[mythtv-users] Playstation 3 as UPnP client to MythTV

[Rev Simon Rumble]

Hi folks.

I'm attempting to use a PS3 as the frontend to my Myth system, replacing 
the silent, solid state SD frontend I used to have.  My backend records 
from two DVB-t cards, so I'm recording.  But I've encountered a few 
problems and I'm wondering if anyone else has encountered these, or has 
suggestions of lines of attack.

Ideally Sony would open access to the graphics hardware through the 
"Other OS" feature, and then I could just run native Myth.  
Unfortunately this hasn't happened so I've been forced to use the UPnP 
approach.  This means there's a bunch of features missing, like 
commercial flagging and the ability to delete recordings after watching, 
but I can live with that.  These other problems are more serious.

Solving these would make the PS3 a pretty damn decent frontend, 
especially for people wanting HD.  When it works, 1080i and 720p look 
pretty damn spectacular.  A PS3 frontend has the added benefits of 
Blu Ray playback, UPnP client (for downloaded video) and a games console 
to boot.

** Transport stream support **

The PS3 supports many permutations of MPEG Program Stream(PS), but only 
MPEG2 video with MPEG2 Layer 2 audio[1] inside a Transport Stream (TS).  
Australian DVB-t seems to (sometimes?) use AC3 audio, so inside a TS the 
PS3 can't play it back.  I either get the video with white noise sound, 
or it refuses to play back at all.

It seems my Myth setup sometimes produces TS, and sometimes produces 
things that the PS3 is happy with.  Output from "file" looks like this.  
Interestingly, the files labelled "data" play back, but the TS doesn't.

1020_20090221181900.mpg: data
1020_20090221190000.mpg: data
1020_20090222050000.mpg: MPEG transport stream data
1020_20090222190000.mpg: TeX font metric data (\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377

So the approach I've been looking at is demuxing the TS into a PS in a 
transcode job.  I haven't succeeded yet, so if anyone has a nice script 
I'd appreciate it.  Ideally MythTV would be able to do this as it 
records, because otherwise I can't really watch a program that's still 
recording and there'll be a bunch of hard drive thrashing that could be 
avoided.

What's strange is that my tuners are almost identical.  lspci output:
03:0c.0 Multimedia controller: Philips Semiconductors SAA7134/SAA7135HL Video Broadcast Decoder (rev 01)
04:0f.0 Multimedia controller: Philips Semiconductors SAA7131/SAA7133/SAA7135 Video Broadcast Decoder (rev d0)

So I'm assuming the problem is due to Myth being relatively relaxed 
about the streams it produces, and really all it's doing is pulling out 
the appropriate TS from the multiplex and dumping it to disk.  This is 
fine when mythfrontend (or mplayer or xine or whatever) is playing back, 
but the PS3 is a bit pickier about it.

So has anyone got any suggestions here?  I'd love to find a way to get 
Myth to just product something I can play on the PS3, without having to 
transcode.  I can post up some more diagnostic information if people 
want it.

** Refreshing UPnP shares **

It seems like the PS3 only refreshes listings from the UPnP server after 
being shut down and restarted.  That means any recordings that kick off 
after you boot the PS3 don't show up.  Anyone worked out a way to get 
these listings to refresh?

** Playback stops with FF/RW **

When I fast forward or rewind, playback doesn't restart when I press 
play.  The play icon shows up on-screen, but the playback doesn't 
actually start.  I have to stop and restart the playback to get it 
moving again.  Weird, but not a show stopper I guess.

** Playback while recording **

Related to the UPnP share refreshing thing, if I watch a programme 
that's currently being recorded, it seems the PS3 takes the end time of 
the stream when first started, so it gets to the point where you started 
watching (as coming off the air) and stops.  Kinda annoying -- it'd be 
nice if it just kept reading until the stream stops.

[1] Sony's list of supported video file formats
    http://playstation.custhelp.com/cgi-bin/playstation.cfg/php/enduser/std_adp.php?p_faqid=361&p_created=1193250629&p_sid=rZ74mLcj&p_accessibility=&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MSZwX3Byb2RzPTQmcF9jYXRzPSAmcF9wdj0xLjQmcF9jdj0mcF9zZWFyY2hfdHlwZT1hbnN3ZXJzLnNlYXJjaF9ubCZwX3BhZ2U9MSZwX3NlYXJjaF90ZXh0PWRpdng*&p_li=&p_topview=1

-- 
Rev Simon Rumble <simon at rumble.net>
www.rumble.net

The Tourist Engineer
Because nerds travel too.
http://engineer.openguides.org/

"So you really think that God would plant a bunch of bones in the
 earth to test your faith? Either you're in denial or God has some 
 serious self-esteem issues."
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