mirror of https://github.com/mpv-player/mpv
bandaid build fix
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@15352 b3059339-0415-0410-9bf9-f77b7e298cf2
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@ -547,6 +547,149 @@ Apple,
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<step><para>ÓËÏÍÐÉÌÉÒÕÊÔÅ <application>MPlayer</application></para></step>
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</procedure>
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</sect3>
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<sect3 id="codec-x264">
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<title>x264</title>
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<sect4 id="codec-x264-whatis">
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<title>What is x264?</title>
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<para>
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<systemitem class="library">x264</systemitem> is a library for
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creating H.264 video streams.
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It is not 100% complete, but currently it has at least some kind
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of support for most of the H.264 features which impact quality.
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There are also many advanced features in the H.264 specification
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which have nothing to do with video quality per se; many of these
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are not yet implemented in
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<systemitem class="library">x264</systemitem>.
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</para>
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<itemizedlist>
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<title>Encoder features</title>
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<listitem><para>CAVLC/CABAC</para></listitem>
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<listitem><para>Multi-references</para></listitem>
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<listitem><para>Intra: all macroblock types (16x16 and 4x4 with
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all predictions)</para></listitem>
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<listitem><para>Inter P: all partitions (from 16x16 down to
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4x4)</para></listitem>
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<listitem><para>Inter B: partitions from 16x16 down to 8x8
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(including SKIP/DIRECT)</para></listitem>
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<listitem><para>Ratecontrol: constant quantizer, constant bitrate,
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or multipass ABR</para></listitem>
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<listitem><para>Scene cut detection</para></listitem>
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<listitem><para>Adaptive B-frame placement</para></listitem>
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<listitem><para>B-frames as references / arbitrary frame
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order</para></listitem>
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</itemizedlist>
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<itemizedlist>
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<title>Encoder limitations</title>
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<listitem><para>No real RD</para></listitem>
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</itemizedlist>
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</sect4>
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<sect4 id="codec-h264-whatis">
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<title>What is H.264?</title>
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<para>
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H.264 is one name for a new digital video codec jointly developed
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by the ITU and MPEG.
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It can also be correctly referred to by the cumbersome names of
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"ISO/IEC 14496-10" or "MPEG-4 Part 10".
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More frequently, it is referred to as "MPEG-4 AVC" or just "AVC".
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</para>
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<para>
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Whatever you call it, H.264 may be worth trying because it can
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typically match the quality of MPEG-4 ASP with 5%-30% less
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bitrate.
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Actual results will depend on both the source material and the
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encoder.
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The gains from using H.264 do not come for free: decoding H.264
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streams seems to have steep CPU and memory requirements.
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For instance, on a 1733 MHz Athlon, a 1500kbps H.264 video uses
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around 50% CPU to decode.
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By comparison, decoding a 1500kbps MPEG4-ASP stream requires
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around 10% CPU.
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This means that decoding high-definition streams is almost out of
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the question for most users.
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It also means that even a decent DVD rip may sometimes stutter on
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processors slower than 2.0 GHz or so.
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</para>
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<para>
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At least with <systemitem class="library">x264</systemitem>,
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encoding requirements are not much worse than what you are used to
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with MPEG4-ASP.
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For instance, on a 1733 MHz Athlon a typical DVD encode would run
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at 5-15fps.
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</para>
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<para>
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This document is not intended to explain the details of H.264,
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but if you are interested in a brief overview, you may want to read
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<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>.
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</para>
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</sect4>
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<sect4 id="codec-x264-playback">
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<title>How can I play H.264 videos with <application>MPlayer</application>?</title>
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<para>
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<application>MPlayer</application> uses
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<systemitem class="library">libavcodec</systemitem>'s H.264
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decoder.
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<systemitem class="library">libavcodec</systemitem> has had at
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least minimally usable H.264 decoding since around July 2004,
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however major changes and improvements have been implemented since
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that time, both in terms of more functionalities supported and in
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terms of improved CPU usage.
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Just to be certain, it is always a good idea to use a recent CVS
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checkout.
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</para>
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<para>
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If you want a quick and easy way to know whether there have been
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recent changes to <systemitem class="library">libavcodec</systemitem>'s
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H.264 decoding, you might keep an eye on
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<ulink url="http://mplayerhq.hu/cgi-bin/cvsweb.cgi/ffmpeg/libavcodec/h264.c?cvsroot=FFMpeg">FFmpeg CVS repository's web interface</ulink>.
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</para>
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</sect4>
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<sect4 id="codec-x264-encode">
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<title>How can I encode videos using <application>MEncoder</application> and <systemitem class="library">x264</systemitem>?</title>
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<para>
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If you have the subversion client installed, the latest x264
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sources can be gotten with this command:
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<screen>
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svn co svn://svn.videolan.org/x264/trunk x264
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</screen>
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<application>MPlayer</application> sources are updated whenever
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an <systemitem class="library">x264</systemitem> API change
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occurs, so it is always suggested to use CVS
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<application>MPlayer</application> as well.
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Perhaps this situation will change when and if an
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<systemitem class="library">x264</systemitem> "release" occurs.
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Meanwhile, <systemitem class="library">x264</systemitem> should
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be considered very unstable, in the sense that its programming
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interface is subject to change.
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</para>
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<para>
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<systemitem class="library">x264</systemitem> is built and
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installed in the standard way:
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<screen>
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./configure && make && sudo make install
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</screen>
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This installs libx264.a in /usr/local/lib and x264.h is placed in
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/usr/local/include.
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With the <systemitem class="library">x264</systemitem> library
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and header placed in the standard locations, building
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<application>MPlayer</application> with
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<systemitem class="library">x264</systemitem> support is easy.
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Just run the standard:
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<screen>./configure && make && sudo make install</screen>
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The configure script will autodetect that you have satisfied the
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requirements for <systemitem class="library">x264</systemitem>.
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</para>
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</sect4>
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</sect3>
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</sect2>
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