Framerate, Pulldown, and Audio Conversion

[poerschr]

Hello...

I have finally understood the importance of using a 3:2 pulldown in TMPGenc. I take 29 FPS video, use Avisynth, and convert it to 23 FPS, applying a 3:2 pulldown in TMPGenc (making the video progressive in the process). However, I am having difficulty understanding what must be done to the audio as well...

My source file contains MP3 audio running at 29 FPS. I want to use Virtualdub to extract the MP3 and convert it to uncompressed WAV. Then take the WAV and use a program like AC3Machine to convert the audio to AC3. However, I am unsure what framerate to use??

I found this info here:
https://www.videohelp.com/forum/viewtopic.php?t=178789

But the orginal file that they are discussing does not contain 29 FPS. I can assume that the audio needs to be converted to 23 FPS. I am worried about how the audio and video with sync correctly...

Thanks

[bugster]

When you apply 3:2 pulldown to a 23.97fps video it will play at a framerate of 29.97fps (by repeating certain fields). SO in your case you don't need to do anything to the Audio. It is only when converting from PAL framerate to NTSC framerate that the audio length needs to be adjusted.