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You are here: MacNN Forums > Hardware - Troubleshooting and Discussion > Mac Desktops > DVD Sync problem, interesting side note.

DVD Sync problem, interesting side note.
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Chimera
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Nov 26, 1999, 08:38 AM
 
A friend of mine bought over a VCD this week, and I thought I'd give it a try in my new iMac DV. I opened the .dat file in Quicktime, and it played fine...for about 5 minutes, then the audio went out of sync just like the DVD problem. This leads me to conclude that the problem with the DVD sync issue isn't just confined to Apple's DVD software, and could in fact be a problem with the DVD hardware. Anyone have any thoughts on this?
     
wlonh
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Nov 26, 1999, 11:33 AM
 
another very popular Mac-centric website recently reported that Sony has this issue with its DVD's (at least some models), I assume therefore that this is a fairly widespread issue... no surprise, it is still a relatively new thing, DVD and computers
     
Chimera
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Nov 26, 1999, 11:37 AM
 
Well let's hope it's one that is fixable with a software upgrade, and doesn't require a hardware replacement. One of the main reasons I bought a DV was for the DVD player, and it's useless to me right now. Another thing I was wondering about was if it's a problem with the Quicktime extentions...I'm guessing that the Apple DVD software uses quicktime. Does anyone know of an MPEG player for PPC that doesn't use Quicktime so I can test this theory?
     
smaffei
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Nov 27, 1999, 09:01 AM
 
Audio synching issues have more to do with a DVD disc's encoded bit-rate and the decoder software / hardware (MPEG-2 decoding).

I believe most set-top DVD players have problems with DVDs in which the video is encoded at very high bit-rates or extremely variable bit-rates. The decoder hardware just can't keep up. Fortunately, only a small number of DVDs cause this. Most DVDs never tax the decoders that much.

In the case of Apple's DVD player 2.0bx, all of the MPEG-2 decoding is done in software. There is no MPEG-2 decoding hardware to help (like earlier G3 solutions). Trying to do it all in software is a dicey proposition at best (just look at some PC software-only solutions). Apple will get it right, but a lot of optimization and OS twiddling will be needed.

Hope this helps.
     
bmyers2
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Nov 27, 1999, 02:47 PM
 
a friend and i recently bought DV (he got the SE) and noticed the lip sync problem. i had attempted to determine if it was caused by keeping the controller open (even though it hides itself) etc., looking for the cause but couldn't isolate it. i also wanted to see if i could fix it by pausing then beginning play again. still nothing that left me feeling i had a workaround. finally, i was searching c|net as i'm thinking of buying a player and came across this from a reader who added his own opinion of the Sony DVP-S530D:

"This is a very nice player. The lip sync problem has shown up once for me in the 30 or so movies I have played. A quick pause and play corrects the problem. I like the Sony better than my Toshiba."

it appears this is not an Apple problem as stated above.

     
smaffei
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Nov 27, 1999, 04:39 PM
 
That's funny... I have a Panasonic A310 and have played over 100 rentals. I have never seen an audio synch problem. Tell the poster to return his/her player. It's obviously defective.

Decoders vary from manufacturer to manufacturer. Toshiba being the worst. Sony is usually the best. But, Sony's econoline might be flawed.

Anyway, audio synch problems ARE NOT THE NORM!

[This message has been edited by smaffei (edited 11-27-1999).]
     
disectamac
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Nov 27, 1999, 07:12 PM
 
ok ok, I have to put in my 2 cents because I'm also having the same problemo with the synchronization of audio with video when playing DVD's on my iMac DV SE. The Problem varies from DVD to DVD some movies lose their synch much faster than others.....I noticed the Matrix loses sync every 5 minutes or so (noticably) while Saving Private Ryan loses it every 45 minutes or so and Conan The Barbarian lost it only once throughout the whole flick. I haven't tested out any other DVD's yet but I just bought a whole stack of em so I'll testing all night...."Enter the Dragon" "Kick Boxer" Lethal Weapon 4" and "Black Mask". Who knows I might come across a solution throughout all this testing (highly doubtful)
Ok, Tempory solution: As stated above in instructional format, just hit command + period keys to stop then spacebar to resume playing.......this synchronizes the audio video.
If anyone finds out anything about a software update for this beta player please post it!!! Command period spacebar is becoming uncomfatorbly routine to me.
     
Spartan
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Nov 27, 1999, 09:42 PM
 
I think it's the DVD encoding and the Apple DVD player. First the Apple player is really a beta app that will be improved.
Second the DVD format has a great many variables. Though they say it is a standard, software to encode is constantly being tinkered with. I guess they felt that this would give the consumer the best possible picture as proccessing power for encoding improved. Soon, we are to expect realtime encoding in a home unit. (at a reasonable price). Such varibles as: single sided-single layer, single sided-double layer, double sided-single layer and double sided-double layered, I'm sure do not help with format stability. Not to mention the variable bit rate encoding.

