Kostya's Boring Codec World

I thought I’ve said all what I wanted to say about the current events but apparently life constantly gives new reasons to rant.

Unlike many other people, I don’t believe in some deity but rather in a concept of idiocy. More specifically I believe that (as St Wabuu said) most of the humans are so stupid (thinking is a very energy consuming effort after all), idiocy is a side effect of human imperfection and can be eradicated only with the humanity itself, and that if there’s a way to do some idiotic thing somebody will do it (the Darwin Awards and news from Florida keep proving this version of Murphy’s law). Overall, there’s an abundance of idiocy around us and in the last two years it really demonstrated how our lives can be turned to the worse.

2020 (all ~730 days of it) can be called The Year of Arrogant Idiots. The origin of the virus is not relevant for this case (even if it spawned a lot of bickering and misinformation campaigns), but how it grew into the pandemic and how it was handled afterwards is very relevant. Mostly it is remembered for the things like #hugachinese campaign initiated by some Italian mayor (after all, having a close bodily contact with a stranger not merely removes the stigma but also should decrease the chances of transmission for any disease) and the various things from “trust me, I’m a doctor” people.

By those I mean primarily WHO and various heads of local healthcare systems but others qualify as well. I doubt you can give a better explanation why it was so hard to accept that the virus is primarily transmitted by air (even if it does not fall into “airborne” classification for some purely theoretical reasons), that calling it “mild” did not help things, or that the virus gives a mildsevere damage to the immune system so betting on herd immunity and exposing children to it was a dubious idea at best. And that’s not counting all the people who think they know even better and thus can ignore the known facts for being inconvenient (I feel they resort to a circular reasoning “masks/vaccines do not work because we won’t allow those to be used on us”). Thanks guys, without you this year would not be as crappy or as long!

The following 1939 (all 700 days of it and counting) can be called The Year of Selfish Idiots (not that the other idiotic traits are in short supply, it’s just this particular one has been driving this year down). The year started when a certain group of people (if they deserve to be called people at all) decided to act on their beliefs that occupying and plundering another country would do them more good than developing their own country instead. I can understand the initial period of confusion when good decisions were hard to make, but it was followed mostly by the decisions that can be called short-sighted only if you’re a complete diplomat.

You may not like Ukraine or not care about it at all but you should realize that if the aggressor is not stopped it won’t be satisfied with that and will use the resources and people from captured territories to attack other countries (they’re not even hiding the plans of not merely expanding to former USSR borders but conquer Finland, Poland and maybe other bits of Europe). And if some selfish idiot thinks that USA will be left alone and does not need to help other countries at all—well, russians believe Alaska is rightfully theirs as well as a bit of California, and that’s not talking about the whole “USA is our greatest enemy and should be destroyed” rhetoric. Also that’s not counting empowering other terrorist states like Iran, DPRK and that part of Yemen (who also build their ideology on hating USA).

There’s a miniature version of all of this in Israel—it has a certain person who valued staying as a prime minister more than serving his country, whose efforts to grow terrorist threat finally came to fruition last year. And he’s still friends with russia because it’s friends with other terrorist states (at least that was his excuse).

So what other countries do? Follow their selfish interests that hurt them in the long run: here in Germany we had at least two chancellors who willingly traded German interests for cheap russian gas (some argue it’s been a tradition since 1980s when they decided that cheap gas from USSR is more important than supporting Polish struggle for independence), or, in more recent events, the previous minister of defence is remembered for not doing anything with the significantly increased defence budget except giving her son a ride on a helicopter. Or there’s a situation where Europe decided to help Ukraine with munition but because of some selfish idiots who wanted to sponsor domestic industry more than to fulfil the pledge the promised amount has not been delivered (resulting in a current stalemate on the front-line). Speaking of Europe, those countries that try to help russia for cheap resources forget that being a russian ally makes you their backstabbing target (so far I think only Germany in WWII period evaded that fate—by backstabbing first). And there’s USA where politicians decided that their local political ambitions are a good reason to hold foreign aid hostage.

As I mentioned earlier, such decisions may have bad consequences for the whole world and for their country as well (but if the politicians made sane reasonable decisions I’d not have a reason to name them selfish idiots). And if you say “it’s the will of the people” then those people are no different (at least they may have an excuse for not having an idea about things outside their backwater town). America got great not all by itself but rather by setting the rules by which other countries agreed to play, and thus not eliminating the threat to the system (and russia openly declares ruining this system as one of its goals) will only lead to the downfall of USA. The same can be said about Temporarily Occupied West Taiwan which started to prosper only after its involvement in the world trade—a position which a certain selfish idiot will likely sacrifice for small territorial gains.

I don’t know why it’s just last two years. There are no facts (known to me at least) that show any factors causing the recent sharp increase in idiocy in human population. So it looks more plausible to me that the overall idiocy kept accumulating until the already stressed supports of society finally gave way under overload and external crises.

Do I think the situation can be improved? Hardly. The majority of population will be against any kind of reforms (especially where people are expected to think and/or to learn) for the obvious reason that I don’t need to repeat. So even if the current issues will be resolved, what prevents it from repeating again? After all we still have not learned a lesson from the pandemic (IMO people just got tired and decided to pretend that the virus does not matter and those frequent disruptions due to many people still falling ill from it also do not matter) and a frank and unambiguous statement from Temporarily Occupied West Taiwan that it intends to occupy the rest of Taiwanese territory and why should we hope that this upcoming conflict will be handled in a better way?

