DigitByte Software for Windows, Mac, iPhone, iPad, iPod – free download
1. Click the Open Video button, select a video file from your computer, then this program will play it automatically.
2. Here is the key point, please try to compare the audio and mouse lip, or subtitle to sync audio/video. If audio is played before video, click the Audio skip forward button or press the hotkey i. If audio is played after video, click the Audio skip backward button or press the hotkey p.
Click the Skip backward button or press the hotkey q to repeat the last scene so that you can correct time shift between audio and video at the same scene more times.
Click the Original audio button or press the hotkey o to reset the audio if needed.
3. If you think you have sync audio/video at the position of the movie, click the Add a synchronization point to the list button. It is better to add 2 points at the near beginning and end of out of sync position of the movie. If you want to add the third sync point to the list, it is better in the middle of out of sync position of the movie.
4. Click the Calculate start button to set Video start time or Audio start time automatically. Click the Calculate end button to set Video end time or Audio end time automatically.
Note: You may enter Video start time or Audio start time manually. For example, If you think the movie is sync at the beginning, you enter 0 as Video start time or Audio start time, do not use the calculated value from the sync points. If the movie is out of sync from the beginning, it is better to use the calculated value from the sync points.
Normally it is better for Video end time and Audio end time to use the calculated value from the sync points.
5. Preview the output video to check if the output is sync.
6. If there is no problem, then click the Convert button to start the conversion.