void describeWriterParamsInContext( OFX::ImageEffectDescriptor& desc,
				    OFX::EContext               context )
{
	OFX::StringParamDescriptor* filename = desc.defineStringParam( kTuttlePluginFilename );
	filename->setLabel( kTuttlePluginFilenameLabel );
	filename->setStringType( OFX::eStringTypeFilePath );
	filename->setCacheInvalidation( OFX::eCacheInvalidateValueAll );
	desc.addClipPreferencesSlaveParam( *filename );

	OFX::ChoiceParamDescriptor* channel = desc.defineChoiceParam( kTuttlePluginChannel );
	channel->setLabel( kTuttlePluginChannelLabel );
	channel->appendOption( kTuttlePluginChannelAuto );
	channel->appendOption( kTuttlePluginChannelGray );
	channel->appendOption( kTuttlePluginChannelRGB );
	channel->appendOption( kTuttlePluginChannelRGBA );
	channel->setDefault( 0 );

	OFX::ChoiceParamDescriptor* bitDepth = desc.defineChoiceParam( kTuttlePluginBitDepth );
	bitDepth->setLabel( kTuttlePluginBitDepthLabel );
	bitDepth->appendOption( kTuttlePluginBitDepth8 );
	bitDepth->appendOption( kTuttlePluginBitDepth16 );
	bitDepth->setDefault( 0 );
	
	OFX::BooleanParamDescriptor* premult = desc.defineBooleanParam( kParamPremultiplied );
	premult->setLabel( kParamPremultipliedLabel );
	premult->setDefault( false );
	
	OFX::PushButtonParamDescriptor* render = desc.definePushButtonParam( kParamWriterRender );
	render->setLabels( "Render", "Render", "Render step" );
	render->setHint("Force render (writing)");

	OFX::BooleanParamDescriptor* renderAlways = desc.defineBooleanParam( kParamWriterRenderAlways );
	renderAlways->setLabel( "Render always" );
//	renderAlways->setDefault( false );
	renderAlways->setDefault( true ); // because tuttle is not declared as a background renderer

	OFX::IntParamDescriptor* forceNewRender = desc.defineIntParam( kParamWriterForceNewRender );
	forceNewRender->setLabel( "Force new render" );
	forceNewRender->setEnabled( false );
	forceNewRender->setIsSecret( true );
	forceNewRender->setIsPersistant( false );
	forceNewRender->setAnimates( false );
	forceNewRender->setCacheInvalidation( OFX::eCacheInvalidateValueAll );
	forceNewRender->setEvaluateOnChange( true );
	forceNewRender->setDefault( 0 );
}
void describeWriterParamsInContext( OFX::ImageEffectDescriptor& desc,
				    OFX::EContext               context )
{
	OFX::StringParamDescriptor* filename = desc.defineStringParam( kTuttlePluginFilename );
	filename->setLabel( kTuttlePluginFilenameLabel );
	filename->setStringType( OFX::eStringTypeFilePath );
	filename->setCacheInvalidation( OFX::eCacheInvalidateValueAll );
	// the file doesn't need to exist, the writer will create it!
	filename->setFilePathExists(false);
	desc.addClipPreferencesSlaveParam( *filename );

	OFX::ChoiceParamDescriptor* channel = desc.defineChoiceParam( kTuttlePluginChannel );
	channel->setLabel( kTuttlePluginChannelLabel );
	channel->appendOption( kTuttlePluginChannelAuto );
	channel->appendOption( kTuttlePluginChannelGray );
	channel->appendOption( kTuttlePluginChannelRGB );
	channel->appendOption( kTuttlePluginChannelRGBA );
	channel->setDefault( 0 );

	OFX::ChoiceParamDescriptor* bitDepth = desc.defineChoiceParam( kTuttlePluginBitDepth );
	bitDepth->setLabel( kTuttlePluginBitDepthLabel );
	bitDepth->appendOption( kTuttlePluginBitDepth8 );
	bitDepth->appendOption( kTuttlePluginBitDepth16 );
	bitDepth->setDefault( 0 );
	
	OFX::BooleanParamDescriptor* premult = desc.defineBooleanParam( kParamPremultiplied );
	premult->setLabel( "Premultiplied" );
	premult->setDefault( false );
	
	OFX::ChoiceParamDescriptor* existingFile = desc.defineChoiceParam( kParamWriterExistingFile );
	existingFile->setLabel( "Existing File" );
	existingFile->appendOption( kParamWriterExistingFile_overwrite );
	existingFile->appendOption( kParamWriterExistingFile_error );
	if( OFX::getImageEffectHostDescription()->hostName == "TuttleOfx" )
	{
		// Only Tuttle is able to do that, because we disable the computation
		// using the IsIdentity Action. This is not in the OpenFX standard.
		existingFile->appendOption( kParamWriterExistingFile_skip );
	}
	//existingFile->appendOption( kParamWriterExistingFile_reader ); // TODO: not implemented yet.
	existingFile->setDefault( eParamWriterExistingFile_overwrite );

	OFX::BooleanParamDescriptor* copyToOutput = desc.defineBooleanParam( kParamWriterCopyToOutput );
	copyToOutput->setLabel( "Copy buffer to output" );
	copyToOutput->setHint( "This is only useful if you connect nodes to the output clip of the writer." );
	copyToOutput->setDefault( false );

	OFX::PushButtonParamDescriptor* render = desc.definePushButtonParam( kParamWriterRender );
	render->setLabels( "Render", "Render", "Render step" );
	render->setHint("Force render (writing)");

	OFX::BooleanParamDescriptor* renderAlways = desc.defineBooleanParam( kParamWriterRenderAlways );
	renderAlways->setLabel( "Render always" );
	renderAlways->setHint( "This is only useful as a workaround for GUI applications." );
	renderAlways->setDefault( true ); // because tuttle is not declared as a background renderer

	OFX::IntParamDescriptor* forceNewRender = desc.defineIntParam( kParamWriterForceNewRender );
	forceNewRender->setLabel( "Force new render" );
	forceNewRender->setHint( "This is only useful as a workaround for GUI applications." );
	forceNewRender->setEnabled( false );
	forceNewRender->setIsSecret( true );
	forceNewRender->setIsPersistant( false );
	forceNewRender->setAnimates( false );
	forceNewRender->setCacheInvalidation( OFX::eCacheInvalidateValueAll );
	forceNewRender->setEvaluateOnChange( true );
	forceNewRender->setDefault( 0 );
}