DDP image - could someone shed a full light on it ?

[ISedlacek]

After some usual ocassional small troubles with burning a master CD and discussions with some plants, seems that sending DDP image could be the most reliable and straight way of sending the master ...

I can either get an older Sequoia version or to use Wave Editor for that.

Could someone please give a full insight what this DDP image exactly means (including the term), what it consists of(I noticed there are several files belonging to it, not just one), what are its advantages and disadvantages, whether it is OK just to upload it (some people say it should be rather burnt on the CD) etc ?

Thanks

[cichy]

DDP -Disc Description Protocol

not much info but : DDP consists of data that will be recorded on CD / DVD "to help manufacturers have a consistent and complete description of the input media for use in glass mastering of CD."

some more info on DVDs here : Disc Description Protocol | Rivergate Software Inc.
but i'm sure there are some DDP exerts here to give us some useful info on DDP audio focused

[Greg Reierson]

Originally Posted by ISedlacek

After some usual ocassional small troubles with burning a master CD and discussions with some plants, seems that sending DDP image could be the most reliable and straight way of sending the master ...

If you can send the image electronically then it's a great deal. If you want to send it on some physical medium other than Exabyte tape then it's a bit more risky. It's becoming more likely that you'll end up with a run of CD-ROM discs of your DDP image NO MATTER HOW WELL YOU LABEL THE MASTER...


GR

[Jerry Tubb]

This might shed a little light on the subject:

DCA - FAQs

Support :: Frequently Asked Questions

It's recommended to send the clearly labelled DDPi to replication on a DVD-R instead of a CD-R.

JT

[Adebar]

Originally Posted by Greg Reierson

If you can send the image electronically then it's a great deal. If you want to send it on some physical medium other than Exabyte tape then it's a bit more risky. It's becoming more likely that you'll end up with a run of CD-ROM discs of your DDP image NO MATTER HOW WELL YOU LABEL THE MASTER...


GR

If you send a DDP image on a physical medium, than DVD-RAM in a cartridge would be the best solution because of the follwing points:
- nobody at the plant would accidently replicate the DDP image on CD
- because of the DVD-RAM structure and the writing process the best data medium on disc.
- the cartridge protects the disc against pollution.

DDPs advantage really come true with file transfer together with checksum, for example the MD5. Description of that you can find here
Support :: Knowledge Database

The Disc Description Protocol exist of 4 folder. The first 2 contain the audiofiles and the PQ data which will be in the P and Q channel of the CD-Audios data stream.

The redundancy of audiofiles + separate PQ data is higher than the redundancy of the CD-Audios data stream with the cross interleaved Reed Solomon code (CIRSC). The higher redundancy on the DDP can be seen at the size of the image. For a CD-Audio with 700 MB the DDP files size is about 800 MB.

[lowland]

Originally Posted by Greg Reierson

It's becoming more likely that you'll end up with a run of CD-ROM discs of your DDP image NO MATTER HOW WELL YOU LABEL THE MASTER...

A worrying development, Greg: have you found that to be the case even when the (well-labelled) CDA DDP master is on a DVD-R?

The CD-ROM thing happened to me with my first DDPi three or four years ago when I provided it on CDR. Since then I've always used DVD and have not had a problem.

[Greg Reierson]

Originally Posted by lowland

A worrying development, Greg: have you found that to be the case even when the (well-labelled) CDA DDP master is on a DVD-R?

The CD-ROM thing happened to me with my first DDPi three or four years ago when I provided it on CDR. Since then I've always used DVD and have not had a problem.

Same thing happened to me, Nigel. I asked the guy at the shop and he said every incoming master gets taken out of the case, all docs are trashed, the master is placed in a sleeve and shipped off for replication. The guy cutting the glass didn't notice the large DDPi label. No safeguards. Not enough knowledgeable people in the process.

I have not had it happen with a well labeled DVD. I ship all DDP electronically directly to the plant now. It helps to know the guy at the other end!

I like Adebar's DVD-RAM in a cartridge idea. I'll try that next time I have to ship in a physical medium. But I can already see the guy at the shop breaking it out of the cartrige...


GR

[Cellotron]

Originally Posted by Greg Reierson

\
I like Adebar's DVD-RAM in a cartridge idea. I'll try that next time I have to ship in a physical medium. But I can already see the guy at the shop breaking it out of the cartrige...

It should be noted that many plants (perhaps even a majority) - while readily accepting DVD-R and DVD+R - can NOT accept DVD-RAM. If you wish to send this format I would strongly recommend consulting with the plant first to make sure they have DVD-RAM compatible drives hooked up as an input device to their glass mastering facilities workstation. DLT might be another more "fail safe" format to send physical DDPi in on - again I'd recommend consulting with the specific plant you are using first to make sure they are set up for this.

