I have the following to make a 2x2 grid of videos. I would however like to add the audio from the second (top right) video into the output. Is this possible, everything I find seems to talk only of 1 video and I am a bit stuck.
ffmpeg \
-i input0.mp4 -i input1.mp4 -i input2.mp4 -i input3.mp4 \
-filter_complex \
"[0:v][1:v]hstack=inputs=2[top]; \
[2:v][3:v]hstack=inputs=2[bottom]; \
[top][bottom]vstack=inputs=2[v]" \
-map "[v]" \
finalOutput.mp4