[MEncoder-users] Terrible results with x264

Grozdan neutrino8 at gmail.com
Thu Dec 23 15:18:24 CET 2010


On Thu, Dec 23, 2010 at 2:13 PM, belcampo <belcampo at zonnet.nl> wrote:
> Joseph Miller wrote:
>>
>> On Wed, Dec 22, 2010 at 4:19 PM, Jason Cumiskey
>> <jason.cumiskey at gmail.com> wrote:
>>>
>>> Hi,
>>>
>>> I have just started using x264 to encode my dvds.  I am going for
>>> quality, not speed.  I am basing my -x264encopts off of the
>>> recommendations from
>>> http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-x264.html
>>>
>>> Here are the commands I issue (I am using 2 pass encode):
>>> mencoder -dvd-device /dev/dvd1 dvd://1 -alang eng -aid 128 -oac mp3lame
>>> -lameopts cbr:br=128:vol=7 -vf
>>> pullup,softskip,crop=704:480:10:0,hqdn3d=2:1:2,harddup -ovc x264
>>> -x264encopts
>>>
>>> pass=1:bitrate=1400:subq=1:partitions=all:8x8dct:me=umh:frameref=1:bframes=3:b_pyramid=normal:weight_b:threads=auto
>>> -o movie.h264
>>>
>>> # Pass 2
>>> mencoder -dvd-device /dev/dvd1 dvd://1 -alang eng -aid 128 -oac mp3lame
>>> -lameopts cbr:br=128:vol=7 -vf
>>> pullup,softskip,crop=704:480:10:0,hqdn3d=2:1:2,harddup -ovc x264
>>> -x264encopts
>>>
>>> pass=2:bitrate=1400:subq=6:partitions=all:8x8dct:me=umh:frameref=6:bframes=3:b_pyramid=normal:weight_b:threads=auto
>>> -o movie.h264
>>>
>>>
>>> On pass 2, I change subq to 6 and frameref to 6 (as recommended in the
>>> docs link above to speed up 1st pass and have higher quality for 2nd
>>> pass).Can anyone see anything obviously wrong in my command chain?  The
>>> resulting video is heavily pixelated and mplayer shows a bitrate of
>>> 0kbps.
>>>
> FYI. multi-pass does NOT add any quality, it's only usefull when you have a
> hard-limit of size to obey. If you need to put the result on a
> cd/usb-stick/DVD or something like that, then you can get max-quality given
> a fixed size.
> If that is not the case use a qp=16-26 for very good to very acceptable
> quality. You can leave out the bitrate when you choose Quality instead of
> Size.
>>
>> My experience has been that the bitrate option either doesn't work
>> very well, or I don't know how to use it.  Use qp=20 or so and you'll
>> get good quality.  I have just started using the presets as well and
>> preset=placebo gives very nice results.  Something like
>> qp=20:preset=placebo:pass=1 then switching to pass=3 for 2nd encoding
>> gives nice results and decent filesize.  I'm assuming that
>> preset=[veryslow|slower|slow] would probably also give good results.
>>
>> -Joseph
>> _______________________________________________
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>> MEncoder-users at mplayerhq.hu
>> https://lists.mplayerhq.hu/mailman/listinfo/mencoder-users
>
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>

Why are you both recommending qp? How many times do experienced
encoders and the devs themselves need to mention that qp should NOT be
used since it's "very dumb" compared to crf, which is the preferred
option?

Gee, people, stop giving bad advice or just keep quiet if you don't know :)

About multipass, I do not have any issues with it nor get pixelated results


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