This problem can not only occur with downloaded movies. It can also be presented with videos made by us to publish on our YouTube channel , for example and even in videos recorded by us and uploaded to social networks.
Although it may seem complex to fix this problem, there are several ways to solve it in a simple way and in the following article we will explain how to correct the audio of a delayed or out-of-sync video easily.
What to do to fix the synchronization problem?
In the first place, in order to solve this problem, it is necessary to know the origin of this problem. In this way we can identify the type of lag, which is usually of two types: constant and progressive.
There is a very useful tool called VirtualDub that will allow us to detect the type of desynchronization and, later, to fix it. All you have to do is go to the audio properties of the file and evaluate the duration of both the image and the video.
In this way we can determine if the lag is continuous or progressive. If the duration of the audio and video is the same or similar, we will be facing a constant desynchronization. On the other hand, if both are different, we will find ourselves before a progressive desynchronization.
With this tool you can see the properties of the video by accessing the File option and then clicking on File Information. In that option you will be able to see different data of the video, however, what interests us is in the Length section.
How to fix progressive desynchronization with VirtualDub?
In order to solve this type of lag we will have to separate the audio and video files to adjust the size and duration, making them coincide and later rejoin them as a single file.
The first thing to do is open the program and click on the File option and then on Open Video File. Then we will have to go to the audio menu to be able to create an audio file without video and select the No Audio option.
Later we will have to go to the video section to do the same. We will have to go to the Direct Stream Copy option and then click on the File option and Save as AVI.
In this way we will have already created a video file without audio and what we will have to do now is open the new audio file and incorporate it.
For this we will have to go to audio and select the Audio From Other File option and we will only have to choose the original video and this will be incorporated only as audio.
In this way we will have audio and video with the same duration, having eliminated the problem of progressive lag and we will only have to synchronize it. For this we will have to go to Video and click on the Frame Rate option .
A menu will be displayed and the option Change so video and audio durations match will have to be selected. After that we will have to save the file and that’s it.
How to fix constant desynchronization with VirtualDub?
The procedure for solving a constant offset in an audio file is relatively straightforward. The first thing to do is open the file from File and select the Open Video File option .
We select the video that we want to fix and once it is open we will have to go to the audio section and select the Interleaving option .
A menu will be displayed where we will have to add the amount of delay or advance time that we want to synchronize the video. It is important to note that positive numbers will delay the audio relative to the image, while negative numbers will advance it.
The audio track by delay field measures the values in milliseconds, so if you want to advance 1 second, you will have to enter 1000 ms and check.