Best regards,
Steve Berson

[Jerry Tubb]

For that matter I guess we could send replication the DDPi on a $5 1GB flash drive.

A client spends a thousand bucks (or more) with you to master a project, give 'em a flash drive.

The drive could also contain the PQ Log and any additional instructions.

JT

[Cellotron]

Originally Posted by Jerry Tubb

For that matter I guess we could send replication the DDPi on a $5 1GB flash drive.

A client spends a thousand bucks (or more) with you to master a project, give 'em a flash drive.

The drive could also contain the PQ Log and any additional instructions.

JT

Nice idea - but again - although it seems "simple" (just plug it into an open USB slot on the computer) some plants will not readily accept this.

I feel people are under the impression that glass mastering facilities run their work stations in a similar way as studios in that they keep up with the latest consumer technologies for backing up and delivering data.

My experience is that most often this is not the case - they generally are very rigid as to what "input devices" are connected to the workstation, will not do any changes or upgrades very quickly, and very often make sure that the workstation is kept free of any software or hardware but what was originally setup by what is usually a turn key system provider. The idea behind this is to exactly standardize work flow and to make sure that once things are running correctly nothing messes with this - as any downtime or processing errors means lots of lost dollars. On the other end of this equation I've seen this results in having to deal with some serious mind boggling p.i.t.a's though - i.e. I know of one case where the plant refused to unzip a DDPi compressed in a zip folder - and made the ME re-upload it uncompressed.

So again - if you were wanting to send in DDPi on a USB flash drive I'd contact the specific plant first and make sure they were ok with this.

OT of the thread - I do really like getting mixes delivered on USB pen drives as usually getting the files off of these is even easier than getting them off of external hard drives. I also really like the idea of USB pen drives as a delivery format to clients wanting data files only instead of burning discs - as copying time to the pen drive generally is way less than burning and error checking a CD-R or DVD-R disc. Been contemplating buying a batch of them with my logo imprinted on them - but so far can't justify the cost of doing this vs. just buying discs. I have a feeling this could change sooner than later though.

Best regards,
Steve Berson

[Jerry Tubb]

Originally Posted by Cellotron

OT of the thread - I do really like getting mixes delivered on USB pen drives as usually getting the files off of these is even easier than getting them off of external hard drives.

Same here Steve, I've been seeing this more and more. Also with small bus powered HDD.

No need to even hook up a power supply. Just connect via USB or FW, download, and get to work.

Cheers - JT

[ISedlacek]

I just wonder - why exactly it is recommended to send the DDP image on CD/DVD medium ?? I thought that the advantage of DDP image is that you avoid any medium and can just directly upload it to the FTP and the plant will download it ... And you also don´t have to send anything physically (which requires time), but you can upload it instantly within few minutes. If you have to burn it on a medium, then send it by post etc. , it does not bring that big advantage. I still cannot see any reason why uploading should not be equal (or even better) to burning it on a CD/DVD

[lowland]

And on that topic, what sort of times are people finding/expecting for an upload to the plant? The one time I've done this (about nine months ago to save the producer a round trip of several hundred miles), it took five or six hours for a 60 minute CD.

I think my upload speeds are probably a bit better now, but it appears much more convenient to just write an image from SADiE and then burn it to DVD at high speed - whole job done in half an hour or less, then let the postman take it from there.

[ISedlacek]

Well, the internet speed is just a technical local aspect. For example I have 10Mbit/sec both upload and download, so uploading the whole CD is just a question of few minutes for me ... My question was whether there can be some complication with uploading/downloading DDP image in general, comparing to burning it to DVD

[Adam Dempsey]

OT of the thread - I do really like getting mixes delivered on USB pen drives as usually getting the files off of these is even easier than getting them off of external hard drives.

Originally Posted by Jerry Tubb

Same here Steve, I've been seeing this more and more. Also with small bus powered HDD.

No need to even hook up a power supply. Just connect via USB or FW, download, and get to work.

A side note to this: Bonus content for fans on USB-stick albums.
We'll see how it goes, given discovered virus issues with flash drives (PC only?), as per at the Pentagon...

[Adebar]

Originally Posted by ISedlacek

I still cannot see any reason why uploading should not be equal (or even better) to burning it on a CD/DVD

thumbsup

Yes, upload DDP with checksum also for me is better than burning a physical medium.

