[FFmpeg-user] Generete one second of black video and relative silence audio with the same duration

[Gian Maria Allibrante]

How can I generate a black mp4 video with relative silent audio track with ffmpeg, I need the audio and video tracks to correspond to the duration of 1 second.

ffmpeg -f lavfi -i color=c=black:s=1920x1080:r=24/1 -c:v h264 -f lavfi -i anullsrc=cl=stereo:r=44100 -video_track_timescale 90k -c:a mp3 -b:a 320k -ar 44100 -ac 2 -t 1 out.mp4

VIDEO FORMAT CONTAINER DURATION: 3.026000

VIDEO STREAM DURATION: 3.000000

how can i match these durations?

Thanks a lot!