You would need to run a command to build the video from your PNG files and merge with the audio… I do this using ffmpeg. Here is an example, that you might have to adjust for your environment (I use a Mac)
ffmpeg -framerate FRAMERATE -i "VIDEONAME_%06d.PNG" -i $VIDEOFILE -map 0:v -map 1:a\? -vcodec libx265 -pix_fmt yuv420p "VIDEONAME_slp.mp4"
- FRAMERATE is your framerate
- VIDEONAME is the name of the video file without the extension, that you will find in all your PNG files
- VIDEOFILE is your source file with the extension. It will be used to extract the audio
As I ran into some of the issues you mentioned, I created a script for Mac to automate the backup of the PNG file. Never lost a single frame since then, despite many crashes! (in all fairness, some of the crashes I have experienced are my fault, since I am running a beta version of macOS). But Video AI has its fair share of bugs too!
You can find more information here:
I would say the quality with libx265 is pretty good, maybe others with more experience will comment. I haven’t looked at the actual command used by Video AI since I have stopped relying on this.
Please let us know if you need additional information about ffmpeg. Hope this helps.