[mischa janisch]

Originally Posted by ISedlacek

Well, the internet speed is just a technical local aspect. For example I have 10Mbit/sec both upload and download, so uploading the whole CD is just a question of few minutes for me ... My question was whether there can be some complication with uploading/downloading DDP image in general, comparing to burning it to DVD

In my experience quite the oposite is true - DVDs get damaged, ripped out of the box, copied and mislabeled (with the above mentioned problems to follow) and sometimes lost, while an upload containing an MD5 Checksum (which is mandatory with all the major label plants where I work) is a fast and secure method of delivering where I didn't experience any problems so far...

[GeorgeZ]

Originally Posted by ISedlacek

I just wonder - why exactly it is recommended to send the DDP image on CD/DVD medium ?? I thought that the advantage of DDP image is that you avoid any medium and can just directly upload it to the FTP and the plant will download it ... And you also don´t have to send anything physically (which requires time), but you can upload it instantly within few minutes. If you have to burn it on a medium, then send it by post etc. , it does not bring that big advantage. I still cannot see any reason why uploading should not be equal (or even better) to burning it on a CD/DVD

Hello my colleague from CZ :-)

I think it depends on the factory processing procedures. We at GZ Lodenice accept both the FTP option and the physical disc option. The first one has the advantage of quick and no-delay delivery of the source data; the presence of the MD5 checksums (or similar) is necessary. The second one is more traditional way but sometimes there are reading problems so the master has to be sent again.

See our Technical conditions for the formats we accept:

CD Audio Technical Conditions

[sonare]

Several people have commented on running and including a MD5 checksum-- anyone care to explain whether or not a checksum is part of the process?

I have heard from several knowledgeable MEs that if a DDP image will open it is fine, and that if it won't open the internal checksum test has failed.

Comments, anyone?

Rich

[PieterS]

MD5 is not part of the DDP spec, but can be added as a safety option.

Pieter Stenekes

[sonare]

My question really had to do with whether MD5 is neccesary if the DDP will open if data integrity is good, and won't if it isn't?

Rich

[PieterS]

Don't know if it opens if the checksum test fails, depends on what part is damaged.

If the test fails the plant should ask to resend the files.

[CDS]

Originally Posted by ISedlacek

After some usual ocassional small troubles with burning a master CD and discussions with some plants, seems that sending DDP image could be the most reliable and straight way of sending the master ...

I can either get an older Sequoia version or to use Wave Editor for that.

Could someone please give a full insight what this DDP image exactly means (including the term), what it consists of(I noticed there are several files belonging to it, not just one), what are its advantages and disadvantages, whether it is OK just to upload it (some people say it should be rather burnt on the CD) etc ?

Thanks

DDP is the best way to submit your CD project to the pressing plant for several reasons:

1) You avoid the read errors of a CD-R (PMCD) when copying your image into the plant's computer to cue it up for the manufacturing line. Most engineers will tell you there is no difference with CD-R and DDP but having worked in the optical industry for 7 years, I have found there is a difference in my opinion (too much tech jargon to go into it here, there is another thread where some other guys and I discussed this and you can likely find it in search).

2) In addition, DDP images are processed differently than CD-R masters and your resulting replicas will be 1:1 exact to your source masters.. aka 0% error rate.

3) Submitting your DDP is ok on DVD-R as the plant's analytic gear will tell them that DDP is present on the disc and they can indeed create a glassmaster directly from this DVD-R. The preferred method is to use FTP (or even our format service) to deliver DDP as you eliminate the risk of a bad DVD-R disc or a hard drive/flash drive failure.. but the hard drive/flash drive failure thing is highly unlikely these days.

[Bob Olhsson]

The very first thing a plant does is test your CD-R for errors and then convert it to a DDP.

I just don't see that much advantage to sending DDPs other than the ability to FTP them. The disadvantage is that any problems with a DDP are going to be real expensive and a plant may not be willing to share the financial responsibility if they didn't make the DDP.

[dcollins]

Originally Posted by CDS

DDP is the best way to submit your CD project to the pressing plant for several reasons:

1) You avoid the read errors of a CD-R (PMCD) when copying your image into the plant's computer to cue it up for the manufacturing line. Most engineers will tell you there is no difference with CD-R and DDP but having worked in the optical industry for 7 years, I have found there is a difference in my opinion (too much tech jargon to go into it here, there is another thread where some other guys and I discussed this and you can likely find it in search).

Did the other guys decide it couldn't possibly be true?


DC

[GeorgeZ]

Originally Posted by sonare

My question really had to do with whether MD5 is neccesary if the DDP will open if data integrity is good, and won't if it isn't?

