Adapting masking thresholds for encoding a low frequency...

Data processing: speech signal processing – linguistics – language – Audio signal bandwidth compression or expansion

Reexamination Certificate

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Reexamination Certificate

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07627481

ABSTRACT:
An improved audio coding technique encodes audio having a low frequency transient signal, using a long block, but with a set of adapted masking thresholds. Upon identifying an audio window that contains a low frequency transient signal, masking thresholds for the long block may be calculated as usual. A set of masking thresholds calculated for the 8 short blocks corresponding to the long block are calculated. The masking thresholds for low frequency critical bands are adapted based on the thresholds calculated for the short blocks, and the resulting adapted masking thresholds are used to encode the long block of audio data. The result is encoded audio with rich harmonic content and negligible coder noise resulting from the low frequency transient signal.

REFERENCES:
patent: 5394473 (1995-02-01), Davidson
patent: 5502789 (1996-03-01), Akagiri
patent: 6128593 (2000-10-01), Hu
patent: 6195633 (2001-02-01), Hu
patent: 6240379 (2001-05-01), Yin
patent: 6308150 (2001-10-01), Neo et al.
patent: 6453282 (2002-09-01), Hilpert et al.
patent: 6456963 (2002-09-01), Araki
patent: 6772111 (2004-08-01), Araki
patent: 6799164 (2004-09-01), Araki
patent: 2006/0161427 (2006-07-01), Ojala
Chang et al. “On the Possibility of Only Using Long Windows in MPEG-2 AAC Coding”. Lecture Notes on Computer Science, LNCS 253, 2002, pp. 663-670.
Chang et al, “Using Only Long Windows in MPEG-2/4 AAC Encoding,” Lecture Notes in Computer Science Lhrcs 3333, 2004, pp. 151-158.
ISO/IEC FCD 14496-3 Subpart 4, May 15, 1998. In: Information Technology—Coding of Audiovisual Objects [CD-ROM], 4 files. (References on enclosed CD-ROM).
Grill, B. et al., ISO/IEC FCD 14496-3 Subpart 1, May 15, 1998. In: Information Technology—Very Low Bitrate Audio-Visual Coding [CD-ROM]. (References on enclosed CD-ROM).

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