[mythtv-users] Preserving HDTV AC3 audio stream whilst transcoding

[Jesper Sörensen]

Anthony Vito wrote:

>>There's also a post on the devel list refering to some work done by other
>>people on a fast MPEG2 decoding algorithm. They were able to get 62fps
>>from a 720p stream on a 933MHz P3 with a Geforce 2 MX440. If we could
>>do something similar with the MythTV MPEG2 decoder, I suspect that a
>>lot of my problems would go away. Even using the pcHDTV people's Xine
>>tweaks (which I think use the XvMC Nvidia specific extension) would be
>>a big help.
>>    
>>
>
>As I assumed, and was confirmed on the devel list, MythTV uses ffmpeg
>for mpeg2 decoding. They sync up the code every once and while. I will
>be diving into the wonders of ffmpeg C code and attempting to
>implement what is in that paper. I hope to release patches against
>MythTV for people to "try out" as I go. First, I'm going to spin off
>an email to the guy that wrote it and see if he wants to donate ;)
>  
>

I've read the paper and it sure is very interesting. It sounds like the 
holy grail for HDTV, but I can't help but feel that it sounds a bit too 
good to be true though, and I'm sure there's a bit more to it than 
what's in the paper. If there was an easy way to increase performance by 
order of magnitudes I think the ffmpeg guys would know about it. I 
really really hope I'm wrong though! :-) Maybe you should check with the 
ffmpeg list before you dive into the code, since they are the experts on 
this kind of stuff...