Repository update
I have updated my PPA archive with the latest & greatest fixes from 0.21 & ffmpeg.
All packages are built with –enable-mmx & the i386 packages with –cpu=pentium4 for that extra little kick 
The patch for the doubled h264 interlaced recorded show length from mythtv trunk is included.
Also, I found a bug in my port from the old ffmpeg code to the new, which caused a seg-fault with the AC3 audio that started coming through on TV ONE, which is fixed as well.
And, finally, I have built the plugins from the 0.21-fixes branch with the matching revision, as this can cause random seg-faults if you have plugins not built from the core that it’s running with.
So, update and let me know how you get on.
Cheers,
PK
August 16th, 2008 at 1:04 pm
I’ve upgraded both my myth machines ( one i686 , one amd64 ) to your 18161/14773 version from apt using
apt-get update; apt-get install mythtv mythplugins
Looks good , frontend segfaults are now very rare , time seems to scale correctly , woot!
Is there any chance of a deb-src repository ??
I would still like to roll my own with your most recent src so i can add coreavc support to get around the dualcore cpu limitation in ffmpeg. The source on your download page still seems to be version 18021/14509 - a deb-src would take the load off your homeip.
For some reason mythfrontend using ffmpeg decoding will only go to 100% on 1 core , Xorg & mythbackend use about 40-50% together of the other core when playing back live or recorded tv3 - giving a stutter every 5 seconds or so.
Looking at svn.mythtv.org/trac it appears as though myth/ffmpeg cannot multithread freeviewnz’s type of encoding to 2 different cores , hence the reason i would like to recompile for coreavc support.
Coreavc was above 90% in both cores , but gives smooth playback…
Matt
August 16th, 2008 at 1:28 pm
This project sounds really interesting …
http://www.bitblit.org/gsoc/g3dvl/index.shtml
If i’m reading it correctly , it is going to offload a lot of the video decoding to the GPU using the xvmc framework - hopefully speeding up native ffmpeg h264 decoding ..
Matt
August 16th, 2008 at 3:22 pm
Matt, I have updated the NZ Freeview page http://pkendall.homeip.net/?page_id=8 with the deb-src line so you should be able to download the source from the repository.
I am also keeping an eye on that project. Hopefully he, or someone else, will continue to work on the project after GSoC is over and complete the h.264 work.
August 16th, 2008 at 7:29 pm
Hi Paul, I installed from your Ubuntu repository about a week ago. It worked fairly well, though was a little unstable, especially on TV1, which I see you have addressed in your latest update. I had to revert back to the main trunk build however because I found after installing the patches my DVD playback turned to custard - everything became unstable, and half my DVD’s (ripped or original) would not play at all. This was the same using the internal player, mplayer or xine. Now I have reverted it is fine again. Any known issues here? Would your latest build address anything along these lines?
August 16th, 2008 at 11:04 pm
worked perfectly on amd64 - patched with dshowfilter just in time to see the evers-swindell twins win gold with smooth playback
I’ll do the same for i686 shortly…
Matt
August 17th, 2008 at 1:39 pm
Matt,
which version of coreavc do you have? I have 1.7 and it gives split green images on TV1! Can you show your config line for coreavc?
August 18th, 2008 at 8:25 pm
James,
I don’t see why my updates should cause a problem with mplayer or xine for DVD playback! I am certainly looking at why I get a blank screen on some DVDs. When I get this though I just hit pgdn and all starts to work. I think it’s getting stuck on some static frame or something.
August 23rd, 2008 at 1:45 pm
For coreavc 1.7 i’m using the following config:
registercodec -r $REGISTRY -k “HKLM\\Software\\IniFileMapping\\CoreAVC\\Settings\\C:\\coreavc.ini” -v “ilevels=2 olevels=2 di=3 deblock=7 ai=0 crop1088=0 vmr_ar=0″
which was the default listed on http://code.google.com/p/coreavc-for-linux/wiki/RegisterCoreAVC , i have not experimented with any of the above values - crop1088=1 and maybe di=4 ( linear blend ) may be worth trying.
Best results seem to require both “video as timebase” and “opengl for vsync” timing enabled in mythtv. Video output is set to standard/xv-blit for size above 1200×700 with max cpu=2 , osd = chromakey , interlacing = none
The actual display resolution i’m using is 1280×1024 as a component tv out ( for my 28 inch widescreen crt ) so in effect mythtv is actually downscaling 1920×1088 to 1280×720(ish) in realtime during playback. 720p TV1 & TV2 are playing back close to their native res.
There is a small amount of video/audio sync difference which i haven’t been able to solve but it’s 50ms or less , i think i’m used to ignoring it already , native ffmpeg decoding has better sync but will not go beyond 100% cpu - ie. will not utilize multiple cores.
In terms of required cpu performance my AMD dual core 5200+ with an Nvidia 8500GT maxes to about 130% usage for dshowserver , and 40%-50% for X11 & myth while watching TV3 - all taken from ‘top -d1′ in a background xterm.
dmesg |grep ogo reports 5200 bogomips per core , i would guess that a dual core 4800 should also cope with TV3 - Intel Core Duo’s are more efficient doing this sort of video decoding work so the cpu speed requirements would most likely be even lower.
WARNING. An ATI video card is a definite no no due to the hopeless xv acceleration compared to Nvidia’s most recent x86-64 driver.
Phew , seems like a bit of an essay , but the mythbox performance info may help others …
Matt
September 8th, 2008 at 11:28 pm
Hi Paul,
You have previously mentioned using scripts to keep your ffmpeg/nz patched mythtv upto date with the 0.22 mythtv trunk?
I was wondering if you would mind sharing them. I am just curious how you are doing it. I would like to track the svn version of myth a bit more often but find it a bit tedious doing the ffmpeg stuff.
I also don’t really understand why mythtv isn’t using a more recent ffmpeg. I have looked around and have found no mention of a plan to update it. Are we always going to have to patch myth to make it work in nz or is there some plan to update it? Kinda seems like a very odd situation to me - great multimedia software with extremely outdated dependencies, so I guess I must be missing something?
September 9th, 2008 at 4:49 pm
Hi Carey.
I have an ffmpeg checkout with mythtv patches applied and a checkout of Mythtv 0.21-fixes.
I then have a script that updates both and copies over from ffmpeg to mythtv. Problem is that there is usually some manual work to resolve conflicts and add extra stuff to the mythtv libav*.pro files when new stuff is added ti ffmpeg.
September 10th, 2008 at 8:43 am
Hi Paul
Thanks for your hard work.
I have been trying to build the latest SVN version of FFMPEG with your ffmpeg-latm.patch applied. I have just discovered that the patch I downloaded from you web page doesn’t seem to be the same patch that you are using on mythtv_0.21.0+fixes18254+ffmpeg15219+latm package. The Latmaac.c file is missing from the patch and there may be other changes that I don’t know about. Can you release you latest ffmpeg-latm.patch if you have one. Thanks heaps.
Aaron