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-   -   I heard this about DVD's.... (https://www.dvinfo.net/forum/dvd-authoring/25411-i-heard-about-dvds.html)

Jake Russell May 4th, 2004 10:24 AM

Yeah I feel your pain. I'm lucky as I don't have to explain that they don't have a dvd tape. :-) that's a good one.

Na I think it's pretty widely available info. Even all the reports on the news(UK) mentioned it when dvd recorders hit the street. If the info doesn't stick then it doesn't...

I think that it depends who you're talking about as far as consumers goes. The folks that pop to the store and buy Matrix really don't have to worry much! It has a lot more to offer than VHS but how many people still don't use the VHS player to the max! Even if users don't use the dvd player they can still access a lot of extra content and features.

The problem I guess is that dvd and desktop video is cheaper and more readily available now. This means that people who don't know what they are doing are doing! I mean how many 'dvd authors' haven't read dvd demystified and the app manual. No nothing about the dvd spec. No nothing about compression. No nothing about the different dvd standards and so on!

Jake

Peter Moore May 4th, 2004 11:19 AM

VHS is worthless for anything but random access TV recording.

DVD-Rs, while they do have some compatibility issues (which are almost non-existant with newer players), are still the best consumer-grade recordable media available. They beat the pants off of anything magnetic, and have longer lifespans than CD-Rs.

Jake, I did not know bitrate restrictions would be any different between DVD-Rs and replicated DVDs. Why would that be?

Alessandro Machi May 4th, 2004 11:23 AM

Duplication houses that are asked to make a "couple of dvd's" by their customers have then hear about how "the DVD copy played in these two computers but not the third computer", or "the DVD copy played on the computer and one DVD machine but not the older DVD machine", or "the DVD copy played but dropped sound or picture every now and then"....

I hear JVC just came out with a VHS/Super-VHS to DVD all in one unit. Finally, one of the big companies will get to hear the complaining that the rest of use hear from time to time. I'm not doing DVD duplicating yet but I hear and see the pitfalls from others who offer the service.

And the last two BetaCam SP Edit masters that I had DVDs made from had flaws on both DVD's that would have never happened on a straight VHS copy.

Dan Euritt May 4th, 2004 12:26 PM

there seems to be a bit of fud-mongering on dvd-r in this thread? or have i mis-interpreted what's been said.

i have personally sold well over 500 dvd-r's here in the u.s. and abroad, with zero returns... i created every disc in-house, everything from shooting to editing to compressing to authoring to burning, including designing and printing the covers... we are talking about multiple projects here, not just one authored dvd.

i've seen at least one person claim to have had the same xlnt results with over 1,000 dvd-r's that he created and sold.

i have outlined what works for me in at least one other thread on this forum, if your results differ it's probably because you are cutting corners, or not fully adhering to the dvd spec... yes, there may be issues with dvd players sold before 2000, but when they cost only $40 each, most people will have multiple players, including game players that work great for dvd-r's.

most of the discs i've sold were done at vbr peak rates that exceeded 9 Mb/s, so there are no bitrate advantages with replicated vs. duplicated dvd's... afaik, there is only one dvd-legal spec for dvd players, and it does not differentiate between replicated vs. duplicated dvd's(??).

Alessandro Machi May 4th, 2004 12:31 PM

There are several things aspects to DVD duplication to consider. A duplicator who is asked to make straight copy DVD's from existing video content will use a DVD-Recorder and make a straight across DVD copy. These DVD record machines appear to have at best a 75-80% success rate.

Dan, congratulations on your success making DVD's. I believe there are some people out there that have a very high success rate making their own DVD's, it's just that not every project is "worthy" of loading into a computer when the client doesn't want to spend that much to make a straight DVD copy from existing material.

Peter Moore May 4th, 2004 02:21 PM

I've never had a single problem with DVD-R. Granted I haven't done hundreds or even thousands, so this is just annecdotal. I have, however, had lots of problems with DVD+R.

Maybe it depends on the media. I think duplication houses do cut corners sometimes. I've seen duplicators actually put labels on DVDs and, while they're centered well, this is still a huge no-no. So dropouts like that are not necessarily related to the fact that DVD is a DVD-R.

Now, that is not to say there is not a difference. Clearly there is - manufactured DVDs have much better reflectivity than DVD-Rs. DVD-Rs are basically an imitation of a real DVD. They try to make the laser bend exactly the same way, but they're not perfect all the time. Hence some players can see them and some can't. But I think every player bought in the last couple of years will have absolutely no problem with a quality DVD-R assuming everything else (authored to be compliant, no labels, etc.) is optimal.

