Question:
Why do DVD players still have pauses when there is a layer change?
My first DVD player was a cheap player from comet, about £160 at the time in the summer of 2000. The performance was good but it was very basic, couldn't do anything with DTS wouldn't play cd-rs ect but had NO layer change and I mean none. When I first started watching DVD's I didn't even know there were supposed to be pauses when the layer changed.
Since then now having more DVD olayers in the house and watched films round others houses they all had layer change. I just got a Pioneer 360 which is amazing but still you can notice the layer change, this is the same for Toshiba and Sony players I have seen. More expensive players may get rid of this but why do any players have them when one of the first ever budget players which is servely outdated now has no visible layer change?
I even reconnected it recently to check I wasn't remebering things with tinted glasses but there was definetely no visible layer change.
I think to stop the layer change the player needs to "read ahead"
Like the cd walkmans that you can shake and they dont skip because the player has a buffer storing 7 or so seconds ahead. I may be wrong but i was thinking this years ago when dvd players 1st came out and the layer change came to light. Always though it would become a thing of the past when new players came along but ive not read this is happening. Its all down to money i supose.
im sure PC DVD players dont suffer from this as they do buffer what they are reading..
I could be barking up the wrong tree though :confused:
My Laser disc player still has a 9 second head spin to read the other side of the disc so i can handle 0.9 sec layer change :)
Originally posted by Spooksta
im sure PC DVD players dont suffer from this as they do buffer what they are reading.. Yep that's true.
I agree I thought this would be sorted out by now, especially like I said my first budget player which as I pointed was not exactly great when it came to features and reading discs had no layer change. If it could be done back then then I don't see wghy we still have this problem?
Say you're watching a Superbit DVD, with DTS chosen for audio. You're looking at ~9mbps - just over 1 megabyte per second. Of course, most DVDs are well below this level of data.
Is it really so hard or expensive for manufacturers to add 2MB of RAM to their players, and then disconnect the reader from the decoder (ie, reader->RAM->decoder instead of reader->decoder)?
All but the cheapest of cheap supermarket, no-name players should feature this - and should have done for years.
Having said that, layer changes on my Tosh SD110E used to be almost unnoticeable, but are taking longer and longer as the months go by. I think the motor's on its way out. It's beginning to sound like a dying cat as it pulls the laser back to the start of the disc.
The cheapo supermarket models often feature pc dvd drives internally which can be upto 12x speed where as the japs design their dvd players from the ground up with custom designed dvd drives of only 2x speed normally. So the cheapo players have no visible layer change where as the jap models do. Of course you might pay a price with the cheapo models of more noise and worse long term reliability but the reality is when it comes to layer changes the chinese designed players are often better as they can access the data much faster. You'll often find picture search is better on the chinese players too for the same reason. Many of them go to 8x picture search with full motion animation and not a series of frames. Also media and format compatibility is often better on the chinese players. However actual picture and sound performance, dvd compatibility and long term reliability is obviously in the jap players favour.
On the subject of the latest generation of players, do they tolerate scratches and dust better than my 1st gen player would (ye olde Samsung 709)?
I've tried borrowing one or two DVDs from friends, and because the discs are in slightly less-than-pristine condition, I get playback problems :( My DVD-ROM drive doesn't have any of this, but that might also be down to buffering...
Superbit dvd's are encoded in a way that the layer change is not visable, I think other movie studios should take note.
My mate has just bought a new player which has dual lasers so when the 1st laser reaches the end of the layer the 2nd is already in place to start playback on the next layer so that you don’t get any noticeable pause.
I don’t really have much of a problem with the pause during layer change as it is very slight on my Sony, but it really bugs me when the change is in the middle of a conversation or something where it just jumps out at you and then a couple of seconds later the scene ends. Surely they can offset the data on the DVD to coincide with the closest scene change. :mad:
Originally posted by Nostromo
My mate has just bought a new player which has dual lasers so when the 1st laser reaches the end of the layer the 2nd is already in place to start playback on the next layer so that you don’t get any noticeable pause.
I don't think it works like that. A dual laser pickup is normally one laser optimised for dvd media and another optimised for cd media. Besides doesn't the laser actually start from the centre and work out to the edge so when it finishes at the edge it has to go back to the centre to start reading the second layer? In which case how would the second dvd laser help? The mechanism still has to move across the surface before it can start reading again. Unless of course the drive has two seperate mechanisms which would involve extra motors and electronics. I've never seen this and it would be much more expensive to make. I can't see them doing this just to eliminate the layer change. Much easier just to fit a bit of buffer ram so that the drive reads ahead slightly.
