[mythtv] dvd revisited (and remoted)

Larry Matter mythtv-dev@snowman.net
Sun, 22 Dec 2002 03:13:33 -0800 (PST)

For those that are interested, I got videolan working tonight playing a
dvd remotely.  Here is a quick summary:

On my 10/100 lan, it works fine.  Over 802.11b, it totally sucks.  I was
not surprised that it sucked, but I was surprised at how much it sucked. 
It was like watching a slideshow (and I was 5 feet from the AP).

As far as this being a solution to my original post, it is workable, but
not ideal so I'm not sure how much further I will take this - at this
point the benefit seems more that it would be "cool" rather than useful.

You control the VideoLan server via telnet; you will need some code to get
this to work with lirc.  There is no rew/ff and no menus/chapter
selection.  You start the movie, pause, resume and stop.  Pause takes
about 2 seconds to kick in.

dhcp on the client is a problem unless you use multicast.

audio sync was not perfect but good enough that it didn't bother me.  CPU
utilization on my athlon 1200Mhz was about 15%.  There was the occasional
hicup even when playing locally even though CPU was low - not sure why.

Larry Matter

>> Van: Thor Johnson <thormj@ieee.org>
>>> [mailto:mythtv-dev-admin@snowman.net]On Behalf Of Henk Poley
>>>> Van: Ray <maillists@sonictech.net>
>>>>> On Sat, Dec 14, 2002 at 10:23:45AM +0100, Henk Poley wrote:
>>>>>> That DOES sound great but I don't think it is practical unless you
>>>>>> have the server recompress the DVD before shipping it over the
>>>>>> ethernet (not that should be much of a barrier since cpu is
>>>>>> getting cheaper every day).
>>>>> Recompressing DVD (and no scaling) to DivX in realtime takes a
>>>>> P2400 HyperThreading.  But I guess it should take less when doing
>>>>> it in a lower resolution.  The Videolan.org guys seem to be able to
>>>>> do it.
>>>> I'm probably missing something but low to medium end Athlons are
>>>> already compressing 640x480 TV captures with Myth so DVD resolution
>>>> shouldn't be that much harder.
>>> Could also be some Intel sponsored 'benchmark' I read.  Don't know at
>>> what resolution DVD works.  btw, I know it's pretty useless to
>>> reencode at a higher resolution than your (..analog..) TV set can
>>> display.
>> Why do we need to decompress->recompress for dvd->remote viewer? How
>> about we just pipe the commands & mpeg2 stream back and forth? If you
>> need to overlay something, have it done on the frontend...
> On ethernet there's not really a problem, no.
> But AFAIK, we were (also) talking about WiFi, the "11Mbit/s" is at
> hardware-level. The frequencyband used is open (not licenced) so you
> have quite some 'noise'. The maximum data throughput is about half that,
> 5.5Mbit/s.
> MPEG2 (at 2GB/hr) -> ~4.55Mbit/s but there's some overhead, and you
> don't want to be at the 'edge' since there can be more interference now
> and then (microwave etc.)
> DivX gives good performance at half that bitrate... Thus
> recompression...
> Yup, there is faster WiFi (22Mbit and 54MBit) but tests I've seen
> suggest that current 54MBit solutions only connect at ridiculous near
> distances of 3-4 meters. More than that and there won't even be a
> connection. But things can change quickly in computerland.
>  	Henk Poley <><
> _______________________________________________
> mythtv-dev mailing list
> mythtv-dev@snowman.net
> http://www.snowman.net/mailman/listinfo/mythtv-dev