[MPlayer-translations] CVS: main/DOCS/xml/ru codecs.xml,1.22,1.23
Diego Biurrun CVS
syncmail at mplayerhq.hu
Thu May 5 15:27:01 CEST 2005
CVS change done by Diego Biurrun CVS
Update of /cvsroot/mplayer/main/DOCS/xml/ru
In directory mail:/var2/tmp/cvs-serv17707/ru
Modified Files:
codecs.xml
Log Message:
bandaid build fix
Index: codecs.xml
===================================================================
RCS file: /cvsroot/mplayer/main/DOCS/xml/ru/codecs.xml,v
retrieving revision 1.22
retrieving revision 1.23
diff -u -r1.22 -r1.23
--- codecs.xml 29 Nov 2004 19:43:29 -0000 1.22
+++ codecs.xml 5 May 2005 13:26:59 -0000 1.23
@@ -548,6 +548,149 @@
</procedure>
</sect3>
+
+<sect3 id="codec-x264">
+<title>x264</title>
+
+<sect4 id="codec-x264-whatis">
+<title>What is x264?</title>
+<para>
+ <systemitem class="library">x264</systemitem> is a library for
+ creating H.264 video streams.
+ It is not 100% complete, but currently it has at least some kind
+ of support for most of the H.264 features which impact quality.
+ There are also many advanced features in the H.264 specification
+ which have nothing to do with video quality per se; many of these
+ are not yet implemented in
+ <systemitem class="library">x264</systemitem>.
+</para>
+
+<itemizedlist>
+<title>Encoder features</title>
+ <listitem><para>CAVLC/CABAC</para></listitem>
+ <listitem><para>Multi-references</para></listitem>
+ <listitem><para>Intra: all macroblock types (16x16 and 4x4 with
+ all predictions)</para></listitem>
+ <listitem><para>Inter P: all partitions (from 16x16 down to
+ 4x4)</para></listitem>
+ <listitem><para>Inter B: partitions from 16x16 down to 8x8
+ (including SKIP/DIRECT)</para></listitem>
+ <listitem><para>Ratecontrol: constant quantizer, constant bitrate,
+ or multipass ABR</para></listitem>
+ <listitem><para>Scene cut detection</para></listitem>
+ <listitem><para>Adaptive B-frame placement</para></listitem>
+ <listitem><para>B-frames as references / arbitrary frame
+ order</para></listitem>
+</itemizedlist>
+
+<itemizedlist>
+<title>Encoder limitations</title>
+ <listitem><para>No real RD</para></listitem>
+</itemizedlist>
+
+
+</sect4>
+
+<sect4 id="codec-h264-whatis">
+<title>What is H.264?</title>
+<para>
+ H.264 is one name for a new digital video codec jointly developed
+ by the ITU and MPEG.
+ It can also be correctly referred to by the cumbersome names of
+ "ISO/IEC 14496-10" or "MPEG-4 Part 10".
+ More frequently, it is referred to as "MPEG-4 AVC" or just "AVC".
+</para>
+<para>
+ Whatever you call it, H.264 may be worth trying because it can
+ typically match the quality of MPEG-4 ASP with 5%-30% less
+ bitrate.
+ Actual results will depend on both the source material and the
+ encoder.
+ The gains from using H.264 do not come for free: decoding H.264
+ streams seems to have steep CPU and memory requirements.
+ For instance, on a 1733 MHz Athlon, a 1500kbps H.264 video uses
+ around 50% CPU to decode.
+ By comparison, decoding a 1500kbps MPEG4-ASP stream requires
+ around 10% CPU.
+ This means that decoding high-definition streams is almost out of
+ the question for most users.
+ It also means that even a decent DVD rip may sometimes stutter on
+ processors slower than 2.0 GHz or so.
+</para>
+<para>
+ At least with <systemitem class="library">x264</systemitem>,
+ encoding requirements are not much worse than what you are used to
+ with MPEG4-ASP.
+ For instance, on a 1733 MHz Athlon a typical DVD encode would run
+ at 5-15fps.
+</para>
+<para>
+ This document is not intended to explain the details of H.264,
+ but if you are interested in a brief overview, you may want to read
+ <ulink url="http://www.cdt.luth.se/~peppar/kurs/smd151/spie04-h264OverviewPaper.pdf">The H.264/AVC Advanced Video Coding Standard: Overview and Introduction to the Fidelity Range Extensions</ulink>.
+</para>
+</sect4>
+
+<sect4 id="codec-x264-playback">
+<title>How can I play H.264 videos with <application>MPlayer</application>?</title>
+<para>
+ <application>MPlayer</application> uses
+ <systemitem class="library">libavcodec</systemitem>'s H.264
+ decoder.
+ <systemitem class="library">libavcodec</systemitem> has had at
+ least minimally usable H.264 decoding since around July 2004,
+ however major changes and improvements have been implemented since
+ that time, both in terms of more functionalities supported and in
+ terms of improved CPU usage.
+ Just to be certain, it is always a good idea to use a recent CVS
+ checkout.
+</para>
+<para>
+ If you want a quick and easy way to know whether there have been
+ recent changes to <systemitem class="library">libavcodec</systemitem>'s
+ H.264 decoding, you might keep an eye on
+ <ulink url="http://mplayerhq.hu/cgi-bin/cvsweb.cgi/ffmpeg/libavcodec/h264.c?cvsroot=FFMpeg">FFmpeg CVS repository's web interface</ulink>.
+</para>
+</sect4>
+
+<sect4 id="codec-x264-encode">
+<title>How can I encode videos using <application>MEncoder</application> and <systemitem class="library">x264</systemitem>?</title>
+<para>
+ If you have the subversion client installed, the latest x264
+ sources can be gotten with this command:
+ <screen>
+ svn co svn://svn.videolan.org/x264/trunk x264
+ </screen>
+ <application>MPlayer</application> sources are updated whenever
+ an <systemitem class="library">x264</systemitem> API change
+ occurs, so it is always suggested to use CVS
+ <application>MPlayer</application> as well.
+ Perhaps this situation will change when and if an
+ <systemitem class="library">x264</systemitem> "release" occurs.
+ Meanwhile, <systemitem class="library">x264</systemitem> should
+ be considered very unstable, in the sense that its programming
+ interface is subject to change.
+</para>
+<para>
+ <systemitem class="library">x264</systemitem> is built and
+ installed in the standard way:
+ <screen>
+ ./configure && make && sudo make install
+ </screen>
+ This installs libx264.a in /usr/local/lib and x264.h is placed in
+ /usr/local/include.
+
+ With the <systemitem class="library">x264</systemitem> library
+ and header placed in the standard locations, building
+ <application>MPlayer</application> with
+ <systemitem class="library">x264</systemitem> support is easy.
+ Just run the standard:
+ <screen>./configure && make && sudo make install</screen>
+ The configure script will autodetect that you have satisfied the
+ requirements for <systemitem class="library">x264</systemitem>.
+</para>
+</sect4>
+</sect3>
</sect2>
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