Today, I released Semplice Version 2.11. It contains the fixes I mentioned were needed last time, namely that the SACD ISO-handling software I had been relying on had suddenly decided to disappear from the Internet and thus needed replacing in its entirety. The fix essentially consists of switching to using sacd as the ISO extractor instead, which is still downloadable -though it doesn't appear to be actively maintained. I've also cloned the sacd repository so that, should that ever suddenly disappear, I'll have my own copy to rely on.
The irony here is that around five years ago, when I first wrote the precursor software to Semplice, I used sacd as the ISO extractor and only switched to odio-sacd when I realised that sacd was a fork of odio-sacd: I wrote an explanatory piece as to why I was, back then, choosing the odio-sacd software over the forked sacd offering. Several years later, the tables have turned, the original has been withdrawn and I'm forced to revert back to using the fork!
This means that the technical issue which drove me to use odio-sacd in the first place re-raises its head: sacd requires Intel/AMD streaming SIMD extensions and therefore won't run on non-Intel and non-AMD processors. That basically means Semplice cannot convert SACD ISOs to FLAC on the Raspberry Pi, which is a regression I regret but can do nothing about. To be honest, though: anyone doing major SACD manipulation on a Raspberry Pi is obviously keen on pushing very heavy stones up exremely steep hills. It's not exactly a high-powered multimedia powerhouse, put it that way! That said, the rest of Semplice (even converting DSF files to FLAC) will work just fine on the Pi, so there's that.
This Semplice release also includes a subtle improvement to the way Semplice converts an SACD ISO file into other formats. Forced to look at my code for the first time in quite a while, I realised that I had been applying a hard cut-off of audio frequencies above 24,000Hz at the point of conversion to FLAC, regardless of what sort of FLAC you were outputting to. That made sense, I think, because whilst some people claim to be able to hear frequencies up to 22KHz, no-one born on planet Earth seriously claims to be able to hear anything above that, so the filter was cutting out frequencies which simply and physically are inaudible: no harm done.
In retrospect, I should have realised that people working with SACD tend to not want to be quite so blunt with their inaudible audio data as that! It remains necessary to cut-off high frequencies even so: if you don't, then the Nyquist-Shannon sampling theorem raises its head. This theorem says you can perfectly reproduce an audio signal provided there are definitely no frequencies above half your sampling rate. If you leave frequencies in the signal above that, they are likely to be 'reflected' back down into the very-much-audible part of the signal, thereby sounding as distortion. If you cut off everything above 20KHz, for example, then you can safely sample at 40KHz and have no ultrasonics-becoming-audible problems. My previous SACD ISO cutoff at 24KHz was done, I vaguely seem to remember, because I assumed people would want their resulting FLACs to play at 48KHz. It was slightly unfortunate, then, that Semplice went on to offer to create Hi-Res FLACs (at 88.2KHz) and Super Hi-Res FLACs (at 176.4KHz): the 24KHz cut-off would certainly mean that those FLACs would not contain audible ultrasonic distortion, because the cut-off was so aggressive that nothing even approaching the Nyquist-Shannon sampling limit would be present in the audio signal. However: it also meant that rather a lot of the ultrasonic signal was being chopped off, for technically no real reason.
However, given the opportunity for a new release, and a query about lossless SACD conversion from a certain reader from Goa, I've now refined the extraction process. If you're extracting your SACD ISO to normal FLACs (or any of the lossy formats), the cut-off is now applied at 21KHz; if to a Hi-Res FLAC, it's done at 43KHz; and for a Super Hi-Res FLAC, the cut-off is now only applied for frequencies higher than 87KHz. In all cases, in other words, the cut-off is applied at (approximately) half the sampling rate of the output FLAC format, thus complying with Nyquist-Shannon, with a bit of slack to allow for less than perfect filtering. It means normal FLACs are output with slightly more frequencies cut-off than before, but either Hi-Res format will retain vastly more ultrasonic data than before. This, of course, also means that either of the Hi-Res FLAC format files will end up being a fair bit larger than they used to be; standard FLACs will end up slightly smaller than in Version 2.10.
In practice, I doubt anyone could actually hear the difference. But anyone keen not to lose audio data can now be assured that Semplice's SACD ISO conversions will lose much less of it than before (and what it does lose, you won't care about anyway!).
Anyway: all that aside, how do you get hold of the new Semplice version and its sacd sidekick? Well: be aware that sacd is only automatically installed for you during a fresh installation of Semplice. If you were to take Semplice's Miscellaneous menu Option 3, in other words, you'll certainly obtain Semplice Version 2.11, but you won't get sacd installed automatically. So if you do the standard update process, you would additionally need to install sacd manually, which is described step-by-step at this page of the User Manual, and specifically Section 4 of that page. Failure to do this manual sacd installation won't break Semplice at all though, until the point where you ask it to do an SACD ISO conversion -when the program will spot the lack of sacd and direct you to that page of the User Manual anyway!
I think the better option for most people, therefore, is simply to perform a fresh installation of Semplice, by opening a terminal and typing
cd
wget doco.absolutelybaching.com/seminst
bash seminst
The fresh installation will silently replace the existing one and, since it's a fresh install, sacd will be auto-installed for you. Note that however you obtain Semplice 2.11, the upgrade does not remove odio-sacd if it is already present on your system (it just won't use it any more).
Anyway: all that aside, the changelog has been updated with more specifics; relevant portions of the Semplice documentation have also been updated (if any references to "odio-sacd" remain, they are an error and should be notified to me).
So: the short version is, sorry for the drama foisted upon me by the mysterious disappearance of a piece of code I had been relying on, but everything now works as before and Semplice is still a capable SACD ISO management tool. I've also cloned the sacd software repository to my own server, so if anything likes this happens again, I won't be in quite such a mess as I was this time! Good luck with the upgrade and, for the Left Pondians amongst you, happy Independence Day!