Some cameras write large video in many MP4 fragments. To use these spans in a video editor or media player you should join them together. The simplest way is to use FFmpeg.
To join you should create two files:
1. A list of MP4 files. Save it as "list.txt" with a content:
file 00001.MP4 file 00002.MP4 file 00003.MP4
Every line of this file must contain a word "file" and a MP4 file name.
2. A batch file. Save it as "join.bat":
@echo off "ffmpeg.exe" -f concat -i "list.txt" -vcodec copy -acodec copy "out.mp4" pause
Place these files in the same folder with your *.mp4 files and then execute join.bat to get your files joined.
Using Video Artifact
Extended editions of Video Artifact can join MP4 files when importing using third party FFmpeg.exe. They select required spans automatically. But a manual joining is required if you use a Basic edition.