Transfer rate: refers to the amount of information that is transferred in one second and can be between 150KB / s (first types units of CDs) and over 3000 KB / s (in modern units). Transfer rate depends primarily on the access time and operating speed CD drive.
Throughput: is a parameter that directly influences the transfer rate and access time is determined and compared with the first type of CD singles named speed, working with a transfer from 150KB/second and who have developed then 2xSpeed speeds, the 4xSpeed, the 8xSpeed etc. is now reaching up to 24x, which corresponds, at least theoretically, a transfer rate of 300KB/s. This way at higher speeds such as 32x 24x, 42x or 52x transfer rate is very high.
Successor is conventional music CD SACD (Super Audio Compact Disc). Now, this standard can be used only one player specific. The standard has not yet been implemented.
On SACD technology is much improved, as one of the barriers between technologies is the Super Audio CD DSD (Direct Stream Digital). Simple in fact, DSD is the shortest route between their place of registration and listener’s year. Standard recording format uses filters for recording and playback, adding a degree of noise tolerance. DSD remove all filters, recording the original signal on a bit directly on Super Audio CD unprecedented for an audition.
Super Audio CD playback offers high quality CD for both standard and new format for Super Audio CD. Hybrid Super Audio CD layer is another format for SACD and CD conventional format.
Recording. PCM (Pulse Code Modulation) used for conventional CDs decimation filter requires a filter to record and copying the playback example. For example the input signal is passed through a modulator delta-sigma at 1 – bit (64fs), after which is the last print a decimation filter that processes the signal from one bit to 20 bit and this is the signal recorded on CD in the CD conventional signal. From the CD the 20 bit is passed through digital interpolation filter which changes it to 24 bit signal after entering the delta-sigma modulation action to recover the 1bit signal (64fs), it eventually passes through a low pass filter that processes the analogue signal processing the output signal. After this whole entire process input signal is identical with output signal, with small exceptions. These small exceptions were corrected by SACD technology, where DSD eliminate the need of using all these filters, allowing sound to be recorded directly in the original format a bit.
Processing technology PSP (Pit Signal Processing) is a warranty that offers quality and a SACD recording original technology. This prints an invisible watermark on the disc in the form of text or images, which provide the best sound possible at the moment for music.
DVD: The CD recording space varies depending on the technology, i.e. the higher the Mule pits even more space to win the specifications for diameter 120mm.Defining the specifications for the CDs successor followed a different path, with arguments, confusion and manoeuvring. It all started bad with Mathsushita Electric and filmmakers Thoshiba Time / Warner with their technology for the Super Disc (SD) on the one hand, and Sony and Philips with their technology Multimedia CD (MMCD), the other part. The two disc formats were incompatible, asking if victory is possible for the VHS / Beatmax. Under the IT industry pressure, major manufacturers’ consortium formed to develop a single DVD standard. DVD_ROM standard, resulted in late 1995, was a compromise between the two technologies.
So the DVD is the successor to the CD, this format is more reliable, data recording area be they audio, video is bigger. The first commercial DVD-18 title, The Stand, was created in October 1999. But to achieve 18 DVD currently, will pass through a stage intermediate-DVD 14 – (two layers on one side, a layer on the other side) because it was easy produced. Besides the physical formats exists two application formats: DVD Video and DVD-Audio.
With a size similar to the CD (120mm diameter and 1.2 mm thick), the DVD gives us a storage space of up to 17GB with transfer rates higher CD-ROM and CD access time similar -ROM.
DVD formats
Unlike CDs, there are five physical formats (books) of DVD
DVD-ROM drive is a high capacity storage medium
DVD digital video storage support of feature films
DVD-Audio is similar to CD audio format
DVD-R provides a single registration and is similar to CD-R’s
DVD-RAM Rewritable DVD was the first product arrived in stores and appeared as a result of competition between DVD-RW and DVD RW
DVDs can have different capacities:
DVD-5 disc is single-sided, single layer 4.7 GB capacity
DVD-9 is single-sided disc with two layers, with 8.5 GB capacity
DVD-10 will be a dual disc with a single layer, with 9.4 GB capacity
DVD-18 will increase capacity to 17 GB and will be double, double layer
In general, the DVD began to gain as many positions, computer games began to be printed on DVD and games for TV consoles. At the latest cameras videotape is becoming history. New standards were introduced (for example: DVD recording directly on the recording camera). The format for the camera is unlike any other in both in diameter as capacity. There are many possibilities, we must give free rein to imagination and entertainment will come by itself.
