[MPlayer-DOCS] CVS: main/DOCS/xml/en mencoder.xml,1.73,1.74
Guillaume Poirier CVS
syncmail at mplayerhq.hu
Wed Jul 6 00:11:26 CEST 2005
CVS change done by Guillaume Poirier CVS
Update of /cvsroot/mplayer/main/DOCS/xml/en
In directory mail:/var2/tmp/cvs-serv11742/en
Modified Files:
mencoder.xml
Log Message:
More options documented in XviD encoding guide
Index: mencoder.xml
===================================================================
RCS file: /cvsroot/mplayer/main/DOCS/xml/en/mencoder.xml,v
retrieving revision 1.73
retrieving revision 1.74
diff -u -r1.73 -r1.74
--- mencoder.xml 4 Jul 2005 05:37:27 -0000 1.73
+++ mencoder.xml 5 Jul 2005 22:11:23 -0000 1.74
@@ -2710,6 +2710,57 @@
If you are looking for speed, you should disable this option before
starting to consider reducing <option>me_quality</option>.
</para></listitem>
+
+<listitem><para>
+ <emphasis role="bold">chroma_opt</emphasis>
+ Is intended to increase chroma image quality around pure
+ white/black edges, rather than improving compression.
+ This can help to reduce the "red stairs" effect.
+</para></listitem>
+
+<listitem><para>
+ <emphasis role="bold">lumi_mask</emphasis>
+ Tries to give less bitrate to part of the picture that the
+ human eye cannot see very well, which should allow the encoder
+ to spend the saved bits on more important parts of the picture.
+ The quality of the encode yielded by this option highly depends
+ on personal preferences and on the type and monitor settings
+ used to watch it (typically, it will not look as good if it is
+ bright or if it is a TFT monitor.
+</para></listitem>
+
+<listitem><para>
+ <emphasis role="bold">qpel</emphasis>
+ Increases the precision of the motion estimation from halfpel to
+ quarterpel.
+ The idea is to find better motion vectors which will in return
+ reduce bitrate (hence increasing quality).
+ However, quarterpel precision motion vectors are coded in the
+ bitstream with a few bits, so if the content do not feature
+ enough possibilities to find better motion vectors through
+ <option>qpel</option>, it will in fact hurt compressibility.
+ Unfortunately, there is no way to foresee the possible gains of
+ <option>qpel</option>, so you need to actually encode with and
+ without it to know for sure.
+ </para><para>
+ <option>qpel</option> can be almost double encoding time, and
+ requires as much as 30-60% more processing power to decode.
+ It is not supported by all standalone players.
+</para></listitem>
+
+<listitem><para>
+ <emphasis role="bold">gmc</emphasis>
+ Tries to save bits on panning scenes by using a single motion
+ vector for the whole frame.
+ This almost always raise PSNR, but significant slows down
+ encoding (and also needs more processing power to decode).
+ Therefore, you should only use it when you have turned
+ <option>vhq</option> to the maximum.
+ <systemitem class="library">XviD</systemitem>'s GMC (which are
+ more sophisticated than DivX's are not supported by all
+ standalone players.
+</para></listitem>
+
</itemizedlist>
</sect2>
</sect1>
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