FFmpeg AVI to MP4: Use FFmpeg Command to Convert AVI to MP4 Lossless & Free

FFmpeg is a useful command line tool with which users can do some simple conversion tasks. However, FFmpeg is not easy to operate for newbie users. In this article, we will show you the detailed steps on free FFmpeg avi to mp4 conversion, from the very first step of downloading the tool to converting mp4 file. The guide on using FFmpeg command to convert avi videos to mp4 is basic and simple, and even a novice can convert using the command lines shared in the article.

Feel Complicated? Try Free FFmpeg Alternative

Don't want to bother with command line? Try free FFmpeg avi to mp4 converter alternative, it will convert among different almost all digital formats, like avi, mov, mkv, mp4, 3gp, wmv and more with no quality loss and fast speed. The operation is easy with user-friendly UI.

Part 1: Step-by-Step Guide on FFmpeg Convert AVI to H264 MP4

FFmpeg is available for Windows, Linux and Mac operating systems. Below we will show you how to free convert avi files to mp4 using FFmpeg on Windows. The steps on other platforms are basically the same.

Download FFmpeg on Computer

Go to FFmpeg official site and navigate to the download page. There are builds for three different OS in 32-bit and 64-bit. Download the version based on the operating system of your computer.

Extract FFmpeg Files

After the package is downloaded, you will get a zip file. The zip file won't do any avi to mp4 conversion and now you need to extract FFmpeg from the folder. First download a free zip extractor named 7-Zip.

Use the extractor to extract the file, and create a new folder in C drive named FFMPEG. Copy and paste the contents of the extracted folder into the created folder in C drive.

Enable FFmpeg in Command Line

To allow us to use FFmpeg command to transcode avi format to mp4, we need to enable the tool in the command line first to allow FFmpeg avi to mp4 converter to be recognized by the system.

Click the Start Menu > right click on Computer and select Properties > click on Advanced system settings in the system windows > open Environment Variables > now click Edit button and enter ;c\ffmppeg\bin (note the semi-colon) in the Variable value field and then click OK.

Run FFmpeg Command Tool

The FFmpeg is installed and enabled for converting avi videos to mp4 and you only need to open it and enter the command line. To open FFmpeg, click Run and type cmd and press the Enter button > Then enter cd\ and press Enter > enter cd FFmpeg and the tool will open > enter cd bin and press Enter > now enter ffmpeg.exe and press Enter. And this means that the tool is open and ready to convert avi to mp4 using FFmpeg command line.

Start Free FFmpeg AVI to MP4 Conversion

Now comes to the step to let FFmpeg convert avi to h264 mp4. For this purpose, simply input the command line as the picture below:
ffmpeg -i input.avi -cvodec libx264 -acodec libfaac output.mp4

More tips on converting avi videos to mp4 with FFmpeg:
To enable avi to mp4 command line in FFmpeg lossless without transcoding, enter the command line:
ffmpeg -i infile.avi -acodec copy -vcodec copy outfile.mp4

To batch convert avi files to mp4 with FFmpeg command line, enter:
for %%a in ("*.avi") do ffmpeg -i "%%a" -c:v libx264 -preset slow -crf 20 -c:a libvo_aacenc -b:a 128k "newfiles\%%~na.mp4"
pause

To compress avi video, enter the command line below:
ffmpeg -i input.avi -vcodec msmpeg4v2 -acodec copy output.avi

To adjust the output quality of free avi to mp4 conversion with ffmpeg, you can set the bit rate:
e.g.: ffmpeg -i input.avi -c:v libx264 -b:v 500K -c:a copy out.mp4

To cut certain part of the video, using -t (output duration) and -ss (starting point) options:
e.g.: ffmpeg -ss 00:01:30 -i input.avi -c:v copy -c:a copy -t 5 output.mp4 

To resize the output mp4 for iPhone, iPad other mobiles, using -s option:
e.g.: ffmpeg -i movie.avi -c:v libx264 -s:v 854x480 -c:a copy out.mp4

Part 2: Best FFmpeg Alternative to Convert AVI to MP4

Set aside unpredictable issues during the converting process, it's maybe a little bit hard to follow the above steps in installing or converting using command line. Why bother? Other free FFmpeg alternatives can do the same job, well and easily.

MacX Video Converter Free Edition, a simple & free alternative to FFmpeg to convert avi files to mp4. Users can not only convert avi videos to mp4 using FFmpeg alternative lossless in high quality, but also freely convert among 200+ popular formats, be it in 8K, 5K, 4K uhd, hd or sd resolution. The best part is that it's a lot easier to use: drag the original avi file and select mp4, the rest will be done.

How to Use Alternative to FFmpeg Command to Convert AVI to MP4

First download the FFmpeg avi to mp4 alternative converter (Mac version or Windows version). The latest macOS Sierra and Windows 10 are supported.

Step 1: Launch the converter and click "Add File" button to load AVI file. You can also drag and drop the avi video into the program. You can load multiple avi files to batch convert.

Step 2: To convert AVI video to MP4, select "MP4 Video" H.264 or MPEG 4 from the profile list. In addition to the two file sites, the FFmepg alternative can convert mov, mkv, 3gp, mts, wmv, mov and many more.

Step 3: Make necessary editing to the mp4 file like trimming, cropping, adding watermark or subtitles etc. Then click the "Browse" to choose a folder to save the output mp4 video.

Step 4: Press the "RUN" button to start to losslessly convert AVI to MP4 using FFmpeg alternative converter. The whole conversion will be finished with fast speed with multi-core CPU and hyper-threading technology applied.