How to change audio track in movie

Himanshu Panchal

May 5, 2017
I have a full HD movie with English audio track in it.
So my question is can it be possible to download only different language audio track and merge in that movie for different audio track like HINDI


Jun 15, 2017
*Disclaimer: I am considering you have not violated any copyright laws and hence willing to help you.*

Yes it is possible. You will need to download a video editing software. Some free softwares are: Wax, VSDC Video Editor, Lightworks. Some paid softwares are Adobe Premiere, CyberLink PowerDirector, etc.

You Drag and drop the new audio track and delete the old one. You might want to make sure it is in Sync with the video.
NOTE: You need a computer that will be capable of editing videos.

Not for switching audio tracks (or adding subtitle or chapter tracks). Most of the file formats we think of as "movies" (.mp4, .avi, .mkv, .wav, etc) are actually just container formats. They contain a video file (usually in h.264 or h.265, though some older ones are in MPEG4 or XVID), an audio file(s) (variety of formats including AAC and MP3, multiple files for multiple audio tracks), subtitles, and a chapter listing. Some containers also support extras like cover art. The container glues all these files together into one file to make it easier to move the movie around.

When you're swapping or adding an audio track, all the computer has to do is copy each of these component files out of the container (called demuxing, or de-multiplexing), then create a new container with the old component files + new audio track (called muxing). It's basically a glorified copy operation, which any computer can do. You only need a high-end computer if you're re-encoding the video (reducing its quality and size, or converting it to a different video format that's more compatible with your playback devices).

The tricky part of mixing audio and video from different sources is properly synchronizing it. The offset (delay between when the video starts and when the audio starts) is easy - the time offset is usually stored in a file added to the container. The harder part is when the video and audio have been encoded at different framerates. The most common mixup is the video is encoded at 29.97 FPS (which exists for archaic reasons) while the audio is encoded assuming 30 FPS video. Or vice versa. This causes the audio to slowly lose sync as the movie plays (at a rate of 0.03 frames per second, or 1 second in 16.7 minutes). Usually you can fix this by correcting the video playback FPS to match what the audio is expecting (usually stored at the beginning of the video file). But I've encountered stubborn formats where changing this value seemed to make no difference. And if you've got a movie with variable framerates (common when there is film and video mixed together), forget about it.