Do not crash when transcoding a non existing file (regression from eea27b8), fixes #141

src/libs/av/impl/TranscodeResourceHandler.cpp

@@ -33,7 +33,6 @@ namespace Av
 	TranscodeResourceHandler::TranscodeResourceHandler(const std::filesystem::path& trackPath, const TranscodeParameters& parameters)
 		: _transcoder {trackPath, parameters}
 	{
-		_transcoder.start();
 	}
 
 	Wt::Http::ResponseContinuation*

src/libs/av/impl/Transcoder.cpp

@@ -48,11 +48,12 @@ Transcoder::Transcoder(const std::filesystem::path& filePath, const TranscodePar
 , _filePath {filePath}
 , _parameters {parameters}
 {
+	start();
 }
 
 Transcoder::~Transcoder() = default;
 
-bool
+void
 Transcoder::start()
 {
 	if (ffmpegPath.empty())
@@ -61,20 +62,13 @@ Transcoder::start()
 	try
 	{
 		if (!std::filesystem::exists(_filePath))
-		{
-			LOG(ERROR) << "File '" << _filePath << "' does not exist!";
-			return false;
-		}
+			throw Exception {"File '" + _filePath.string() + "' does not exist!"};
 		else if (!std::filesystem::is_regular_file( _filePath) )
-		{
-			LOG(ERROR) << "File '" << _filePath << "' is not regular!";
-			return false;
-		}
+			throw Exception {"File '" + _filePath.string() + "' is not regular!"};
 	}
 	catch (const std::filesystem::filesystem_error& e)
 	{
-		LOG(ERROR) << "File error on '" << _filePath.string() << "': " << e.what();
-		return false;
+		throw Exception {"File error '" + _filePath.string() + "': " + e.what()};
 	}
 
 	LOG(INFO) << "Transcoding file '" << _filePath.string() << "'";
@@ -163,7 +157,7 @@ Transcoder::start()
 			break;
 
 		default:
-			return false;
+			throw Exception {"Unhandled format (" + std::to_string(static_cast<int>(_parameters.format)) + ")"};
 	}
 
 	_outputMimeType = formatToMimetype(_parameters.format);
@@ -181,11 +175,8 @@ Transcoder::start()
 	}
 	catch (ChildProcessException& exception)
 	{
-		LOG(ERROR) << "Cannot execute '" << ffmpegPath << "': " << exception.what();
-		return false;
+		throw Exception {"Cannot execute '" + ffmpegPath.string() + "': " + exception.what()};
 	}
-
-	return true;
 }
 
 void
@@ -223,6 +214,8 @@ Transcoder::readSome(std::byte* buffer, std::size_t bufferSize)
 bool
 Transcoder::finished() const
 {
+	assert(_childProcess);
+
 	return _childProcess->finished();
 }
 

src/libs/av/impl/Transcoder.hpp

@@ -40,8 +40,6 @@ namespace Av
 			Transcoder(Transcoder&&) = delete;
 			Transcoder& operator=(Transcoder&&) = delete;
 
-			bool			start();
-
 			using WaitCallback = std::function<void()>;
 			void			asyncWaitForData(WaitCallback cb);
 
@@ -58,6 +56,8 @@ namespace Av
 		private:
 			static void init();
 
+			void start();
+
 			const std::size_t		_id {};
 			const std::filesystem::path	_filePath;
 			const TranscodeParameters	_parameters;

src/libs/subsonic/impl/Stream.cpp

@@ -26,6 +26,7 @@
 #include "database/Track.hpp"
 #include "database/User.hpp"
 #include "utils/IResourceHandler.hpp"
+#include "utils/Logger.hpp"
 #include "utils/FileResourceHandlerCreator.hpp"
 #include "utils/Utils.hpp"
 #include "ParameterParsing.hpp"
@@ -147,24 +148,30 @@ handleStream(RequestContext& context, const Wt::Http::Request& request, Wt::Http
 {
 	std::shared_ptr<IResourceHandler> resourceHandler;
 
-	Wt::Http::ResponseContinuation* continuation = request.continuation();
-	if (!continuation)
+	try
 	{
-		StreamParameters streamParameters {getStreamParameters(context)};
-		if (streamParameters.transcodeParameters)
-			resourceHandler = Av::createTranscodeResourceHandler(streamParameters.trackPath, *streamParameters.transcodeParameters);
+		Wt::Http::ResponseContinuation* continuation = request.continuation();
+		if (!continuation)
+		{
+			StreamParameters streamParameters {getStreamParameters(context)};
+			if (streamParameters.transcodeParameters)
+				resourceHandler = Av::createTranscodeResourceHandler(streamParameters.trackPath, *streamParameters.transcodeParameters);
+			else
+				resourceHandler = createFileResourceHandler(streamParameters.trackPath);
+		}
 		else
-			resourceHandler = createFileResourceHandler(streamParameters.trackPath);
+		{
+			resourceHandler = Wt::cpp17::any_cast<std::shared_ptr<IResourceHandler>>(continuation->data());
+		}
+
+		continuation = resourceHandler->processRequest(request, response);
+		if (continuation)
+			continuation->setData(resourceHandler);
 	}
-	else
+	catch (const Av::Exception& e)
 	{
-		resourceHandler = Wt::cpp17::any_cast<std::shared_ptr<IResourceHandler>>(continuation->data());
+		LMS_LOG(API_SUBSONIC, ERROR) << "Caught Av exception: " << e.what();
 	}
-
-	continuation = resourceHandler->processRequest(request, response);
-	if (continuation)
-		continuation->setData(resourceHandler);
-}
-
 }
 
+} // namespace API::Subsonic::Stream

src/lms/ui/resource/AudioTranscodeResource.cpp

@@ -180,23 +180,30 @@ AudioTranscodeResource::handleRequest(const Wt::Http::Request& request,
 {
 	std::shared_ptr<IResourceHandler> resourceHandler;
 
-	Wt::Http::ResponseContinuation* continuation {request.continuation()};
-	if (!continuation)
+	try
 	{
-		const std::optional<TranscodeParameters>& parameters {readTranscodeParameters(request)};
-		if (parameters)
-			resourceHandler = Av::createTranscodeResourceHandler(parameters->file, parameters->transcodeParameters);
-	}
-	else
-	{
-		resourceHandler = Wt::cpp17::any_cast<std::shared_ptr<IResourceHandler>>(continuation->data());
-	}
+		Wt::Http::ResponseContinuation* continuation {request.continuation()};
+		if (!continuation)
+		{
+			const std::optional<TranscodeParameters>& parameters {readTranscodeParameters(request)};
+			if (parameters)
+				resourceHandler = Av::createTranscodeResourceHandler(parameters->file, parameters->transcodeParameters);
+		}
+		else
+		{
+			resourceHandler = Wt::cpp17::any_cast<std::shared_ptr<IResourceHandler>>(continuation->data());
+		}
 
-	if (resourceHandler)
+		if (resourceHandler)
+		{
+			continuation = resourceHandler->processRequest(request, response);
+			if (continuation)
+				continuation->setData(resourceHandler);
+		}
+	}
+	catch (const Av::Exception& e)
 	{
-		continuation = resourceHandler->processRequest(request, response);
-		if (continuation)
-			continuation->setData(resourceHandler);
+		LOG(ERROR) << "Caught Av exception: " << e.what();
 	}
 }