DC 6.0 Formats
- Rasmus Hjelmberg Duemose Hansen
- Tobias Thornfeldt Wolters
Digizuite supports converting assets to different formats.
For instance, a thumbnail is automatically generated for a wide range of file types, allowing for an easy visual identification of assets in, e.g., the Media Manager.
The entire system related to formats and their conversions is referred to as the transcode system.
This section covers the most important concepts related to configuring and using formats in Digizuite.
Format definition
A format has a format type, which is defined by a file extension. Examples of supported format types are:
webpjpegpngmp4movavimp3pdf
A format defines the output of a transcode, which is the process of converting an input file from one encoding to another. When an asset is transcoded to a format, the end result is called a rendition.
Digizuite comes with a set of predefined formats primarily used for thumbnails and previews. These formats can be edited. You can also define new formats. Both predefined and new formats can be configured from the Media Manager’s General settings → System administration → Formats page.
By default, thumbnails are automatically generated for all assets as webp files with transparency, optimized for efficient loading on web pages.
When defining a new format, the following parameters can be set:
Name: A unique name of the format.
Description: An optional, more elaborate description of the format. This is visible to users when downloading a rendition that uses the format. It can, e.g., be used to describe which use cases the format is intended for.
Format type: The type of the format.
Immediately generated for: The asset types for which renditions of the format should be generated immediately when an asset’s file is uploaded or replaced. See below for more information.
Format purpose: Indicates if the format should be used e.g. for thumbnails, large thumbnails, video previews, etc..
Channel filter: Limits the visibility of the format based on channels. More details can be found here
Asset type filter: Limits the visibility of the format based on asset type. More details can be found here.
Download replace mask: Controls the file name when downloading renditions of the format.
Depending on the chosen format type, a number of different parameters will appear. Most parameters should be self-explanatory. However, a short description of some of the key features can be found here.
Generation
Renditions of assets can be either generated on-demand or pre-generated.
If a rendition of an asset is requested but has not been generated yet, it is always automatically generated. This feature is referred to as on-demand transcoding and makes it possible to ensure that renditions are only generated when needed. Thus, storage space is not wasted on saving renditions that are never used.
The transcode system also supports pre-generating renditions before they are requested. This is, e.g., useful for thumbnails and previews, which are always needed. However, it can also be used to automatically start time-consuming transcodes of large videos that are likely to be requested.
Renditions can be pre-generated in two ways:
On upload and replace: This can be configured with the “Immediately generated for” parameter when defining a format, as described above. Note that if a new format is defined with this setting, existing assets in the system must be republished to pre-generate renditions of the format for these assets.
Triggered from an automation: The automation step “Generate asset renditions” can be used to pre-generate renditions based on more complex conditions. For instance, an automation can be set up to pre-generate renditions for videos with a certain size or when an asset is published to a specific channel folder.
For most formats, it most likely suffices to rely on on-demand transcoding.
No matter if a rendition is requested on-demand or pre-generated, it is never generated if it is already available. If the definition of a format changes, the corresponding renditions are automatically re-generated when they are requested again.
Note that renditions of a specific format can not be generated for all input file types. For instance, renditions of video or audio formats can not be generated for image assets such as png, jpeg, and webp since it does not make sense to create a video or an audio file from an image. However, renditions of image formats can be generated for most common input file types. Thus, even though a limited set of output formats are available, a wide range of input formats are supported.
Format visibility
The visibility of a format can be controlled via download qualities and format filters.
Download qualities
One use-case for defining a format is to make it easy for users to download renditions of assets in this format. However, by default, a format is not visible in the download dialog in the Media Manager. The visibility of formats in the download dialog can be controlled from the general settings page in the Media Manager, where it can be configured for individual user groups.
Note that the configured download formats only affect the visibility of formats in the download dialog and does not affect security. Thus, a user is able to request a rendition of a format that is not visible to the user, as long as the user has access to the asset.
Format filters
A format can be defined with a channel filter and/or an asset type filter.
A format is only visible for an asset if the asset passes both the channel filter and the asset type filter.
Channel filter:
A format is visible for an asset if the asset is published to at least one of the specified channel folders. A format is also visible for an asset if the asset is published to at least one sub channel folder of one of the specified channel folders.
If no channel folders are specified, no visibility filtering is applied based on channel folders.
Asset type filter:
A format is only visible for an asset if the asset has one of the specified asset types.
If no asset types are specified, no visibility filtering is applied based on asset types.
Note that the configured format filters only affects which formats the backend indicates can be streamed and downloaded for assets. Consequently, if a user has read access to an asset, the user can request renditions of all formats that can be generated for this asset, independent of whether the asset passes all format filters.
Custom renditions
In addition to the formats defined on the system administration page, it is possible to allow users to request custom renditions of formats that the users define on-the-fly. This can be done via the “Custom rendition” button in the download dialog shown above or by calling the endpoint <api-url>/DigizuiteCore/LegacyService/api/renditions/<asset-id>/custom.
A user must have at least one of these two roles Asset_Can_Download_Custom_Quality or Asset_Can_Download_Any, to gain access to the custom rendition download functionality.
Custom renditions are always generated on-demand. However, if the exact requested rendition has already been generated, it is reused. Custom renditions are automatically cleaned up if they have not been downloaded in a while. By default, custom renditions are cleaned up after 30 days. This can be configured from the general settings page in the Media Manager. Only custom renditions are cleaned up.
Deletion
It is possible to manually trigger the deletion of renditions. This can be done via the automation step “Delete asset renditions”. Note that the automation step only deletes a rendition if it is available. Consequently, renditions that are in the process of being generated are not deleted.