Why Audio, Subtitles, and Video Become Out of Sync
After translating between different languages, the length of sentences will change, and the duration of pronunciation will generally also change. For example, when translating from Chinese to English, the length of sentences will definitely be different, and the time it takes to pronounce the Chinese sentence and the English sentence will generally also be different.
Chinese: 有多远滚多远 (Get as far away as possible)
English: Get out of here as far as you can!
Chinese: 滚远点 (Go away)
Japanese: ここから出て行け。(Koko kara dete ike.)
If the original Chinese pronunciation in the video takes 2 seconds, and after translating and dubbing into English, the duration may be 4 seconds, which will inevitably lead to asynchronization.
How to Synchronize Them (Regardless of Quality, Just Synchronize)
As mentioned above, if the duration before translation is 2 seconds and the duration after translation is 4 seconds, if you only need them to be synchronized, regardless of the speed of speech or the speed of the video, you can directly accelerate the audio by 2 times, so the duration of 4 seconds can be shortened to 2 seconds, naturally achieving synchronous alignment. Or you can slow down the video, extending the original 2-second segment to 4 seconds, which can also achieve alignment.
Specific Operation Method for Audio Acceleration to Achieve Alignment:
- In the software interface, select "Automatic Audio Acceleration" and uncheck "Automatic Video Slowdown."
- Open the menu Tools - Options, and set the maximum audio acceleration multiple to
100.
This will achieve synchronization, but the drawbacks are obvious: the speech speed fluctuates.
Operation for Video Slowdown to Achieve Alignment:
Uncheck "Automatic Audio Acceleration" in the software interface and select "Automatic Video Slowdown."
Open the menu Tools - Options, and set the maximum video slowdown multiple to 20.
This can also achieve alignment, with the speech speed remaining unchanged and the video slowing down, but the video also becomes fast and slow.
If you just want simple alignment and don't care about the quality, you can use these two methods.
Better, More Acceptable Synchronization Methods
Obviously, the above synchronization methods are not practical. Audio that is too fast or video that is too slow is unacceptable, and the experience is too poor. For better results, you can enable both "Automatic Audio Acceleration" and "Automatic Video Slowdown" simultaneously.
Specific Operation:
When selecting the faster mode or OpenAI mode, try to use the medium or larger model and select "Overall Recognition."
In the software interface, select "Automatic Audio Acceleration" and "Automatic Video Slowdown," and set a small overall acceleration value, such as 10%.
Open the menu Tools - Options, and set the maximum audio acceleration multiple to 1.8, which means the maximum speech speed is accelerated to 1.8 times the normal speed. You can manually change it to 2 or 1.5, etc., a value greater than 1.
Open the menu Tools - Options, and set the video maximum slowdown multiple to 2, which means slowing down to 0.5 times the normal speed. You can change it to 3 or 5, etc., a value greater than 1.
After the above operations 1-3, it may still not be aligned, because the maximum value is limited. When the maximum value is reached and it is still not aligned, it will give up and directly delay the subtitles. Then you can continue to adjust the subtitle-related options in the menu Tools - Options.
Is There a Perfect Synchronization Method?
Apart from manual intervention, such as simplifying translations and adding transition screens, no perfect method that can be automatically implemented by a program has yet been found.
To simultaneously ensure that in very long or very short videos, in any language translation and dubbing, the goals of "acceptable audio acceleration range," "acceptable video slowdown range," and "mouth opening and closing moments coincide with the start of speech" can be achieved automatically by a program, it seems like an impossible task. Apart from manual adjustment, there is no perfect method.