Transcoder Extension

Extension for Transcoder app for Windows

Build an app that extends the Transcoder app, adding additional source and target formats. An example Transcoder extension, Animated GIF Creator with full source code is here and is in the Windows Store. You can use the Transcoder.Extension class in your project to help in the implementation of a Transcoder Extension:

public sealed class GifCreator : IBackgroundTask
{
    public async void Run(IBackgroundTaskInstance taskInstance)
    {
		var deferral = taskInstance.GetDeferral(); 

		var logoFile = await Package.Current.InstalledLocation.GetFileAsync("Assets\\Logo.png");

		var extension = new Transcoder.Extension
		{
			Price = await Transcoder.Extension.GetPriceAsync(), 
			SourceType = "Video",
			SourceFormats = new string[] { ".mp4", ".mov", ".wmv", ".avi" },
			DestinationFormats = new string[] { ".gif" },
			LogoFile = logoFile,
			TranscodeAsync = this.TranscodeGifAsync
		};

		extension.Run(taskInstance, deferral);
    }

    public IAsyncAction TranscodeGifAsync(StorageFile source, StorageFile destination, ValueSet arguments)
    {
        return AsyncInfo.Run(async delegate (CancellationToken token)
        {
			... todo: write transcoding here
		});
	}
}	

Transcoder Protocol

Create a Windows Universal App that exposes an application service. Read this article on MSDN on how to create and consume an app service. To work in Transcoder, the app service needs to follow a specific protocol, responding to messages that have "Command" properties:

Get Description

Gets the description of the app service

Input

Property	Type	Description
Command	String	"GetDescription"

Output

Property	Type	Description
DisplayName	String	the localized display name of the hosting application
PublisherName	String	the localized publisher name of the hosting application
Version	String	the version of the hosting application in the store
Price	String	the localized price of the hosting application in the store or "0" for free apps
LogoFileToken	String	the token for a square .png image at 50x50 px minimum size created by using the SharedStorageAccessManager.AddFile API
SourceType	String	"Audio" or "Video"

Get Source Formats

Get the source formats that the app service supports

Input

Property	Type	Description
Command	String	"GetSourceFormats"

Output

Property	Type	Description
Formats	String	the source formats that the transcoder takes separated by commas (for example ".wmv,.avi,.mp4")

Get Destination Formats

Gets the destination formats that the app service supports

Input

Property	Type	Description
Command	String	"GetDestinationFormats"

Output

Property	Type	Description
Formats	String	the destination formats that the transcoder takes separated by commas (for example ".wmv,.avi,.mp4")

Transcode

Input

Property	Type	Description
Command	String	"Transcode"
FileTokens	String	a JSON array containing JSON objects with SourceToken and DestinationToken string properties. The file tokens are generated by using the SharedStorageAccessManager.AddFile API
Quality	String	Source, Custom, HD1080p, HD720p, Wvga, Ntsc, Pal, Vga, Qvga
Width	UInt	(optional) width of destination file if Quality is "Custom"
Height	UInt	(optional) height of destination file if Quality is "Custom"

Output

Property	Type	Description
Status	String	"OK" if successful, or an error message to show to the user in the case of a problem.

Errors in Extensions

If you use the Transcoder.Extension class, throwing an exception in your extension will show that message in the exception to the user in a Toast notification from Transcoder.