[MEncoder-users] Terrible results with x264

[Joseph Miller]

On Thu, Dec 23, 2010 at 9:18 AM, Grozdan <neutrino8 at gmail.com> wrote:
> 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
>>> _______________________________________________
>>> MEncoder-users mailing list
>>> 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?
>

Maybe if the devs would have mentioned that in the man page under the
crf option or the qp option, I would have known.  I've always received
very good results using qp 10-20.  Now that I know, I will use crf in
the future.

-Joseph