[mythtv-users] MythTV Companion for iPad Update

Robert McNamara robert.mcnamara at gmail.com
Fri Dec 2 20:26:32 UTC 2011


On Fri, Dec 2, 2011 at 12:12 PM, Matt Emmott <memmott at gmail.com> wrote:

>
>
>>
> Very cool. I notice it takes some time to "spin up" the stream. Is that
> something that can be sped up as the app matures? What's the bottleneck? I
> assume the Mythtv box is what's doing the transcoding before sending the
> stream to the iPad; is it just a matter of CPU power on that end?
>
>
>
You need to have at least one segment of video completed before you can
start playback.  In fact, you really want more than one just in case.  My
app currently waits for the transcoder to be on segment 4 or greater, so
that there's at least 30 seconds worth of completed content the gauge the
average transcode speed and see whether the backend is going to be able to
keep up with a real live stream.

Yes, it's basically CPU constrained, and dependent on how
conservative/complete the app decides to be in making sure the selected
transcode profile is sustainable over time.  I can set it to start playback
after a single segment is completed, but that doesn't leave a lot of room
for error-- if the first 10 seconds of the movie are all black screen, the
transcode will occur at a blistering pace-- but what happens when you're
following behind that at real speed and the transcoder gets to, say, the
shootout scene from the Matrix?  The app needs to be able to handle that
kind of thing.

The other option is to allow people to pre-transcode, and any stream which
is already transcoded would start immediately.  But the reality is, if
you're transcoding on the fly, you need to think carefully about handling
the above situations.  Having to pre-transcode would make it pretty
pedestrian.

Robert
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