It's cheap and beginner friendly and very easy to learn. There is an overwhelming amount of ESP32 boards, variants and software which is daunting when you're just getting into embedded development.
I can assure you that audio codec testing is a through science. Tools such as PSNR, PEAQ or POLQA all have limitations and cannot fully replace a human listener. Those familiar with the topic are often vocal critics of audiophile bullshit.
No, this is nowhere near pseudoscience, psychoacoustics is an established field of science.
Yea same with me. Unless you have a perfect setup this is good enough. Though if you want to do a little experiment, try Fatboy Slim's Kalifornia, the beginning is notorious for destroying transform based codecs.
If anything those tests make it easier to find subtle differences, which is good if transparency is the goal. I don't think that makes them fundamentally flawed. They are used throughout the industry, making results comparable.
Of course there are other ITU tests that work without hidden references, looping or even A/B comparison. They require a much bigger listener pool, are more expensive and take longer, thus used less often during development.
I spent half my professional career doing listening tests (MUSHRA and P.800), specifically on test items like Tom's diner. 128 kbps mp3 ist fairly easy to pick out, especially if you can compare it to the original. Double the bitrate and it's a real challenge.
Modern codes like opus are much more efficient. At high bitrates they are fully transparent and anybody who claims to be able to hear a difference is full of shit. Put them in a controlled setting and they fail every time.
If used in a small device like a hearing aid, a 2x factor can have a significant impact on battery life.
VoIP in general experiences full packet loss, meaing if a single bit flips the entire packet is dropped. For radio links like Bluetooth it's possible to deal with some bit flips without throwing the entire packat away.
Until 1.5 Opus PLC was in my opinion it's biggest weakness, compared to other speech codecs like G.711 or G.722. A high compression ratio causes bit flips to be much more destructive.
As for making moeny, Bluetooth codecs have no license fees.
I remember seeing published numbers based on instrumented code, but could not find it.
I did a quick test with the Google implementation (https://github.com/google/liblc3) which is about 2x faster than Opus. To be honest, I expected a bigger difference, though it's just a superfical test.
A few things that also might be of relevance why they picked one over the other:
- suitability for DSPs
- vendor buy-in
- robustness
- protocol/framing constraints
- control
"Inferior" is relative. The main focus of LC3 was, as the name suggests, complexity.
This is hearsay: Bluetooth SIG considered Opus but rejected it because it was computationally too expensive. This came out of the hearing aid group, where battery life and complexity are a major restriction.
So when you compare codecs in this space, the metric you want to look at is quality vs. CPU cycles. In that regard LC3 outperforms many contemporary codecs.
Regarding sound quality it's simply a matter of setting the appropriate bitrate. So if Opus is transparent at 150 kbps, and LC3 at 250 kbps thats totally acceptable if that gives you more battery life.
I'm glad this was rejected. The author consideres violations of PEP8 to be broken code that doesn't generate exceptions.
Lots of people treat PEP8 as the word of god, but apparently have not bothered to read it. "Many projects have their own coding style guidelines. In the event of any conflicts, such project-specific guides take precedence for that project."
I've spent hours looking over code before delivering to FAANG. Our company had put a clause into the contract that our code was free of any GPL'd code. It happened before and it was discoved. The whole thing was a very expensive excersice. I'm aware that many small startups, 90% of which go bust anyways, just ignore licenses but that doesn't work when you play with the big boys.
If this tool was trained on open source code, what license does the generated code have? At least with Codepilot people were able to generate verbatim GPL code with typos and everything. More importantly, I wonder if companies behind these type of tools offer legal or financial protections in case GPL code sneaks in and leads to expensive law suits.
> Could Throat mics be the ultimate in high quality audio for cheap?
How can those microphones even capture fricatives or plosives in decent quality? Most of the vocal tract lies behind the throat. I looked for some examlpes and they all sound terrible.
If you want good and cheap audio, get an off-brand USB large diaphragm condenser mic, for example this:
A commonly used way to create an discrete sine wave efficiently is to use an IIR oscilator. If it needs to be long running, use a real sin to correct for rounding errors every N samples. If you're using something like Q30 fixed point that correction doesn't have to happen that often.