 | tel: 01892 861 730 |
| tel: 01892 861 730 |
Digital Versatile Disc (DVD-Video, DVD-ROM) |
DVD, the large capacity media that is quickly taking over the world!!! DVD doesn't stand for Digital Video Disc as most would assume, the format was designed as an incredibly large-capacity storage format (4.7g to 17g capacity compared to CD's 0.7g), with the large capacity providing a perfect platform for high definition video and audio signals. DVD-Video Discs are DVD discs mastered using the MPEG-4 standard to store an entire high quality movie, plus one or more soundtracks (a Dolby Digital version, sometimes a DTS track, and of course several languages of those soundtracks). |
DVD-Audio (DVD-A) |
DVD-A is a relatively new audio focussed application using the DVD hardware. Rather than hold large amounts of video in MPEG-4 format as with DVD-Video, the large capacity of DVD media is dedicated to storing music not only in 6 channels (rather than the classic stereo 2 channels) as with Surround Sound movie soundtracks, but also in Advanced Resolution Audio format. A higher recording quality than CD and Dolby Digital or DTS. These discs very often have video material on too (such as music videos, bonus features, lyrics). True DVD-Audio discs made using the Advanced Resolution Audio format will require a specifically compatible DVD player to play them. However, many recording studios are also including the soundtrack in DTS or Dolby Digital format as well. The advantage of this is that any player is compatible, but DTS or Dolby Digital cannot offer the higher sound quality of Advanced Resolution Audio. |
Super Audio CD (SACD) |
SACD is very similar to DVD-A. Rather than be based on DVD technology, SACD disks are more like CDs with a high resolution layer on them. Pure SACDs will only playback in dedicated SACD players, or DVD players compatible with the technology. These discs use similar high quality compression to DVD-A and many are mastered in 6 channel surround too. Hybrid SACD disks are more like a cross between SACD and CD, standard CD players can playback these discs playing the Hybrid layer, and dedicated SACD decks would play the higher quality SACD layer. |
Compact Disc (CD) |
A CD is the term for the physical disc that digital music commonly comes on and doesn't necessarily mean it is a disc that will play music when put in a CD player. If the CD is encoded in Compact Disc Digital Audio (CD-DA) format then this is the case. But CDs can also be used to store files for computers (CD-ROM), interactive audio visual content as Compact Disc Interactive (CD-I), photos as Kodak Photo CD, and DVD-Video's unpopular (in the UK at least) predecessor Video Compact Disc (VCD) and Super VCD (SVCD). |
Mpeg Layer 3 (MP3) |
MP3 is a compression algorithm that compresses music to a much smaller size than a CD would. So if music was stored as an MP3 file you could fit 10, 20 maybe even 50 times more songs on! However, the more you compress a song the worse it sounds and even the highest quality MP3s are easily outshone by a quality CD. While some CD and DVD players have started picking up on MP3 playback, it is still a PC format that requires a PC to create and playback. |
DIVX |
DIVX hasn't had anywhere near the level of publicity that MP3 has, yet it is remarkably similar. The main difference being the a DIVX is essentially a compressed DVD!!! At a high compression rate (again severely affecting quality) it is possible to even fit a whole DVD movie onto a single CD. As with MP3s this will require a PC to play and very few consumer DVD players are able to play the format. |
Recordable DVD Formats (DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM) |
The hot subject of the moment for potential DVD Recorder buyers. In short, whether you go for a DVD-R/RW or DVD+R/RW recorder you won't notice any difference between the two formats (except maybe for the cost of blank discs) and over time more and more players are offering both formats anyway!! DVD-R and DVD+R are both write once formats, with DVD-R having more success playing in older DVD players with DVD+R only tending to work in newer models. DVD-RW and DVD+RW are re-recordable formats with -RW being fractionally more compatible with older players than +RW. The odd one out is still DVD-RAM though. Where RW discs (of the plus or minus type) use a linear recording format, RAM uses Random Access Memory (as the acronym would suggest). This means DVD-RAM devices are much more capable of recording information onto a disc, whilst playing a different track of off the disc, at the same time. DVD-RAM media is also notably more robust lasting many thousands of rewrites where DVD-RW or DVD+RW would only last a thousand. However, DVD-RAM will only playback in devices specifically made to be compatible. |