merging 2 editing videos without saving them using ffmpeg [closed]

Question

I want to combine 2 videos assume even they are edited among themselves

How normally we do

video 1:

ffmpeg -i 1.mp4 -filter:a "volume=0.0" test1.mp4

video 2:

ffmpeg -i 2.mp4 -filter:a "volume=10.0" test2.mp4  

now I can combine them using

ffmpeg -i test1.mp4 -i test2.mp4 -filter_complex [0:v:0][0:a:0][1:v:0][1:a:0]concat=n=2:v=1:a=1[outv][outa] -map [outv] -map [outa] out.put.mp4

So my question is, Is there a way to make this 3 steps process into 1 step and without saving files of step 1 and step 2

I do know that we can combine into one using && but my main query is there a way to do without saving the files of video1 and video2 that edited files

Hope I'm a bit clear with my query

Question edited/added:

ffmpeg -i test.mp4 -filter:a "volume=8.0,atempo=4.0" -vf "transpose=2,transpose=2,setpts=1/4*PTS" -s 640x480 test.mkv 

can we do all these options also in the merge command(operations like change video Speed, resolution, rotation, framerate, and trim)?

Vesting

Answer 1

Apply the volume filters before feeding the audio streams to concat.

ffmpeg -i test1.mp4 -i test2.mp4 -filter_complex "[0:a:0]volume=0.0[a0];[1:a:0]volume=10.0[a1];[0:v:0][a0][1:v:0][a1]concat=n=2:v=1:a=1[outv][outa]" -map [outv] -map [outa] output.mp4

Lacustrine

thanks a lot, for that can we also change video Speed, resolution, rotation, framerate can these also be changed. If possible please write the command it helps a lot thanks again! – Vesting

sir I have updated the question once check the "Question edited/added: part" thanks a lot sir – Vesting