[mythtv] less CPU-intensive MPEG-2 decoding in CVS

[James Armstrong]

Doug Larrick wrote:

> Jeremiah Morris wrote:
>
>> Just a quick announcement about a recently added feature:
>>
>> The latest CVS now includes a version of libmpeg2
>> (http://libmpeg2.sourceforge.net) as an alternative to the FFMpeg-based
>> video decoding. FFMpeg still handles the demuxing, but the video can be
>> handed to libmpeg2 instead. This takes significantly less CPU on my test
>> machines, so it's good for lower-end systems; my 450MHz Cube can finally
>> handle SDTV.
>
>
> On my P4 3Ghz, libmpeg2 and libavcodec seem to take about the same
> amount of CPU time, with libavcodec a tiny bit *faster*.  Both are
> compiled with -march=pentium4 .  I tested a 1080i clip and a 480i clip
> (both from ATSC sources).  XvMC is definitely disabled, and mythfrontend
> prints out the message that it's using libmpeg2.
>
> Am I doing something wrong, or is this expected?
>
>  
>
I saw the same thing when I tested. Same tests I was getting about 64% 
Idle with libavcodec and %63 Idle with ffmpeg.

- James