What does Dolby of iQiyi do?

Dolby of iQiyi is used to improve stereo quality and provide users with a better audio-visual experience.

The Dolby of iQiyi is Dolby Pro Logic, which is a surround sound system developed by Dolby Company in the United States. Dolby surround system is a cinema sound system successfully developed by Dolby Laboratories in the United States to improve stereo quality.

Four-channel stereo is synthesized into two channels by a specific encoding method during recording, that is, the original four signals of left channel (L), right channel (R), middle channel (C) and surround channel (S) are synthesized into LT and RT composite dual-channel signals after encoding, and the encoded dual-channel composite signals LT and RT are restored to four encoded left, right, middle and surround signals by a decoder during playback.

In order to make ordinary families enjoy similar effects to cinemas, Dolby Laboratories has simplified and concentrated the Dolby stereo film system, and successively introduced Dolby surround sound system and Dolby directional logic surround sound system. Dolby power amplifier, which we often talk about, mostly refers to AV power amplifier with Dolby directional logic surround sound decoder and certified by Dolby Lab.

Extended data:

Dolby professional logic principle:

Dolby directional logic surround sound for sound symmetry, surround speakers use left surround speakers and right surround speakers, which are respectively output from the power amplifier, so the output of Dolby directional logic surround sound is commercially called five channels. However, because the left and right surround speakers are connected to one channel and output the same surround channel information, they are still four channels in essence.

There are also six-channel and seven-channel Dolby directional logic AV amplifiers in commerce. The so-called six-channel is to output the center channel with two amplification lines, which are connected to the left center speaker and the right center speaker respectively. But the left and right center speakers are connected to a center channel, so it is actually four channels.

Seven-channel is to divide the surround sound channel into four channels for output, that is, left rear surround sound and right rear surround sound, and use four surround speakers respectively, which becomes seven-channel output. The four surround speakers of seven-channel output are all connected to one surround channel, which can only be regarded as four-channel output.

Therefore, AV power amplifier with Dolby directional logic decoder, whether it is five-channel output, six-channel output or seven-channel output, is essentially four-channel. The frequency range of left, middle and right channels of Dolby directional logic surround sound can reach 20-20000Hz, which can meet the requirements of the whole range, but the frequency range of surround sound channels is relatively narrow, only 100-7000Hz.

References:

Baidu Encyclopedia-Dolby Professional Logic