Jake Russell May 4th, 2004 07:31 PM

<<<-- Originally posted by Dan Euritt : most of the discs i've sold were done at vbr peak rates that exceeded 9 Mb/s, so there are no bitrate advantages with replicated vs. duplicated dvd's... afaik, there is only one dvd-legal spec for dvd players, and it does not differentiate between replicated vs. duplicated dvd's(??). -->>>

Oh my gosh! for you maybe but that just isn't true my friend for thousands of others. WOW. I must of saved more people than you've got discs 10 times over atleast by telling them to encode their audio to AC-3. Bing, oh the disc works now! Keep the avg. down. Bing no video break-up! Along with many other things that it helps artifacts, audio dropouts etc.

There are many many things that can cause problems with recordable media. There are many many people out there(in the UK anyway) that don't have 3 or 4 players! even if they are $40 in the US.

500 sold for one person can be totally different for someone else(even with replicated discs)! Just cause you didn't hear doesn't mean all was ok! But that said it may be that it was. I know people that have sold over 5000 ħr discs and never had a problem but I also know people that sold about 80 and gave up on dvd. I have discs here that are basically exactly the same except the bitrate and as soon as the max gets to 7.2 Mbps+ you can hear the laser starting to struggle. Anyway to say that there are no bitrate advantages with replicated vs. duplicated dvd's is just crazy to me. I really wish we could all just go ahead and use 10.08 CBR give or take fitting content on the disc but that's just not real!

Ok ok a dvd-r is a dvd-r not a dvd-video. The Forum is very clear about this and dvd-r has it's own book type in the specification series. Or should I say several. There is one for dvd-rom, dvd-video, dvd-r 1.0, dvd-r(G) 2.0, dvd-r(A) 2.0, dvd-rw and the list goes on So no there is one spec but it's divided up into books which may have more than one version. The dvd player should look for things to be spec complient and one of those things is regional information.

Now for instance dvd-r's can not be specific region encoded and so the control area of a disc in premastered. The region informaion in the control area must match the VMG(video manager) and many people have been bitten by this. Pressed or burnt discs. If you used a build from the HD(or a .img) with dvdsp 2 the RCM(region code mask) will be flagged as 192 not 0(regions 7 & 8 disabled the rest ok). So if you then use toast to write to DLT or ħr it'll will not be spec legal unless you change it with a 3rd party app.

So although there are many things that can cause problems with ħr there are many things that can go wrong with replicated projects aswell and lets face may people here don't have, or possibly want spec level control over things.

Peter,

It's to do with the sectors and ECC blocks, basically way data is cached when the player is playing recordable media. More than one rotation is needed to get all the ECC block info read then calculated blah die blah so the disc has to spin more than once in order for the data to be transfered.

Jake

Peter Moore May 4th, 2004 09:08 PM

So what is a safe max bitrate to use for DVD-R? I've gone as high as 9.5 mbps without a problem, at least not in my Toshiba player.

Jake Russell May 5th, 2004 04:21 AM

That is a tricky one as I'm sure you know :-) I mean as always it depends on the numbers you're looking to use or send out and the control of where the disc will play. What encoder you'll use, whether you use AC-3 audio, brand of dvd and if the player likes that brand etc. I mean there isn't a number and the fact is that the job of the compressionist is a bit more complex than ok the dvd-r will take a max of x Mbps. The idea is to keep the bitrate as low as possible and get the best quality they can. Some footage will look fine at low Mbps where other footage will benifit from the high bitrate at certan points.

Not all encoders are equal so while BitVice does as it's told compressor doesn't and will spike so the settings can be adjusted to account for this (sometimes).

I'd say you should look at keeping the max at 7.x Mbps maybe if you use AC-3 audio. But as the world changes and more and more new players are bought the recordable media option is becoming more 'compatible'. I guess you just have to do a risk assesment of whether a complaint is acceptable given the risk.

The rep houses are dropping run prices and min units required also dvd-r was originally a single format and then made into two. General version intended for home use and Authoring intended for professional use. 3.95 GB Authoring media is still the most compatible recordable format as far as I'm aware.

That's funny though cause my old Toshiba is one of the best test machines I've ever had. It's one that will tell me how hard it's working and it's got a bitrate monitor so I can really keep an eye on things and check the bandwidth 'hollywood' movies are using. Oh and I'm not sure this has been mentioned yet but burn speed plays a big role also. Always master at 1x.

Jake

Alessandro Machi May 5th, 2004 05:24 AM

What is the bit rate that Hollywood uses?

Jake Russell May 5th, 2004 05:35 AM

There is no magic number. All footage therefor discs are different. They will segment re-encode also to make sure the blacks are black and the right datarate is used frame by frame.

I spoke to Jess Bowers at NAB but didn't get a chance to talk about encoding really just authoring. But some use avg. of 3.5-4 and others use a CBR of 10 (total bandwidth).

Hollywood doesn't always get it right though and nor do the manufacturers hence the reason hollywood have problems also.

