[MPlayer-dev-eng] Old arm hardware

[Jonathan Andrews]

On Tue, 2012-09-25 at 21:12 +0200, Thomas Orgis wrote: 
> Am Mon, 24 Sep 2012 20:36:38 +0100
> schrieb Jonathan Andrews <jon at jonshouse.co.uk>: 
> 
> > This partly a feature request, partly a cry for help.  I'd live a
> > "--disable-video" option for configure, would solve some problems if
> > building just an mp3 audio player.
> 
> I might be going wildly out of line here, but what about just building
> an mp3 audio player instead of MPlayer in a rare video-less
> configuration? I hope folks aren't upset when I point out that
> dedicated music players tend to have some convenience in the UI for
> that purpose that MPlayer may lack, being focused on playing videos
> (come to think about things like volume adjustment between tracks).
> 
> 
> Alriighty then,

Ok, I guess you need a bit more info :-)

> 
I've written a front end with visuals, menus and button controls. At the
moment its tested and running on a desktop PC linux.   This front i've
also compiled and tested on the target, it runs OK, it drive the
buttons, display etc. 

I hoped to port across mplayer and control it with named pipes.  I need
things like the audio resampler.

My front end (imaginatively called "player") starts the an mplayer
instance in background like this :

sprintf(mplayer_cmd,"mplayer -quiet -input file=%s -af resample=44100,volume=1 -ao pcm:file=%s \"%s\" &",FIFO_MPLAYER,FIFO_AUDIO,filename);
system(mplayer_cmd);

My front end not only sits between the mp3 player and the display (a 128
x 32 pixel VFD) it also needs to drive the audio DAC.

I can replace mplayer with any old mp3 player process assuming the
following :
1) I can compile for arm target using old toolchain. 

This is important  as I need the work done by the hijack kernel. This is
quite elderly, i've tried compiling my code with a more modern gcc but
the kernel barfs as the elf loader format (and many other things) has
long since changed.
http://empeg-hijack.sourceforge.net/

2) The player needs to produce 44.1Khz 16 bit stereo interleaved audio
regardless of the MP3s native bitrate and present it to the front end
somehow (using named pipes at the moment).  The frontend drives the DAC
hence is sandwiched between the mp3 player process and the audio output.

3) I can communicate with the player process somehow, pause, change
tracks etc - nothing fancy.

I welcome any constructive suggestions.

At the moment i've taken an elderly ish mplayer tree and am trying to
hack out all the video related code so it will at least build.... ho
hum .... I am of course struggling !

I've tried just playing with makefiles but the internals of mplayer have
no distinction between video and audio functionality hence its trying to
built lots of stuff that doesn't stand a chance of working on the
target :-(

Thanks,
Jon