5 ms·
How does it deal with the audio ring buffers on the various devices? Does it just try to start them all at the same time, or does it take into account the samp
by Dwedit 1y ago
How does it deal with the audio ring buffers on the various devices? Does it just try to start them all at the same time, or does it take into account the sample position within the buffer?
- brcmthrowaway 1y agoThis is my question, does it do interpolation or pitch bending
- cosmotic 1y agoAnother issue is seeking in compressed audio. When seeking (to sync), some API's snap to frame boundaries.
- cosmotic 1y agoI solved this by decompressing the whole file into memory as PCM.
- freemanjiang 1y agoGreat question! There's two steps: First, I do clock synchronization with a central server so that all clients can agree on a time reference. Then, instead of directly manipulating the hardware audio ring buffers (which browsers don't allow), I use the Web Audio API's scheduling system to play audio in the future at a specific start time, on all devices. So a central server relays messages from clients, telling them when to start and which sample position in the buffer to start from.
- camtarn 1y agoInteresting. Feels like this might still have some noticeable tens-of-millisends latency on Windows, where the default audio drivers still have high latency. The browser may intend to play the sound at time t, but when it calls Windows's API to play the sound I'm guessing it doesn't apply a negative time offset?
- serial_dev 1y agoSo it doesn't need to use the microphone? I guess from the "works across the ocean" comment and based on this description. I would have thought you would listen to the mic and sync based on surrounding audio somehow but it's good to know that it's not needed.
- freemanjiang 1y agoYup no microphone. It's all clock sync