Category Archives: tip

Segmenting Video with ffmpeg

To stream video with HLS, you need to divide your video into segments of a fixed duration and add them to a playlist. In the book I use Apple’s HTTP Live Streaming tools to do this. Here’s an example using mediafilesegmenter:

$ mediafilesegmenter -f /Library/WebServer/Documents/vod

This command takes the video ( and writes out the segments and the playlist to the /Library/WebServer/Documents/vod directory. Unfortunately, Apple’s tools will only work on a Mac.

However, recent versions of ffmpeg can also output HLS compatible files. Given a video as input, it will divide it into segments and create a playlist for us.

Here’s the equivalent of the command above using ffmpeg:

$ ffmpeg -y \
 -i \
 -codec copy \
 -bsf h264_mp4toannexb \
 -map 0 \
 -f segment \
 -segment_time 10 \
 -segment_format mpegts \
 -segment_list "/Library/WebServer/Documents/vod/prog_index.m3u8" \
 -segment_list_type m3u8 \

We use ffmpeg‘s segment muxer to segment the video. We can specify the segment duration with the -segment_time option. The last argument passed to ffmpeg is the path to where the segments should be written; it contains a format specifier (%d) similar to those supported by the printf function in C. The %d will be replaced with the current sequence number. In this example, the segments will be named fileSequence0.ts, fileSequence1.ts, and so on.

And that’s how you process a video for streaming with HLS using ffmpeg. There are other examples in the book, including how to use ffmpeg to segment a live video stream, so if you want to learn how, buy your copy today.

In part 2 we’ll look at how to segment video using ffmpeg’s hls muxer.