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CD Speed with video CDs

PostPosted: Wed Jan 22, 2003 5:50 pm
by MediumRare
I've tried to do a transfer rate test or quality check with CD speed on a video CD and have had no luck: the disk does not spin up during transfer test and the q-check does not start. Also CD-Speed does not react to the Stop-command. About the only way to break this off is to press the eject button.

I have a Liteon LTR 48246S and am running Windows-XP, SP1.

Has anyone seen this behaviour ? Thanks.

G

PostPosted: Wed Jan 22, 2003 10:07 pm
by cfitz
I tried it using an SVCD on my Memorex 48MAXX (rebadged LiteOn 48246S), and saw the same behavior. My LiteOn 166S DVD-ROM drive behaved essentially the same way, although it did at least spin-up at the start of the transfer rate test before stalling.

On my Yamaha CRW3200EZ, however, the tests do run.

As an alternative for burn quality testing, try CD Doctor ( http://www.cdrlabs.com/phpBB/viewtopic. ... 5549#45549 ). It works with LiteOn drives and did run correctly on the 48246S even with an SVCD inserted. Strangely, the green read-activity LED did not flash during the test, and the maximum extraction speed was limited to about 32-36x.

Apparently the drive is programmed to avoid noisy high-speed spinning while video is playing. Interesting, and how polite! I knew that the DVD-ROM drive did this for DVDs, but didn't know the CD-RW drive did the same for VCD/SVCDs.

cfitz

PostPosted: Thu Jan 23, 2003 8:09 am
by MediumRare
cfitz- thanks for your experience. I know about CD Doctor. I spent at least 2 days after Christmas going through my junk box doing post mortems and have been using it routinely since.
Strangely, the green read-activity LED did not flash during the test, and the maximum extraction speed was limited to about 32-36x.

I had noticed the slow transfer rate with the VCDs but didn't quantify it like you did. I tend to use only one type of medium for the VCDs and thought that might be the issue. I'll try my DVD (LTD-163) and have a look at the blinkin' lites when I get home tonight.
Edit:
The LTD 163 behaves the same as your 166S, cfitz. The LED on the 48246S lights up only during the spinup phase of CD Doctor. The Doctor does not like the DVD- dies with memory error.
Apparently the drive is programmed to avoid noisy high-speed spinning while video is playing. Interesting, and how polite!

Sometimes its better to be impolite. :D

What appeals to me with the CD-Speed quality scan is the simultaneous presentation of the transfer rate and the error count. Prior to your work on making CD Doctor useable to non-oriental(ist)s (thanks!!), I usually used the surface scan option.

G

PostPosted: Fri Apr 04, 2003 5:50 pm
by MediumRare
I looked at these idiosyncracies with the latest CD-Speed version 1.02e (see New CDSpeed version, 1.02e) and there were some changes from 1.02:
- CD quality test now works with video CDs and SVCDs (previously no reaction)
- Transfer Rate test now works for video CDs
- Transfer Rate test for SVCDs: disk spins up (10 seconds) and stops with following error
Code: Select all
ILLEGAL MODE FOR THIS TRACK (056400)

(previously: hang in spinup phase, have to press eject button)

So it looks like the fixes Erik Deppe made in the mean time are not limited to issues with Nvidia motherboards.

Many thanks to Erik for the fixes! :D

G

PostPosted: Fri Jun 20, 2003 5:24 pm
by Inertia
The lower reading speed when (S)VCD discs are inserted is normal for readers, and is by design.

This is because (S)VCD discs being ISO 9660 CD-ROM/XA Mode 2 Form 2 have no supplementary error correction and use 2,324 bytes of the 2,352 bytes in the sector for content. These types of discs are not considered error critical because they do not contain data, but streaming graphics and music.

In contrast ISO 9660 CD-ROM Mode 1 has 2,048 bytes of user data and 276 bytes of ECC (Error Correction Code) containing redundant error correction information.

Mode 1 discs have the ability to correct errors with the supplementary error correction and are designed to be read at full speed. The slower reading speed of Mode 2 Form 2 (S)VCD discs is a measure used to improve reading accuracy since if errors occur, there is no second chance of correction.

PostPosted: Sat Jun 21, 2003 9:24 am
by MediumRare
Thanks for the comment, Inertia. I figured as much. I guess we have to accept this, especially since this is Mode 2 data designed to be read at > 1x speed, in distinction to audio- which is the other common Mode 2 data.

It's funny, though, that even scanning tools are limited to the lower speed and can check audio discs at a full gallop. It was a surprise to me because nobody had mentioned it and even now, it's not well known. I'm still curious how many other drives are limited- I haven't seen any other results. (I've started a thread in the CD-RW forum about this).

G

PostPosted: Sun Jun 22, 2003 8:41 pm
by Inertia
You're welcome, MediumRare. :)

CD audio is not Mode 2, but CD-DA format (Red Book). Mode 1 and Mode 2 are part of the CD-ROM ISO 9660 specification (Yellow Book).

See The Sector Formats of Compact Discs for an overview of the various audio and data formats.

PostPosted: Tue Jun 24, 2003 4:32 am
by MediumRare
Inertia wrote:CD audio is not Mode 2, but CD-DA format (Red Book). Mode 1 and Mode 2 are part of the CD-ROM ISO 9660 specification (Yellow Book).

:oops: Of course. That makes it even harder to read at high speeds, though.

Thank you for the reference too- that's one thing I appreciate about your contributions: you not only share your knowledge but also point us at a source for more.

G