Audio Reactivity: support direct mic/line input
Current system introduces latency. See discussion here: https://discord.com/channels/783806589991780412/784197548918177842/1064373338295783564
2 Replies
Thank you for the feedback and suggestions!
What makes us think this is an issue? This isn’t an issue with Open Brush, but rather how Windows ‘listens to’ (and plays back) an audio input (microphone) to the speakers (playback, which is what Open Brush uses for activating the audio reactive brushes)
How have we tested: Plug a line input either direct into a motherboard or through a USB audio input device (Focusrite 2i2 for example). The audio is captured in real time (as can be seen in OBS or any recording software) but that input isn’t captured for Open Brush as Open Brush only captures audio playing outputs not audio inputs.
To get the audio input to be captured for the audio reactive brushes, it needs to be turned into an Audio Output. By clicking ‘listen to this device’ in the recording/microphone preferences within Windows, you can turn the input into an output for Open Brush but then you can hear the captured audio playing back with a 50-100ms delay. The brushes react perfectly to the audio that is playing, but this audio is 50-100ms behind the live feed coming from the DJ to the audience due to Windows default behavior.
To replicate this behavior, plug in a line input, sound capture device, or microphone. In the recording settings click ‘listen to this device’. In Open Brush draw a line with audio reactive brushes and play a sound into the line input. Make a sound for the audio input - clap a few times into the mic, or play a source into the audio capture device. The brushes react at the moment the PC ‘plays’ the sound, which is 50-100ms delayed from when the sound was captured. This is entirely a windows issue but could, in theory, be resolved through bypassing the need to ‘play back’ the audio input and instead capturing the audio input directly to cause the brush reactions.
Because the issue isn’t a bug with Open Brush but could be resolved by having a line input used for audio reactive rather than just output devices, I placed the request as a new feature for consideration. Understanding that it was unlikely to happen, but never know unless you ask. 🙂
Your suggestions are great, and we will try those out. SoundFlower is a popular way to turn an audio input to an output with minimal lag for streamers, but that’s Mac only. VB-Cable might work and have lower lag than Windows built in ‘listen to this’ feature. We will try it and report back!
Thanks again!
Updates:
1. This video articulates the issue with the latency/delay of 'listening to this device' on a standard line-input on Windows https://www.youtube.com/watch?v=fAI9NE_QDis That delayed audio is what Open Brush grabs for the reactive audio brushes, thus the brushes the audience sees bounce 50-100ms behind the beat to the music the audience is hearing.
2. I tried VB-Cable. I don't think this works for what we're trying to do. VB Cable takes an Audio *Output *and routes it to an Audio Input. This is almost the inverse of what we're trying to do. This allows audio output from an app such as Teamspeak to be routed to an 'audio input' to be grabbed by OBS or other software. (Voicemeter Banana, by the same devs does allow routing of the mic-input to the audio output, but it has the same 50-100ms delay I'm trying to get rid of)
3. We'll need to buy a USB microphone or audio interface that supports Microphone levels within the Sound Playback settings (see video from 1 above). We had been using a Zoom H1 audio interface but this doesn't show Microphone levels within the sound playback settings (just 'listen to this device' from the record settings, which results in the latency from 1 above we want to avoid) . Ideally we wouldn't have to buy extra hardware to get rid of the latency, and Open Brush could support line-in or Mic input directly, but again we are super extra happy with Open Brush, so if we have to pay a bit extra for hardware to resolve this for our shows, it's no problem at all.
Open Source Bug
YouTube
Listen to your microphone voice without delay (mic monitor passthro...
Monitor your mic without delay. Tested with Arozzi Colonna, works with Blue Yeti USB mics, and many other USB mics. Will not work with audio jack microphones most likely. Let me know which mic you have in the comments!
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