How can I use FFmpeg to either merge segmented M4S files or locate the init file?

Help & Support
2

You must use the MP4Box tool, which is a part of the GPAC (Multimedia Framework for Multimedia Packaging) project, to combine segmented M4S (MPEG-DASH) files into a single media file or identify the initialization (init) file using FFmpeg. For use with MP4 files that are fragmented, such as those used in MPEG-DASH, MP4Box was created. The procedures to combine segmented M4S files or obtain the init file are as follows:

1. Install GPAC (MP4Box)

Download GPAC (MP4Box) from the official website at https://gpac.wp.imt.fr/downloads/ if it isn’t already on your computer. Observe the installation guidelines designed for your particular operating system.

2. Merge Segmented M4S Files

Use the MP4Box command to combine segmented M4S files into a single MP4 file. Go to the directory where your M4S segments are located and run the following command:

MP4Box -dash 10000 -frag 1000 -rap -out merged.mp4 segment1.m4s segment2.m4s ... segmentN.m4s

  • -dash 10000: Specifies the segment duration in milliseconds. Adjust this value as necessary.
  • -frag 1000: Determines the fragment duration in milliseconds. Adapt this value to suit your requirements.
  • -rap: Enforces random access points (keyframes) at the beginning of each fragment.
  • -out merged.mp4: Specifies the output file name, which will contain the amalgamated segments.
  • segment1.m4s, segment2.m4s, ..., segmentN.m4s: Replace these with the actual file names of your segmented M4S files.
  • This command will consolidate the segments into a solitary MP4 file named merged.mp4.

3. The Initialization (Init) File can be found here:

  1. The initialization (init) file for MPEG-DASH commonly ends in.mp4. You can use a simple script or command to locate the init file based on the naming convention or by looking at the contents of the segments. The first segment or initialization information for the media streams is often denoted by the init file.
  2. In Linux or macOS, for example, you can use the ls command to display the files and find the init file based on its naming pattern:

ls -1 *.mp4

The init file should be listed among .mp4 files that this program enumerates in the directory.

4. Validate the Merged File or Init File

Once the segments have been combined or the init file has been located, you may use FFmpeg or another multimedia player to confirm the accuracy of the content and functionality of the resulting media file.

This is how you can merge segmented M4S files into an init file using FFmpeg.

For more queries related to this refer to:

1 Like