Compatibility of DVD

DVD is compatible with most other optical media storage (but there is a distinction between DVD and DVD-ROM below:

• CD audio (CD-DA) -- All DVD players and drives will read audio CDs (Red Book). This is not actually required by the DVD spec, but so far all manufacturers have stated that their DVD hardware will read CDs. On the other hand, you can't play a DVD in a CD player. (The pits are smaller, the tracks are closer together, the data layer is a different distance from the surface, the modulation is different, the error correction coding is new, etc.)
• CD-ROM is compatible with DVD-ROM -- All DVD-ROM drives will read CD-ROMs (Yellow Book). However, DVD-ROMs are not readable by CD-ROM drives.
• CD-R maybe compatible with DVD-ROM -- The problem is that CD-Rs (Orange Book Part II) are invisible to DVD laser wavelength because the dye used in CD-Rs doesn't reflect the beam. This problem is being addressed in many ways. Sony has developed a twin-laser pickup in which one laser is used for reading DVDs and the other for reading CDs and CD-Rs. Samsung has also announced dual-laser using a holographic annular masked lens. These solutions provide complete backwards compatibility with millions of CD-R discs. Philips has also stated that its DVD-ROM drives will read CD-Rs. In addition, new CD-R Type II blanks that will work with CD-ROM and DVD are supposedly in development. In the meantime, some first-generation DVD-ROM drives and many first-generation DVD-Video players will not read CD-R media.
• Is CD-RW is compatible with DVD -- CD-Rewritable (Orange Book Part III) discs can not be read by existing CD-ROM drives and CD players. CD-RW has a lower reflectivity difference, requiring automatic-gain-control (AGC) circuitry. The new MultiRead standard addresses this and some DVD manufacturers have already suggested they will support it. Supposedly the optical circuitry of DVD-ROM drives and DVD players is good enough to read CD-RW. CD-RW does not have the invisibility problem of CD-R .
• Video CD maybe compatible with DVD -- It's not required by the DVD spec, but it's trivial to support the White Book standard since any MPEG-2 decoder can also decode MPEG-1 from a Video CD. Panasonic, RCA, Samsung, and Sony models play Video CDs. Japanese Pioneer models play Video CDs but American models don't. Toshiba players don't play Video CDs

  VCD resolution is 352x288 for PAL and 352x240 for NTSC. The way most DVD players and Video CD players deal with the difference is to chop off the extra lines or add blank lines. When playing PAL VCDs, the Panasonic and RCA NTSC players apparently cut the entire 48 lines (17bottom and none off the top. The Sony looks better. [Does anyone know if it cuts 24 lines off the top and the bottom, or if it scales the full picture to fit?]

  Most DVD-ROM computers will be able to play Video CDs (with the right software), since its already possible with current-model CD-ROM computers.

  Note: Many Asian VCDs achieve two soundtracks by putting one language on the left channel and another on the right. They will be mixed together into babel on a stereo system unless you adjust the balance to get only one channel.

• Photo CD is NOT compatible with DVD -- DVD players could support Photo CD with a few extra chips and a license from Kodak. No one has announced such a player. Most DVD-ROM drives will read Photo CDs (if they read CD-Rs) since it's trivial to support the XA and Orange Book multisession standards. The more important question is, ``Does the OS or application support Photo CD''
• CD-I NOT compatible with DVD -- Most DVD players will not play CD-I (Green Book) discs. However, Philips has announced that it will make a DVD player that supports CD-I. Some people expect Philips to create a DVD-I format in attempt to breathe a little more life into CD-I (and recover a bit more of the billion or so dollars they've invested in it).
• Enhanced CD is compatible with DVD -- DVD players will play music from Enhanced Music CDs (Blue Book, CD Plus, CD Extra), and DVD-ROM drives will play music and read data from Enhanced CDs. Older ECD formats such as mixed mode and track zero (pregap, hidden track) should also be compatible, but there may be a problem with DVD-ROM drivers skipping track zero (as has been the case with some new CD-ROM drivers).
• Laserdisc is NOT compatible with DVD -- Standard DVD players will not play laserdiscs, and you can't play a DVD disc on any standard laserdisc player. (Laserdisc uses analog video, DVD uses digital video; they are very different formats.)

  However, Pioneer and Samsung have announced combo players that will play laserdiscs and DVDs (and also CDVs and audio CDs). Denon is rumored to have an LD/DVD player in the works also.