[FFmpeg-user] Brighten dark video before reducing size?

[Gilles]

Hello

	Using a basic Sony camcorder, I recorded a two-hour conference whose
picture is a bit dark.

I tried applying a filter in AviDemux and saving the file, but for
some reason, there's no sound when played in VLC :-/

Before trying other NLE applications (VirtualDub, Sony Vegas, etc.), I
was wondering if ffmpeg could apply some filters before further
reducing the filesize?

FWIW...
1. here's what the original file looks like:

Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p, 720x576 [SAR
64:45 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc

Stream #0:1[0x80]: Audio: ac3, 48000 Hz, 5.1(side), s16, 448 kb/s

2. Using the following command, ffmpeg reduces the original 9GB to
340MB:

ffmpeg -i input.mpg -c:v libx264 -vf scale=iw/2:-1 -preset faster -c:a
ac3 -ab 192k output.mp4

Thank you.