Patent Review
Patent No: US 8,630,861 B2
Publication date: *Jan. 14, 2014
Inventor: Wei-Ge Chen, Sammamish, WA (US); Chao He Redmond, WA (US)
Summary:
A mixed lossless audio compression has application to a unified lossy and lossless audio compression scheme that combines lossy and lossless audio compression within a same audio signal. The mixed lossless compression configures a transition frame between lossy and lossless coding frames to produce seamless transitions. Some of the obstacles wile unifying lossy and lossless audio compression
techniques include:-
Transition between lossy and lossles compression can introduce certain audible discontinuities in the decoded audio signal. In simple words, audible noise can be produced when switching between lossy and lossless compression.
In lossy compression schemes, audio signal samples on an overlapped window basis, whereas lossless compression techniques do not. Redundantly coding the overlapped portion with both lossy and lossless compression may reduce the achieved compression ratio.
To tackle these obstacles, the inventor has provided a solution to divide the signal into frames
(separately for lossy and lossless) and mixed lossless frames that serve as transition between the two other types. These mixed lossless frames are compressed by performing a lapped transform on an overlapping window in the lossy compression case followed by inverse lapped transform to produce a
single audio signal frame, which is losslessly compressed.
Patent link: https://google.com/patents/US8630861B2
Patent No: US 8,630,861 B2
Publication date: *Jan. 14, 2014
Inventor: Wei-Ge Chen, Sammamish, WA (US); Chao He Redmond, WA (US)
Summary:
A mixed lossless audio compression has application to a unified lossy and lossless audio compression scheme that combines lossy and lossless audio compression within a same audio signal. The mixed lossless compression configures a transition frame between lossy and lossless coding frames to produce seamless transitions. Some of the obstacles wile unifying lossy and lossless audio compression
techniques include:-
Transition between lossy and lossles compression can introduce certain audible discontinuities in the decoded audio signal. In simple words, audible noise can be produced when switching between lossy and lossless compression.
In lossy compression schemes, audio signal samples on an overlapped window basis, whereas lossless compression techniques do not. Redundantly coding the overlapped portion with both lossy and lossless compression may reduce the achieved compression ratio.
To tackle these obstacles, the inventor has provided a solution to divide the signal into frames
(separately for lossy and lossless) and mixed lossless frames that serve as transition between the two other types. These mixed lossless frames are compressed by performing a lapped transform on an overlapping window in the lossy compression case followed by inverse lapped transform to produce a
single audio signal frame, which is losslessly compressed.
Patent link: https://google.com/patents/US8630861B2
Well explained.
ReplyDeleteaudible noise can be produced when switching between lossy and lossless compression.
ReplyDeleteNicely explained..Concise and precise
ReplyDeleteAudio compression is useful in applications like speech recognition.
ReplyDeleteInteresting application as it saves memory.
ReplyDelete