[MPlayer-users] Comparison of some current ffmpeg lossless codec

[Steven Ellis]

I'm after a decent lossless codec for TV capture so
i'm particularly interested in the new FFV1 codec
FFMPEG has introduced. Sadly with my SAA7134 based
FlyVideo 3000 capture using a recent CVS build of
ffmpeg fails quite badly (massive number of frame
drops). For this initial analysis I had to use a file
captured off air using ffmpegrec which is part of the
NVRec tools.

At the moment I usually capture off air using
ffmpegrec in mjpeg video and mp3 audio, but the
standard quality settings defined by the tool are 3-15
which results in average quality capture. Also note
that i'm usually capturing PAL video in CVD resolution
(352x576) for later transfer to SVCD. I find I get too
many framedrops if I up the resolution to 480x576 or
higher.

Anyhow I decided to extract the same section of video
using the following scripts

mencoder -vf lavcdeint,hqdn3d  -aspect 4:3 sl_405.avi
-oac copy -ovc lavc -lavcopts
vcodec=huffyuv:vstrict=-1:vhq:psnr  -noskip -ss 20:00
-endpos 0:30   -o huffy.avi

mencoder -vf lavcdeint,hqdn3d  -aspect 4:3 sl_405.avi
-oac copy -ovc lavc -lavcopts
vcodec=ffv1:vstrict=-1:vhq:psnr  -ss 20:00 -noskip
-endpos 0:30   -o ffv1.avi

mencoder -vf lavcdeint,hqdn3d  -aspect 4:3 sl_405.avi
-oac copy -ovc copy -ss 20:00 -endpos 0:30  -noskip 
-o copy.avi

mencoder -vf lavcdeint,hqdn3d  -aspect 4:3 sl_405.avi
-oac copy -ovc lavc -lavcopts
vcodec=mjpeg:vhq:psnr:vbitrate=16000  -noskip -ss
20:00 -endpos 0:30   -o mjpeg.avi

mencoder -vf lavcdeint,hqdn3d  -aspect 4:3 sl_405.avi
-oac copy -ovc lavc -lavcopts
vcodec=ljpeg:vhq:psnr:vstrict=-1 -noskip -ss 20:00
-endpos 0:30   -o ljpeg.avi

This gave me a file with the original source material,
as well as using a couple of other codecs. I also
found that the -vf options cleaned the video up quite
a bit.

Anyhow the file sizes after all of this are -

113905404 Jul  2 21:31 huffy.avi
96817054 Jul  2 21:32 ljpeg.avi
49491046 Jul  2 21:28 ffv1.avi
28818326 Jul  2 21:31 copy.avi
16239032 Jul  2 21:32 mjpeg.avi

Looking at the 3 lossless codecs shows there is very
little difference. The re-compressed but filtered
mjpeg file managed to look better than the off air
original, but didn't come close to the lossless
codecs.

Now if only I could capture using either ffmpeg or
ffmpegrec off my card in ffv1 without dropping frames
i'd be very happy.

Hope this is of interest to you all.

Steve



=====
--
If you listen very carefully you can sometimes hear the dolphins sing

pinguellis at yahoo.co.uk

__________________________________
Do you Yahoo!?
SBC Yahoo! DSL - Now only $29.95 per month!
http://sbc.yahoo.com