That is an old CPU, so will be challenged with real-time video encoding
and the log doesn't have a streaming session so can't see if any encoding lag
Could be something else, and we'll need another log to see, but at first guess, I'd suspect your CPU is being pegged at 100% (or close to it) and system getting unstable (something has to give, and your seeing the audio get out of sync)
Have you learned how to use Task Manager (Performance) and monitor h/w resources for bottlenecks?