If the problem was just turning up on computers that would be one thing. Tracable to software. It is when the sync runs out on dedicated set top players that the format stands on shakey legs. It doesn't matter how much or little you pay for a set top unit, it should perform its one task, DVD decode, without fault. One would expect problems on the computer side.

Note: A friend of mine has a Gateway (he bought it before I knew him) with the built to order DVD. I believe it has a hardware decoder. Guess what, it looses sync as well. Though it is very movie specific. The Waterboy is horrible, more than a half second off, with audio before video.

This is a problem not for Apple but for the DVD consortium. If some movies play and others play poorly, they have to track down the variables in disc encoding, because it is obvious that Apple has developed the player according to some sort of "Book" standard provided by them.

I guess it would be appropriate for someone (of us) to compile a list of movies, good, bad and ugly, that pose problems for the iMac DV and its player. At least until the software fix arrives.

My contributions:
Bugs Life: apparent snyc loss but they are animated so it's hard to tell. Geri's game, on the same disc bas bad sync at the start, gets better over time.

Gattacca: Sync seems to be on the money for the widescreen side. I have not tried the fullscreen side (why should I?)
     
Chimera
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Nov 27, 1999, 09:50 PM
 
The thing is, as stated in my original post, it's not just a problem with Apple's DVD software, it happened with Quicktime too when I attemtped to play an MPEG VCD with it. This means it's possibly a hardware issue, or maybe just a problem with the Quicktime MPEG extension which I assume is used by the DVD software too.
     
smaffei
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Nov 28, 1999, 11:08 PM
 
Whaaaa? Spartan, as far as I am concerned, DVD is not a "shakey" format as long as you buy good equipment. Manufacturer does matter since they use DIFFERENT decoders.

Toshiba players are notoriously bad. Sony and Panasonic have gotten the highest ratings for their players.

Anyway, do you realize how difficult it is to properly decode an MPEG-2 stream in software? It's processor intensive and very fault-intolerant. I'm suprised that the beta version works as well as it does.

The reason the synch problem is more apparent on some is because of bit-rates. Higher and widely variable bit rate (for video) DVDs require more processor attention. Thus, causing less processor time to be paid to the audio.

Try this. Before playing a DVD on Apple's Player, try making sure that the 2 channel stereo is selected instead of the 5.1 channel. The extra 3 channels are not needed and are just bogging down the processor. This might help with the synch problem.

     
JDRaven
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Nov 29, 1999, 12:12 PM
 
Hey, smaffei:

You said:
>Try this. Before playing a DVD on Apple's Player,
>try making sure that the 2 channel stereo is selected
>instead of the 5.1 channel. The extra 3
>channels are not needed and are just bogging
>down the processor.

Where is this selection taking place? Is this a DVD player pref? Or is is specific to the disc you're using?

Incidentaly, something I haven't heard anyone mention in the months since the issue surfaced is allocating more RAM to the player. I gave mine a ton of memory, and the errors like pixelizing while selecting menu items disappeared. There is still an occasional skip between chapters, but I only have Bug's Life to test this with...my 2 year old son loves the movie, as well as the fact that it plays on Daddy's "m'puter".
     
disectamac
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Nov 29, 1999, 05:36 PM
 
very good note one the ram as just mentioned...it seems to me that allocating more memory to apps solves alot of minor problems when running software....and for some reason or other I found that I have to allocate more memory to alot of apps when running at higher screen resolutions....
Example:.....running netscape..downloading a compressed file....stuffit expander launches and errors while unstuffing...this happened at the highest resolutions iMac DV SE allows....never at lower resolutions....I then gave stuffit expander more Ram to run on....problem was solved.
     
iMacHappy
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Nov 30, 1999, 01:45 PM
 
Readers on the MacInTouch site claim that DVD sync problems can be avoided by simply turning off virtual memory. Has anyone tried this, and does it work? -wish I was at home to try it out!
     
MAlan
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Nov 30, 1999, 02:03 PM
 
I still had a problem with out of sync while watching the wedding singer with virtual memory off.

It happened 4 times throughout the movie. Its not so bad really but I have to agree with disectamac and smaffei. Firstly as smaffei stated doing the encoding entirely in the software is a hard thing to pull off. I'm amazed Apple has been able to do it as well as they have. And as Disectamac stated some DVD's definetely lose sync more than others. A bugs life didn't lose sync at all for me while the wedding singer did.

