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AirPRO Playout Based on Rivendell

Questions and Answers

Q. Is AirPRO a "fork" of Rivendell?
A. Not exactly. We've not previously been active members of the Rivendell development team and are not trying to "split" development in any way. In fact, we hope to feed back any new additions or features to the Rivendell developers, as that is the base of the system. We're still relying on the upstream Rivendell base, we're just tailoring it for a slightly different set of users in much the same way different Linux distributions focus on different user requirements.

Q. Why a new name and release, not just patches?
A. Previously we released a sequence of patches for various versions of Rivendell which could be applied before compiling and installing the code. These patches allowed installation on Linux Mint/Ubuntu, addressed several internationalisation issues such as date and meter formats and backported bug fixes from later versions to avoid the need to upgrade an entire station to resolve minor bugs. To indicate these changes we modified the version number from (for example) "2.19.3" to "2.19.3.RT.4", where "RT.4" would indicate the fourth patch release for this version. This was confusing for everyone. People would ask for support for Rivendell but in fact would be running the customised code. Others would contact us for support with the patches only to discover they had not been installed. Therefore, a clearly different identity was required as it is not right that this modified code be mistaken for Rivendell, even though we want to credit the Rivendell authors in full.

Q. What caused the need for this and what are the issues you're trying to solve?
A. For our station, First FM in Oxford UK, we needed a system that would run on Linux Mint as this distribution incorporates a large number of multimedia components ideal for audio production, as opposed to CentOS which is the standard recommended for Rivendell. We also needed a stable database structure to allow the use of custom in-house solutions and scripts. With Rivendell we found writing such things challenging as the database schema would change regularly, often between point releases. This made it almost impossible for us to update the system as any change required an almost complete "rip out and replace" of the entire station. While there are very good reasons for the design decisions made in Rivendell, at our and many other stations this can be completely impractical, yet we still need rapid access to bug fixes and new features.

The purpose of AirPRO is to, as much as is possible, give a "stable" database structure to a station while providing a playout system that can be installed on Linux Mint. A "stable" database does not mean that Rivendell was in any way unreliable, it means that changes will not be made to the actual data structure unless absolutely vital. This also does not mean that new features and fields can't be added, but when they are we will attempt to implement them in a "compatible" way using additional tables where possible with only major version changes implementing substantial changes. The aim being to avoid the need wherever possible of having to re-write existing scripts or applications that need to talk to the database directly. For exactly the same reasons, Rivendell has a policy that third parties should not talk directly to the database and should instead use provided APIs. While we agree with this philosophy and recommend it where possible, it has resulted in challenges when required data is not available or clearly visible via this method. It also requires a full understanding of the API options available, which might not always be practical for a member of station staff requiring a "quick fix" in order to implement some new solution for their station. For this reason, we regard the SQL database as being the core asset of the playout system and while manipulation of this is not to be advised, it provides a well-known and well documented table structure for those wishing to extend or customise their station.

While fixing the structure in this way might imply we could become less "cutting edge" than Rivendell, our aim is for long term compatibility and stability between versions. This does not mean new features won't be added, in fact we believe that having this relatively fixed database structure will allow third parties greater ease to create new software and hardware designed to fully integrate with the system.

Q. Can I move from an existing Rivendell system to AirPRO?
A. If you're running any version of Rivendell before version 3 then yes, this should be possible at present. We have currently fixed the database to match Rivendell 2.19.3 (database schema 275) so if you use this or any prior version you should be able to upgrade to AirPRO 2.21. However, if you are running Rivendell version 3 onwards this is not directly possible without additional work, as it's not possible to automatically revert back to an earlier Rivendell database structure. Before attempting any migration ensure you have a full external backup of your system and keep a safe copy of this backup until you are certain it's no longer required.

Q. If I run AirPRO can I move to Rivendell at a later date?
A. As of AirPRO 2.21 yes as long as it's Rivendell version 2.19.3 or later, however this might not be possible with later versions of either AirPRO or Rivendell. It is possible in future there may be database changes that make the two incompatible, but as of AirPRO 2.21 the database should be fully compatible with Rivendell 2.19.3. Please note however that versions of Rivendell from version 3 onwards will automatically update your AirPRO database structure making it much more challenging to revert back to AirPRO from Rivendell. As always ensure you have a full backup before attempting any migration.

Q. How does installing AirPRO compare to Rivendell?
A. This depends on the method of installation. Rivendell provide an "appliance" image allowing a system to be up and running pretty quickly, however this relies on the CentOS 7 Linux distribution which we felt was not optimal for a multimedia working environment. Installing Rivendell on other Linux versions can be much more challenging compared to AirPRO as source code modification and installation of multiple dependencies will almost certainly be required.

AirPRO however is designed to be straghtforward to install on Linux Mint, one of the most common desktop versions of Linux. While the process still requires some techical familiarity with Linux, when following our installation notes no unexpected or undocumented changes should be required and the process can be completed in as little as 30 minutes.

One of the motivations for the initial release of AirPro was to ease installation on Linux Mint and Ubuntu. After spending some time attempting to install Rivendell 3.3.0 on a system that had run 3.2.0 and experiencing multiple new dependency errors, it became obvious that this was not something that could be easily accomplished by anyone not familiar with the internal workings of the system. As a result, patches to the source were required and it became obvious we would be better off creating a custom version incorporating these changes, our required additions and in general backporting any required bug fixes to avoid "chasing a moving target".

Q. Does this mean you have any kind of dispute with the Rivendell developers?
A. Absolutely not, in fact we have nothing but admiration for them. The design structure of Rivendell is excellent, the coding is superb and the direction the system is taking is both understandable and correct for the target audience. However, we believe there are a large number of users that would benefit from a version of the system tailored to run on Linux Mint with customisations aimed towards an non-US user base.

Q. Does the world need yet another playout system?
A. How much choice is too much? The Windows market is pretty much saturated with options, with the best costing a substantial amount of money. However, Windows is becoming less relevant and harder to manage for 24/7 operation with Linux being the obvious alternative. We are not aware of any other playout system for Linux that is as fully featured and equivalent or better than the best systems for Windows, other than Rivendell. By resolving many of the issues previously preventing adoption of Rivendell and helping ease installation on Mint, we aim to bring those features and the stability of Linux to a wider audience.

Q. How reliable and fully featured is it?
A. As far as reliability goes it's a double win. Not only is the reliability of Linux well documented (the majority of internet servers rely on Linux for continuous non-stop operation) but since you have complete manual control of all updates, there's no question of an unwanted automatic reboot taking you off air.

AirPro and Rivendell offer all the features of a modern playout system including a built-in music scheduler, voice tracking and additional utilities such as presenter "cart walls" as well as full automation. It's also designed and fully configurable to interface with industry standard music and traffic scheduling systems.

At present remote voice-tracking is accomplished by RDP desktop access to a studio PC. This is something we hope to rapidly improve and implementing this is one of the issues we had with a dynamic database structure leading to the creation of AirPRO. However, despite this sounding slightly inelegant, it's not turned out to be a serious limitation and we regularly voice-track around 10 hours per day via this method on a city-wide FM station. However, a web based remote voice-tracker is one of the highest priorities on our list of features we wish to add.

It's also worth mentioning that some of the original Rivendell components are hard coded to run on a 1024x768 monitor. While these will display fine on a higher resolution widescreen display, we have improved and wish to further improve this. For a main studio playout machine at present you may wish to set the screen resolution to 1024x768 even on a modern widescreen monitor, to ensure the log window fills the screen completely.

We've run Rivendell and now AirPro at First FM in Oxford for over six years without any issues and it's in use at stations large and small across the world.


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