CD and DVD Resource – CD DVD Information, CD formats, DVD formats, Mastering Enhanced Discs





		How long can the CD and DVD formats survive? There has been no shortage of speculation on the survivability of the physical disc formats. Speculators have been predicting the demise of the optical disc for years. Even Bill Gates weighed in on the subject in a 2005 speech that predicted the end of the optical disc formats altogether (CD, DVD and even Blu-ray). So, why haven’t all the CD and DVD manufacturing shops shuttered their windows and closed their doors? The fact that this has not materialized (many years later) may indicate that there are other forces at work here. There is no doubt that usage of CDs and DVDs is down in some sectors – there are indicators that the numbers of manufactured retail discs and sales of optical media have dropped. For the most part, this is because more consumers are downloading content and/or choosing to view their movies and programs from on-demand services, which are growing in numbers and sophistication. However, one can argue that there is and always will be a need for some kind of physical media in some shape or form for specific scenarios… so why not the Optical CD/DVD? Perhaps the most significant fact keeping the optical disc format alive is that the CD/DVD formats are the most cost-effective portable memory format in existence! The closest portable memory format to the CD or DVD is the USB thumb drive. The cost to manufacture a basic USB (with comparable memory to a CD-ROM) is at 10 - 20 times higher than the cost to manufacture a disc, and that doesn’t include loading the data to the USB! The optical disc (Audio CD, CD-ROM, DVD Video and DVD-ROM) is manufactured using only 3 basic components: polycarbonate, aluminum, and laquer. From a manufacturing standpoint, there is no comparable media (from a cost per MB standpoint) that can compete with the optical formats. The only thing that may compete with the CD right now is, oddly, the Internet and On-Demand technologies. But, these aren’t free either! (take a look at your yearly Cable bill, Satellite bill, and/or Internet Service bill, and you’ll realize this fairly quickly!) Not only is the optical disc technology the most cost–effective to manufacture, but it is also the most widely-adopted portable physical media format in the world today…. Optical disc technology is found in most computers, virtually all vehicles, portable stereo systems, and in most homes around the world. So, if the optical formats (which include CD, DVD and Bluray) are the most cost-effective to manufacture and are the most widely adopted, then why would we expect them to disappear overnight? We likely will not see the format disappearing anytime soon. Will there ever be a more cost-effective format? That remains to be seen (most likely, it will be when a new optical format is released, such as a next generation optical disc, as was the case with Bluray discs – which is basically an upgrade to the original optical technology). The fact is there will always be a need to store and distribute physical content cheaply and securely. Optical discs will likely be there to fill that gap for a long time to come. What is the difference between a PRESSED and BURNED CD or DVD? Although the discs may look very similar, there is a world of difference between a Recordable disc that has been burned, and a “Pressed” (or “Glass Mastered”) disc that has been manufactured. Before going into the specifics of RECORDABLE versus MOLDED DISCS, it would help to explain the very fundamentals of how a disc plays music or video. Let’s use the AUDIO CD as an example. How an Audio CD plays “music”. First, a standard Audio CD is said to have 16 bits and 44.1 khz/s. These specifications actually refer to a digital alphabet. But, unlike the English alphabet with 26 letters, this digital alphabet only has 2 letters – which are 0 (off) and 1 (on) ! The term 16 bits refers to the number of letters in each digital word (Example: 0101010101010101 would be a 16-bit digital letter! A 16 bit digital alphabet would actually provide 65,536 possible combinations (the digital “vocabulary”). The 44.1khz refers to how many of these “digital letters” would be read in a second off of a compact disc (44,100 per second). In effect, the laser reading a CD is actually reading 44,100 words made up of 16 digital letters per word (“1’s” and “0’s”) each and every second! That data forms the information that the computer translates to music from an Audio CD. Now back to our question… how is a recordable CD-R or DVD-R different from a Pressed CD or DVD? For a recordable disc, the digital letters ON (1) and OFF (0) are represented by holes that are shot through a layer of DYE on the CDR by a recording laser. The laser shoots this hole to represent an OFF (0) letter and leaves the DYE intact to represent an ON letter (1). This is why this process is refered to as “burning” a disc... i.e. the disc is actually being burned with holes by a laser in the photo-sensitive dye layer of the disc! On a pressed disc, however, the disc is manufactured with microscopic bumps (ON) and valleys (OFF) to represent the two digital letters of the digital alphabet. A Glass master is used to produce a piece of nickel that acts as the stamper for the CD (same applies to DVDs and even Bluray). Each manufactured CD would have a unique custom nickel stamper. The stamper has all of the hills and valleys of the Master CD on it, and is used to transfer the information to the finished disc in a molding process that molds plastic pellets (polycarbonate) to the finished product. To watch a video of the CD/DVD/Bluray molding process, click here. Although these discs are all the same size and similar color and shape, the underlying technology and manufacturing process differs tremendously. So now you know…. CD-R (recordables) and CD-ROMs (read-only memory) are not all the same! To recap: A “pressed” disc with music or video on it would be manufactured with the data imprinted right on the copies. A Recordable CD, DVD or Bluray disc is actually manufactured with a DYE that can be written to with a laser device. Before there were recordable discs, the original CD and DVD players were only able to PLAY discs and not WRITE to them. These players used lasers to read bumps and pits on the surface of the disc and convert the data stream to binary for a computer or a chip to translate into sounds, videos, images, etc. Recordable CD , DVD and Blu-ray Drives have the added ability to burn holes in the DYE of a recordable disc, thereby allowing small scale production of CDs and DVDs.

