[MPlayer-users] Re: Newbie problems starting mencoder

D Richard Felker III dalias at aerifal.cx
Thu Sep 25 11:00:59 CEST 2003


On Thu, Sep 25, 2003 at 02:09:25AM -0500, Jonathan Rogers wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> D Richard Felker III wrote:
> >This is greatly oversimplified. Please do not tell people to use these
> >filters unless they really apply. For example, they will butcher
> >content made with tv cameras!
> >
> Of course it's a great oversimplification. That's why I pointed to 
> encoding-tips.txt. Besides, how would my advice result in butchered 
> recordings from TV cameras? My explanation was far more in depth than 
> the instructions Amit was using, so I don't see how I caused harm. If 
> you want me to quote all of "encoding-tips.txt" and all other advice 
> I've found, I could do that, but some people are capable of using URLs.

Using -vf detc=dr=1 or -vf ivtc=1 with tv cam content (interlaced 50
or 60 fps) will drop at least 1 out of every 5 "frames" (actually
field pairs since frames don't exist), and additionally try to make
progressive frames by rematching fields with less difference between
them, which will reorder (and thus misorder) fields! So it's a very
bad idea. Before selecting whether to encode as-is, deinterlace, or
reverse telecine, you must be sure you know what kind of content
you're dealing with! Actually the new vf_pullup can deal with mixed
progressive/pulldown content properly, but it still could be a bad
idea with true interlaced video...

> >>It's also a bad idea to use VBR MP3 in an AVI, since there are often 
> >>sync problems. A better place to start would be MPlayer's own 
> >>documentation.
> >
> >
> >Please stop this too. VBR mp3 is known to work great with all major
> >players and VBR in general is part of the avi standard. If someone is
> >getting desync, it's a result of using a broken version of lame or a
> >very broken player, not a problem with VBR in general. Downgrading
> >lame to 3.90 might help.
> 
> So what's Andre Bruce's problem? Have you tested "all major players" 

My guess is that it might be the problem with recent lame versions.

> yourself? As you say, there are broken players, so concessions may have 
> to be made. It's similar with the MPEG-4 aspect ratio tag. It may be in 
> the standard and we all know MPlayer respects it, but which other 
> players do?

WMP, DivxPlayer/Playah, WinAmp, and all other windows players I've
heard of play it fine. And of course mplayer, xine, etc. do too. Very
different issue from the aspect thing.

Rich



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