Playing VCDs bad for DVD players?

[hankys]

Hello,
I was wondering if playing VCDs is bad for (or slowly deteriorates) DVD players?
Thank you.

[adam]

I think any damage playing vcds does to your dvd player is negligable. Theoretically anytime you play anything on your dvd player it causes deterioration but I don't really think that vcds would be anymore damaging than dvds. They spin slower and dont require nearly as much processing power from the player.

[MPereira]

hankys:

I have the DVP-S560D too and, to last time it worked I noticed the "effort" to recognize burned VCDs (CDR or CDRW).

Now the player is dead, but I don't think media is guilty. Seems to me that this model, and other recent models from Sony, have a serious project problem. Take a look in this forum:

http://www.audioreview.com/reviews/DVD/product_47678.shtml

Good luck!

[ktnwin]

adam,

I have a question about your statement "DVD player spins slower for VCD". Is this really true ?

Let say for a DVD disc, it spins at 1X (at ID) to 2X (at OD), BTW, these are the numbers I made up, please correct me.

What are the numbers for VCD disc?

Also, for XVCD and SVCD, the DVD player must spin faster than a VCD due to higher bitrate.

I have create an XVCD at about 4000pbs and my DVD spins like crazy trying read at the XVCD disc at that bitrate (more than 3X the VCD bitrate). I can really hear the motor stressing so I TURNED OFF THE DVD PLAYER AS QUICK AS I CAN before the motor get burned.

[hankys]

Hi guys, thanks for the info! Unfortunately, looks like I might have purchased a lemon DVD player unfortunately....next time I'll check out audioreview.com!

[adam]

I know that vcds are read by a dvd player at 1X, svcds are read at 2X, and I believe the max speed that current loaders read at is 16X although anything above 10X or so doesnt really affect playback it just decreases seek time.

I don't know how the read speed correlates to the speed at which the disk spins but I can only assume that the faster its being read the faster it must be spinning. I know that dvds spin at between 200 and 500 RPM depending on the track that is being read. I assume that svcds spin significantly slower and vcds even more so but I have no idea what the numbers would be.

The speed at which a disk spins during playback is constantly being adjusted because the outside of the disk is actually spinning faster than the inside but as I understand it, the dvd player attempts to maintain a constant speed according to the information it has regarding the specific track it is playing. Any overflows or underflows are handled by its buffer.

[kinneera]

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On 2001-09-27 12:49:40, adam wrote:
I don't know how the read speed correlates to the speed at which the disk spins but I can only assume that the faster its being read the faster it must be spinning. I know that dvds spin at between 200 and 500 RPM depending on the track that is being read. I assume that svcds spin significantly slower and vcds even more so but I have no idea what the numbers would be.
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Both CDs and DVDs store data as series of data pits (or holes in a dye layer). DVDs use a form of bluelight laser that has a higher frequency and thus can read a higher density of data than CDs - this is where most of the extra storage space comes from. The spin speed is the SAME regardless of the media, the correlation to data rate is merely a result of how much data can be read from a sector per unit of time. Since the data on a DVD is so much denser, a much greater amount of data can be read from one sector on one pass of the read laser, thus at 1x spin speed, ~8-10x as much data can be read from a DVD.

Different tracks are read at different speeds because of the implementation of CAV (constant angular velocity), which is to say that the drive alters the spin speed such that the outer tracks move at approximately the same speed as the inner tracks, thus maintaining a stable data rate. This is where read speed ranges (i.e. 14x-32x, etc.) come from.

VCDs are designed to have a data rate that creates packets that correspond to sectors on the media, thus a standard VCD requires only a 1x spin speed. SVCDs are about double that value, requiring a 2x spin speed. Because the data is less dense, high bitrates on CD media require much higher spin speeds (a DVD bitrate would require something around an 8x spin speed on CD), which may add extra wear to your drive. Others (read, most) DVD players will just choke because the drive can't pull the data fast enough to properly maintain the MPEG stream, and cause broken-up stuttering video. This WON'T hurt your drive, but you won't want to watch it, obviously.

[ktnwin]

Hi kinnera,

thanks for the clarification. You have answered my question very clearly.

However, I believe there is a confusion in your statement below:
"Different tracks are read at different speeds because of the implementation of CAV (constant angular velocity), which is to say that the drive alters the spin speed such that the outer tracks move at approximately the same speed as the inner tracks, thus maintaining a stable data rate. This is where read speed ranges (i.e. 14x-32x, etc.) come from. "

To my knowledge:
CAV = constant angular velocity, the RPM is constant, data rate change from low at ID to high at OD. This is how hard disc works. CD-ROM and DVD-ROM also work like this when you read data from it (as opposed to playing music or video).

CLV = constant linear velocity, data rate is constant and RPM change from high at ID to low at OD. This is the mode DVD player use to play DVD as well as VCD,SVCD,XVCD

You must have meant CLV instead of CAV in your statement.

[kinneera]

Sorry, I always get that backwards.

[hankys]

Great, thanks guys!