[mythtv-users] Transcoding and deinterlacing, and other transcode issues

[Brad Templeton]

On Thu, Jun 15, 2006 at 10:14:47AM +0200, Niels Dybdahl wrote:
> But 1080i contains two fields which are from different points in time, so
> you have either (1080i) 50 pictures/second of 1920x540 pixels (0.99 Mpx) or
> 50 pictures/second of 1280x720 pixels (0.88 Mpx). So you only save 10%. On
> the other hand moving images (where each 1080i field is different) will be
> sampled up from 540 lines to 720 lines and that probably compresses better
> than a real 720 line image.

With movies or other items shot on film, the real frame rate is 24fps.
But at any rate, transcoding 1080i to 1280x1080i would certainly save
some space at no lost of viewed information.   My own experiments going
to 1280x540p and 1280x720p have shown good reduction, but there it's
subjective.   1280x1080i clearly is discarding only information that would have
been discarded at the last instant on viewing.

When I watch 1080i it's shown bob and weave, and then xv reduces it to 1280x720p to
go to my screen.
> 
> >       d) "Streaming" quality transcodes of SDTV that fit within
> >> >            your upstream bandwidth (384K or 512K for example.)
> >
> >And I should note that long term, a cool tool would be one to
> >act like the slingbox and do this in real time.
> 
> 
> Isnt this what MythStreamTV is capable of?

The docs describe it as streaming to WMP.  I have not tried it with linux
streamers yet to see if it does that.