Audio Garbled and Out Of Sync using v18 on OSX 10.15.2 Cataliina

[pixelpixel]

Hi All!

Thank you for all the great work on Syphon!!! I’m creating a separate thread from the other audio issue as I’m not sure this is related to that one.

Unfortunately, I’ve been having an issue recently with most (almost all) of my recordings where a significant portion of the audio that is recorded alongside video is coming through garbled. I’ve exhausted my own ability to unravel this and wanted to reach out for some guidance on what else I could try to identify and resolve this.

The garbling usually starts near or at the beginning and sounds (to my untrained ears) like the recording rate is slower than the playback rate, it’s choppy, artifacts, seems sped up. The audio is then ending before the video ends which leads me to believe it is becoming ahead of time. The weird thing is that the audio will not be corrupted like this for the entire recording, there will be several minute long periods in an 8 minute video where the recording sounds flawlesss (albeit out of sync). The video quality is perfect and recording smoothly at ~60fps the entire time. I have not been able to identify any specific reasons that make it worse/better.

Here’s a description of my setup:

• OS: OSX 10.15.2 Catalina
• Storage: nvme ssd inside a recent 15″ macbook pro
• Video: h.264 -> 1080×1080 coming in from an OpenFrameworks source
• Audio: Linear PCM -> SoundFlower 2CH 44100 being fed audio by a Multi-Output Device containing SoundFlower 2CH and Built-in Output (both confirmed to be 44100)

This setup has worked well for the past several years and the audio problems seem to have come about in recent months (which seems to coincide with v18/catalina updates?) I’ve tried playing with drift correction in the multi-output device but it did not seem to affect anything (I tried enabling it on both devices, separately). I also tried using other encodings (Photo, Prores) and had no luck.

The source of the audio is Ableton Live which is set to 44100 and is using the Multi-Output Device {Built-In Output / SoundFlower 2CH} to send the audio to my speakers and to soundflower which is then selected from syphon recorder.

If anyone has any idea or suggestions or if anything is unclear, please let me know! Thank you!!!

[bangnoise]

I know there have been problems with Soundflower on Catalina, which may or may not be the issue here. Have you tried BlackHole?

[Author]

Posts