FFmpeg Linux Command Line Examples: Merging Separate Audio and Video Files

In this article, we will explore some practical examples of using FFmpeg's command-line interface to merge separate audio and video files into a single file. With its powerful features and flexibility, FFmpeg is an essential tool for anyone working with multimedia content.

One common use case is when you have separate audio and video files that need to be combined. For instance, you might have a video file (INPUT_FILE.mp4) without any audio, and an audio file (AUDIO.wav) that you want to add to the video. In this scenario, FFmpeg's command-line options come in handy.

Let's take a closer look at some of these options. The `-c:a` option stands for 'select all the audio stream from source files' and then encode it with an AAC encoder. Similarly, the `-c:v copy` option is a short form of `-codec:v copy`, which means copying the video stream from the source files to the destination file.

For example, if you want to combine two files (INPUT_FILE.mp4 and AUDIO.wav) without re-encoding the audio or video, you can use the following command:

ffmpeg -i INPUT_FILE.mp4 -i AUDIO.wav -c:v copy -c:a aac OUTPUT_FILE.mp4

In this command, `-i` specifies the input source file. The output file is specified as `OUTPUT_FILE.mp4`. When you run this command, FFmpeg will take the video and audio streams from the input files and combine them into a single output file in AAC format.

To ensure compatibility, it's recommended to use MP4 or MKV as the container (file extension) for your output file. This is because these containers can accept both video and audio codecs.

Another common scenario is when you have separate audio and video files that need to be re-encoded to a specific format. For example, if you want to convert an AVI file to MP4 with AAC audio, you can use the following command:

ffmpeg -i INPUT_FILE.avi -c:v copy -c:a aac OUTPUT_FILE.mp4

In this case, FFmpeg will take the video stream from the input AVI file and copy it to the output MP4 file. The audio stream will be re-encoded to AAC format.

By using these simple commands, you can efficiently merge separate audio and video files into a single file that's compatible with most media players and devices.

Ffmpeg linux command line examples