[mythtv-users] HDTV on Myth -- is it a "myth?"

[James Armstrong]

>>Have you read the recent ALSA discussions on the
>>-dev list?
>>    
>>
>
>Yes. I downleveled ALSA to 1.0.5 with no change in
>symptoms.  I'm outputting AC3 via optical out.  Oddly
>enough, if I "hide" my sound output device I can get
>Xv to play the 720p stream at full speed with no
>sound.  XvMC still runs at half-speed, however, even
>with no sound.
>
>  
>
I have sound playback issues with hdtv content also. Audio stutters or 
sounds like it is underwater. Mainly with abc. Mplayer plays the same 
file with no problems at all so alsa is working, mythtv just has a 
problem with keeping up with sending audio out to alsa. I even have a 
problem playing some recordings I made using 720x480, 2200 bitrate. 
Audio is constantly stuttering.

>>XvMC is a PITA because of the way it barely fits
>>into the Myth video 
>>output architecture.
>>    
>>
>
>I have not found any development docs which hint at
>this architecture. I'm not afraid of C++, but it makes
>it a little difficult to contribute to the project
>when the only documentation I can find is the source
>code.  I just lack the time to invest to figure out
>the architecture on my own.
>
>  
>
>> You can't apply filters; you
>>have to deal with the 
>>fact that there are fewer in-flight video buffers
>>(frames); seeking is 
>>more difficult because the decoder has to have all
>>the reference frames 
>>for non-I frames, etc.  Software decoder is just
>>more flexible.
>>    
>>
>
>I think my needs are very simple.  I have an output
>device that is locked to 1080i.  I want to play 1080i
>streams unmodified to the output device.  720p streams
>will have to be rescaled to 1080i on playback, and so
>will 480i or 480p.  I just want to view recorded TV
>programs and DVDs.  If the video processing does the
>"right thing" there should be no need for filtering,
>right?
>
>I have noticed that my "myth" question has not
>received a flood of messages like "I'm using it and it
>works great."  Jarod and I are running Athlon systems
>with mucho trouble, and I've had responses from three
>Pentium users (yourself included).  Of the P4 users,
>two are working fine and one is not.  I guess just not
>many people are using Myth with HDTV monitors yet. 
>>From the breathless MythTV promotion by EFF
>(http://www.eff.org/broadcastflag) I would have
>thought HDTV were a lot more debugged.
>
>
>  
>
I also have a wierd problem, fast forward works on hdtv content until I 
get a blast of noise then I can only ff 1 second at a time but the 
timeline jumps 10 seconds. I have not been able to finish watching the 
last three recordings of Joan of Arcadia because about 30 minutes into 
the playback, it starts playing from the beginning, I can never seem to 
get to the end of the show. I am in the process of transcoding one of 
the shows to see is I can watch the transcoded file. Besides that, 1080i 
looks great.

- James