Archive for the ‘nymphcast’ Category

Purgatory or Hell: Escape from eternal Alpha status

January 17, 2021 Leave a comment

Many of us will have laughed and scoffed at Google’s liberal use of the tag ‘Beta software’ these past years. Is the label ‘Beta’ nothing more than an excuse for any bugs and issues that may still exist in code, even when it has been running in what is essentially a production environment for years? Similarly, the label ‘Alpha’ when given to software would also seem to seek a kind of indemnity for any issues or lacking features: to dismiss any issue or complaint raised with the excuse that the software is still ‘in alpha’.

Obviously, any software project needs time to develop. Ideally it would have a clear course through the design and requirements phase, smooth sailing through Alpha phase as all the features are bolted onto the well-designed architecture, and finally the polishing of the software during the Beta and Release Candidate (RC) phases. Yet it’s all too easy to mess things up here, which usually ends up with a prolonged stay in the Alpha phase.

A common issue that leads to this is too little time spent in the initial design and requirements phase. Without a clear idea of what the application’s architecture should look like, the result is that during the Alpha phase both the features and architecture end up being designed on the spot. This is akin to building a house before the architectural plans are drawn up, but one wants to starts building anyway, because one has a rough idea of what a house looks like.

When I began work on the NymphCast project [1] a few years back, all I had was a vague idea of ‘streaming audio’, which slowly grew over time. With the demise of Google’s ChromeCast Audio product, it gave me a hint to look at what that product did, and what people looked at it. By that time NymphCast was little more than a concept and an idea in my head, and I’m somewhat ashamed to say that it took me far too long to work out solid requirements and a workable design and architecture.

Looking back, what NymphCast was at the beginning of 2020 – when it got a sudden surge of attention after an overly enthusiastic post from me on the topic – was essentially a prototype. A prototype is somewhat like an Alpha-level construction, but never meant to be turned into a product: it’s a way to gather information for the design and requirements phase, so that a better architecture and product can be developed. Realising this was essential for me take the appropriate steps with the NymphCast project.

With only a vague idea of one’s direction and goals while in the Alpha phase, one can be doomed to stay there for a long time, or even forever. After all, when is the Alpha phase ‘done’, when one doesn’t even have a clear definition of what ‘done’ actually means in that context? Clearly one needs to have a clear feature set, clear requirements, a clear schedule and definition of ‘done’ for all of those. Even for a hobby project like NymphCast, there is no fun in being stuck in Alpha Limbo for months or even years.

After my recent post [2] on the continuation of the NymphCast project after a brief burn-out spell, I have not yet gotten the project into a Beta stage. What I have done is frozen the feature set, and together with a friend I’m gradually going through the remaining list of Things That Do Not Work Properly Yet. Most of this is small stuff, though the small stuff is usually the kind of thing that will have big consequences on user friendliness and overall system stability. This is also the point where there are big rewards for getting issues fixed.

The refactored ring buffer class has had some issues fixed, and an issue with a Stop condition was recently resolved. The user experience on the player side has seen some bug fixes as well. This is what Alpha-level testing should be like: the hunting down of issues that impede a smooth use of the software, until everything seems in order.

The moral of this story then is that before one even writes a line of code, it’s imperative that one has a clear map of where to go and what to do, lest one becomes lost. The second moral is that it’s equally imperative to set limits. Be realistic about the features one can implement this time around. Sort the essential from the ‘nice to have’. If one does it right now, there is always a new development cycle after release into production where one gets to tear everything apart again and add new things.

Ultimately, the Alpha phase ends when it’s ‘good enough’. The Beta phase ends when the issue tracker begins to run dry. Release Candidates exist because life is full of unexpected surprises, especially when it concerns new software. Yet starting the Alpha phase before putting together a plan makes as much sense as walking into the living room at night without turning a light on because ‘you know where to walk’.

