[FFmpeg-user] Cannot find a matching stream for unlabeled input pad 7 on filter Parsed_concat_2

[Randy Johnson]

On October 29, 2020, Edward Park <kumowoon1025 at gmail.com> wrote:
> Hi,
>
> > Can you please elaborate on the (1+1) part?
> > I see here https://trac.ffmpeg.org/wiki/Concatenate 
> > 
> > that n=x where x is the number of input segments
>
> Since there is a video stream and an audio stream in each segment
> (1+1), for 4 segments there should be 8 inputs.
>

I changed the output but still get the same error:


Cannot find a matching stream for unlabeled input pad 7 on filter
Parsed_concat_2

Here is the command:

ffmpeg \
-loop 1 -framerate 30 -t 1.32 -i filler640480.jpg -i f.mp4 -y \
-loop 1 -framerate 30 -t -451.356 -i filler640480.jpg -i 9.mp4 -y \
-f lavfi -t 0.1 -i anullsrc=channel_layout=mono:sample_rate=48000 \
-filter_complex "
[0:v]setsar=1[v0];[2:v]setsar=1[v1];[v0][4:a][v1][4:a]concat=n=8:v=1:a=1"
-vsync 2 0225-grid.mp4

Any other ideas what could be wrong?

>