Sudden and mysterious drop in encoding speed

[orbsplateau]

Sudden and mysterious drop in encoding speed

I have backed-up about 25 DVDs using recent freeware versions of Rebuilder (and CCE SP 2.67). My system usually managed an encoding speed of 0.75 to 0.78 (I know it’s not spectacular, but c’mon it’s a PIII).

During the last 3 or 4 backups however, the encoding speed has averaged between 0.58 and 0.61. It may not seem like a big difference, but that’s running at 0.78% of its original speed. Each encoding process now takes roughly 30% (or 3-5 hours) longer than before.
The CPU is still running at 100% capacity, but everything is just taking longer.

I can’t think of why this drop in performance has occurred... besides installing the latest batch of security updates for Win2k, I haven’t installed anything on my system nor have I changed any of the settings.

I recently upgraded to the Pro version of Rebuilder. I also performed a full HD defragmentation and a complete virus/spyware sweep. I also tried running Rebuilder after disabling nearly all the memory resident programs. Still... no luck. I can’t get it to go any faster than 0.62.

Any ideas why this might be? I have included my system specs below.

Your help will be very much appreciated!


System:
PIII 733Mhz, 512MB RAM running Windows 2000 SP4 + updates
2 x 7200RPM 80 GB harddrives (partitioned and defragmented to optimize performance)

Tried both DVD ReBuilder 0.93 (free) and 1.00 RC5.1(Pro)

Using CCE SP 2.67 Retail - 4 pass encoding. De-interlace with DeComb - the rest are all default options.

[DK]

did you use decomb before?
filters will slow you down

you cannot compare one title to another in terms of speed
so are you absolutely sure that your average speed really is an AVERAGE value or maybe just the speed for one particular title which you did before the last (slower) ones?

did all titles have the same aspect ratio?

[orbsplateau]

thank you for your reply.

yes, i've used decomb from nearly the very beginning since it was suggested in an article (for animatied shows).

most of the stuff I've encoded has been TV shows like Futurama, Family Guy, Arrested Development, Yes Prime Minster... etc.
The aspect ratio is usually 4:3

Not all the DVD's I used to backup achieved 0.77 - but they ranged between 0.70 at the lowest and 0.78 at the highest. The only times I'd seen a speed below 0.70 was during the first 30 seconds or so while it was getting up to speed.

I noticed the big drop in speed during the encoding of the last 4 disks

They were,
Yes Prime Minister disk 2 (~7.5 GB) 4:3 - avg speed 0.60
Yes Prime Minister disk 3 (~7.7 GB) 4:3 - avg speed 0.60
The best of Triumph (~ 7GB) 4:3 - avg speed 0.62
Not Another Teen Movie -Uncut (~ 7GB) 16:9 - avg speed 0.64

[OvERaCiD23]

Re-run a disc that was working at higher speed. If the speed it encodes at is lower now, then you might have an issue. While encoding, sort your processes in task manager by CPU usage; is CCE using 99% or is something stealing from it?

[Boulder]

yes, i've used decomb from nearly the very beginning since it was suggested in an article (for animatied shows).

Don't deinterlace when your final destination format is DVD for watching on the TV. That's a good rule of thumb for any encode.

[orbsplateau]

Don't deinterlace when your final destination format is DVD for watching on the TV. That's a good rule of thumb for any encode.

how come?
and by TV do you mean a standard TV or even a HDTV or a computer monitor.


and as OvERaCiD23 suggested...
I think i will re-encode some of my older DVDs to see if I can get it done at the same speed.

[Boulder]

how come?
and by TV do you mean a standard TV or even a HDTV or a computer monitor.

I suppose HDTV is an interlaced display as well as a regular TV, at least there's interlaced HDTV stuff in the Avisynth usage forum at times. By deinterlacing you lose quality and motion smoothness. IMO deinterlaced footage is far more jerky than the regular footage shot on film (that is, progressive by nature).

A computer monitor is a progressive display which means it'll show the combing unless you either deinterlace during encoding or during display.