To throw in my two cents...the audio sync problem might be helped if there was a way to upgrade the video RAM. 8 MB is probably pushing it for this application which probably causes more memory to be taken up by the DVD's video stream leaving little for the audio.
     
Grendel
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Dec 1, 1999, 09:19 PM
 
I really doubt the problem is with the 8mb video card since the wallstreet powerbooks have an old 4mb video card and play DVD's just fine. My best bet is that the sync problem is caused by the DVD's being decoded using software rather than a chip. Both wallstreet powerbook and the lombard powerbook have inferior video cards as compared to the new imac but are great at playing DVD's because they use a special chip for decoding.

------------------
     
Grendel
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Dec 1, 1999, 09:21 PM
 
I really doubt the problem is with the 8mb video card since the wallstreet powerbooks have an old 4mb video card and play DVD's just fine. My best bet is that the sync problem is caused by the DVD's being decoded using software rather than a chip. Both wallstreet powerbook and the lombard powerbook have inferior video cards as compared to the new imac but are great at playing DVD's because they use a special chip for decoding.

------------------
     
josesoto
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Dec 2, 1999, 01:16 AM
 
I also have the out of sync problem but theres something else. I cant get the volume to go reasonably high when playing DVD. I have to get close to my imac to hear it.I dont have this problem on games cds or regular use

Help someone
     
Syco
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Dec 2, 1999, 02:36 AM
 
Jose........have you went into the sound in the control panels and raised the olume level there?........I play with mine all the time..between mp3's movies and games.....mine works great.......oh well.......good luck.....hope thatz the only prob you have.....
     
burp
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Dec 2, 1999, 09:11 AM
 
Have you tried pressing the '+' button in the controller to raise the volume in the DVD player?

-burp
     
josesoto
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Dec 2, 1999, 11:03 AM
 
Yes I have tried all that, you guys think I should exchange the imac?
     
josesoto
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Dec 2, 1999, 11:40 AM
 
Problem FIXED

I called apple today and they told me that the DVD player was design to lower de volume a little bit so if you plug in an amplifier the audio would not be distorted.
     
blizaine
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Dec 2, 1999, 12:02 PM
 
Now if there was only a fix for the sync...

[This message has been edited by blizaine (edited 12-02-1999).]
     
Savvy
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Dec 2, 1999, 06:33 PM
 
Did Apple say anything about the audio level not being lowered if you use an iSub? It is going to be somewhat disappointing to not be able to turn the volume up once the iSubs come out. I mean, whats the point of watching movies if they are only at a medium volume. In quiet parts in movie, you really have to strain to hear anything. I would say this is a poor decision on Apples part. Shouldn't the user be able to turn the volume down on the iMac if his amp is distorting? Don't they give us any credit?
     
josesoto
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Dec 3, 1999, 04:48 PM
 
Guys I have a BIG Problemo

Photoshop 5.0.2 shows white as yellow, I called adobe but they wanted to charge me 2 dollars a minute so I hung UP hahaa . Please HELP

It must be something whit the monitor I guess
     
burp
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Dec 3, 1999, 05:52 PM
 
Seems like you need a monitor calibration. Try to use the Adobe Gamma control panel that should have come with PS and tweak the monitor.

-burp
     
josesoto
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Dec 3, 1999, 07:32 PM
 
no calibration needed because photoshop 4 shows perfect white . Anything ?
     
burp
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Dec 3, 1999, 08:31 PM
 
Sounds very strange indeed. You should post it under a new topic (if you haven't already) in the third party application discussion. You'll probably find people there who are more knowledgable than me .

-burp
     
mac-at-kearsarge
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Dec 4, 1999, 12:52 AM
 
OK! Now...getting back to the correct topic (Apple DVD player and Sync problems).

As I understand it from reading the post in this topic, the problem is software and not hardware, right? Therefor, in theory, Apple will be coming out with updates that (I hope will fix this)?

I ask because I'm going to be buying an iMac DV/SE this week; and although playing DVDs is not terribly important. I would like it to work the way it's supposed to.

Getting off the subject again (sorry)...has anyone with one of these new iMacs tried the firewire ports (with any type of device)? If so, did they work as expected or does Apple need to work out some of the kinks there too?
iGeek
     
josesoto
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Dec 4, 1999, 10:15 AM
 
I called apple , Again , and I was told that they are working hard on the fix for the dvd sinc and is goin to be software . I supose is goin to be an upgrade for apple dvd player or something
     
mac-at-kearsarge
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Dec 23, 1999, 06:01 PM
 
Here the solution finally...
http://forums.macnn.com/cgi-bin/Forum5/HTML/001133.html

This topic shows where to get the patch and it's quality
iGeek
     
   
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