3 ms·
The description "real-time" varies in meaning depending on the application and acceptable average and maximum latency. The un-informed usually thinks "real-tim
by redis_mlc 6y ago
The description "real-time" varies in meaning depending on the application and acceptable average and maximum latency.
The un-informed usually thinks "real-time" means "hard real-time", but that's seldom necessary, so one can save on additional expense and effort by using a regular linux distro and removing most of the daemons and file location indexing.
I've done real-time development (for Space Shuttle, rocket and balloon projects), and largely all I care about is if a circular buffer can be emptied in time before it fills. That's one technique for avoiding latency variation issues.
The versions of linux that you would normally encounter aim for music real-time, which is about 10 ms latency. 30 ms is considered to be bad.
Most of the pro Yamaha synths use linux as the embedded OS, and some of the code is downloadable (they attempt to comply with the letter of the GPL.) So you can go down to Guitar Center and do a real-time test anytime yourself. :)
The iPhone is pretty good for music, because it was designed to have low latency when playing.
https://www.synthtopia.com/content/2018/02/17/10-years-later-android-audio-quality-still-lags/ https://www.synthtopia.com/content/2018/02/17/10-years-later...
https://superpowered.com/androidaudiopathlatency https://superpowered.com/androidaudiopathlatency
Looks like Wind River discontinued RTLinux, which was hard real-time (a real shame actually, as it removes one of the few hard real-time options):
https://en.wikipedia.org/wiki/RTLinux https://en.wikipedia.org/wiki/RTLinux
- codetrotter 6y agoThe Akai MPC X and its siblings run Linux too. Based on buildroot according to someone that looked into it. https://niklasnisbeth.gitlab.io/mpc-internals/ https://niklasnisbeth.gitlab.io/mpc-internals/ However I don’t remember the GPL being mentioned anywhere when I had my MPC X. I sold it recently because of not having any money. But I hope to own one again in the future. If I ever do have one again I will probably have a closer look at what it says about the GPL, and then try and get a copy of all of the open source portions of the firmware directly from Akai.
- aasasd 6y agoJust as an aside, you probably (and hopefully) don't need to have the unit to download the manual—which is where the licenses are likely mentioned. Though this one seems to direct the user to Akai's site. E.g. https://www.mpc-tutor.com/akai-mpc-manuals/ https://www.mpc-tutor.com/akai-mpc-manuals/
- Darkphibre 6y agoAs someone that worked at Microsoft on the XAudio 2 for the Xbox 360 & Windows Phone stacks... holy heck that android audio path is painful to read. >.<;; We went with a 5.33ms quantum on the Xbox 360 (vs. Window's 10ms), and tried to stay out of the way as much as possible to ensure minimal latencies: https://docs.microsoft.com/en-us/windows/win32/xaudio2/xaudio2-audio-graph https://docs.microsoft.com/en-us/windows/win32/xaudio2/xaudi...
- kijiki 6y ago> Looks like Wind River discontinued RTLinux Xenomai is still under somewhat active development.
- redis_mlc 6y agohttps://gitlab.denx.de/Xenomai/xenomai/-/wikis/home https://gitlab.denx.de/Xenomai/xenomai/-/wikis/home