Thought some of you might be interested with this: Simple CLI app that reads ffmpeg-generated vstats_*.log files and retrieves: Low/average/peak q and low/average/peak video bitrate. Source code is *.au3/AutoIt (234 lines).
Interesting to know:
1. T.V. noise, a.k.a. 'snow' (digicam recording), when encoded with these settings: MPEG-4 part 2/vtag xvid, 640x480, 30 fps, quantizer at 4; peaks at 33,687.6 kbits/s (average at 27,042.81 kbits/s).
2. Black frames (is-this-thing-on? black), when encoded with these settings: MPEG-4 part 2/vtag xvid, 640x480, 30 fps, with a ridiculously large set bitrate of 30,000 kbits/s; peaks at 806.9 kbits/s (average at a measly 40.27 kbits/s).
How to generate vstats logs (quick guide/not actual code):
1. %ffmpeg% [input] [your settings] -vstats [output]
2. %ffmpeg% [input] [your settings] -vstats -vstats_file "C:\Output\[specify name]_vstats.log" [output]
This is a command line interface app, but you can drag & drop log files to it. It is also absolutely free.