In order for your organisations' RSS feeds to work with Flex, they must meet certain requirements. These specifications are based on the standard needs of third-party platforms rather than specific customisations.
Meeting the standards of best practices for feeds to be submitted to Apple Podcasts will set your feeds to up well to be compliant with Acast Flex, with specific details below.
Audio format
Audio files trafficked through media should be in MP3 CBR format. We accept files with a bitrate up to 256kbps, but the ingestion process will convert them to MP3 CBR 64kbps mono and 128kbps stereo.
We do this to ensure a constant bitrate - this is a requirement of the dynamic audio engine, to ensure that dynamic content like ads are stitched in the exact right point of the file. We do not offer variable bitrates by provider.
Based on the requirements of external third-party podcast platforms such as Spotify, we strongly advise the use of MP3 files within your own RSS feed.
Persistent GUIDs
An episode’s GUID needs to be retained as the RSS XML is updated, otherwise episodes will be seen as a new episode within the Flex system and potentially appear as duplicate.
GUIDs must uniquely identify the episode within the show, and should not change during the history of the episode. Reflecting a standard adhered to by third-party podcast platforms, any changes to a GUID will result in the episode being treated as new by our data pipeline.
Change of enclosure URLs for updated episodes
Changes to the enclosure URL of the audio file within the RSS feed will be interpreted as a change of content, and will trigger the Flex system to re-import the episode.
Changes to the audio file that do not result in a changed enclosure URL will not be detected by the Flex system, since the import engine will detect the file as already imported. Changing the enclosure URL but retaining the GUID and publish date will ensure that the updated episode does not appear as new within the Acast data pipeline or third-party podcast platforms.