ReadLineFromFile();
-		if (cur != _T("# keyframe format v1")) throw _T("Invalid keyframes file.");
+		if (cur != _T("# keyframe format v1")) throw _T("Invalid keyframes file, missing header.");
 		cur = file.ReadLineFromFile();
-		if (cur.Left(4) != _T("fps ")) throw _T("Invalid keyframes file.");
+		if (cur.Left(4) != _T("fps ")) throw _T("Invalid keyframes file, missing FPS.");
 		cur = cur.Mid(4);
 		double fps;
 		cur.ToDouble(&fps);

aegisub/frame_main_events.cpp

@@ -689,7 +689,7 @@ void FrameMain::OnExportSubtitles(wxCommandEvent & WXUNUSED(event)) {
 				scripts[i]->Reload();
 			}
 			catch (const wchar_t *e) {
-				wxLogError(e);
+				wxLogError(_T("Error while reloading Automation scripts before export: %s", e.c_str());
 			}
 			catch (...) {
 				wxLogError(_T("An unknown error occurred reloading Automation script '%s'."), scripts[i]->GetName().c_str());

aegisub/gl_text.cpp

@@ -263,7 +263,7 @@ OpenGLTextTexture::OpenGLTextTexture(int w,int h) {
 
 	// Allocate texture
 	glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA8,width,height,0,GL_ALPHA,GL_UNSIGNED_BYTE,NULL);
-	if (glGetError()) throw _T("Could not allocate Text Texture");
+	if (glGetError()) throw _T("Internal OpenGL text renderer error: Could not allocate Text Texture");
 }
 
 
@@ -350,7 +350,7 @@ void OpenGLTextTexture::Insert(OpenGLTextGlyph &glyph) {
 	glBindTexture(GL_TEXTURE_2D, tex);
 	glTexSubImage2D(GL_TEXTURE_2D,0,x,y,imgw,imgh,GL_LUMINANCE_ALPHA,GL_UNSIGNED_BYTE,alpha);
 	delete[] alpha;
-	if (glGetError()) throw _T("Error uploading glyph data to video memory.");
+	if (glGetError()) throw _T("Internal OpenGL text renderer error: Error uploading glyph data to video memory.");
 }
 
 

aegisub/mkv_wrap.cpp

@@ -313,7 +313,7 @@ void MatroskaWrapper::GetSubtitles(AssFile *target) {
 	if (tracksFound.Count() == 0) {
 		target->LoadDefault(true);
 		Close();
-		throw _T("File has no known subtitle tracks.");
+		throw _T("File has no recognised subtitle tracks.");
 	}
 
 	// Only one track found

aegisub/options.cpp

@@ -410,7 +410,7 @@ void OptionsManager::Load() {
 	// Read header
 	TextFileReader file(filename);
 	wxString header = file.ReadLineFromFile();
-	if (header != _T("[Config]")) throw _T("Invalid config file");
+	if (header != _T("[Config]")) throw _T("Configuration file is invalid");
 
 	// Get variables
 	std::map<wxString,VariableData>::iterator cur;
@@ -495,7 +495,7 @@ int OptionsManager::AsInt(wxString key) {
 	if (cur != opt.end()) {
 		return (*cur).second.AsInt();
 	}
-	else throw _T("Undefined name");
+	else throw _T("Internal error: Attempted getting undefined configuration setting");
 }
 
 
@@ -507,7 +507,7 @@ bool OptionsManager::AsBool(wxString key) {
 	if (cur != opt.end()) {
 		return (*cur).second.AsBool();
 	}
-	else throw _T("Undefined name");
+	else throw _T("Internal error: Attempted getting undefined configuration setting");
 }
 
 
@@ -519,7 +519,7 @@ double OptionsManager::AsFloat(wxString key) {
 	if (cur != opt.end()) {
 		return (*cur).second.AsFloat();
 	}
-	else throw _T("Undefined name");
+	else throw _T("Internal error: Attempted getting undefined configuration setting");
 }
 
 
@@ -531,7 +531,7 @@ wxString OptionsManager::AsText(wxString key) {
 	if (cur != opt.end()) {
 		return (*cur).second.AsText();
 	}
-	else throw _T("Undefined name");
+	else throw _T("Internal error: Attempted getting undefined configuration setting");
 }
 
