FFmpeg has three concatenation methods:
1. concat video filter
Use this method if your inputs do not have the same parameters (width, height, etc), or are not the same formats/codecs, or if you want to perform any filtering.
Note that this method performs a re-encode of all inputs. If you want to avoid the re-encode, you could re-encode just the inputs that don’t match so they share the same codec and other parameters, then use the concat demuxer to avoid re-encoding everything.
ffmpeg -i opening.mkv -i episode.mkv -i ending.mkv
-filter_complex “[0:v] [0:a] [1:v] [1:a] [2:v] [2:a]
concat=n=3:v=1:a=1 [v] [a]”
-map “[v]” -map “[a]” output.mkv
2. concat demuxer
Use this method when you want to avoid a re-encode and your format does not support file-level concatenation (most files used by general users do not support file-level concatenation).
$ cat mylist.txt
file ‘/path/to/file1’
file ‘/path/to/file2’
file ‘/path/to/file3’
$ ffmpeg -f concat -safe 0 -i mylist.txt -c copy output.mp4
For Windows:
(echo file ‘first file.mp4’ & echo file ‘second file.mp4’ )>list.txt
ffmpeg -safe 0 -f concat -i list.txt -c copy output.mp4
3. concat protocol
Use this method with formats that support file-level concatenation
(MPEG-1, MPEG-2 PS, DV). Do not use with MP4.
ffmpeg -i “concat:input1|input2” -codec copy output.mkv
This method does not work for many formats, including MP4, due to the nature of these formats and the simplistic concatenation performed by this method.
If in doubt about which method to use, try the concat demuxer.
Also see
FFmpeg FAQ: How can I join video files?
FFmpeg Wiki: How to concatenate (join, merge) media files
FOR MP4 FILES
For .mp4 files (which I obtained from DailyMotion.com: a 50 minute tv episode, downloadable only in three parts, as three .mp4 video files) the following was an effective solution for Windows 7, and does NOT involve re-encoding the files.
I renamed the files (as file1.mp4, file2.mp4, file3.mp4) such that the parts were in the correct order for viewing the complete tv episode.
Then I created a simple batch file (concat.bat), with the following contents:
:: Create File List
echo file file1.mp4 > mylist.txt
echo file file2.mp4 >> mylist.txt
echo file file3.mp4 >> mylist.txt
:: Concatenate Files
ffmpeg -f concat -i mylist.txt -c copy output.mp4
The batch file, and ffmpeg.exe, must both be put in the same folder as the .mp4 files to be joined. Then run the batch file. It will typically take less than ten seconds to run.
.
Addendum (2018/10/21) –
If what you were looking for is a method for specifying all the mp4 files in the current folder without a lot of retyping, try this in your Windows batch file instead (MUST include the option -safe 0):
:: Create File List
for %%i in (*.mp4) do echo file ‘%%i’>> mylist.txt
:: Concatenate Files
ffmpeg -f concat -safe 0 -i mylist.txt -c copy output.mp4
This works on Windows 7, in a batch file. Don’t try using it on the command line, because it only works in a batch file!