Concat 2 video and add watermark first video ffmpeg I have a Video #1, it has audio. Also I have a Video #2, with audio too. I would like to concat the #1 and #2 (or play #1 first, and then #2) and then add a watermark in #1 for the rest of the video, preserving audio timestamps.
I used this command but the watermark appears on the #2 video?
ffmpeg -i Video1.mp4 -i Video2.mp4 -i watermark.png
   -filter_complex
       &quot;[1][2]overlay=5:5[v2];
        [0][0:a][v2][1:a]concat=n=2:v=1:a=1&quot;
   -c:v libx264 -crf 21 -c:a aac -b:a 384k -ar 48000 -movflags  faststart Out.mp4
Concatenate can be found from this link
In case of using same codec
!echo &quot;file 'video_1.mp4'&quot; &gt; list.txt
!echo &quot;file 'video_2.mp4'&quot; &gt;&gt; list.txt

Add watermark at (x=1, y=1) coordinated
!ffmpeg -y -f concat -safe 0 -i list.txt -i watermark.png -filter_complex &quot;overlay=1:1&quot; output.mp4

I don't quite understand your description, but i think it fits your title.