FFmpeg Segment Naming and CSV List Generation

This guide explains how to split video files into smaller segments using FFmpeg, customize the resulting filenames using specific naming patterns, and automatically generate a CSV list of all created segment files. By utilizing FFmpeg’s built-in segment muxer, you can easily automate video splitting and maintain a structured index of your output files for post-processing or distribution.

Configuring Segment Naming Patterns

To split a video into segments, use FFmpeg’s segment muxer (-f segment). You can control the filenames of the generated segments by using C-style printf format templates or date-and-time variables.

1. Sequential Numbering

The most common naming pattern uses %d (or %0Nd for zero-padded numbers) to number segments sequentially.

ffmpeg -i input.mp4 -f segment -segment_time 10 -reset_timestamps 1 output_%03d.mp4

In this command: * -segment_time 10 splits the video every 10 seconds. * -reset_timestamps 1 resets the timestamps at the beginning of each segment. * output_%03d.mp4 creates sequential files named output_000.mp4, output_001.mp4, output_002.mp4, and so on.

2. Timestamp-Based Naming

If you want the filenames to represent the actual date and time of creation, enable the -strftime option.

ffmpeg -i input.mp4 -f segment -segment_time 10 -strftime 1 -reset_timestamps 1 "output_%Y-%m-%d_%H-%M-%S.mp4"

This will name the files based on the system time when the segment was written (e.g., output_2023-10-27_14-30-00.mp4).

Generating a CSV List of Created Files

FFmpeg can automatically generate a list of all created segment files using the -segment_list and -segment_list_type options.

To generate a standard CSV file listing the output segments, add these options to your command:

ffmpeg -i input.mp4 -f segment -segment_time 10 -segment_list segment_list.csv -segment_list_type csv -reset_timestamps 1 output_%03d.mp4

Explanation of List Options:

-segment_list segment_list.csv: Specifies the filename and path for the generated list.
-segment_list_type csv: Forces FFmpeg to format the list as a CSV file.

The generated segment_list.csv file will contain a structured table in the following format, including the file name, segment start time, and segment end time:

output_000.mp4,0.000000,10.000000
output_001.mp4,10.000000,20.000000
output_002.mp4,20.000000,30.000000

This CSV file can be directly imported into database systems, Excel, or custom scripts for further processing.