best options for video post-processing?

theYinYeti · 02-05-2006, 03:57 PM

Hello,

My aim is to get the most of my old VHS tapes.

My PC is not powerfull enough to clean and encode video from Composite1 in real-time.
So I thought I should first get the "raw" video and sound (real time), and then post-process this video.

So, here's what I do:
FIRST PASS (line splitted for better readability)

Code:

mencoder -tv
driver=v4l2:device=/dev/v4l/video0:input=1:fps=25:norm=SECAM:alsa:amode=1:decimation=2:
quality=75:width=384:height=288 -o /local/tmp/test3.avi -oac copy -ovc copy -ofps 25 tv://

This way, I get a half-size video (384*288) very near the quality I get from Composite1/xawtv.
There is one drawback: each minute of video is roughly 250MB big !!
That's why I don't use the full size (768*576)... even though I wish I could...

The post-processing must be done to reduce the file-size, and I also hope to clean it; indeed, here is a screenshot of the video (that's how the VHS is...); I'm sorry, it is a big file, I don't have the tools on this PC to reduce it:
http://yves.gablin.club.fr/test3-1.png

SECOND PASS
So I tried to clean and reduce the video this way, getting the general look of this command from what "File2DIVX3Pass" is trying (and failing) to execute, and refining it from what I understand from mencoder manual page. (splitted for better readability)

Code:

mencoder -noskip -fps 25 -ofps 25 -vf hqdn3d,pp=hb/vb/dr,cropdetect
-oac mp3lame -lameopts cbr:br=128 -ovc lavc
-lavcopts vcodec=mpeg4:vhq:vqmin=2:vqmax=31:keyint=25:vbitrate=29232:vpass=1
-o test3p1.avi  test3.avi

The result is awful !

Are the optons I use wrong? Or is there an entirely better method (that would allow me to have full-size if possible)?
Thanks for any help,

Yves.

Emerson · 02-05-2006, 04:11 PM

1. I remember there was an option for XviD to do kind of pre-encoding with relatively low CPU usage to enable real-time recording. I my be wrong here or this feature may be deprecated though.

2. Using full resulotion probably won't be big improvement in quality because VHS has only ~250 lines of resulotion.
3. Doing creative video work is giving much better results if you can see what you are doing. Your fellow countryman Mean has written a wonderful program for this very purpose, it's called Avidemux.

theYinYeti · 02-06-2006, 05:39 AM

Thanks for the input!
I'll look into that.

Yves.