SMP and DVD2SVCD

[sehh]

After a long and extensive test of DVD2SVCD on my SMP hardware, i've
come up with a short list of tips that might be useful to other SMP people.

Here we go:

1) Due to limitations in the video encoding procedure (Avisynth and CCE),
it is impossible to use SMP to its full potential. As a result while
the video encoding is taking place, cpu usage will only go up to 50-60%.

2) Some of the utilities used by DVD2SVCD do support SMP properly, but
since the video encoding is the most important and most time consuming,
it means that in general your SMP hardware is not used properly and
most of the time its going to waste (if you are not using the computer
at the same time with the encoding procedure).

3) Under WinXP for example, it is easy to see the cpu usage of Anysynch
and CCE during the video encoding procedure in the Task Manager, under
the Processes tab.

4) It is important to note, that most of the utilities used in
the whole DVD2SVCD process do not use 100% cpu usage on SMP
hardware, and some times they are limited by the slow storage
device (slow IDE drives). For example:
- DVD2AVI uses ~19% cpu usage on my system
- the subtitle extraction uses ~30% cpu usage.
- BeSweet is not SMP friendly and uses 50% (one cpu only).

This leaves us with loads of free cpu cycles.

5) Now if you have multiple harddrives on SCSI, or a RAID system
(i wouldn't suggest this on IDE), you can actualy encode TWO
movies at the same time without any problems.

How to encode two movies at the same time:

1) Load DVD2SVCD, insert the first DVD disk, and change any
settings on DVD2SVCD. Select 'Eject DVD' from the 'DVD Rip' tab.
Start the ripping.

2) Once the DVD is ejected from the DVD, insert another DVD and
load another DVD2SVCD. Under the 'Misc' tab, click on the
'Default Output Folder' button and click on 'Set default output
folder'. Select a folder on a different harddrive if possible.
Start the ripping.

3) In case you have TWO DVD drives then you may start both
procedures at the same time, without having to change disks.

Now what happens is that both movies will be converted at around
the same time they would have been converted in single conversion,
plus around 30 min of time of overhead.

For example, i encode:

DVD 1: City Of Angels (114 min)
DVD 2: American Beauty (121 min)

DVD 1 takes ~4.5 hours to encode.
DVD 1 and DVD 2 take ~5 hours to encode.


My hardware:
Asus A7M266-D Dual Athlon
2x Athlon MP (1.2ghz, oc'ed to 1.4)
768 mb ram (Crucial DDR PC2100 REGISTERED)
Adaptec 29160 64bit PCI Ultra160 SCSI
2x IBM Ultrastar Ultra160+ LVD SCSI (18g, 10000rpm each)
Pioneer DVD-305S 10x DVD SCSI

[chips144]

Just a few comments about your post. A few weeks ao, I tried exactly what you describe. Running 2 separate dvd2svcd projects simultaneously. Of course, I started by choosing different default ouptut folders for the two projects and completed the rip of the first dvd before starting the second dvd. I actually took both to completion (burned the cd's). I also found that the total time was approximately equal to the time normally used for just one dvd with about 1 hour extra added for overhead. My results were, however, slightly less than optimal. When I played the first movie, the video was correct, but the audio was from the second dvd. Actually it was quite funny. I didn't bother to try to figure out what went wrong. I just tossed the coasters and processed each dvd independently.
After reading your post, I think you hit the nail-on-the-head. I am using a Sony Vaio, P4 1.7GHz running Windows XP and the latest version of dvd2svcd. My problem probably, as you pointed out, was the fact that both outputs were being written to the SAME IDE hard drive. You stated that if possible they should be done to different hard drives and also you would not recommend doing this on IDE drives. In your opinion, why do you think this is the case? It would certainly be something to remember the next time I go for a computer upgrade.

[sehh]

I can only guess what the problem is in your case. Although i do have
a few guesses. I've come up with a bug in dvd2svcd, were the output
of sound and/or video is temporarily stored in the same place over
and over again.

You may also experience what you've seen, by processing two movies
one right after the other. This is a rare bug.

For example, i've had my second movie start with a part of the video
from the first movie.

Ofcourse this has nothing to do with SMP i think, its just a problem
in the temporary storage.

At the end of the day, my testing and research has shown that on todays
fast computers it is more productive to run TWO dvd2svcd processes at
the same time, because most parts of the processing do not use the full
potential of poweful computers.

[GreenDrazi]

sehh,
Although I agree in principal that a dualie (SMP) will not get you twice the power (or speed), your further conclusion about two encodes at once and cpu usage would tend to make me think otherwise. But your position needs a little more facts about the encodes and what filters were used to be of any real use to anyone but yourself.
I’m encoding on a Athlon 2100+ (single cpu) setup with 512megs of DDR333 memory and get nearly 90% to 95% cpu usage (WinXP) on a typical encode of mine. Right now, I’m encoding some animation using IVTC, bicubic resize, sharpen, temporal smoother, and anti-noise filter. So, trying a second simultaneous encode is just out of the question and I’m doubtful that a dualie would help out these filters.
Can you try a test with two identical encodes - one encode with only one cpu and antoher with both cpu’s (same board, please!).
Let us know what filters you are using and at what bitrates.

[sehh]

First of all, please remember that IDE takes a huge chunk of cpu
usage. Thus my U160 system will use 0% cpu usage for all disk
processing (including the dvd ripping from the scsi dvd drive).

Indeed you are right about the settings, they make a difference.

Here are the most important ones that i use:
- DVD rip with Internal routines
- iDCT algorithm set to 32bit SSE MMX
- No audio downsample (48->44)
- Audio Output mode Stereo
- Use mpeg2dec2.dll instead of mpeg2dec.dll
- Sharpen and TemporalSmoother to default
- Bitrate (800min CDs) max 2530, avg 2230
- Encoder CCE 2.50, Multipass VBR, 4 passes
- Q.Factor 30 (for use in RoBa Multipass VBR)
- Rip subtitles Permanent

Thats it, i hope i haven't forgotten anything.

Now about the test of single vs. smp, running the procedure in SMP
mode gave me about 30% faster processing. It is not much, because
as i've already mentioned most of the utilities used in DVD2SVCD are
not SMP aware, or they are single threaded. Thus they only use
on cpu. That is why i suggested to process two movies at the same time,
so as to use the full potential of an SMP machine.

GreenDrazi, i hope i've answered your question. Let me know if you'd
like me to do some specific test, or if you'd like me to explain
something else.