[FFmpeg-user] Concat image & video

[Петр Жуков]

Hello, my work needs (me) to find a solution to question:
1. How to concat image & video -> to result video. To create a video from
image I used command:
ffmpeg -loop 1 -i poster.png -c:v libx264 -t 30 3.mp4
And to concat 2 videos I used command:
ffmpeg -i 1.mp4 -i 2.mp4 -filter_complex "concat=n=2:v=1:a=1" 3.mp4
but command like this does not work:
ffmpeg -loop 1 -i poster.png -t 30 -i 1.mp4 -filter_complex
"concat=n=2:v=1:a=1" d:\3.mp4
How to concat image, for 5 secs & video next right after, in one command?
Is it really possible, does someone know this?
...
And, may be this can clear something:
ffmpeg -i input1.mp4 -i input2.webm -filter_complex "[0:0] [0:1] [1:0]
[1:1] concat=n=2:v=1:a=1 [v] [a]" -map "[v]" -map "[a]" 3.mp4
this concats 2 video files using streams from them: v = [0:0] & [1:0],
a=[0:1] & [1:1] and [v] [a] is output streams, and -map - maps them to the
streams in output file.

Thanks.