Loop Video Playlist with FFmpeg Concat Demuxer

This article explains how to use the FFmpeg concat demuxer to create and continuously loop a playlist of video files. You will learn how to format your playlist text file, apply the loop option, and configure the FFmpeg command for either saving the looped output to a file or broadcasting it as a stream.

Step 1: Create the Playlist Text File

The concat demuxer requires a plain text file containing the list of videos you want to play. Create a file named playlist.txt and list your video files in the order you want them to play. Use the following format:

file 'video1.mp4'
file 'video2.mp4'
file 'video3.mp4'

Note: If your video files are in a different directory, use absolute paths or relative paths. Ensure all listed videos have the same resolution, frame rate, and codecs to prevent playback issues.

Step 2: Use the FFmpeg Command to Loop the Playlist

To loop the playlist, you must place the -loop 1 option before the input flag (-i). This tells the demuxer to start reading from the beginning of the text file once it reaches the end.

Option A: Loop and Save to a Finite File

When rendering to a local file, an infinite loop will result in an infinitely growing file. You must specify a duration limit using the -t parameter (in seconds).

ffmpeg -f concat -safe 0 -loop 1 -i playlist.txt -t 600 -c:v libx264 -c:a aac output.mp4

• -f concat: Specifies the concat demuxer.
• -safe 0: Allows the use of relative or absolute file paths.
• -loop 1: Enables infinite looping of the input list.
• -i playlist.txt: Defines the input playlist file.
• -t 600: Stops the recording after 10 minutes (600 seconds).
• -c:v libx264 -c:a aac: Re-encodes the video and audio to ensure seamless transitions during the loops.

Option B: Stream the Loop Infinitely (RTMP/SRT)

If you are streaming to a platform like YouTube, Twitch, or a custom RTMP server, you can loop the playlist indefinitely without setting a time limit. You should also add the -re flag to read the input at native frame rates.

ffmpeg -re -f concat -safe 0 -loop 1 -i playlist.txt -c:v libx264 -preset veryfast -c:a aac -f flv rtmp://your-server-url/stream-key

• -re: Reads the input at the native frame rate (required for real-time streaming).
• -f flv: Sets the output format suitable for streaming.

Why Re-encoding is Recommended

While stream copying (-c copy) is faster and uses less CPU, it often causes sync issues, frozen frames, or crashes at the transition points when looping. Re-encoding the video (-c:v libx264) forces FFmpeg to generate consistent timestamps across all loops, ensuring a seamless and stutter-free playback experience.