DFS 11.1 - 8 Serving media

All files from Digizuite are served using the media pipelines. 

It is configurable which one is used and this is controlled by a config parameter in DFS.Settings.config:

DFS.Settings.config

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <settings>
		<setting name="DFS.MediaPipeline" value="dfsmedia"/>
	</settings>
  </sitecore>
</configuration>

Understanding the request

The dfsmedia pipeline is accessible on the following endpoint: http(s)://<sitecore>/dfsmedia

The syntax of the URL is: dfsmedia/[SiloId]/[AssetId]-[Quality]/resize/[Width]x[Height]/cropsize/[Width or ratioX]x[Height or ratioY]/cropmode/[Mode]/cropposition/[Position]/outputimageformat/[Format]/compress/[0-100]/options/[Options]

If a parameter is not optional, it may be discarded, but it has to follow the order above. For instance if you want to compress only, then the following scheme is used: 

dfsmedia/[SiloId]/[AssetId]-[Quality]/compress/[0-100]

Each parameter is described as follows:

*Optional

Digizuite transcode system - fallback image

In digizuite DAM 5.10.x the transcode system has change DC 5.10 Breaking changes - Transcode system. What that means for the DFS connector is that, when requesting rendition that hadn’t been generated yet a fallback image will be returned and the statuscode is 202 (Accepted). The fallback image is of type svg and controlled by Digizuite. Once the rendition is ready in Digizuite is will be served to the mediahandler in Sitecore.

By default the DAM for Sitecore connector is configured to use the fallback logic, if the rendition is not ready. It is possible to disable this, so the request will stay open until the rendition is ready.

To disable the fallback logic open the config file DFS.Settings.config and locate the setting property <setting name="DFS.MediaPipeline.UseFallbackImageIfUnavailable" value="true"/> change the value to false and reload the site. Now when requesting images that is not ready, the connection will stay open until it finishes.

Examples

Here are some use cases, that shows how the media handler works and how it is used in different situations.

This is the shortes url, these are the required parameters. Here we request the assetId 192 and the quality format id 3 (rendition from Digizuite).
/dfsmedia/baeefe6b74df44be8a2bccfb2c57af8e/192-3

Resize the image to a width of 350 px and keep the aspect ratio of the height.
/dfsmedia/baeefe6b74df44be8a2bccfb2c57af8e/192-3/resize/350x0

Resize the image to a width of 350 px and a height of 350 px. This will not respect the aspect ratio of the image.
/dfsmedia/baeefe6b74df44be8a2bccfb2c57af8e/192-3/resize/350x350

Crop, this is the shortest use of the crop feature, this will set the cropmode to AspectRatioBased and then set the resizing width to 400 and the height to 100.
/dfsmedia/baeefe6b74df44be8a2bccfb2c57af8e/192-3/cropsize/400x100

The above url would be the same as this.
/dfsmedia/baeefe6b74df44be8a2bccfb2c57af8e/192-3/resize/400x100/cropsize/400x100/cropmode/AspectRatioBased

This will crop with an aspect ratio 4:1 and crop from the top left corner and then resize down to width 400 px and height 100 px.
/dfsmedia/baeefe6b74df44be8a2bccfb2c57af8e/192-3/resize/400x100/cropsize/400x100/cropmode/AspectRatioBased/cropposition/TopLeft

Understanding the DigizuiteMediaCache

The DigizuiteMediaCache is where everything, except videos, is saved. The cache location is configurable and is located in DFS.Settings.config

DFS.Settings.config

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <settings>
	  <!-- Path to DAM For Sitecore MediaCache. The following is supported: 
             -UNC (\\server\example\cahcepath)
             -Full path (C:\example\cachepath)
             -Relative path (/App_Data/cachepath)      
      -->
      <setting name="DFS.CacheLocation" value="/App_Data/DigizuiteMediaCache"/>
	</settings>
  </sitecore>
</configuration>

The default location is in the website root under App_Data/DigizuiteMediaCache/.

Files are cached based on the request made to the asset. An example request could be: http(s)://<sitecore url>/dfsmedia/29a605d46a3340418c16542f7272c3ec/110-50035

According to the specification of the URL, this request has the following properties:

• AssetSiloId: 29a605d46a3340418c16542f7272c3ec 

• AssetId: 110

• FormatId: 50035

The cache is then build using a naming scheme. Each asset is placed in a sub-folder which has the name of the assetid. In the case of the example, the path in which the file is saved would be App_Data/DigizuiteMediaCache/110

The filename is then constructed based on the given properties using the following scheme:

{Assetid}_{formatid}_{width}_{height}_{options}.{extension}

where width, height and options are not used, if not requested (i.e. not used in the example), which means in the example, the requested asset would have the following name:

110_50035.{extension}

The extension is retrieved from the file saved in the cache. The naming scheme enable unique names and hence the extension can be extracted from the file in the cache. Originally, the file is saved with the correct extension based on what is served from the Digizuite.

