[MPlayer-users] copy protection
j.a.l at free.fr
Thu Jul 24 19:47:15 CEST 2003
Corey Hickey wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> Damion de Soto wrote:
>> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
>> D Richard Felker III wrote:
>>> Actually, there is a rather nasty copy protection scheme used in many
>>> DVDs... I'm halfway being sarcastic about this, but somewhat serious:
>>> Nasty broken telecine. Discs which mix hard and soft telecine at
>>> random, or use very weird telecine patterns which are difficult to
>> I see heaps of problems relating to telecine, and see various warnings
>> etc on some of my DVDs that use it.
>> Can someone explain exactly what hard/soft telecine is and why mplayer
>> plays it fine, but you can't rip/encode it. (or have i got that wrong
>> Or point me to a website, i've googled a bit, but the most detailed
>> description I found was 'telecine - converting film to video'
> The best decription I've found of telecine and all the associated
> framerates is here:
> When we say hard or soft telecine we refer to the stage at which the
> telecining occurs. Soft telecine video is 23.976 fps, and it is intended
> that hardware video players telecine this before sending the signal to a
> television. Mplayer says "telecine detected", but doesn't actually do
> any telecining because there's no need to do so for a computer monitor;
> mplayer just displays the video as-is, at 23.976 fps.
> Hard telecined video has been telecined in advance before being stored
> on the disc. Mplayer says this is progressive video, because the data
> doesn't say "telecine me". :) Since the telecining has been done
> already, the video is at 29.97 fps, and mplayer switches to that rate.
> Though not all 29.97 fps video is hard telecined, it seems that with
> regard to DVDs that is usually the case.
> Encoding soft-telecined video is not a problem. You just have to specify
> -ofps 23.976 so mencoder doesn't try to make 29.97 fps video.
> Hard-telecine isn't a problem either now, because Richard's detc filter
> can selectively drop the extra fields and leave us with nice, clean
> 23.976 fps.
> The problem is that some DVDs start out soft-telecine, then switch to
> hard-telecine, then back to soft, etc. The interval between switching
> back and forth can be variable and completely random - I've even seen
> DVDs where that switch after less than a second. At the moment, the detc
> filter can't properly handle this situation:
> The other problem Richard refers to, if I understand him correctly, is
> when the hard-telecine doesn't follow the usual 3:2 pulldown pattern,
> but some other weird method of converting 23.97 fps to 29.97 fps.
someone can point to dvd that have this problem ?? (zone 2 for me ),
could help to fix the "problem".
Like many i had pb encoding many dvd ( wrong fps, dup frame, etc... ),
found a solution, just willing to make some further tests...
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