It is interesting to learn that downloading a file in large size can be easier if the entire file is separated into video and audio parts to download and finally merge the separated parts into a whole. Talking about merging two separated files into one, it is important because this concerns the final output quality. This article will shed some light on how to merge MP4 and M4A files into one within some clicks. Let’s get started in no time!

Part 1: Why Download Video and Audio Files Separately

To be honest, downloading video and audio files separately is not news to us because we have actually lived in an age of perusing efficiency for so long and downloading a multimedia file can be efficient if video and audio files are separated. Moreover, many popular multimedia sharing websites including YouTube have been introducing a DASH mechanism (Dynamic Adaptive Streaming over HTTP) for 1080p and 480p videos.

This is an adaptive bitrate streaming technology where a multimedia file is partitioned into one or more segments and delivered to a client using HTTP. Out of the box, you will get two separated files (of course one in video and one in audio) instead of one when you download the multimedia files to your hard drive.

Downloading video and audio files separately turns out to be more efficient and more popular nowadays. However, when you finish downloading separated files, you will need to merge them together in order to stream it as a whole, that being said, with video and audio files in parallel during playback.

To be honest, not many apps can merge MP4 and M4A automatically and seamlessly. For example, FastestTube cannot do that. But you can try ffmpeg to merge MP4 and M4A files into one later after you download video and audio files separately.


Part 2: Merge MP4 and M4A Files into One with ffmpeg

In this section, we just want to walk you through an exciting process for merging MP4 and M4A into one with ffmpeg. Normally when you finish downloading video and audio files, you will get something like videoplayback.mp4 and videoplayback.m4a respectively.

To begin with, make sure you have downloaded and installed ffmpeg in your hard drive.

Now move on to the essential steps for merging MP4 and M4A into one.

Step 1: Open a Command Prompt window in your downloads folder and run the following command.

In case of MP4 format (all, except 1440p 60fps & 2160p 60fps):

ffmpeg -i videoplayback.mp4 -i videoplayback.m4a -c:v copy -c:a copy output.mp4

In case of WebM format (1440p 60fps and 2160p 60fps):

ffmpeg -i videoplayback.webm -i videoplayback.m4a -c:v copy -c:a copy output.mkv

Step 2: Sit back and wait until ffmpeg finishes merging audio and video into a single file named "output.mp4".

I believe some of you have already grasped the technique to merge MP4 and M4A into one using ffmpeg. It is not much technical but if you still feel it difficult to do so, you may consider our next recommended tool for help.

Part 3: Merge MP4 and M4A Files into One with Leawo Video Converter

Besides ffmpeg, Leawo Video Converter is also worth the mentioning. This professional tool is developed to convert video and audio files from one format to another without losing any quality. With GPU-accelerating technology, this tool can perform 6x higher speed than rivals in the same category. More than 180 popular video and audio formats are well supported, including MP4 and M4A. In addition, this tool has the ability to support users with merging files within clicks.

Just as I said above, 100% quality of original files will be well preserved after merging or conversion, making this tool really professional and popular among users from the globe. In terms of editing original files, this tool has provided rich features to do so, including trimming the file length, cropping the file size, adding watermark, turning 2D to 3D, removing noise, etc. All these features enrich user experience a lot and escalate the popularity of this tool.

When it comes to merging MP4 and M4A into one using Leawo Video Converter, I believe the following tutorial guide will be helpful to you.


Step 1: Download and install Leawo Video Converter.

Click the button below to download and install the tool to your hard drive. Launch it by clicking the Video Converter icon on the home interface after installation completes.


Step 2: Add audio and video file to the tool.

Click Add Video to import the separated video and audio files to the tool. Note that there is a merge button next to Convert, hit on it to merge two separated files into one.


Step 3: Change the output format.

Click Change under the format drop down menu to browse for target output format.


Step 4: Merge and convert the file.

Click Convert from the toolbar and set a directory to save the output file on the displayed sidebar. Then, click the round button Convert to kick off the process. When it is done, you will get a whole file with your video and audio file merged.

Basically, this tool is suitable for even beginners and all they need to do is just a few clicks. Best of all, they will get a merged file without compromising on quality.


Part 4: Check and Play Merged Video with Ease

When you finish merging the video and audio files into one, you will need a media player to play it smoothly. Leawo Blu-ray Player is a good choice here. This media player is 100% free and it has provided support for DVD, Blu-ray, ISO, and 4K HD playback as well as other media files. It basically plays everything, including region-locked files.

It supports a wide range of media files, let alone MP4 and M4A. For those who require a .mkv converter, they can get it from this player when they upgrade to a premium version. That means they can convert their DVD, Blu-ray, ISO etc to .mkv for playback on other devices smoothly within this player. You should give it a shot if you have interest to this feature.

To play back your merged file, Leawo Blu-ray Player will do you the best.

Step 1: Download and install the media player.

Click the button below to download and install the free media player.

Step 2: Load the merged file to the player.

Click Open File from the home page to load the merged file to the player.


Step 3: Edit the playback options.

Click the settings button to enter the settings page. Here you can set the playback like subtitles, video and audio preferences on your own.


Step 4: Enjoy the playback.

Now sit back and enjoy the playback of your merged file. You may change the settings during playback as well. Just right click to enter the settings page and do the job.


Part 5: Conclusion

In this article, we have shown users why downloading video and audio files in a separated way is needed and trending these days. Evidently, efficiency comes first during downloading a multimedia file, especially for large file sizes. Besides, many multimedia providers like YouTube has also introduced the DASH mechanism for users to download video and audio files separately. Like we said in the above section, merging two separated files is not easy for some tools, but we still have some good choices here, for example, ffmpeg and Leawo Video Converter.

Ffmpeg aims to merge two separated files using commands, which turns out to be a bit complicated for beginners or novices. While Leawo Video Converter is perfect for both beginners and experienced users. It has some practical features for users to not only convert files but also edit files until users are satisfactory. I do like the customization part because this allows general users to make their movie making dream come true within clicks. When it comes to merging MP4 and M4A into one using this tool, it is also very handy and users just need a few clicks to do so. The output quality is well assured, to be honest.

The last but not least, when you get a merged file, you might want to play it back smoothly. Leawo Blu-ray Player is here for you. This freeware has served so many users across the globe as a 6-in-1 media player. It is not only a media player but it can actually serve as your own media playback assistant. Basically, you can drop every media file for playback here. It will give a supreme movie experience in return! Despite all-powerful features it offers, it still remains a handy player even for beginners.