It somewhat amuses me how people discover they can use deflate to estimate text complexity or similarity. The reason for that is that this compression algorithm was essentially a by-product of efforts to estimate the string complexity. The original paper states it outright that the compression algorithm is “an adaptation of a simple copying procedure discussed recently” (referring to A. Lempel and J. Ziv, “On the complexity of finite sequences,” IEEE Trans. Inform. Theory, vol. IT-22, pp. 75-81, Jan. 1976). Apparently it went the full circle, proving that their original approach to complexity was right and that the authors (who did more work in that field than if field of compression) should be celebrated for this subject as well.

There are several approaches to designing the architecture that may reasonable at a quick glance but prove to be rather bad in the long run. One of those is monolith design (where the software is an interconnected mess where you cannot isolate any part without breaking half of it) and its variation panelák, a monolith that looks like it has modular structure but in reality those modules are often connected by undocumented interfaces and removing one of those may break the rest—just look at systemd, a modern init system that for some reason has to reimplement various previously stand-alone services as its components in order to function properly (like network management).

But recently I’ve noticed another, rather opposite, design pattern that nevertheless leads to equally bad outcome: having a simple but rather useless core that anybody can implement but won’t be satisfied with, which leads to creating a lot of (often competing) extensions that rarely get supported by the majority, ending up with a mess that you can’t rely upon. I think the appropriate metaphor here would be amoebas: something with a small core, amorphous body, cloning itself and the resulting clones may end up very different from each other over time (and detrimental to your health).
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A year ago I wrote why I’d like to be excited by RISC-V but can’t. I viewed it (and still view) as slightly freshened up MIPS (with the same problems as MIPS had). But the real question is what does it offer me as a developer of multimedia framework?

Not that much, as it turns out. RISC-V is often lauded as a free ISA any vendor can edit but what does it give me as an end user? It’s not that I can build a powerful enough chip even if hardware specifications are available (flashing an FPGA is an option but see “powerful enough” above) so I’m still dependent on what various vendors can offer me and from that point of view almost all CPU architectures are the same. The notable exceptions are russian Elbrus-2000 where instruction set documentation is under NDA (because its primary application being for russian military systems) and some Chinese chips they refuse to sell abroad (was it Loongson family?).

Anyway, as a multimedia framework developer I care about SIMD capabilities offered by CPU—modern codecs are too complex to write them in assembly and with a medium- or high-level language compiler you don’t care about CPU details much—except for SIMD-accelerated blocks that make sense to write using assembly (or intrinsics for POWER). And that’s where RISC-V sucks.

In theory RISC-V supports V extension (for variable-length SIMD processing), in practice hardly any CPUs support it. Essentially there is only one core on the market that support RISC-V V extension (or RVV for short)—C920 from T-Head and it’s v0.7.1 only (here’s a link to Rémi’s report on what’s changed between RVVv0.7.1 and RVVv1.0). Of course there’s a newer revision of that core that features RVVv1.0 support but currently there’s only one (rather underpowered) board using it and it’s not possible to buy anyway. Also I heard about SiFive designing a CPU with RVVv1.0 support but I don’t remember seeing products built on it.

And before you offer to use an emulator—emulation is skewed and proper simulation is too slow for practical purposes. Here’s a real-world example: when Macs migrated from PowerPC to x86, developers discovered that the vector shuffle instruction that was fast on PowerPC was much slower on Rosetta emulation (unlike the rest of code). Similarly there’s a story about NEON optimisations not giving any speed-up—when tested in QEMU—but made a significant performance boost on real hardware. That’s why I’d rather have a small development board (something like the original BeagleBoard) to test the optimisations if I can’t get a proper box to develop stuff on it directly.

This also rises a question not only about when CPUs with RVV support should be more accessible but why they are so rare. I can understand the problems with designing a modern performant CPU in general let alone with vector extension and on rather short term but since some have accomplished it already, why is it not more common? Particularly SiFive, if you have one chip with RVV what prevents adding it to other chips which are supposedly desktop- and server-oriented? I have only one answer and I’d like to be proven wrong (as usual): while the chip designers can implement RVV, they were unable to make it performant without hurting the rest of CPUs (either too large transistor budget or power requirements; or maybe its design interferes with the rest of the core too much) so we have it mostly on underwhelming Chinese cores and some SiFive CPU not oriented for a general user. Hopefully in the future the problems will be solved and we’ll see more mainline RISC-V CPUs with RVV. Hopefully.

So far though it reminds me of a story about Nv*dia and its first Tegra SoCs. From what I heard, the company managed to convince various vendors to use it in their infotainment systems and those who used it discovered that its hardware H.264 decoder worked only for files with certain resolutions and they somehow used a CPU without SIMD (IIRC the first Tegra lacked even FPU) so you could not even attempt to decode stuff there with a software decoder. As the result those vendors were disappointed and made a pass on the following SoCs (resulting in a rather funny Tegra-powered microwave oven). I fear that RISC-V might lose interest of the multimedia developers with both the need to rewrite code from RVVv0.7.1 to RVVv1.0 and the lack of appealing hardware supporting RVVv1.0 anyway—so when it’s ready nobody will be interested any longer. And don’t repeat again the same words about open and royalty-free ISA. We have free Theora format that sucked and was kept alive because “it’s free”—when it was improved to be about as good as MPEG-4 ASP there was a much better open and free VP8 codec available. Maybe somebody will design a less fragmented ISA targeting more specific use cases than “anything from simple microcontrollers to server CPUS” and RISC-V will join OpenRISC and others (…and nothing of the value will be lost).

P.S. Of course multimedia is far from the most important use case but it involves a good deal of technologies used in other places. And remember, SSE was marketed as something that speeds-up working with Internet (I like to end posts on a baffling note).