I stream a church service to FaceBook and YouTube using vMix 27.0.0.85. We use a 1080/60fps stream with FB using H.264 and YT using HEVC. The picture quality is very good, but now I've started experiencing audio drops during the stream. It's not heard inhouse nor in the monitor earphones on the vMix laptop. Laptop is running NVIDIA 3070 GPU, 32 gb Ram, 1 TB ssd, gigabit ethernet with a full gig fiber connection to the internet. Laptop is not under any load, render times are less than 10 ms. Streams are solid red. I am using 2 PTZOptics 20x NDI cameras.

As a test, I've switched the YT stream back to H.264 with 8 mbps bitrate. FB is 4.5 mbps bitrate.

The audio seems to drop or pause in 1 sec increments. Works, pauses, works, pauses, etc. Might clear up for a bit then start again.

I'm beginning to think using HEVC is just not stable enough. I only did this to get a better quality image with less data, but not sure it's worth it.

Any suggestions?

If I'm not wrong YT supports AV1 as one of the first platforms. You can try that instead of H.265.
Generally I would recommend only one type of encoding. If you stream to different platforms this could mean that you stream in the lowest common factor but if your system is powerful enough and bandwidth is high enough you can do multiple stream in different encodes.

Hi there, have you found any solution? I am experiencing the same - audio is dropping on Youtube, but not in the headphones. H264 did not help :/