Podlove Publisher 1.6

The latest release of the Podlove Publisher finally comes with extensive support for chapter formats for both episode assets and podcast feed support. Although most of this stuff is buried under the hood and there are no visible changes to the UI, let us explain what has actually changed, why this is a big deal and where we want to move from here.


The Podlove Publisher has been focusing on extended metadata from the beginning and chapter marks have been of particular interest ever since because we strongly believe that timeline-related information is a way to significantly increase the value of podcasts for the audience.

We have some plans on how to integrate more of this kind of metadata in the future but we think simple chapter structures are a good start, are rather easy to author and using the Podlove Publisher that information is finally easy to broadcast to the clients too.

So far, the only way to bring chapter information to podcast clients was to use MPEG-4 media files (.mp4) and use tools like Garageband to embed Apple’s more or less proprietary “atoms” to put chapter marks, links and pictures into that files. The iPod (and later the iPhone) read these atoms and provided the chapter information to the user. So far, so good.

The problems were many: Apple’s format was (and remains) officially undocumented (although successfully reengineered), it was restricted to MPEG-4 files and the client needs to download the whole file before being able to present chapters to the user.

We want to ease this process, make it less dependent on proprietary formats and allow extraction of structural information before downloading the media files. The first result was the definition of the Podlove Simple Chapters specification. The next step is the deep integration of that format in the Podlove Publisher.

So what’s new?

So what does the update bring to the table? For a start, the Publisher can now read PSC files natively so that you can use PSC files as episode assets as a source for chapter timeline information. We support the all fields of the specification, including links and images. However, you have to wait until a future update to the Podlove Web Player that this information is passed through to the web page.

In addition to reading PSC format the full chapter information is now communicated in the podcast’s feeds to the client. Every client that is interested in chapter information can now retrieve it directly from the feed and use that information – even before downloading any media file. So the chapter information is totally independent of the media files and can be used by podcast directories, podcast search engines (like Poodle) or other apps without ever having to download any media file.

The Publisher also supports other chapter formats on input like the previously preferred mp4chaps format or WebVTT, but we really think PSC is the most robust way to go.

Partnering with Auphonic

Although the Podlove Publisher is totally independent from other systems we have been conspiring with the great audio web service Auphonic on many levels. We have a very basic integration of Auphonic in the Publisher right now (by reading metadata from Auphonic production files configured as episode assets) but want to integrate it even more as the usefulness of Auphonic for audio podcasting can’t praised enough.

Auphonic has also achieved a lot for podcast metadata behind the scenes: it’s the first service worldwide to actually implement chapter information for MP3 — which has been specified since 2006 — including links and pictures and they have also triggered standardization of chapter marks for Ogg files too.

And starting today, Auphonic offers an interface to add links and images to chapters, write these to all kinds of media files and to create Podlove Simple Chapters too. So if you are into creating high-value structured podcasts, the available infrastructure has improved significantly.

The future of the timeline

The Podlove Simple Chapter specification and its integration in the Podlove Publisher is just the start. Behind the scenes, we are discussing much more detailed metadata concepts to form the Podlove Timeline. But it’s too early to speak about this and we have decided to go forward with this rather simple approach that can make podcasts much better today.

Right now, we are asking podcast client developers to embrace the Podlove Simple Chapter format as a means to improve the experience of the audience and to make us all more independent from complex media file structures that are expensive to load and difficult to parse.

So go and try the Podlove Publisher and test if it suits your needs. We are certainly not addressing everyone’s needs yet but we are moving fast and we have a strong roadmap that will bring a lot more cool stuff to you soon.

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