【正文】 s major consumer electronics manufacturers group。 DTS usually use much larger bit rate 1536bps. If other conditions are the same, is a bit more quality is better, this assertion is wrong? Unfortunately, the answer to this question is not so easy, because the Dolby Digital ( abbreviated as DD ) and DTS data pression circuit is different. For example, a coding efficiency very low signal, even if the bit rate is very high, also just wasted bits and disc space, but does not improve sound quality. Once a system is said to be transparent, increase the bit rate without causing it to improve the sound quality. In addition because the DTS bit rate higher than Dolby, need takes up more space, if the DVD disk capacity constraints, may produce adverse effects on image quality, or to increase the additional cd. Dolby ProLogic surround sound ( Dolby Pro Logic ) is Dolby developed a surround sound system. It is the four track stereo recording by a specific encoding means for the synthesis of two channel, the original left channel ( L ), the right channel ( R ), the center channel ( C ), surround channel ( S ) of the 4signal, encoded into LT, RT posite double channel signal, replay through the decoder will encoded twochannel posite signals LT and RT reduction for encoding the left, right, in around four, each stem and independent signal, amplified respectively input left, right, center and surround sound speakers. In order to playback symmetry reasons, surround speakers using the left and right surround speakers, respectively, from the output of the amplifier, so the business to Dolby ProLogic surround sound output called channel five. But due to a left, right surround sound speakers connected in a channel, the output is the same as the surround channel information, the essence is still four channel. The business also has six channels and seven channels Dolby Pro Logic AV amplifier. The six track is the central channel two amplifying circuit is respectively connected with the output, in left center speaker and right center speaker. But left, right center speaker connected to a center channel, it is essentially a four channel. Seven channel surround sound channels is divided into four channel output, . left rear surround, right rear surround sound, and adopts four surround sound, which became a seven channel output. But the output of the seven track four surround speakers are connected in a surround channel, also can calculate the output of four sound channels. So with Dolby Pro logic decoder AV amplifier whether five channel output, six channels of output or the seven output channels, is essentially a four channel. Dolby ProLogic surround sound in the left, right, three channel frequency range can reach 2020210Hz, can meet the full range of requirements, but surround channel frequency range is narrow, only 1007000Hz. Dolby E is designed for digital TV broadcast and postproduction and the design of a 畢業(yè)設(shè)計(jì)（論文）外文資料 5 professional audio coding system. Using the Dolby E, a AES / EBU channel can send up to 8channels of high quality digital audio stream, and also can be loaded Dolby digital control data signals (often called the metadata, including the Dolby digital mono mode, dynamic range, type, output level automatic adjustment of parameters, to ensure that users can correct Dolby digital program ). Dolby E with its advanced coding algorithm and higher data transmission rate, can ensure the digital TV audio signals through as many as 10cycle coding decoding or other editing process, and does not cause quality deterioration. Dolby E audio can be associated with various formats of video signal is a good match, won39。s first production of magic tape recording equipment manufacturers. Later, he is responsible for the development of the pany developed the world39。s first practical VCR portion of an electronic circuit. In 1957 Dolby graduated from Stanford University, University of Cambridge, Marshall won the British provided scholarships, study of Lband X light. In 1961 he received a doctor39。t because video interference blind audio, sound burr or other distortion. Dolby E audio and video frames in the sequence are pletely corresponding, can achieve precise audio and video integrated editing. More importantly, by use of this new type of coding technology, the existing radio and television system without largescale transformation can spread multichannel digital TV audio signals, thereby greatly reducing the system cost. Dolby E application is in digital television stations intermediate transfer, from a local television program transmitted by satellite to another local TV station. Dolby E in conveying to the transmitting terminal will be converted to PCM audio, and then encoded into Dolby digital signal, transmitted to thousands of households. Therefore, consumers in the home can be directly received by Dolby E signal, but only receives a digital signal on channel . In order to avoid the confusion, usually Dolby E called transfer coding system, and Dolby will be called to launch digital coding system. Dolby E standard data transfer rate is / sec (20bit / 48kHz for audio signal ), typical operating mode is +2, using six channel transmits a surround sound signal, the other two channel transmission of twochannel matrix coding signal ( such as Dolby ProLogic surround sound ) or dual mono stereo signal. Can also work in other modes, such as with two mono signal+1+1 pattern, three way stereo signal 3x 2 mode and a six single channel signal6x 1 mode. Dolby39。 for each license 畢業(yè)設(shè)計(jì)（論文）外文資料 9 production of the product prototype ( prototype ) test。 the disadvantage of reducing coding efficiency, because of the need to transfer the bit allocation information while occupying a part effective bits. To the adaptive method did not get encoder clear bit allocation