		What are the different CD /DVD optical disc formats? CD (Compact Disc): CD (or compact disc) is a broad term used to describe all 12cm (5”) discs that have a capacity of 650MB/700MB or hold 74/80minutes of Audio. The exists several formats: AUDIO CD – the standard music CD format which plays in car stereos and boom boxes. MP3 CD – a newer format that works with select players that support MP3 audio only, the MP3 CD can be used to play music in computers and audio players that support MP3 playback. DATA CD – this is the standard computer disc format used for storage of data. It can be further broken down into different burning formats, such as ISO, DDP, Mac, PC, etc Enhanced CD – this is an AUDIO CD that has a data section which can be used to store video, pictures, MP3s or other computer-related data also. Mini-CD (mini compact disc): A mini CD is a 3” round disc that can be used to store audio, video or computer data with a capacity of 180MB/200MB or 20 – 22 minutes of CD-quality audio. The mini-round disc can be used in most tray-style and clip-on style drives, but their use in drives that suck the disc in for playback are not recommended. Always refer to your player’s instruction manual before using a mini-CD in your player. DVD-5 Video DVD-5 Video is a single layer DVD with a capacity of 4.5GB/4.7GB formatted to playback video in a standard DVD player. Because the DVD-5 contains only a single layer of usable data, it is used primarily for shorter programs and is more common for short movies, tv programs and corporate or instructional DVDs that are typically less than 1 hour. Although you can fit more than 1 hour of video on a DVD, the video will need to be compressed to fit. The more compressed a video is, the lower the quality of the image. It is typically not suggested to include more than 120 minutes of video on a DVD-5 for most projects. DVD-9 Video A DVD-9 Video is the dual layer version of the DVD-5. The capacity of a DVD-9 is 8.5GB/8.7GB formatted to playback video in a standard DVD player. The majority of full length feature films are replicated onto the DVD-9 format in order to maintain picture quality. Longer feature films may require a second disc and sometimes the second disc need only be a DVD-5. DVD-ROM DVD-ROM refers to the computer data format of the DVD. This format will not play back in DVD players. Rather, this format is used to store computer data, computer programs, or large databases of images and files. The DVD-ROM can be manufactured in either single layer (4.5GB/4.7GB) or dual layer (8.5GB/8.7GB) formats for extra capacity. Mini-DVD A mini DVD is a 3” round disc that can be used to store video or computer data with a capacity of approx 1.2GB. The mini-round disc can be used in most tray-style and clip-on style drives, but their use in drives that suck the disc in for playback are not recommended. Always refer to your player’s instruction manual before using a mini-DVD in your player.

		Are all CDs and DVDs equal? The short answer is No. Not all CDs and DVDs are created equal. Besides the difference between recordable discs and pressed discs, there are a variety of different injection molding machines ranging from the original manufacturing lines of the late 80’s and early 90’s to the much more efficient, faster and automated manufacturing lines manufactured in the past 5 years. The technology has advanced tremendously over the past couple of decades, and continues to evolve. Some manufacturers are still running the same lines from the early nineties. It is best to work with a CD or DVD manufacturer that has updated manufacturing lines. Click here to see a video of a plant running the latest technology for CD/DVD. I am a musician… should I burn, or should I press my CD? The question of burning versus pressing a Music CD is actually not a complicated one. Simply put, if you anticipate you will sell more than 500 discs during your lifetime, it is cut and dry…. Get your discs professional pressed! The cost will often be lower than burning CDs at this quantity. If you don’t think you can sell (or even giveaway) 500 discs if your life depended on it, consider getting 50 or 100 burned discs made up. The advantages of a pressed disc are many: Five reasons why you should Press your CD, not burn it: A professional can tell the difference at a single glance The discs can be tracked by radio stations (using the ISRC code system) The discs will have important identifying codes inscribed in the mirror band, which help identify counterfeits! The cost is actually lower (when running a minimum 500 or more discs) The quality of the finished product is better. Conclusion: Since it costs less, and offers the advantages listed above… why not have your CD manufactured in the same way as all of the famous big-named artists?

		How should I prepare my Master CD or DVD for mass replicating? Microforum Services Group has some great tips on preparing your Master CD or DVD for mass replicating. Following these tips will ensure your product can be manufactured for the masses without any problems. How can I create an Audio CD with a bonus video on it (i.e. an enhanced CD)? an Enhanced Audio is a lot like making two discs within a disc. Most popular CD burning software will allow you to burn a multiple sessions on one CD. To create an Enhanced Audio CD, it is very important that you burn your Audio CD first using your music files and leave the session open. Afterwards, you can create a regular data CD and add videos, pictures, or anything you like. Use your CD burning software to burn this on the same CD you burned the music on and this time, make sure you close the session or finalize the CD. You can test your CD by playing it in a Standard CD Player in a car. When you place the CD in your computer, you will notice it will have two separate sections, the music that will play in iTunes or Windows Media Player, and the data that you can see in your file explorer. This is normal as the music section is treated as it's own CD and the data is treated as another CD. How can I create a DVD Video with a bonus PDF file or other data files for computer use (i.e. an enhanced DVD)? Creating an Enhanced DVD Video can be easily done with most DVD Authoring Softwares such as Adobe Encore or Apple DVD Studio Pro. First, the DVD Video must be authored according to the software's instruction manual. Once you've finished this, place all the files you wish to use in a single folder on your computer. Refer to the software's instructions on how to include this data on your DVD and burn your disc. You can test your DVD by playing it in a Standard DVD Player. When you place the DVD in your computer, you will see an “AUDIO_TS” and “VIDEO_TS” along with whatever data you have included on the DVD.



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