Help please<3 audacity audio short/ glitchy

ive been using audacity to upload to final cut and ive been having problems matching the video with audio. I tried making a multi media clip but the audio has been shorter than the video. I am not sure why the audio has been a little shorter and it wont align with the video. its at the same setting we have had it before so im not sure why:(( is there a way to fix this ? If youre able to help, will send a coffee giftcard as a thank you <3 if you have any questions please let me know. im very new to this i dont know how a lot of things work. thanks in advance. i can send a video o f the problem as well. any other resources would be helpful too!

Try slowing down the audio so its duration matches the video

Usually that’s related to a problem with the original audio/video file. It seems to be more common with the more compressed formats (MPEG-4 or similar, and sometimes MPEG-2). Some kind of corruption in the time codes, or something.

The audio, once separated, is usually perfect. If there are 48,000 samples-per-second there are exactly 48.000 samples-per-second. (That’s in the digital domain. When recording and playing-back the clock in the ADC & DAC is not perfect, down to the exact sample-count.)

…MP3 (and some other lossy formats) adds a few milliseconds of silence to the beginning (and to the end) so it will add samples making the file a little longer and the audio can lag the video when they are re-multiplexed. But that doesn’t happen with WAV or FLAC or other lossless formats.