A transcoder and method of transcoding therefore

Abstract

A transcoder comprises a receiver ( 101 ) which receives input data representing an encoded signal and comprising first encoding data and first parametric extension data. The encoded data is fed to a decoder ( 103 ). The output of the decoder ( 103 ) is fed to an encoder ( 105 ) which generates second encoded data according to a different encoding protocol or with different encoding parameters. The first parametric extension data is fed to an extension data processor ( 109 ) which generates second parametric extension data directly from the first parametric extension data. The second encoded data and the second parametric extension data is combined in an output processor ( 107 ) to generate a transcoded signal comprising separately determined parametric extension data. The parametric extension data may be Spectral Band Replication (SBR) or Parametric Stereo (PS) extension data for an audio bitstream. Improved quality and reduced complexity is achieved by the separate transcoding of the parametric extension data.

Description

technical field [0001] The present invention relates to transcoders and transcoding methods therefor, and in particular to transcoding of audio signals. Background technique [0002] In recent years, there has been a dramatic increase in the distribution and storage of A / V content in digital form. As a result, a number of coding standards and protocols have been developed, including, for example, MPEG-2 audio and video coding. [0003] One of the most widely known coding standards for digital coding of audio signals is the MPEG-1 Layer 3 standard, described in ISO / IEC JTC1 / SC29 / WG11 MPEG, IS11172-3, Information Technology-Coding of Moving Picture and Associated Audio for Digital Storage Media At up to about 1.5 Mbit / s, Part 3: Audio, MPEG-1, 1992 introduced this encoding standard, which is generally called MP3. For example, MP3 enables digital PCM (pulse code modulation) stereo audio recordings of 30 or 40 gigabit songs to be compressed into eg 3 or 4 gigabit MP3 files. T...

AI Technical Summary

Problems solved by technology

[0016] Generally, this will result in a loss of quality

The problem of transcoding is further complicated when encoding schemes are combined with parametric extensions such as SBR and / or PS

Since these extensions represent parts of the signal that have a parametric form, transcoding can be expected to cause greater quality degradation than representing the waveform as faithfully as possible

[0017] Also, the complexity of transcoding may increase due to parametric extensions, since the decoder must process incoming extension data and the encoder must produce new extension data

This may result in, for example, increased cost, increased computational requirements, increased latency, etc.

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