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What is Meridian Lossless Packing (MLP) ?

DVD-Audio is a format specifically designed to provide the highest possible audio fidelity capable on DVD. The audio fidelity of DVD-Audio far exceeds the quality of conventional CD's and audio on DVD-Video.

DVD-Audio's Limitation

DVD-Audio still has a maximum transfer rate of about 9.6 Megabits-per-second. If you record 6 channels at 24/96, your data rate is 13.8 Megabits-per-second, which exceeds the limitation. How do you get around this problem?

MLP - Meridian Lossless Packing is the data-reduction technique selected for DVD-Audio. MLP sounds better because it is a lossless data algorithm. It is not like MP3 for instance. You get back exactly what you put it, so it does not distort or change any of the audio information. MLP on average reduces the size of the file by about 50%. So, with MLP you can put 6 channels of 24/96 on the disk, and still not hit the 9.6 Mbs data limitation. MLP can also be used to simply get longer recording times onto the disk.

Background

Meridian Lossless Packing, or MLP, is an audio coding scheme using proprietary technology, that has been developed over three years by Meridian Audio and its associates.

Lossless Packing

Unlike perceptual or lossy data reduction, lossless coding does not alter the final decoded signal in any way, but merely 'packs' the audio data more efficiently into a smaller data rate for transmission. MLP is a simple-to-decode method optimised for the new requirements brought about by applications like DVD Audio, and in particular has been optimized to enable more opportunities for multichannel and for audio at high sample rates with high precision.

Why Lossless Packing?

We want to deliver the very best listening experience to end-users. These days that means multichannel for surround sound, more bits to get the highest possible dynamic range and higher sample rates to ensure all the nuances of the performance can be delivered. However, the more bits used and the higher the sampling rate is, the more bandwidth is needed to carry the information. Modern high-rate formats like 96kHz 24-bit are capable of carrying more information than is strictly necessary for the human listener, or than is available from modern microphone and converter techniques. This means that such audio streams contain true redundancy. MLP is an audio coding scheme that discovers the redundancy and packs the audio into a smaller space - but in such a way that a simple decoder can recover the original signal exactly bit-for- bit.

Guaranteed Quality

Currently the highest quality sound comes with Linear PCM coding. Unfortunately, distribution formats like CD and DVD do not require the mastering or playback process to be lossless - that is the data can be subtly changed on the way through the production chain.

MLP is a true lossless system. The original data is delivered bit-for-bit at the playback. It even has a method of confirming that the whole chain is lossless. This means that for the first time, the listener can be sure of hearing exactly what the producer intended - bit-for-bit, note-for-note. There is no need for elaborate listening tests to qualify this coding system - it simply guarantees delivery of the original recording, efficiently, over a number of carriers, archive and computing platforms.

Cascadable

MLP is cascadable. This means that a signal can be encoded and decoded multiple times in succession and the output data will always be an exact replica of the original. For the first time in audio, we have a coding system which guards against generation loss!

 

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