FFmpeg is encoding at a lower bitrate than what is specified

Question

I'm fairly new to FFmpeg, I'm using this command: ffmpeg -i "C:\FFmpeg\Handbrake\Trackmania\Trackmania.mp4" -c:v libx264 -preset veryslow -b:v 10000 -fps_mode passthrough "C:\FFmpeg\Handbrake\Trackmania\Compressed\AV1\QSV VERYSLOW.mp4", but FFmpeg is actually encoding at around 300kbps, which result in a horrible video quality. I've tried changing the bitrate, but this doesn't fix the issue

Answer 1

-b:v is bitrate, so 10000 is 10 kbps. You probably want 10000k.