[MEncoder-users] filter question (converting low quality dvds to xvid = larger files)

[Kerry Kirk]

James,

Thanks for the reply.  Yes it is an NTSC video and I also forgot to mention
that I am running a 64bit os if that matters.

Should filters be applied to both passes or to the second pass only?

K.

On Sun, Mar 22, 2009 at 2:44 AM, James Hastings-Trew <jimht at shaw.ca> wrote:

> Kerry Kirk wrote:
>
>> First some background:
>> I am on an Ubuntu 8.10 box and am using MEncoder 2:1.0~rc2-0ubuntu17 with
>> libxvidcore4 2:1.1.2-01ubuntu3 (according to Synaptic)
>>
>> When I convert my dvds to xvid my process is as follows.
>>
>> Using dvdshrink via wine I rip out the parts I want, decrypt them and save
>> the results as an iso.
>>
>> I have a script file that will process as many iso files as I request by
>> mounting each iso as an iso9660 loop and issuing the following commands
>>
>> first pass
>> mencoder -dvd-device /pathtoisofile dvd://1 -nosound -ovc xvid
>> -xvidencopts
>> pass=1:turbo -passlogfile xvidlog -o /dev/null 2>>errorlog
>>
>> second pass
>> mencoder -dvd-device /pathtoisofile dvd://1 -oac mp3lame -lameopts
>> cbr:br=96:vol=8 -alang en -ovc xvid -xvidencopts pass=2:bitrate=900
>> -passlogfile xvidlog -o outputfile.avi 2>>errorlog
>>
>> I generally get a 2 hr movie down to about 650-700 megs.  With a few dvds
>> of
>> very old movies where the quality of the original is lacking the files end
>> up being much larger.  I am guessing that the static and jitteriness(sp?)
>> of
>> some of these old films is the cause of the difference in compression and
>> thus file size.
>>
>> Are there any commands or filters I should add to my encoding commands
>> that
>> might get some better quality xvids out of the older films.  I have used
>> grayscale in the xvidencopts and it does seem to help with the b&w films.
>> Any other ideas?
>>
>>
> Couple of things come to mind - pullup, deinterlace, scaling, cropping,
> hqdn3d. You are encoding the movies without doing any of these things which
> means you are burning bitrate on more frames than you need to (unless these
> are PAL DVDs, you didn't say), more detail than you should be (interlace is
> for TV, not for computers), pixels you don't need (DVDs are encoded at TV
> aspect ratios, generally storing more pixels than the computer needs to
> display them properly), black borders, and noise.
>
> -vf pullup,softskip,pp=lb,hqdn3d,harddup will give you a push in the right
> direction IF the DVD source is NTSC, a movie shot on film, and I can't guess
> at valid values for cropping and scaling, but in gneral a full screen DVD
> with no cropping needs should be scaled to 640x480 to maintain proper aspect
> ratio.
>
>
>
>
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