Thank you to Flash for this Guide


Newbie Guide to DVD Media Testing

You’ve got the discs you’ve got your DVD burner! How do you do a proper test??
Just burning files or films is not really a good conclusive test for the media we need to test the discs to their limit
One essential piece of kit is Nero CD Speed 1.02 which will test your discs for file transfer speed and give an indication as to the quality of the burn.
Examine the disc especially the outer rim for imperfections, I have never found one perfect so don’t be alarmed by this, examine the underside of the disc for irregularities in the dye and scratches on the disc The scratches do net reflect the quality of the disc but have a bearing on the results you may get. Packaging of the discs has improved and as late there have been little or no problems in this area.
Next we need to test the whole of the disc so an ideal movie should be one that has a total file size of just under 4.38gigs which will burn the disc to its limits a the outer edge. For test purposes always burn at the maximum speed rating for that particular disc and do not try to burn at 2x speed if it is a 1x speed rated disc. After the burn examine the burn surface for irregularities and prior to checking the usability do a file transfer scan with Nero CD Speed use a DVD-ROM reader for this preferably one that is critical at reading DVD-R media the resultant scan on a good disc should be like this


Acceptable but not 100% perfect are like this



These show the outer limits if the media



And these show media that is unreliable and the scan has stopped with errors



Now that we have burnt the disc and checked the readability it is necessary to see if it works in as many DVD players as is possible
Firstly check how long it takes to load the intro or menu and listen for any unusual noises from the player drive as it starts to read the disc
Playback the main film and watch the first few minutes for any signs of pixilation or the film freezing
Fast forward and reverse at all speeds to check for continuity and smoothness
Chapter skip forward and reverse to check if it finds the chapter points quickly and easily
Play back the last 10 minutes of the disc and scrutinise the output, the reason for this is that the outer edge of the disc is the most likely area to have any defects.
It is important that the film is tried in as many players as is possible and preferably in a player that you know to be fussy about media
I have a few more players than most and the discs I do have to play in my worst players before I will give it the A OK. I have some new players I am testing ATM and they will play disks I have thrown out because of playback errors, so a good player is not ideal for testing media quality.
I personally only burn Movies which are for backup purposes so my guide is biased this way but you can burn data or PS2 games for the test, the most important thing is to try and make the content on your test disc as near to a full disc as is possible and test it to its limits on as many devices as you can

The type movies to burn for test purposes need specific layout of the VOB structure which can affect the playback of a poor quality disc and for my tests I use three different types
1: A complete movie only with just the intro & title followed by the film which covers the full size of the disc this will give an easy test of chapter skips fast forward and reverse and playback consistency towards the end of the disc
2: A multi movie enabling to select different movies on specific parts of the disc and the ability to select the last movie to scrutinize the outer area of the disc
3: (This is one that will not play if the outer area has errors) Some movies have the habit of having the intro or warning on the last VOB on the disc, meaning that when the movie starts the laser has to jump to the rim of the disc to play it before going back to the title and then play the movie. Any problems with the disc will show up by the way it starts up it can start with a title movie or still and then go blank whilst it searches for the intro, sometimes it will find the intro and play it with errors and others it will remain blank for ages and then go to the start of the film skipping the intro entirely, the worst case it will just remain blank and lock up with disc error. If the intro starts normal and the movie starts to play you have the makings of a good burn.
I think the DVD producers do this deliberately to give us difficulty in making backups of their movies and in difficult cases remastering makes the disc more playable (but that’s another subject)

Remember this disc is supplied to you free for test purposes so please use it this way and not just a disc to add to your collection, do not be put off if your results are not consistent with the other testers if it was there would be no need for the tests in the first place. The test I did on the unreleased Datasafe Maxell dye proved this. My initial tests came up with a very good disc, but the testers has inconsistent results and this problem only came to light because of these results and was subsequently found to be a problem in the Quality Control area at the Maxell factory and that is why these discs never went into full production

Any contributions or comments to this post is welcome

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If I were an in-house paid reviewer, or getting consultancy fees, then I'd do all these things. Unfortunately I have work to do and time is of the essence. I think the DVD/playstation compatibility tests that most reviewers do give sufficient info to the DVD manufacturers whether their disk is OK or not.
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Griff

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quote:

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Originally posted by griff:
If I were an in-house paid reviewer, or getting consultancy fees, then I'd do all these things.

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I can asure you I am not an in house test reviewer and do not get paid for my reviews..

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If you are not prepared to put a little effort into your tests I sujest you do not apply for any more test samples..

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Probably a silly question but here goes.

The green line is Read Spead ?

So whats the yellow line showing ?

Thanks
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Backups provided to any person is on the understanding that you already own the original,or backup provided will be used as a sample and destroyed within 24Hrs.Refs HERE

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quote:

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Originally posted by A7mag3ddon:
Probably a silly question but here goes.

The green line is Read Spead ?

So whats the yellow line showing ?

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Uhm i am using it , it came with nero 5.5.14 but when i click on help> manual i dont get anything.

your answer didnt really help much , both the lines are showing the same thing ? im lost now.
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Backups provided to any person is on the understanding that you already own the original,or backup provided will be used as a sample and destroyed within 24Hrs.Refs HERE

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The yellow line shows the rotational speed of the cd; for a constant angular velocity (CAV) drive this line should remain flat. The green line is the data transfer rate. Since CD's are read from the inside out, the transfer rate increases because the laser sees an increasing linear velocity - for those mathematically minded the linear velocity v = rw, where r is the radius from the centre of the CD to the laser pickup, and w is the angular velocity.

In the real world, data CD's are read in a random way, i.e. the laser moves back and forward over the surface, as it seeks different file sectors, so other factors come into play when determining how good the CD/DVD-R/RW is. The only CD's which are truly read from inside to outside are audio, which don't have a file structure as such.
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Griff

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What should a Mac user use to test DVD's, and what tests can be made using a Mac?

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Originally posted by Paul Reading:
What should a Mac user use to test DVD's, and what tests can be made using a Mac?

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got nero cd speed how would i put the graphs on the test report

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I like "YOUR" method of how "YOU" test "YOUR" discs Flash,but bear in mind m8y,we all have "OUR" own methods and means of testing "OUR" own discs,and for those of us that do know what were doing,Nero cd speed still doesnt reflect the fact that a movie used dvd disc will be acceptable in every standalone dvd player!Every laser,whether it be dvd,ps2,xbox etc reads differently and in my eyes we`ll all know if a tested dvd disc is any good from our own good ol` fashion methods.
But yes,deffinitely a good point/start for the newbies out there who want to contribute in testing the discs in a more "testing" way.
on a more lighter note:-dont ya just love it when you come across a disc that does everything you ever wanted,only for that disc to be discontinued,and then its back to square 1.NOT.
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quote:

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Originally posted by SEARCHER:
on a more lighter note:-dont ya just love it when you come across a disc that does everything you ever wanted,only for that disc to be discontinued,and then its back to square 1.NOT.

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Hiya,

I'm a newbie to media testing and I think your guide is very useful and helpful. Thanks Flash.

Nice web-site too dude.

I'm going to make some changes to my reviews now.
Thanks again
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Any backups supplied to you are on the understanding that you own the original

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