What is DVD?

DVD stands for Digital Versatile/Video Disc, DVDR stands for DVD Recordable and DVDRW for DVD ReWriteable. If you're familiar with regular audio/music CDs or regular DVD-Video discs, then you will know what a recordable DVD looks like. A recordable DVD stores up to 2 hours of very good quality DVD-Video, including several audio tracks in formats like stereo, Dolby Digital or DTS and also advanced menu systems, subtitles and still pictures that can be played by many standalone DVD Players and most computer DVD-ROMs. If you choose to lower the video quality it is possible to store several hours video on a recordable DVD using low bitrates and low resolution with video quality more like VHS, SVHS, SVCD, CVD or VCD. It is also possible to have up to 4.37 GB ordinary data or mix DVD-Video and data on a recordable DVD that can be played by most computer DVD-ROMs. There are three competing DVD Recording standards, DVD-R/DVD-RW and DVD+R/DVD+RW have pretty similiar features and are compatible with many standalone DVD Players and most DVD-ROMs while DVD-RAM has less DVD Player and DVD-ROM compatibility but better recording features.

DVD-R and DVD-RW

DVD-R was the first DVD recording format released that was compatible with standalone DVD Players. DVD-R is a non-rewriteable format and it is compatible with about 93% of all DVD Players and most DVD-ROMs. DVD-RW is a rewriteable format and it is compatible with about 80% of all DVD Players and most DVD-ROMs. DVD-R and DVD-RW supports single side 4.37 computer GB DVDs(called DVD-5) and double sided 8.75 computer GB DVDs(called DVD-10).

DVD+R and DVD+RW

DVD+R is a non-rewritable format and it is compatible with about 89% of all DVD Players and most DVD-ROMs. DVD+RW is a rewritable format and is compatible with about 79% of all DVD Players and most DVD-ROMs. DVD+R and DVD+RW supports single side 4.37 computer GB DVDs(called DVD-5) and double side 8.75 computer GB DVDs(called DVD-10).

DVD+R DL

DVD+R DL or called DVD+R9 is a Dual Layer writeable DVD+R. The dual layered discs can hold 7.95 computer GB (called DVD-9) and dual layered double sides 15.9 computer GB (called dvd-18).

DVD-R DL

DVD-R DL or called DVD-R9 is a Dual Layer writeable DVD-R. The dual layered discs can hold 7.95 computer GB (called DVD-9) and dual layered double sides 15.9 computer GB (called dvd-18).

DVD-RAM

DVD-RAM has the best recording features but it is not compatible with most DVD-ROM drives and DVD-Video players. Think more of it as a removable hard disk. DVD-RAM is usually used in some DVD Recorders.

DVD Sizes

The DVD sizes can be a bit confusing. There are basicly 4 different DVD Sizes:

DVD-5
holds around 4 700 000 000 bytes and that is 4.37 computer GB where 1 kbyte is 1024 bytes. DVD+R/DVD+RW and DVD-R/DVD-RW supports this format. Also called Single Sided Single Layered. This is the most common DVD Media, often called 4.7 GB Media.

DVD-10
holds around 9 400 000 000 bytes and that is 8.75 computer GB. DVD+R/DVD+RW and DVD-R/DVD-RW supports this format. Also called Double Sided Single Layered.

DVD-9
holds around 8 540 000 000 bytes and that is 7.95 computer GB. DVD+R supports this format. Also called Single Sided Dual Layered. This media is called DVD-R9, DVD-R DL, DVD+R9, DVD+R DL or 8.5 GB Media.

DVD-18
holds around 17 080 000 000 bytes and that is 15.9 computer GB. DVD+R supports this format. Also called Double Sided Dual Layered.

NOTE: In the computer world is 1 KB data = 1024 bytes so 4 700 000 000 bytes / 1024 = 4 589 843KB / 1024 = 4482MB / 1024 = 4.37GB.

DVD+R/DVD+RW/DVD+R DL and DVD-R/DVD-RW exact sizes

DVD-R/DVD-RW = 4 706 074 624 bytes ( 4488 MB )
DVD+R/DVD+RW = 4 700 372 992 bytes ( 4482 MB )
DVD+R DL = 8 547 993 600 bytes ( 8152 MB )


DVD Write and read speeds

Single Layer(4.7GB) write speeds

1x (CLV) = about 58 minutes
2x (CLV) = about 29 minutes
2.4x (CLV) = about 24 minutes
4x (CLV) = about 14.5 minutes
6x (CLV/ZCLV) = about 10-12 minutes
8x (PCAV/ZCLV) = about 8-10 minutes
12x (PCAV/ZCLV) = about 6.5-7.5 minutes
16x (CAV/ZCLV) = about 6-7 minutes

Dual/Double Layer(8.5GB) write speeds

1x CLV = about 105 minutes
2.4x CLV = about 44 minutes
4x CLV = about 27 minutes

Single Layer (4.7GB) read speeds

1x read speed is 1.321MB/s = ~56 minutes
6x CAV (avg. ~4x) read speed is max 7.93MB/s = ~14 minutes
8x CAV (avg. ~6x) read speed is max 10.57MB/s = ~10 minutes
12x CAV (avg. ~8x) read speed is max 15.85MB/s = ~7 minutes
16x CAV (avg. ~12x) read speed is max 21.13MB/s = ~5 minutes

NOTE: write speed time and read speed time is not the same because writing requires some extra steps and also does the faster writing above 6x usually use lower write speeds for some parts of the dvd. 4x DVD speed = 36x CD speed.

 

Pilfered word-for-word from Videohelp.com:

http://www.videohelp.com/dvd

 

????? Pilfered word-for-word from Videohelp.com
hey, i never said it was my writing and i just want more people can see it!