[mythtv] Live transcode while recording

[Steve Heistand]

René Bühlmann <buehlmann at gmx.ch>, said on Sun Nov 30, 2008 [10:23:09 PM]:
} Hi all,
} 
} I hope this message does not get posted twice now (subscribed with the wrong address ;) ).
} If it does.. i'm sorry.
} 
} I'm planning to implement live transcoding for mythbackend. This will
} make it possible to stream livetv with a lower bandwith (e.g. over the
} web) or record a show in a different codec than it was broadcasted.
} My plan is to extend the recording profiles for dvb sources to allow
} transcoding and let the recorder do the actual transcoding prior sending
} the stream to the "RingBuffer" (btw. is there a real ringbuffer in
} mythtv or QT?). For the transcoding, i will use libavcodec.
} An HTTP streaming server integrated into the mythbackend would then
} allow the streaming of livetv to any software like WMP, Windows Mobile,
} iphone without the need to install additional software.
} 
} Is there already some work done or are there any other suggestions on
} how to do this?

unless you are just wanting to do this for fun I would say it may be too much
hassle. There are a number of companies trying to do this in all kinds of
ways. though not integrated into mythv. just take an HD source and output
in realtime something that is lower bandwidth in some form or lossey or lossless
codec.  They arent cheap and they patent everything they can bribe a patent
office for. (your country's legal caring about US patent laws may vary)

I spent a couple years doing just this for an company trying to use FPGAs
for the processing power.  In the end it was too expensive a product to be 
useful. :(

But the first step is just pick a codec, determine the format of its data
stream and work backwards into whatever source type you want to attach to.
the hairpulling part is deciding what knobs to enable in the data format.


-- 
"Why is it so hot inside this handbasket?"
--
Steve Heistand
steve at heistand.org