4 ms·
Truly is it uncompressed PCM WAV audio? In that case 44kHz 16-bit 1-channel is 705 kbps. Are there not any good nonproprietary lossless low latency audio codec
by zaroth 6y ago
Truly is it uncompressed PCM WAV audio? In that case 44kHz 16-bit 1-channel is 705 kbps.
Are there not any good nonproprietary lossless low latency audio codecs? A brief look at Wikipedia shows a couple that are 5ms or lower, but either they are proprietary or they are low bitrate.
- tleb_ 6y agoOpus has frame sizes down to 2.5ms. See https://en.m.wikipedia.org/wiki/Opus_(audio_format)#cite_note-ValinAES135-8 https://en.m.wikipedia.org/wiki/Opus_(audio_format)#cite_not...
- staticfloat 6y agoYou pay a price for the super-small frame sizes; much worse compression ratios. Frame sizes smaller than 10ms disable the LPC and hybrid coding modes, which are quite advantageous. [0] In my experiments with transmitting realtime audio signals using Opus, 10ms frame sizes are acceptable for 1-way synchronicity (e.g. if you want the user to perform an action and hear the result as simultaneous with the action) but it's definitely the upper bound. From what I remember my signal processing professor say, the threshold to try and hit is 7ms total latency for truly undetectable processing, but I can't find a reference for that, so take it with a grain of salt. [0] https://www.opus-codec.org/docs/html_api/group__opusencoder.html https://www.opus-codec.org/docs/html_api/group__opusencoder....
- jarmitage 6y agoSee for example: Robert H. Jack, Tony Stockman, and Andrew McPherson. 2016. Effect of latency on performer interaction and subjective quality assessment of a digital musical instrument. In Proceedings of the Audio Mostly 2016 (AM '16). Association for Computing Machinery, New York, NY, USA, 116–123. DOI: https://doi.org/10.1145/2986416.2986428 https://doi.org/10.1145/2986416.2986428 https://scholar.google.com/scholar?cluster=13472622195552899495 https://scholar.google.com/scholar?cluster=13472622195552899...
- declnz 6y agoJamulus uses Opus for this reason (balance with quality) AIUI
- spacechild1 6y agoAs do SoundJack, SonoBus and probably many other similar apps.
- wmleler 6y agoThe JackTrip Virtual Studio uses an inexpensive Raspberry Pi, and connects a low latency hardware codec directly into the Pi's bus, to achieve a latency of 1mS. At that level, the only other latency you have to worry about is the speed of light (through the internet). I've just published an article about the Virtual Studio at https://wmleler1.medium.com/setting-up-your-virtual-studio-6a9fbea56f08 https://wmleler1.medium.com/setting-up-your-virtual-studio-6...