Concatenating Two Videos and Two Audios - 2020

We're going to use a video, "San Francisco (Be Sure to Wear Flowers in Your Hair)" by Scott McKenzie (BeSureToWear.mp4) as a sample.

To make it more simple, we're going to merge (concatenate) the same video one after another.

The command looks like this:

ffmpeg -i BeSureToWear.mp4 -i BeSureToWear.mp4 -filter_complex '[0:v] [0:a:0] [1:v] [1:a:0] concat=n=2:v=1:a=1 [v] [a]' -map '[v]' -map '[a]' BeSureToWearConcat.mp4

From the command output below, we can check how ffmpeg does follow the command:

Stream mapping:
  Stream #0:0 (h264) -> concat:in0:v0
  Stream #0:1 (aac) -> concat:in0:a0
  Stream #1:0 (h264) -> concat:in1:v0
  Stream #1:1 (aac) -> concat:in1:a0
  concat:out:v0 -> Stream #0:0 (libx264)
  concat:out:a0 -> Stream #0:1 (libfdk_aac)

The concatenated output: BeSureToWearConcat.mp4

IN this section, we'll concatenate two audio files following the guide from How to concatenate(join, merge) media files . We'll concatenate the same two audio files from the same audio file: BeSureToWearFlowersInYourHair.mp3.

The command looks like this:

ffmpeg -f concat -i mylist.txt -c copy Two_BeSureToWearFlowersInYourHair.mp3

mylist.txt:

file ./BeSureToWearFlowersInYourHair.mp3
file ./BeSureToWearFlowersInYourHair.mp3

Output file: Two_BeSureToWearFlowersInYourHair.mp3.