Rich

PieterS is right.
When the text files (I mean DDPID, DDPMS, ...) are broken, probably it won't open or you will see clearly incorrect ISRC codes or PQ coding, because almost all information there are fundamental. But when there is any error in binary file(s) - due to bad RAM chip or HDD failure or FTP transfer error - you can be in very serious trouble. Binary files for CD-ROMs, DVD-ROMs, DVD-Videos and other formats with EDC/ECC data inside are possible to diagnose as bad but without them or pure audio tracks NOT!!

So it is always better to send the MD5 checksums for all the DDP files and we will do the check. It is only aprox. one to five minutes of extra work (eg. using MD5summer) for the customer to do it and it will help both sides to have the product the customer wants.

Regarding Bob Olhsson's post:
We do both processes in one step. During reading of the CD the drive reports any C2 error on the screen and the DDP files are written simultaneously on a hard drive. When the DDP files are completely written on the HDD then the CD is verified by the second, repeated reading process comparing stored values with the new ones. It is also possible to repair bad sectors by reading them again and again (scratched CD/DVD, bad burning) until the whole DDPs are good.

[mischa janisch]

Originally Posted by GeorgeZ

So it is always better to send the MD5 checksums for all the DDP files and we will do the check. It is only aprox. one to five minutes of extra work (eg. using MD5summer) for the customer to do it and it will help both sides to have the product the customer wants.

I don't see why NOT including a MD5 Checksum is even an option. We always do all the 'administrative' work (creating MD5 Checksums, Zip/Stuff the DDP Fileset, includeaditional PQ - TXT files if required) while doing final QC listening of the load back of the DDP files. All of this happens in the background while listening so no time is lost - no additional work is required... After listening all we do is opening the FTP, connecting to WAM!NET or in case of sonybmg their MMB - upload the Archive and be done.

[CDS]

Originally Posted by dcollins

Did the other guys decide it couldn't possibly be true?


DC

At the end of the day the discussion ended on a note that the technicalities was too small to really matter. When your CD-R master is ripped at the plant, there are a certain level of errors your CD can have and still pass the Eclipse Image Analysis scan. My perspective is when your CD is copied with Image Copy (also from Eclipse), it performs its own error correction on your disc image.

DDP however bypasses the errors as it is read from the hard disk and does not contain any.

CD-R premaster replication is considered - Retail Quality
DDP master replication is considered - Reference Quality

Again, most people will not hear a difference between a CD-R replica and a DDP replica.. then you have some that can. Its not enough of a difference in resulting quality where to most engineers it makes a difference.

But keep this in mind... When CDs where mastered from Sony 1630 digital tapes burning glassmasters at the mandatory 1X speed.. compare lets say an original Thriller (Mike Jackson) CD from early 90's and the 25 anniversary edition (which was replicated from CD-R at 4X speed glassmastering) and judge for yourself.

-Will

[Bob Olhsson]

Originally Posted by CDS

DDP however bypasses the errors as it is read from the hard disk and does not contain any...

The last I knew hard drives had far greater raw error counts than CD-Rs. The hefty error-correction just makes this transparent to the user.

[CDS]

Originally Posted by Bob Olhsson

The last I knew hard drives had far greater raw error counts than CD-Rs. The hefty error-correction just makes this transparent to the user.

The raw error count you speak of deals with sector storage and not playback error correction. If your comparing a 500GB hard drive with a 650MB sized CD-R then sure you have an argument, though if you compare a 650MB section of a hard drive to a CD-R then there is no comparison with error rates.

Some insight:

CD-R error rates when reading PCM data affects your sound quality. CD-R was never designed to be a manufacturing master because the traditional "pits and lands" (small bumps) of a silver compact disc is "faked" on CD-Rs as opaque burn patterns which "tricks" the rom laser into thinking they are pits and lands. The truth is, CD-R can never give you 1:1 exact representation of your source master because of this.. the laser just can not catch 100% of this burned pit and land information... so the result you get from CD-R masters is best to how good the equipment can read these burned marks on your media.

With DDP, the LBR processes raw information and adds a scramble table to the CD sectors for the first time... this is equivalent to burning your CD-R master, but instead, the LBR are burning the proper pits and lands into the glassmaster. THis is why DDP is superior, you simply are getting a 1:1 clone of your source master... with CD-R premasters you are manufacturing copies of your CD-R which is not 1:1 as the original if you run MD5 hash test on them.

You can however get 1:1 clones of a silver compact disc because the proper pits and lands bumps are there to bounce the laser.

The Taiyo Yuden dye currently does the best job at burning these fake pits and lands, thus this is why they produce the lowest error rates in testing, but there are still errors.

CD-R is similar to getting a tan from a tanning salon machine,
DDP is similar to getting a tan on the beach from the actual sun.

I hope this makes sense.

-Will