How to solve audio/video sync issue on my mp4 screenrecording?

Question

I'm relatively new to video editing and struggling to solve a problem whereas the video (i.e my lips) is out of sync with the audio (i.e my voice). The beginning of the video is fine but by the end the sync is totally off.

Things I have tried so far:

1. auto-sync audio based on waveform (DaVinci Resolve)
2. run it through Handbraker to get constant frame rate (tried 23.976fps or 24fps)
3. update sound/camera drivers if this was a playback issue

Here are some of the information I get through the MediaInfo tool on the first part of total 45min recording.

VIDEO

• frame rate 23.976 in DaVinci Resolve (22.783 fps by MediaInfo)

• .mp4 (H.264) file recorded with IceCream Screenrecorder (i will
  change to OBS for next video)

• 6min 51s length

• 720p HD camera with dual microphones

AUDIO

• sampling rate 44.1kHz (MediaInfo / Audacity)

• 24.00fps in DaVinci Resolve

• 6min 49s length

The mic i use is integrated in my new Lenovo IdeaPad L340-17IRH Gaming and provides better quality than my blue snowball mic. It is currently set in the settings on 2ch, 16bit, 48kHz (can the diff. with sampling rate 44kHz be the issue).

What am I doing wrong here? What else can I try?

Thanks in advance for your help, VERY APPRECIATED.

Answer 1

Try tsMuxer as it will allow you to change the frame rate without re-encodingn https://www.videohelp.com/software/tsMuxeR

Answer 2

Check what sample rate and frame rate your camera records at. A lot of video stuff defaults to 48kHz, not 44.1kHz. Make sure everything in your recording and editing processes uses matching sample rates and frame rates throughout. Using a different device for audio to video is liable to introduce some drift unless their clocks are synced together (most non professional gear can’t do this). Even so, you should get a large amount of drift over under 10 mins or so if they are all on the same frame rates and sample frequencies.

Answer 3

At work, if I receive disparate audio and video sources (which happens pretty often), I will make multiple small edits to the audio in order to keep the dialog in sync with the picture. Is conforming the audio in such a manner using Resolve or another NLE (Avid, Final Cut, Pro Tools, Reaper, etc.) an option for you?