LiFe
29th December 2005, 00:07
TG Daily (http://www.tgdaily.com/2005/12/27/mpeg-4_als_lossless_audio_standard/)
JCN Newswire features a press release this morning from Japan's NTT Corporation, announcing that the lossless audio encoding standard it proposed three years ago for inclusion in the MPEG-4 codec, has formally been approved. The result is an amended MPEG standard called MPEG-4 ALS (Audio Lossless Coding):
"It is known that we have already used some of standard audio coding schemes such as MP3 and AAC or one for minidisc. These are all perceptual coding that offer a high compression ratio at the penalty of minor waveform distortion at the decoder. These approaches carefully control the quantization distortion based on the characteristics of human hearing. The waveform is different from the original, although perceptually very close to it.
In contrast to perceptual coding, lossless coding assures perfect reconstruction of the waveform without a single bit of difference. This is very important for applications such as waveform editing and archiving high-quality audio signals. At the cost of perfect reconstruction, the compression ratio is limited and the compressed file size varies from 15 to 70 % of the original depending on the statistical properties of the original waveform...The compression performance, however, outperforms ZIP."
JCN Newswire features a press release this morning from Japan's NTT Corporation, announcing that the lossless audio encoding standard it proposed three years ago for inclusion in the MPEG-4 codec, has formally been approved. The result is an amended MPEG standard called MPEG-4 ALS (Audio Lossless Coding):
"It is known that we have already used some of standard audio coding schemes such as MP3 and AAC or one for minidisc. These are all perceptual coding that offer a high compression ratio at the penalty of minor waveform distortion at the decoder. These approaches carefully control the quantization distortion based on the characteristics of human hearing. The waveform is different from the original, although perceptually very close to it.
In contrast to perceptual coding, lossless coding assures perfect reconstruction of the waveform without a single bit of difference. This is very important for applications such as waveform editing and archiving high-quality audio signals. At the cost of perfect reconstruction, the compression ratio is limited and the compressed file size varies from 15 to 70 % of the original depending on the statistical properties of the original waveform...The compression performance, however, outperforms ZIP."