[mythtv-users] Performance of the HD MPEG2 decoders
Todd Ignasiak
ignasiak at gmail.com
Thu Nov 17 18:43:52 EST 2005
I have seen several reports of performance expectations with the
various MPEG decoders, and what I am seeing is not exactly what other
people have seen, so I wanted to start a discussion here. Also, I
thought others might be interested in the performance numbers from a
typical system (if anyone has performance info from other CPUs, or
Unichrome XvMC, please post)..
The main unexpected issues I see are:
- libMPEG2 uses much more CPU than the Standard decoder on my system.
(libmpeg2:80%, Standard: 50%, XvMC: 28%). The 'help' info in the
GUI, and several posts here, say that libMPEG2 should be have lower
CPU requirements. Perhaps this is an x86-64 issue.
- In XvMC mode, playback is great until anything comes up on the OSD.
When that happens, the audio/video becomes choppy until a couple
seconds after the OSD goes away.
- With XvMC and OpenGL-Sync enabled together, the audio/video is
choppy all the time, I never get smooth playback
Performance Info:
System: Athlon64 3200+, ASUS K8V Deluxe Motherboard, NVidia FX5200
Graphics card (AGP 8X), Receiver Cards: HD3000, FusionHDTV3, PVR-500.
Software: Gentoo x86-64 OS, kernel 2.6.14, NVidia Drivers 7676,
MythTV SVN 7737.
HD Content being used: 720P recording of yesterday's episode of Lost,
on ABC (I'll try some performance tests with 1080i content next).
- Standard MPEG Decoder, OpenGL Sync ON, Real-Time priority ON,
De-Interlacing OFF (I'm testing with 720P, but I turned it off anyway,
to avoid any potential problems).
CPU usage: user: 51%, sys: 5%, idle: 44%
Video Quality: good, Audio Quality: good. OSD effect on playback: None
- libMPEG2 Decoder, OpenGL Sync ON, Real-Time priority ON, Deint: Off
CPU Usage: u: 72-80%, sys: 4-5%, idle: 19-25%
Video: good, Audio: good, OSD effect: none
- Standard XvMC Decoder, OpenGL Sync Off, Real-Time ON, Deint OFF
CPU: u: 28%, sys: 3-4%, idle: 65%
Video: Good, Audio: Good, OSD effect: Audio & Video stutter while
OSD is up and for a few seconds after it goes off screen.
- Standard XvMC Decoder, OpenGL Sync ON, Real-Time ON, Deint OFF
CPU: u:20% sys:2% idle: 78%
Video: choppy, Audio: choppy, OSD effect: none - it's already choppy.
More information about the mythtv-users
mailing list