My first DVD player was a cheap player from comet, about £160 at the time in the summer of 2000. The performance was good but it was very basic, couldn't do anything with DTS wouldn't play cd-rs ect but had NO layer change and I mean none. When I first started watching DVD's I didn't even know there were supposed to be pauses when the layer changed.
Since then now having more DVD olayers in the house and watched films round others houses they all had layer change. I just got a Pioneer 360 which is amazing but still you can notice the layer change, this is the same for Toshiba and Sony players I have seen. More expensive players may get rid of this but why do any players have them when one of the first ever budget players which is servely outdated now has no visible layer change?
I even reconnected it recently to check I wasn't remebering things with tinted glasses but there was definetely no visible layer change.
Answers:
I think to stop the layer change the player needs to "read ahead"
Like the cd walkmans that you can shake and they dont skip because the player has a buffer storing 7 or so seconds ahead. I may be wrong but i was thinking this years ago when dvd players 1st came out and the layer change came to light. Always though it would become a thing of the past when new players came along but ive not read this is happening. Its all down to money i supose.
im sure PC DVD players dont suffer from this as they do buffer what they are reading..
I could be barking up the wrong tree though :confused:
Answers:
My Laser disc player still has a 9 second head spin to read the other side of the disc so i can handle 0.9 sec layer change :)
Answers:
Originally posted by Spooksta
im sure PC DVD players dont suffer from this as they do buffer what they are reading.. Yep that's true.
Answers:
I agree I thought this would be sorted out by now, especially like I said my first budget player which as I pointed was not exactly great when it came to features and reading discs had no layer change. If it could be done back then then I don't see wghy we still have this problem?
Answers:
Say you're watching a Superbit DVD, with DTS chosen for audio. You're looking at ~9mbps - just over 1 megabyte per second. Of course, most DVDs are well below this level of data.
Is it really so hard or expensive for manufacturers to add 2MB of RAM to their players, and then disconnect the reader from the decoder (ie, reader->RAM->decoder instead of reader->decoder)?
All but the cheapest of cheap supermarket, no-name players should feature this - and should have done for years.
Having said that, layer changes on my Tosh SD110E used to be almost unnoticeable, but are taking longer and longer as the months go by. I think the motor's on its way out. It's beginning to sound like a dying cat as it pulls the laser back to the start of the disc.
Answers:
The cheapo supermarket models often feature pc dvd drives internally which can be upto 12x speed where as the japs design their dvd players from the ground up with custom designed dvd drives of only 2x speed normally. So the cheapo players have no visible layer change where as the jap models do. Of course you might pay a price with the cheapo models of more noise and worse long term reliability but the reality is when it comes to layer changes the chinese designed players are often better as they can access the data much faster. You'll often find picture search is better on the chinese players too for the same reason. Many of them go to 8x picture search with full motion animation and not a series of frames. Also media and format compatibility is often better on the chinese players. However actual picture and sound performance, dvd compatibility and long term reliability is obviously in the jap players favour.
Answers:
On the subject of the latest generation of players, do they tolerate scratches and dust better than my 1st gen player would (ye olde Samsung 709)?
I've tried borrowing one or two DVDs from friends, and because the discs are in slightly less-than-pristine condition, I get playback problems :( My DVD-ROM drive doesn't have any of this, but that might also be down to buffering...
Answers:
Superbit dvd's are encoded in a way that the layer change is not visable, I think other movie studios should take note.
Answers:
My mate has just bought a new player which has dual lasers so when the 1st laser reaches the end of the layer the 2nd is already in place to start playback on the next layer so that you don’t get any noticeable pause.
I don’t really have much of a problem with the pause during layer change as it is very slight on my Sony, but it really bugs me when the change is in the middle of a conversation or something where it just jumps out at you and then a couple of seconds later the scene ends. Surely they can offset the data on the DVD to coincide with the closest scene change. :mad:
Answers:
Originally posted by Nostromo
My mate has just bought a new player which has dual lasers so when the 1st laser reaches the end of the layer the 2nd is already in place to start playback on the next layer so that you don’t get any noticeable pause.
I don't think it works like that. A dual laser pickup is normally one laser optimised for dvd media and another optimised for cd media. Besides doesn't the laser actually start from the centre and work out to the edge so when it finishes at the edge it has to go back to the centre to start reading the second layer? In which case how would the second dvd laser help? The mechanism still has to move across the surface before it can start reading again. Unless of course the drive has two seperate mechanisms which would involve extra motors and electronics. I've never seen this and it would be much more expensive to make. I can't see them doing this just to eliminate the layer change. Much easier just to fit a bit of buffer ram so that the drive reads ahead slightly.
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