Fortunately, even after you have repeatedly bumped your shins against furniture and fallen over a chair, it’s still not too late to turn on a light and do the limping walk of shame 🙂



NymphCast: on getting a ‘ChromeCast killer’ to a Beta release

December 27, 2020 1 comment

It’s been a solid nine months since I first wrote about the NymphCast project [1] on my personal blog [2]. That particular blog post ended up igniting a lot of media attention [3], as it also began to dawn on me how much work would still be required to truly get it to a ‘release’ state. Amidst the stress from this, the 2020 pandemic and other factors, the project ended up slumbering for a few months as I tried to stave off burn-out on the project as a whole.

Sometimes such a break from a project is essential, to be able to step back instead of bashing one’s head against the same seemingly insurmountable problems over and over as they threaten to drown you into an ocean of despair, frustration and helplessness. You know, the usual reason why ‘grinding’, let alone a full-blown death march, is such a terrible thing in software development.

One thing I did do during that time off was to solve one particular issue that had made me rather sad during initial NymphCast development: that of auto-discovery of NymphCast servers on the local network. I had attempted to use DNS Service Discovery (DNS-SD, mDNS) for this, but ran into issue that there is no cross-platform solution for mDNS that Just Works ™. Before reading up on mDNS I had in my mind a setup where the application itself would announce its presence to the network, or to a central mDNS server on the system, as that made sense to me.

Instead I found myself dealing with a half-working solution that basically required Avahi on Linux, Bonjour on MacOS and something custom installed and configured on Windows, not to mention other desktop operating systems. On the client side things were even more miserable, with me finding only a single library for mDNS that was somewhat easy to integrate. Yet even then I had no luck making it work across different OSes, with the running server instances regularly not found, or requiring specific changes to the service name string to get a match.

The troubleshooting there was one factor that nearly made me burn out on the NymphCast project. Then, during that break I figured that I might as well write something myself to replace mDNS. After all, I just needed something that spit out a UDP Broadcast message, and something that listened for it and responded to it. This idea turned into NyanSD [4], which I wrote about before [5].

I have since integrated NyanSD into NymphCast on the server & client side, with as result that I have had no problems any more with service discovery, regardless of the platform.

Other aspects of NymphCast were less troublesome, but mostly just annoying, such as getting a mobile client for NymphCast. Originally I had planned to use a single codebase for the graphical NymphCast Player application, using Qt’s Android & iOS cross-platform functionality to target desktop and mobile platforms. Unfortunately this ran into the harsh reality of Qt’s limited Android support and spotty documentation [6]. This led me to work on a standard, native Android application written in Java for the GUI and using the JNI to use the same C++ client codebase. This way I only have to port the Qt-specific code on the Android side to the Java-Android equivalent.

Status at this point is that all features for the targeted v0.1 release have been implemented, with testing ongoing. An additional feature that got integrated at the last moment was the synchronisation of music and video playback between different NymphCast devices, for multi-room playback and similar. The project also saw the addition of a MediaServer [7], which allows clients to browse the media files shared by the server, and start playback of these files on any of the NymphCast servers (receivers) on the network. I also refactored the in-memory buffer to use a simple ringbuffer instead of the previous, more complicated buffer.

In order to get the v0.1 development branch out of Alpha and into Beta, a few more usage scenarios have to be tested, specifically the playback of large media files (100+ MB), both with a single NymphCast receiver and a group, and directly from a client as well as using a MediaServer instance. The synchronisation feature has seen some fixes recently already while testing it, but needs more testing to make it half-way usable.

A major issue I found with this synchronisation feature was the difficulty of determining local time on all the distinct devices. With the lack of a real-time clock (RTC) on Raspberry Pi SBCs in particular, I had to refactor the latency algorithm to only rely on the clock of the receiver that was used as the master receiver. Likely this issue may require more tweaking over the coming time to get synchronisation with better than 100 ms de-synchronisation.

I think that in the run-up to a v0.1 release, the Beta phase will be highly useful in figuring out the optimal end-user scenarios, both in terms of easy setup and configuration, as well as the day to day usage. This is the point where I pretty much have to rely on the community to get a solid idea of what are good ideas, and what patterns should be avoided.

That said, it’s somewhat exciting to see the project now finally progressing to a first-ever Beta release. Shouldn’t be more than a year or two before the first Release Candidate now, perhaps 🙂



Categories: nymphcast