{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-9621990","patent":{"patent_number":"US-9621990","title":"Audio decoder with core decoder and surround decoder","assignee":null,"inventors":[],"filing_date":"2016-03-24T00:00:00.000Z","publication_date":"2017-04-11T00:00:00.000Z","cpc_codes":["H04R","G10L","G10L","G10L","G10L","G10L","H04S","H04S","H04S","H04S","H04S"],"num_claims":14,"abstract":"A method performed by an audio decoder for reconstructing N audio channels from an audio signal containing M audio channels is disclosed. The method includes receiving a bitstream containing an encoded audio signal having M audio channels and a set of spatial parameters, the set of spatial parameters including an inter-channel intensity difference parameter and an inter-channel coherence parameter. The encoded audio bitstream is then decoded to obtain a decoded frequency domain representation of the M audio channels, and at least a portion of the frequency domain representation is decorrelated with an all-pass filter having a fractional delay. The all-pass filter is attenuated at locations of a transient. A matrixed version of the decorrelated signals are summed with a matrixed version of the decoded frequency domain representation to obtain N audio signals that collectively having N audio channels where M is less than N."},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Audio decoder with core decoder and surround decoder","description":"A method performed by an audio decoder for reconstructing N audio channels from an audio signal containing M audio channels is disclosed. The method includes receiving a bitstream containing an encode","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-9621990","license":"CC-BY-4.0-like","license_terms":"AI-generated analysis on this page (summary, layman_explanation, technical_analysis, business_analysis, faqs) may be reused with attribution and a visible link back to the canonical URL above. Patent abstracts, claims, and bibliographic data are USPTO public domain.","required_link":"https://patentable.app/patents/US-9621990","citation_suggestion":"Patentable. \"Audio decoder with core decoder and surround decoder\" (US-9621990). https://patentable.app/patents/US-9621990","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-9621990","json":"https://patentable.app/api/llm-context/US-9621990","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-06-06T03:40:13.729Z"}