[mythtv-users] IPad and mythtv.

Christopher Kerr mythtv at theseekerr.com
Mon May 24 03:12:55 UTC 2010

On Mon, May 24, 2010 at 1:03 PM, Jean-Yves Avenard <jyavenard at gmail.com> wrote:
> Hi
> On 24 May 2010 12:36, jedi <jedi at mishnet.org> wrote:
>>    An iPad doesn't meet the technical requirements of a MythTV frontend.
> looks like you're the one defining what the "technical requirements
> are" ... thanks for letting us now of your new role :P

>> It doesn't support any of the file formats normally associated with MythTV.
> This is just as meaningful as stating that the linux kernel doesn't
> support any of the file formats normally associated with MythTV.
> Or saying a windows PC can't play most of the files either because it
> doesn't come with the required 3rd party programs.

He's kinda right about this - hardware accelerated MPEG2 would make
life a lot easier.

>> It's ability to support those file formats purely in software is very limited.
> Really? why is that? .. Actually, don't need to answer.

Now that's an interesting question:

a) is a 1GHz ARM chip fast enough to decode MPEG2 in software?
b) Would a software codec pass Apple's quality control?

> Why is it so hard to consider having ffmpeg compiled on the iPad (or
> any platforms for that matter) and use the hardware decoding engine
> wherever you can (though, I'd assume you would only need it for h264,
> which is the most technically challenging and that the iPad can do
> anyway)

Apple's development terms would likely make DISTRIBUTING ffmpeg a
challenge, although I'm sure it's technically quite possible.

>> Having some other box do the heavy lifting across the network is impractical
>> because such a machine would likely have to forego nice things like VDPAU and
>> would have to handle stuff like 1080i HD-PVR recordings strictly in software.
> This makes no technical sense whatsoever... VDPAU is for playback only
> and even today, isn't used by any of the mythtv backend processing
> facilities whatsoever.
> Less than 2 years ago, no-one considered that you would be able to
> play HD-PVR videos without having at least a dual core > 3GHz either..
> And even then, my 3.3GHz Core 2 Duo could barely cope.

I think what he means is "transcoding 1080i material is slow, because
you have to do both the decoding and encoding in software". He's right
- since it takes a hefty dual core machine just to decode such
material in software, that means you need a hefty quad to be able to
decode + encode in real time.

That said, real time transcoding of SD material is easy - which is
great here in Australia, since there's so little true HD content

- Chris

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