Jumpy frames when using software DVD player

Is your dvd drive using pio or dma ?

Try Reclock.

Yes others will jump all over this, but it could also be caused by IRQ interupts. PCs are multi purpose machines where stand alone DVD players are single purpose. I set up all of my HTPCs as Standard PC when I install the OS, this gives me more control on the IRQ assignments.

If you are viewing the movie over a network, it might be the server. I was having random pauses, doubling the memory on the server cleared that up.

I use Zoom Player with ffdshow and reclock on a 2.4 GHz P4 (over cloced to 2.6). I can't use a lot of the options but no more studdering.

Your problem is the LG rom drive, it simply is not capable of pumping data out fast enough. I had stuttering playback and had the luxury of comparing with other highend systems until I determined it was my LG rom drive. The fastest drive I could find locally was an ASUS with ultra DMA interface.
Use Nero tools to check the data rate of the drive before you change it so you can compare. when I checked my asus drive it only reached 8x but is spec'd for 16x
I'm only running a Celeron 2.9GHz on a cheap Machspeed motherboard but with the ASUS drive and 1GB of DDR400 ram I get smooth playback with FFDShow processing.
Amazingly I never found any discussion regarding the DVD rom drive which I think is a key part of an HTPC.

DVD by it's very nature is only one X.

Years ago we were all using 4x or less with standard DVDs without problems. I personally use a Sony DVD-RW with this speed - nice and quiet (no lawn mower sounds).

The standard DVD specification is as follows...

The drive motor is precisely controlled to rotate between 200 and 500 rpm, depending on which track is being read.

http://electronics.howstuffworks.com/dvd6.htm

This site states that the rotational speed of 4600 rpm (8X)

http://hypertextbook.com/facts/2003/...Montilus.shtml

Computer DVD x factor is not for watching standard DVDs, it is for other computer purposes.

If you are having studdering, I would look elsewhere before blaming it on the DVD (unless of course it is defective).

HDD is naturally not the same as standard DVD. YYMV.

Interesting comments on the DVD rom drives. The last system I tested was new Dell system with a Dual core CPU, 2gb of ram and the DVD rom had an SATA interface. When I tested using my reference DVD, it displayed the exact same stutter at the same scenes. The issue can be reproduced with any DVD that has scenes where a large amount of data is moving horizontally across the screen. In my case I could not get smooth playback until I installed a faster DVD rom drive.

Just for grins, try playing the DVD with the task manager window open to the processes or performance tabs active. In the processes tab, you might have to click on the CPU header to see what processes are grabbing the most cpu time. Obviously in the performance tab, if you hit 100% CPU usage, you will get a big stutter there as well.

As a last cause, some stuttering can be cause by layer changes on the DVD. In that case perhaps a faster DVD drive, or a DVD with more buffer space would over come. One thing to try, but it sounds that you might have already tried, is ripping the DVD to the Hard Drive. This would eliminate the layer changes.

As I stated previously, I use Reclock with ffdshow, using Zoom player and the Descaler Codecs on a 2.4 GHz P4. Not quite enough cpu for 3x resize for my 1080p TV, so I have to settle for 2x.

I would look into four things:
1. Disk activity - are you indexing, google desktop search or windows?
2. Graphics card - try a different card
3. Graphics card - upgrade the drivers
4. Defrag your swap space


Bill