Meridian Lossless Packing

Meridian Lossless Packing, MLP, also known as Packed PCM ( PPCM ) or Dolby Lossless known, is a proprietary lossless compression algorithm for digital sound recordings. The format was designed in view of high-resolution audio and multi-channel applications, such as the DVD (audio ) drafted.

History and Future

Was developed and patented Meridian Lossless Packing Meridian Audio of the company and its partners. The marketing of the license is now on the Dolby Laboratories. In the successor to the DVD, the Blu -ray Disc ( also HD DVD ), the MLP - descendant Dolby TrueHD will be used.

Features

Meridian Lossless Packing Pack offers rates of between about 1.5 and about 3 to 1 depending on the number of channels, type of content and resolutions, with most of the savings from the efficiency of the redundancy between the channels gives: More channels means better yield.

It is suitable for audio material with from 44,100 to 192,000 Hz sampling rate, up to 24 bits per sample and up to 64 and different resolution channels.

For this it is easy to implement and decoding requires relatively little computing power - even in the case of six channels with 96 kHz sampling rate and 24-bit sample depth; important for hardware support. MLP contains mechanisms for correcting errors up to a duration of 2 ms, provides an additional channel metadata in the data stream and at least every 30 ms an entry point for the decoder.

Use

DVD-Audio

The Working Group 4 of the DVD Forum decided that the possibility of MLP use on the DVD audio to be incorporated into the specification, to reduce the data rate and thus increase the seasons. This ensures that the defined maximum transmission rate of a DVD-A of 9.6 megabits per second even with 6 channels at 24-bit / 96 kHz (uncompressed 13.8 Mb / sec.) Is not exceeded and for the highest levels of quality of a DVD- Audio ( 192 kHz/24 bit stereo, multi-channel audio bits) at least 74 minutes of playing time per side and layer 96 kHz are possible at 24.

Alternatives

Free and royalty-free formats such as FLAC or WavPack they are ( still) largely on the PC area.

FFmpeg is a custom decoder for MLP and TrueHD.