If you are confused or in doubt whether you should use a rendition or a dynamic transformation for your content renditions, read on...
Renditions
DAM can store renditions of your main file adjacent to the original asset. These renditions are typically conversions or transcoding of the main file rendered using rules. They can be simple file type conversions or more specific renditions such as crops and trims. Users in the DAM typically are familiar with this mechanism as ‘additional files’. See the article Best practices – DAM Data modelling for more on additional files. The need to generate renditions is typically driven out of the need to have the renditions readily available for use cases where the user or system cannot wait for the conversion to be done on the fly upon delivery. As an example, if you have a large video file, transcoding this into a social media mp4 version may take some time. If you are serving a use case where the user wants to download that file and expects the download to start right away, then this is an ideal candidate to make a rendition ahead of the download using DAM rules.
Dynamic transformations
From assets and their renditions, public links can be generated via Aprimo's in-app CDN. The CDN supports dynamic transformations by adding transformation query parameters to the public link. See the page on public links for detailed information on this.
So the question arises now, what should you do? If you need a black and white version of an image, do you choose to make a rendition for it in DAM or should you just use an on-the-fly dynamic transformation of the public link?
Using dynamic transformation on public links is easy, saves DAM storage, but is highly volatile.
The following reasons can drive you to using renditions instead of dynamic transformations:
Non dynamic / control: Sometimes the ability to create and check (see) the rendition of the content before it goes public is needed; potentially other stakeholders check this content before it goes public. A perfect example are crops. No technology will get all crops right, so you may want to check and if necessary finetune your cropping areas before using them through public links and possibly collaborate with someone on the best crop area for your purpose. If crops are rendered as dynamic transformations, collaborating with someone on the same content is harder to do.
Authenticated access / insights: Public links are anonymous. So for authenticated use cases, you may need to store and serve a rendition from the DAM instead. This will also provide you better and more detailed content insights.
Non digital / channel interchangeability: Not all channels are digital; so if you need a rendition for both digital and non-digital channels, it may be better to serve it from one DAM rendition, so you can track both DAM re-use and public link reuse back over 1 rendition.