[MEncoder-users] rip dvd to mkv, ogm, mp4 script

[Stroller]

On 13 Oct 2008, at 16:29, Laine Lee wrote:
> ...
> I would, however, like to find some way to improve
> quality of the output. It looks really good, but the resulting AVI  
> is only
> 1.4G while the sum of the original VOBs adds up to over 5G for the  
> latest
> title I've worked with, so I suspect that some quality is being left  
> behind.
> Not too much, probably, because I am converting to h264.

Comparing the size of the h264 video to VOB is comparing apples &  
oranges. DVD's vob files use mpeg2, which was dated even at the time  
DVD was first becoming mainstream, but which has low processing  
requirements for playback. h264 is a MUCH higher quality encoding.

BTW: I believe that undvd's "--cont mp4" outputs a more valid  
container format.

You say "it looks really good" - well, that's the important thing. At  
the end of the day, it's only watching movies, and the content of the  
film - the actors, directory, story & cinematography - is the  
important thing. But even if you're a dedicated videophile, the true  
test is the quality that you see - play the rip alongside the DVD &  
see if you can tell any differences. If you can, then fair enough, but  
if you can't, then don't complain just because the file size is small!!

FWIW, I have been using `undvd ... -2 -c -r off` and am really very  
happy with the results. IMO, the "-r off" results - even at the  
default bitrates - can be much better than undvd's default resizing. I  
regard these results as really very watchable indeed.

Actually, ripping "Behind Enemy Lines", I couldn't IIRC tell any  
difference between the DVD & undvd's results at the default (75%?)  
rescaling. "Behind Enemy Lines" is quite a bright and well-lit movie -  
it is only when I compare the rip of "Heat" that I notice fairly minor  
compression artefacts that are not present in the original. I think  
this is because "Heat" contains more dark scenes - all the stuff I can  
pick out is in night skies behind De Nero as he walks along the  
station platform, or behind the cop when he returns home after a long  
day & is silhouetted against the picture window of his home. I think  
that such large areas of "flat colour" are typically problematic for  
video compression, and that in darker areas the results will be  
particularly noticeable, so these are "worst case" scenes for DVD  
ripping. I have a copy of a 2 minutes trailer of "Heat" here in which  
such artefacts are visible and which I will post in a day or two when  
I have had the chance to summarise my comparison comprehensively; I  
want to do some more homework on h264 encoding options before I open  
my gob further. But I have to say that even if I were not to improve  
on the quality of this rip, I am sure you could show it to 100 people  
and less than 10 of them would notice these artefacts. I would be  
pretty happy with these results for most of my viewing.

>> What do you mean by "stuttering"? I would tend to use this to mean
>> quite dramatic pauses in playback, the kind one might ascribe to
>> insufficient CPU on the playback device.
>>
> I just said "choppy". That's meant to be vague. It only means that the
> motion is not as smooth as I know it should be (the way it was on the
> original). But as I stated above, my specified output frame rate
> modification eliminates the problem.

I see that James Hastings-Trew's comments are far more comprehensive  
than any I could give. It might be interesting to know what playback  
system / software you're using, and also the details of the original  
DVD.

>> I have an NTSC PS3 here and expected to see some kind of "pulldown"
>> effect when playing these "PAL" rips, but have been unable to do so.
>> Perhaps it is just my eyes, but apparently to me the effect of
>> different framerates is very minor.
>
> But you do encounter a change between original and output frame rates?

I don't know - I'm not interested in the original framerates.

As I said in my previous post:

    here undvd is producing 29.97fps files from Region 1 NTSC DVDs and
    25fps files from Region 2 PAL DVDs.
    This has been consistent over all the handful of disks I have tried.

This seems to me to be near-as-damnit consistent with PAL 50hz & NTSC  
60hz frequencies, so I had no interest in investigating further. If  
you'd like me to compare the framerates of some of undvd's rips  
against the original movies then post a command for checking the  
framerates of the original DVDs & I'll be glad to do so.

Stroller.