[MPlayer-users] Lossless h264 Encoding

[Ognjen Bezanov]

Guillaume POIRIER wrote:
> Hi,
> 
> On 10/17/07, Ognjen Bezanov <Ognjen at mailshack.com> wrote:
>> Hello!
>>
>> I want to be able to encode to lossless h264 streams using
>> mplayer/mencoder, but I have had no luck so far.
>>
>> I scoured the web and the mailing-lists and so far the only thing I have
>> found is a thread (url:
>> http://lists.mplayerhq.hu/pipermail/mencoder-users/2005-December/002293.html)
>>
>> specifying that setting qp_constant=0 should give me lossless encoding.
>>
>> All well and good, except that when I try setting that option I get the
>> following error:
>>
>> "Option x264encopts: Unknown suboption qp_constant"
>>
>> Has mplayer changed the x264 options for lossless compression?
> 
> Yes, but apparently you didn't even care to read curren't manpage
> 
>        qp=<0-51>
>               This selects the quantizer to use for P-frames.  I- and B-frames
>               are offset from this value by ip_factor and  pb_factor,  respec-
>               tively.  20-40 is a useful range.  Lower values result in better
>               fidelity, but higher bitrates.  0 is lossless.  Note that  quan-
>               tization  in  H.264  works  differently from MPEG-1/2/4: H.264's
>               quantization parameter (QP) is on a logarithmic scale.  The map-
>               ping  is  approximately H264QP = 12 + 6*log2(MPEGQP).  For exam-
>               ple, MPEG at QP=2 is equivalent to H.264 at QP=18.
> 
> 
> :-(
> 
> 
>> How would
>> I enable lossless h264 in mplayer now?
> 
> -x264encopts qp=0
> 
> Guillaume

oh. I feel stupid now :(

I read the manpage before, but I forgot that I had upgraded mplayer 
since then. Sorry for the time wasting :(

Ogi.