[mythtv] [PATCH] Mac OS X video implementation

Jason W jason at backtick.org
Sun Oct 10 10:22:21 UTC 2004

Hi there,

First time poster to this list. Been using MythTV on Linux (split back
end and front end) for quite a few months now as my exclusive DVB
viewing setup and I have recently purchased a PowerBook 15" 1.5 GHz and
just got around to trying MythTV on it. I am using the GPL Qt for Mac
compiled with threading support on OS X 10.3.

Jeremiah Morris wrote:
> For those of you following my QuickTime video patches for Mac OS X, I 
> think I have enough bugs squashed and features cleaned up to propose 
> this for CVS.
> Features include:
> - Use of QuickTime drawing for performance and quality improvements over 
> the existing code
> - Video is properly scaled, based on aspect ratio, size of monitor, 
> overscan and zoom settings, etc.

Both these seem to be working good here on my PowerBook (1280x854)
watching DVB-T content (720x576i @ 50 Hz) over 802.11g. Quickly tested
it on 100 Mbps wired LAN with same results as far as I can see. The
video stutters a bit sometimes, audio seems to stay in sync.

Picture quality looks very good. I have only tested on 16:9
(letterboxing on my 1:1.50 display). I quickly hit the W key to see that
it changed modes and it changed OK, but I didn't check to see if the
aspect ratio and zoom amounts were correct.

I did notice however that de-interlacing isn't working (as mentioned by
others). I have the kernel deint filter selected if at all relevant.
Installed using "make install" and running with "open
/usr/local/bin/mythfrontend.app". If anyone has any idea on why this
might not be working I'll take a poke around and see if I can see
anything. I'm new to MythTV dev and OS X dev so I have no idea where to

> - Ability to show video in floating window, in the dock, on the desktop, 
> or in all these places at once
> - New settings in the database and TV Playback configuration to control 
> the various video options (look at the last two "Playback" setup screens)

Haven't tested any of these two yet.

> One patch note: my testing found the "realtime priority" setting for the 
> video thread to actually decrease performance, so I added an #ifdef 
> disabling this on Mac.  The other changes should be fairly self-evident.

I applied your patch against CVS HEAD with no other patches. In order to
link libmythtv I had to add -framework QuickTime -framework Carbon to
the end of the LIBS line after -lqt-mt (line 22 here).

Is there some other patch that I should be running as well or is this
the only patch which should be required? The OSD background bug
mentioned previously which had been attributed to endian issues seems to
be present here.

With regards to performance, has anyone attempted to apply any PPC
optimizations to the MPEG-2 decoding? I am running just ./configure with
no options at the moment.

In conclusion, this patch seems to be doing great things over here. It
is much appreciated and I hope this feedback helps even if just a little.


Jason Weathered

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