[MPlayer-users] Eagles - Hell Freezes over DVD

[Ni Bo]

Thanks all for your suggestions, expecially Vladimir for your explanations! 
I will give these options a try and see how I go.

Cheers.


>From: Vladimir Mosgalin <mosgalin at VM10124.spb.edu>
>Reply-To: "MPlayer usage questions, feature requests,  bug reports" 
><mplayer-users at mplayerhq.hu>
>To: "MPlayer usage questions, feature requests,  bug reports" 
><mplayer-users at mplayerhq.hu>
>Subject: Re: [MPlayer-users] Eagles - Hell Freezes over DVD
>Date: Thu, 13 Jul 2006 14:29:51 +0400
>
>Hi Ni Bo!
>
>  On 2006.07.12 at 12:42:35 +0000, Ni Bo wrote next:
>
> > I'm only blaming the DVD because the second DVD I tried (Desperado, if 
>it
> > matters?) is of excellent quality overall.  I'm not expecting perfection 
>at
> > this stage as I haven't explored all the options of mencoder, but 
>Desperado
> > I would say is at least a 100% improvement on Hell Freezes Over...
>
>Don't own any of them, however some movies hardly require bitrate over
>1mbps to look great (e.g. Equilibrium compresses that well), while for
>some of the others 3mpbs won't be enough to look exactly as on dvd (I've
>seen this on Ameli). If you want to roughly guess how much bitrate this
>particular movie needs to look nice, just try encoding some parts with
>qscale=2 or 3. It isn't exactly the bitrate you should use for the whole
>movie, but after trying this on several movies you'll understand how to
>use this.
>
> > The command line I used is below (called from a script, hence the '$1',
> > '$2' etc)
> > Video issues with Hell Freezes Over are 'blocky' video, particularly 
>scenes
> > with dark backgrounds, people with dark clothing etc. Also the 'fog'
> > generated on stage appears blocky. (This is one of the reasons I chose
> > Desperado as my second attempt - there's a few smoking scenes)
>
>Fog/smoke scenes are really hard to encode. Both lavc and xvid can't
>deal with them on medium bitrate.
>
>If you have a lot of these effects, first thing you should try is xvid.
>When given enough bitrate, xvid can deal with them pretty well, at least
>better than lavc with qscale=2. Usually, this is enough.
>However, on some scenes, xvid won't be able to produce a nice picture.
>In that case, you have to use lavc with qscale=1. It will use insane
>bitrates, however. On the other case, usually it guesses these kind of
>scenes pretty well, and won't encode anything else with such small qscale.
>If it still doesn't look good on the bitrate you can afford, you should
>try zones feature. I don't know if they work in lavc right now, but at
>least they do in xvid. You can manually give more bitrate to bad-looking
>scenes.
>
> > A second problem was that fast-moving scenes tend to appear 'streaky'.
>
>I don't understand that.. You sure you are not talking about interlacing
>effects?
>
>I see that you don't crop your video. That's not good, are you sure you
>don't need cropping? Uncropped sides of the picture eat your precious
>bitrate.
>
>Also you don't do any ivtc. Unless you have PAL source, you should use
>either -ofps 24000/1001 or both that and some kind of ivtc filter
>(pullup is usually the best). Encoding a telecined movie is a VERY bad
>idea.
>
> > Thanks for your help! Let me know if you need any more info.
>
>Yes I do. Do you watch videos afterwards with or without postprocessing?
>Why do you use vqmin,vqmax,mbqmin and mbqmax if you specify vqscale
>parameter? What bitrate the movie ends with when encoded with vqscale=2?
>Have you tried denoising video before encoding? Can you post all details
>about encoded video (fps, resolution etc)?
>
> > mencoder dvd://1 -aid 128 -ffourcc DX50 -sws 2 -vf scale -zoom -xy $1 
>-ovc
> > lavc -lavcopts
> > 
>vcodec=mpeg4:mbd=1:lumi_mask=0.5:scplx_mask=0.1:vqscale=2:cmp=256:vqmin=2:vqmax=6:mbqmin=2:mbqmax=10:vpass=1
> > -oac copy -o /dev/null
>
>IMHO you should use -vf scale=$1:-2 and ditch -xy -zoom. I'm not sure
>whether scaling takes part on that scale or in the end of the chain.
>
> > I've also tried the xvid codec, but get a 'jerky' picture...
>
>What do you mean by that?
>Also note that due to the way xvid works, only results from second pass
>are useable.
>
>Try the following options:
>-xvidencopts
>pass=1:bitrate=2100:min_iquant=1:max_iquant=4:min_pquant=1:max_pquant=6:min_bquant=2:
>max_bquant=9:me_quality=6:quant_type=mpeg:keyframe_boost=15:trellis:chroma_me:
>chroma_opt:max_bframes=2:hq_ac:vhq=1:autoaspect:bvhq=1
>
>Put it on one line, use desired bitrate instead of 2100 and don't use
>bvhq=1 if you have old xvid (quality would be worse though). Use
>two-pass encoding. In case of good results, you can try decreasing the
>bitrate.
>
>For lavc, try these options for a change (not optimal, but should work
>better than yours):
>
>codec=mpeg4:vbitrate=2100:vqmin=1:lmin=1:v4mv:mbd=2:trell:subcmp=2:cmp=2:precmp=2:
>mv0:autoaspect:vpass=1:mpeg_quant:vqcomp=0.7:vqblur=0.3
>
>The quality would be overally worse than with xvid, however difference
>wouldn't be all that big on high bitrate, and you'll have to use lavc if
>xvid won't be able to encode smoke scenes nicely enough. However, I
>suggest you to play with xvid options first.
>
>--
>
>Vladimir
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