UNC path

The dfsmedia pipeline also supports having a centralized cache, which means multiple servers can have the same cache. This decreases storage, but also performance, because files are then cached on a UNC which is slower than having it locally. This is something each client has to have an opinion on.

Implementation

The new dfsmedia pipeline is implemented as a httphandler, using a pipeline in Sitecore. This pipeline is located in the DFS.Pipelines.config file:

DFS.Settings.config

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
	<pipelines>     
	 <DFS.Services.DFSMedia>      
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.SynchronizeAsset, DFS.Client.Services" role:require="Standalone or ContentManagement" />
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.LoadAssetEntity, DFS.Client.Services" />        
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.GetMediaFromCache, DFS.Client.Services" />
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.NewResizeImage, DFS.Client.Services" />
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.GetMediaFromDigizuite, DFS.Client.Services" />        
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.SaveToCache, DFS.Client.Services" />
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.ResolveFilename, DFS.Client.Services" />
      </DFS.Services.DFSMedia>
    </pipelines>
  </sitecore>
</configuration>

Each step is explained as follows:

This pipeline may be modified according to customer needs. 

Extending the pipeline

If the pipeline is to be extended, for instance if some custom processing needs to be done to the image, then this may be done in between any of the steps above.

The pipeline step should have the following construction:

public class PipelineName : ProcessorBase<DFSMediaPipelineArgs>
{
	public override void Process(DFSMediaPipelineArgs args)
	{
		if (args.Result.StopPipeline)
        {
          return;
        }

        if (args.Request.Download)
        {
          return;
        }

        if (args.Result.Cached)
        {                       
          return;
        }
	    //code goes here
	}
}

Remember to include the custom step in the configuration file!

The object DFSMediaPipelineeArgs contains a Request and a Result. These two objects has the following properties:

Request

Result

Manually deleting cache entries

The cache is invalidating if the image in Digizuite is re-transcoded. The cache invalidation results in all the entries for the given asset, being deleted. If one wishes to manually clear the cache this is also an option. There are two ways in which this can be accomplished:

• Manually deleting the folder in the cache (i.e. delete the folder that has the asset ID of the asset that should be deleted).

• Use the Administration DAM for Sitecore dashboard, it has a function called Image cache where you can delete the cache from through UI. DFS 11.1 - Administration dashboard

Enabling old resizing processor

From version DFS 11.1 the default resizing feature has been rewritten. The resizing it now done in Digizuite, this also requires that DAM version is minimum 5.10.5. If you are connecting to a DAM less then 5.10.5 and you are using the resizing feature, then you must enable the old resizing processor.

Open the DFS.Pipelines.config and look for the pipeline DFS.Services.DFSMedia. This is the default configuration where the new resizing processor is enabled.

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
	<pipelines>     
	 <DFS.Services.DFSMedia>      
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.SynchronizeAsset, DFS.Client.Services" role:require="Standalone or ContentManagement" />
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.LoadAssetEntity, DFS.Client.Services" />        
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.GetMediaFromCache, DFS.Client.Services" />
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.NewResizeImage, DFS.Client.Services" />
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.GetMediaFromDigizuite, DFS.Client.Services" />        
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.SaveToCache, DFS.Client.Services" />
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.ResolveFilename, DFS.Client.Services" />
      </DFS.Services.DFSMedia>
    </pipelines>
  </sitecore>
</configuration>

To enable the old processor, delete the processor <processor type="DFS.Client.Services.Pipelines.DFSMedia.NewResizeImage, DFS.Client.Services" /> and add this processor <processor type="DFS.Client.Services.Pipelines.DFSMedia.ResizeImage, DFS.Client.Services" /> in between GetMediaFromDigizuite and SaveToCache.

It should look like this.

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
	<pipelines>     
	 <DFS.Services.DFSMedia>      
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.SynchronizeAsset, DFS.Client.Services" role:require="Standalone or ContentManagement" />
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.LoadAssetEntity, DFS.Client.Services" />        
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.GetMediaFromCache, DFS.Client.Services" />        
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.GetMediaFromDigizuite, DFS.Client.Services" />        
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.ResizeImage, DFS.Client.Services" />
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.SaveToCache, DFS.Client.Services" />
        <processor type="DFS.Client.Services.Pipelines.DFSMedia.ResolveFilename, DFS.Client.Services" />
      </DFS.Services.DFSMedia>
    </pipelines>
  </sitecore>
</configuration>