 
@@ -543,7 +543,7 @@ wxColour OptionsManager::AsColour(wxString key) {
 	if (cur != opt.end()) {
 		return (*cur).second.AsColour();
 	}
-	else throw _T("Undefined name");
+	else throw _T("Internal error: Attempted getting undefined configuration setting");
 }
 
 

aegisub/subs_grid.cpp

@@ -574,7 +574,7 @@ void SubtitlesGrid::OnRecombine(wxCommandEvent &event) {
 	bool cont;
 	wxArrayInt sel = GetSelection(&cont);
 	int nSel = sel.Count();
-	if ((nSel != 2 && nSel != 3) || !cont) throw _T("Invalid selection");
+	if ((nSel != 2 && nSel != 3) || !cont) throw _T("Invalid selection for recombining");
 	int n = sel[0];
 
 	// Get dialogues

aegisub/subtitle_format_ttxt.cpp

@@ -227,7 +227,7 @@ void TTXTSubtitleFormat::WriteFile(wxString filename,wxString encoding) {
 			WriteLine(root,current);
 			i++;
 		}
-		else throw _T("Unexpected line type");
+		else throw _T("Unexpected line type in TTXT file");
 	}
 
 	// Save XML

aegisub/vfr.cpp

@@ -204,7 +204,7 @@ void FrameRate::Load(wxString filename) {
 
 		// Unknown
 		else {
-			throw _T("Unknown file format.");
+			throw _T("Unknown time code file format.");
 		}
 
 	}

aegisub/vfw_wrap.cpp

@@ -59,7 +59,7 @@ wxArrayInt VFWWrapper::GetKeyFrames(wxString filename) {
 	long hr = AVIFileOpen(&pfile, filename.wc_str(), OF_SHARE_DENY_WRITE, 0); 
 	if (hr != 0) {
 		AVIFileExit();
-		throw _T("Unable to open file.");
+		throw _T("Unable to open AVI file for reading keyframes.");
     }
 
 	// Open stream
@@ -68,7 +68,7 @@ wxArrayInt VFWWrapper::GetKeyFrames(wxString filename) {
 	if (hr != 0) {
 		AVIFileRelease(pfile);
 		AVIFileExit();
-		throw _T("Unable to open stream.");
+		throw _T("Unable to open AVI stream for reading keyframes.");
 	}
 
 	// Get stream data

aegisub/video_provider.cpp

@@ -78,7 +78,7 @@ const AegiVideoFrame VideoProvider::GetFrame(int n,int format) {
 	// Convert to compatible format
 	if (!(frame.format & format)) {
 		if (format & FORMAT_RGB32) tempRGBFrame.format = FORMAT_RGB32;
-		else throw _T("Unable to negotiate formats.");
+		else throw _T("Unable to negotiate video frame format.");
 		tempRGBFrame.w = frame.w;
 		tempRGBFrame.h = frame.h;
 		tempRGBFrame.pitch[0] = frame.w * 4;

aegisub/video_provider_avs.cpp

@@ -315,7 +315,7 @@ PClip AvisynthVideoProvider::OpenVideo(wxString _filename, bool mpeg2dec3_priori
 	// Check if video was loaded properly
 	if (!script.AsClip()->GetVideoInfo().HasVideo()) {
 		AVSTRACE(_T("AvisynthVideoProvider::OpenVideo: No suitable video found"));
-		throw _T("No usable video found in ") + _filename;
+		throw _T("Avisynth: No usable video found in ") + _filename;
 	}
 
 	// Convert to RGB32
@@ -513,7 +513,7 @@ void AvisynthVideoProvider::LoadVSFilter() {
 		}
 		else if (!env->FunctionExists("TextSub")) {
 			AVSTRACE(_T("AvisynthVideoProvider::LoadVSFilter: Couldn't locate VSFilter"));
-			throw _T("Couldn't locate VSFilter");
+			throw _T("Couldn't locate VSFilter for Avisynth internal subtitle rendering");
 		}
 	}
 }
@@ -542,7 +542,7 @@ void AvisynthVideoProvider::LoadASA() {
 		}
 		else if (!env->FunctionExists("asa")) {
 			AVSTRACE(_T("AvisynthVideoProvider::LoadASA: Couldn't locate asa"));
-			throw _T("Couldn't locate asa");
+			throw _T("Couldn't locate asa for Avisynth internal subtitle rendering");
 		}
 	}
 }