For most corporate jobs a single pass on a SD-2000 will do the trick with a bitrate of around 6 Mbps. But you've got the flexibility to go back and segment re-encode.

But sometimes software encoders can do a great job of cleaning up noisy footage, a la DVNC in BitVice.

Jake

Peter Moore May 5th, 2004 09:39 AM

Every so often you see those "superbit" discs with mpeg-2 bitrates in the 9's and up. On the typical DVD-9 with a 2 hour feature and special features, the bitrate for the video is usually only around 4 or 5.

My upcoming release is going to be about 4.5 mbps for video, and another .5 for the AC-3. But that's because I need to fit a 2 hour movie on one DVD-R.

Dan Euritt May 5th, 2004 11:04 PM

<<<-- Originally posted by Jake Russell : I must of saved more people than you've got discs 10 times over atleast by telling them to encode their audio to AC-3... There are many many things that can cause problems with recordable media. There are many many people out there(in the UK anyway) that don't have 3 or 4 players! even if they are $40 in the US. -->>>

you must be dealing with a lot of dvd newbies, if you have to tell 'em to encode with ac-3! that should be a no-brainer with dvd-r.

and if you're from pal land it also explains a lot... england is at least three years behind the u.s. in dvd player penetration, of course you'll have a lot more failures in that environment... that would also explain your fixation with region coding... people that do dvd-r's operate on such a small scale that they have no need for region coding ripoffs.

that said, i just put out a new title, and today i had two people asking why the picture is skipping, lol!! *&($^%!!!

it was my first commercial dvd-lab pro project, so where is the problem? i plugged some of the mpeg files into the pro version of bitrate viewer, and it appears that the average bitrate is about 5300, with the highest peak bitrate only 7644... but the encoder was set to an average bitrate of 6900, with a peak of 9000+ and a bottom bitrate of ~3,500... 112 vbv, gop's of 15, and of course i use ac-3, 384kbps... the same encoder settings as before.

so much for bragging about the high bitrates that i use, tho... advdinfo sez that it's taiyo yuden media, and i just tested several discs on the old 1999 player my neighor has, no problemo... right now i'm looking at the muxer in dvdlab pro, it's a simple project that i can re-mux elsewhere and re-author in dvdlab pro.

i'm not sure that we could call this a dvd-r problem? maybe the sony burner is giving up the ghost after all those copies.

wrt hollywood... you would die to have the same quality source material that they use, so their encoding bitrate isn't too relative to our lowly xl1s material... and all of us have seen bogus hollywood dvd encoding that totally freezes and skips... the authoring they do in hollywood is extremely complicated also, which can really cause problems.

Jake Russell May 8th, 2004 06:06 AM

<<<-- Originally posted by Dan Euritt :
...you must be dealing with a lot of dvd newbies, if you have to tell 'em to encode with ac-3! that should be a no-brainer with dvd-r. -->>>

Oh yes. There are lots of noobs on the apple and dvd boards out there! But that said not many PC authoring apps actually have a AC-3 encoder or even support the import! Right?

<<<-- Originally posted by Dan Euritt : that would also explain your fixation with region coding... people that do dvd-r's operate on such a small scale that they have no need for region coding ripoffs. -->>>

Well actually I guess you missed my point. It was for those people using recordable media. There is region coding on every disc. You just have to flag the regions you want to be able to see the disc or not. If it's got regions 1-8 set to ok then it's still region coded right? Just Region ALL! or RCM 0.

<<<-- Originally posted by Dan Euritt : that said, i just put out a new title, and today i had two people asking why the picture is skipping, lol!! *&($^%!!! -->>>

Hey only 1 is still very good.

<<<-- Originally posted by Dan Euritt : the authoring they do in hollywood is extremely complicated also, which can really cause problems. -->>>

To be honest most aren't that bad and you can track what's going on a lot easier than trying to track a abstraction layer (AL) app. The spec based apps are often a lot easier going on the player than AL apps cause of all the dummy PGCs and loads of pre and post commands being generated send you off all over the place. Normally with spec based apps what is there is suppose to be there and does something but that's not the case with AL apps.

Hope you got the problematic disc playing ok,

Jake
PS. Also looking back, reflectivity & pit size play a part in why some players have problems with high bitrates.

Peter Moore May 8th, 2004 07:34 AM

"Oh yes. There are lots of noobs on the apple and dvd boards out there! But that said not many PC authoring apps actually have a AC-3 encoder or even support the import! Right?"

Almost all the cheap PC DVD tools will support AC-3 stereo. I believe Vegas DVDA will support 6-channel AC-3 as well. And then of course there's Scenarist and Maestro. Probably Adobe Encore too. But most of the cheap bundled stuff won't support 5.1 AC-3 but they will encode your PCM to 2.0 AC-3 usually.


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