[TheSeeker]

how come?
and by TV do you mean a standard TV or even a HDTV or a computer monitor.


He means for ANY display. Its a good rule of thumb to NOT deinterlace because chances are very very good that your on-board hardware deinterlacer in either your tv or your dvd player is much much better than the fielddeinterlace() that decomb uses. Actually deinterlacing could cause more artifacts then not deinterlacing. Just let your hardware do that work for you. Plus, you will see a DRAMATIC increase in the speed of your encodes when not deinterlacing.

[jdobbs]

Have you changed the iDCT setting? That can make a substantial difference in encoding speed. Take a single AVS to use as a benchmark and manually load it into CCE while trying each of the settings (0-7).

[orbsplateau]

Thank you Boulder and TheSeeker for the clarification... looks like I won't be de-interlacing for a while.

To be honest though, it hasn't increased the encoding speed by that much. So... I'm still trying to solve this puzzle.

[Carpo]

as i understand it

leave interlaced if you are going to be watching it on a norm tv screen

de-interlace if you watch your dvds on your pc or projector

[orbsplateau]

Have you changed the iDCT setting? That can make a substantial difference in encoding speed. Take a single AVS to use as a benchmark and manually load it into CCE while trying each of the settings (0-7).

I haven't changed the IDCT setting.... at least not in the last freeware version of Rebuilder, or the current Pro version.

BUT I just remembered that when I first started to use Rebuilder, I followed this advice:

Enabling MPEG2Source("Source",idct=7) changes the MPEG2Source function to use SimpleiDCT from the Xvid project. This decodes the original DVD video at higher (mathematical) accuracy than the default iDCT.

So, I'll run a few tests and report back tomorrow.

Just out of curiousity, is idct=7 the recommended choice?


thanks again for everyone's help.

[TheSeeker]

Just out of curiousity, is idct=7 the recommended choice?


thanks again for everyone's help.

On a speed to quality ratio, yes idct=7 is probably the best choice. The best choice if all your concerned about is quality would be the 64 bit floating point (the IEEE 64 bit has a bug in it if Im not mistaken). But the 64 bit options are much slower. So yes, go with IDCT=7. Im really surprised that disabling deinterlacing with Decomb didnt speed up the encode more.

[Boulder]

Deinterlacing isn't probably done with any content flagged as progressive as that would be useless.

[jdobbs]

So, I'll run a few tests and report back tomorrow.

Just out of curiousity, is idct=7 the recommended choice?Usually yes, but it depends on your processor.

[pg55555]

@orbsplateau
"Using CCE SP 2.67 Retail - 4 pass encoding"

Not directly related to your problem, but I would recomend 2 pass (or maybe 3 pass for very low bitrates). As discussed a lot in this forum, there is very little quality gain after the first encoding pass and practically none after the second one.
Reducing your number of encodings will no increase speed but it will reduce encoding time.

If you have two hard disks, it also help if your source and working/destination directories are in different phisical disks (not just partitions) (Thinking of this, have you changed your RB setup so that the source and working directories are now in the same disk?

[orbsplateau]

well, I tried everything I could think of but NOPE. I'm still not able to get the speed anywhere above 0.65-0.66

I even backed up one of my original DVDs again, and it's clearly slower than when I first performed the backup a month ago.

It's almost as if my CPU or HDD are running slower than they used to.

here's what I've tried:
idct=7
de-interlace with decomb is disabled
source material is on one hard drive and the working directory is on another hard drive. Both have been defragmented.
I've optimized my system's swap file
i've disabled all memory resident programs (including the antivirus program).


I've even tried talking to my computer... you know coaching it and motivating it to go a bit faster, but nothing.

once again... all this happened around the time I installed the latest batch of security updates on Windows 2000.

I'm really stomped... if I can't figure out what's going on by next week, I think i'll just re-install windows.

[Boulder]

Have you tried installing the latest Avisynth alpha/beta/whatever, see the Avisynth development forum.

