mpv/DOCS/DXR3

DXR3/H+ video/audio output plugins manual by David Holm
=======================================================

2001-11-27: -ao dxr3 now works, still a few bugs though
            you might have to reload the em8300 modules
	    after a playback or you might get static the
	    next time you use the dxr3 audio interface.
	    
1. Introduction

The DXR3 and Hollywood+ are two not too different mpeg-(1/2) and ac3
hardware playback cards that came at about the same time as the first
dvd-rom drives hit the market. At that time most computers weren't
powerful enough for synced software dvd playback. And even the faster
(intel-based) computers had troubles with artifacts.
Sigma Designs came up with the great idea to create a hardware
mpeg-(1/2), ac3 decoder. Sigma Designs are known for their realmagic
hardware (or they bought the company who came up with the first
realmagic boards, I don't know which).
Later Creative Labs thought, hey, we also wan't this product, and to
distribute it with our dvd-drives (the DVD Encore packages if I recall
correctly). So they bought the designs for the Hollywood plus and
replaced the circuit used to produce a proper video feed for tv's
called adv7170 or adv7175a depending on which h+ board you own with
a bt865. The reason for this is beyond my understanding as this seems
complete illogical to me, but I have had great experiences with
bt(brooktree) circuits in the past, so I don't mind.
Well, nowadays most people have no use for a mpeg-(1/2) or ac3
hardware decoder since most computers these days have no problem doing
this in software and have cycles left for posprocessing (removing of
artefacts and other garbage produced by compression).
These days, you have two uses for this card:
1. You have a slow computer which you use for vcd/dvd playback
2. You discover what I have done with the implementation of this as
   an audio/video output device for mplayer (read on and you'll find
   out).
   


2. Requirements

 * First of all you will need the DXR3/H+ drivers properly installed,
   including the dev-api.
   These can be downloaded from dxr3.sourceforge.net (I suggest using
   the CVS version since most of the time I use the latest features
   which are only available through cvs)

 * <mplayerdir>/libavcodec from ffmpeg (only required if you intend to
   play formats other than mpeg-(1/2), highly recommended!) there are
   two ways of doing this:
   1. Download and install ffmpeg from ffmpeg.sourceforge.net. 
      Configure it with --enable-shared
   2. Download ffmpeg from ffmpeg.sourceforge.net, copy the entire 
      contents from <ffmpegdir>/libavcodec into <mplayer>/libavcodec 
      (symlinking won't work!). Then edit <mplayerdir>/libavcodec/utils.c 
      and move the line containing register_avcodec(&mpeg1video_encoder); 
      out of the CONFIG_ENCODERS #ifdef block and place it outside, for 
      instance below register_avcodec(&rawvideo_encoder);

 * Run <mplayerdir>/configure and make sure that DXR3/H+ support =yes
   and optionally that libavcodec or ffmpeg.so = yes
   
 From here on compilation (of at least my code ;) should go without
 problems.



3. Usage

After installation you will have two new outdevices in mplayer:
    -vo dxr3	For video output
    -ao dxr3	For audio output 

MPEG-1, MPEG-2, VCD and DVD Notes
There are some notes to take into account here for optimum playback.
When playing any mpeg-(1/2) file, this including usage of the "-dvd"
and "-vcd" options you must either add the "-vc mpegpes" or edit
codecs.conf and make sure videocodec mpegpes is listed above mpeg12.
If you fail to do this you will only get software playback which kinda
spoils most of the useful features of this card except for tv-out ;).
Remember that if you edit the codecs.conf file and move the mpegpes
section will have to specify "-vc mpeg12" if you want to playback
any of these video types _without_ "-vo dxr3"!

DIVX Notes
When playing divx's add "-vc odivx", if you get any other divx codec
to run faster tell me which one because I'll be interested in how it
could possibly be any faster than OpenDivX4Linux...

Other codecs:
Currently they don't work. I'm working on implementing libvo2 which
will be a much more convenient and faster way of working with
vo<->codec interaction. If libvo2 takes longer to develop than I
have estimated perhaps I'll add more codec support to libvo. Otherwise
you'll just have to wait for libvo2. (there is an implementation
for other codecs, but I think it's pretty broken currently ;)


 
4. Contacting me

You can contact me either by e-mailing me, <dholm@iname.com> or by using
icq: 798427
Feedback, bugreports and general suggestions are appreciated (preferably
by e-mail). My name is David Holm for those of you who are incapable of 
reading a heading. ;)