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Dolby Digital到Dolby Digital Plus在介绍Dolby Digital Plus技术之前,我们简单回顾下Dolby Digital技术的历程。Dolby Digital技术的辉煌时期应该是在后LD时代以及DVD时代的中前期,当然在数字电视时代,Dolby Digi- tal技术依然处于主导地位。要在DVD碟片中容纳下一部影片的图像以及5．1声道的音轨,还要保证DVD出色的画面以及声音效果,Dolby Digital的高效率编码技术可以说立下了头功。也正因为上述原因,Dolby Digital的码率只能小于640K,通常维持在384K左右。此后,杜比公司又公布了Dolby Digital Surround EX技术,在5．1声道的基础上增加了一个后中置声道,成为6．1声道,使得整体包围感尤其是当飞机飞越头顶时可获得更出色的效果。同时考虑到大部分AV系统的兼容性,该后中置声道经过矩阵编码后录制在常规的5．1系统的左/右环绕声音轨中,以保证在使用5．1系统时不会丢失任何细节,当然在声音的定位上要略差一些了。7．1系统方面,杜比公司也
Dolby Digital to Dolby Digital Plus Before introducing Dolby Digital Plus technology, let’s briefly review the history of Dolby Digital technology. The glorious period of Dolby Digital technology should be in the post-LD era and in the early DVD era, of course, in the digital TV era, Dolby Digi- tal technology is still dominant. To accommodate the next movie’s image and 5.1-channel audio tracks on a DVD disc, but also to ensure excellent DVD picture and sound effects, Dolby Digital’s high-efficiency encoding technology can be said that the first work. Precisely because of the above reasons, Dolby Digital bit rate can only be less than 640K, usually maintained at about 384K. Since then, Dolby also announced the Dolby Digital Surround EX technology, based on the 5.1-channel added a rear center channel into a 6.1 channel, making the overall sense of envelopment, especially when the aircraft over the overhead Get better results. Taking into account the compatibility of most AV systems, the rear mid-channel is matrix-encoded and recorded on the regular 5.1 system left / right surround sound track to ensure that 5.1 systems will not Lost any details, of course, in the sound of the positioning to be slightly worse. 7.1 system, Dolby also