[jptheripper]

make sure none of your drives slipped into pio mode, that will kill speed

oh as for latest anisynth, thats not recommended. Stay with the recommended, stable version

[Boulder]

The latest Avisynth build is actually stable..or if it's not, please tell me in which way?

orbsplateau: have you noticed any other slowdowns in your system?

[orbsplateau]

Thank you for your ideas.

The DMA/PIO setting was one of the first things I checked (since it happened once before when my DVD player crawled to a halt).

Both hard drives drives are set to UDMA-5.


As for AviSynth, I think I'll re-install the current recommended version... I've already re-installed ReBuilder and CCE.


I wish I had run a Sisoft performance checkup so now I could compare my current results and see why/where my system performance has suffered.
As is, I haven't really noticed slow-downs anywhere else, but encoding is really the only thing that really pushes my computer's CPU.

[TheSeeker]

I'm really stomped... if I can't figure out what's going on by next week, I think i'll just re-install windows.

If you have noticed a drop in overall system speed I would do this (reinstall system). Maybe give Windows xp a try. Unless there is a reason you are using 2000 pro. Win XP is IMO vastly superior to 2000.

[Boulder]

Which reminded me..have you searched newsgroups for messages connecting any slowdowns and W2K's updates?

[jptheripper]

as for dma pio, if have been told if you have a umda5 and a pio device on the same chain, they are both at pio speed, regardless

[Boulder]

as for dma pio, if have been told if you have a umda5 and a pio device on the same chain, they are both at pio speed, regardless
Used to be like that a long time ago..with some old i430xx chipsets IIRC. Nowadays devices are independent when it comes to transfer modes.

[jdobbs]

The latest Avisynth build is actually stable..or if it's not, please tell me in which way?

orbsplateau: have you noticed any other slowdowns in your system?I've had at least two bugs reported in the last month that were corrected by going back to AVISYNTH v2.5.5 -- in one of them a frame in "American Wedding" was being inserted out of place (about 15 frames later in the middle of some non-related footage). I can't recommend upgrading to v2.5.6 yet.

[Boulder]

I've had at least two bugs reported in the last month that were corrected by going back to AVISYNTH v2.5.5 -- in one of them a frame in "American Wedding" was being inserted out of place (about 15 frames later in the middle of some non-related footage). I can't recommend upgrading to v2.5.6 yet.
Have you reported this to the devteam? It might be useful for them to know any possible glitches. The official thread doesn't seem to have any other things but some minor issues regarding error prompts.

Being a common movie, they might be able to replicate it and investigate it further.

[jptheripper]

Used to be like that a long time ago..with some old i430xx chipsets IIRC. Nowadays devices are independent when it comes to transfer modes.

good to now, course i have no idea what chipset im on

[Boulder]

good to now, course i have no idea what chipset im on
Unless you got an old Pentium (or similar), you need not worry :D

[orbsplateau]

Which reminded me..have you searched newsgroups for messages connecting any slowdowns and W2K's updates?

hmm... I think you might be unto something Boulder.

I've always kept my system updated and I've never given a second though to installing MS security patches, but appearently, some updates can slowdown computers and even reduce network speeds.

I haven't found any specific complaints in newsgroups but i really don't know how else to explain it.
chances are that many users might not even notice a 20% drop in system performance.

[Boulder]

hmm... I think you might be unto something Boulder.

I've always kept my system updated and I've never given a second though to installing MS security patches, but appearently, some updates can slowdown computers and even reduce network speeds.

I haven't found any specific complaints in newsgroups but i really don't know how else to explain it.
chances are that many users might not even notice a 20% drop in system performance.
There was one critical (I think) patch for WinXP which caused HD performance to degrade before it was fixed in a later service pack so I wouldn't be surprised at all if a patch would cause such things, especially when not many people use W2K so it might just go unnoticed here.

[jdobbs]

Have you reported this to the devteam? It might be useful for them to know any possible glitches. The official thread doesn't seem to have any other things but some minor issues regarding error prompts.

Being a common movie, they might be able to replicate it and investigate it further.The problem is that I wasn't personally able to repeat it. But it was reported to have been fixed by switching back to v2.5.5.