[mythtv] [PATCH] Add streaming output to transcoder

Geoffrey Hausheer ou401cru02 at sneakemail.com
Fri Aug 15 14:02:42 EDT 2003


On Fri, 15 Aug 2003 09:52:55 -0700 (PDT), "Alan Snyder ax763-at-yahoo.com
|mythtv/1.0-Allow|" <45n5hjimfc0t at sneakemail.com> said:
> 
> 
> I can understand the value of this for straight
> transcoding.  But doesn't the
> same "frameserver" approach also open the way to
> streaming video to a client,
> initiated, for example, through mythweb?  While this
> is a departure from the
> Mythical set-top box vision, it would be very
> practical for people who are stuck
> with another OS on certain machines.  Extension of the
> web interface and
> streaming in Quicktime or another multi-OS format
> would be valuable.
Sure, you can do whatever you want with it (for this purpose, it should
work fine today), however be aware that (a) encoding in real time
(especially if it requires frame processing) may need serious horsepower.
 the raw streams take up a lot of bandwidth, and so they NEED to be
processed in some manner.  I think being able to stream downsampled files
from mythweb would kick ass, but (a) I don't have the uplink bandwidth
for anything but very low quality, and (b) I have no knowledge of how to
write encoders (even using avformat), much less how to make it
streamable.

Just for example decoding mpeg4 streams with mythtranscode on my 1.5GHz
P4 takes about 30% of the CPU.  That means I could decode 3 streams
simultaneously, if my harddrive is up to it, and I don't need to do any
post-processing.  Realistically, my system could maybe handle
downsampling and encoding 1 stream in realtime, assuming that myth isn't
recording another program concurrently.

.Geoff


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