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

Declaring each libx264 option is depreciated. Use the encoding presets instead as the console output indicates. See the FFmpeg and x264 Encoding Guide and FFmpeg: The ultimate Video and Audio Manipulation Tool for more information and some up to date examples. Also note that -bt has been "disconnected" from libx264 so it does nothing for you.

Secondly, your ffmpeg is old. FFmpeg uses Git instead of SVN and there have been thousands of additional commits (around 19202 as of now) and bug fixes since r26076. See Compile FFmpeg on CentOS for compilation instructions or refer to the FFmpeg download page for links to some static builds.