How do I convert a dual audio movie to single audio?

Dual audio refers to a movie, TV show, or other video that contains two audio tracks – typically one in the original language and a second dubbed audio track in another language. For example, an Indian movie may have Hindi audio as the original track and an English audio track dubbed over it for international audiences. While dual audio can be useful for accessing content in multiple languages, there are several reasons why someone may want to convert a dual audio video into a single audio track:

Most playback devices like smart TVs, media streamers, and game consoles will default to playing both audio tracks simultaneously. This results in distracting and confusing audio. Converting to a single track avoids the mixed audio and provides a cleaner experience.

Having two audio tracks takes up extra file size and bandwidth. Removing the secondary track can reduce file size for easier sharing and streaming.

Some viewers simply prefer to watch movies and shows in the original language with subtitles rather than dubbed audio. Converting to the original language track allows this viewing preference.

For language learners, retaining only the foreign language track immerses them in that language and avoids the distraction of switching between languages.

Converting dual audio to a single track allows simplified playback and customized audio that enhances the viewing experience.

Prerequisites

In order to convert a dual audio movie into single audio, you’ll need a few key pieces of software:

• Video editing or encoding software like Handbrake, FFmpeg, or MKVToolNix

• MP3 player or digital media player software like VLC media player to preview the final file

• Source files: find and locate the dual audio video file you wish to convert

Locate Audio Tracks

To locate the audio tracks in your dual audio movie, first you’ll need to open the video file in a multimedia editing program.
Some recommended editors are: Adobe Premiere Pro, Final Cut Pro, or Davinci Resolve.
Once you have the video open in your chosen editor, look in the audio panel or timeline area to identify the different audio tracks. A dual audio movie will typically have two or more audio options available.

Select Audio Track

Most dual audio movies contain two audio tracks – one for the original language audio and another for a dubbed language. The first step is determining which audio track you want to keep.

To select the audio track, open the video file in a video editing program like Adobe Premiere Pro. In the timeline, you will see the video clip with Audio Track 1 and Audio Track 2 listed below it.

Listen to a portion of each audio track to determine the language and quality. Choose the track you want to retain for the final single audio version. This is commonly the higher quality or original language audio.

Right-click the unwanted audio track and select “Detach” or “Unlink”. This will separate the audio track from the video so only the desired track remains attached.

Now when you export the video from Premiere, it will only contain the singled selected audio track.

Remove Unwanted Audio

Once you’ve identified the audio tracks, it’s time to remove the unwanted audio from your video file. The process for removing the audio will vary depending on your specific software.

In most editing programs, you can simply delete or disable the audio track you want to remove. For example, in MOV files, you can open the video in QuickTime Player and uncheck the audio track you don’t want in order to mute it. Other programs like Shotcut allow you to click on an audio track and select “Disable”. In advanced editing software like Adobe Premiere Pro, you can right click on an audio track header and select “Disable”.

Deleting or disabling the unwanted audio track will remove it from the final exported version of your video. Just remember to leave enabled or keep the audio track you wish to retain as the single audio.

Export Single Audio

When you want to end up with a video file that contains only one audio track, you will need to export or reencode the video with just the selected audio track. After locating and selecting the audio track you want to keep, go to your software’s export or encoding settings. For example, in Premiere Pro, go to the Export settings. In the Audio section, ensure only the desired track is checked for export and/or you uncheck the other audio tracks in the timeline (e.g. as described here). This will result in a video file with only the chosen audio track included.

In Davinci Resolve, you can go to the Deliver page for export, then in the Audio section of the export settings, deselect the checkbox for any audio tracks you want to exclude (e.g. as noted here). The resulting file will contain only the single selected audio track.

By controlling which audio tracks or channels get exported, you can accurately obtain an output file with the desired single audio stream. Just make sure to pay close attention to the export settings, and deselect any audio you want to leave out of the final encoded video.

Playback

Once you have removed the unwanted audio track and exported the video with the single desired audio track, it is important to play back the final converted video file to verify everything converted properly. This is a crucial quality check step.

To test:

• Open the converted single audio video file in your preferred video player on your computer.
• Skip to a few different points in the video timeline and listen closely to check there is only the one desired audio track playing.
• Make sure the video file’s audio is in sync with the video throughout.
• Play sections toward the end of the video as well since conversion issues sometimes only occur late in longer videos.

If you notice any issues with the converted file during this playback test such as unwanted audio still present, audio sync/timing problems, or artifacts – then further troubleshooting is required on the conversion process. Refer to the Troubleshooting section for next steps in that scenario.

Once playback testing is completed successfully with the desired single audio track only, the conversion process is complete.

Troubleshooting

There are a few common issues that can occur when converting dual audio to single audio. If you encounter problems, try the following solutions:

Distorted Audio

If the resulting single audio track sounds distorted, the cause could be improper sample rate conversion during the export process. As noted in the Microsoft Support documentation, “the sample rate converter uses linear interpolation when it converts audio files. This behavior creates noise on the audio playback.” To fix this, make sure to export using the same sample rate as the original files.

No Audio Output

If you get no audio when trying to play the converted file, there may be an issue with the digital-to-analog conversion. As noted by SoundGuys, problems can occur when connecting external DACs across various platforms. Make sure all OS and app audio settings are correctly configured for your playback device.

Additional Options

There are other tools and software that users can turn to for converting dual audio besides the main steps outlined above. Some popular alternatives include:

Fre:ac – An open source audio converter and CD ripper. It supports various formats and has advanced options for adjusting output quality.

Any Audio Converter – A straightforward Windows application capable of extracting audio from video files and converting between formats. It has a simple interface but lacks some advanced functionality.

Free Audio Converter – As the name suggests, this is a free program that can convert between audio formats. It has a batch processing feature but may convert slower than premium software.

For users wanting an online solution, FreeConvert allows audio and video format conversion directly in the browser. This avoids needing to download and install desktop software.

While the methods described earlier are the most straightforward for removing dual audio, exploring alternative software can provide more advanced customization options for power users.

Conclusion

In summary, converting a dual audio movie to single audio requires locating the audio tracks, selecting the preferred language track, removing the unwanted second audio track, and exporting the video with only the selected single audio track. Ffmpeg provides advanced command line options for inspecting media files to identify the audio tracks and reencoding videos with customized parameters.

A few final tips for successful single audio conversion include:

• Use ffprobe to inspect media files and identify the index values or language codes for the audio tracks prior to conversion
• Specify the -map option in ffmpeg to include only the desired audio track and exclude all others
• Test the output to confirm single audio playback before deleting the source dual audio file
• Refer to online resources like the RealMod Github repository for examples and best practices converting audio

Following these guidelines helps produce clean single audio encodes from dual or multi audio source videos.