Low complexity mpeg encoding for surround sound recordings
AssigneeSTMicroelectronics Asia Pacific Pte.Ltd.
InventorsSamsudin ., Sapna George
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Abstract
The invention provides for the encoding of surround sound produced by any coincident microphone techniques with coincident-to-virtual microphone signal matrixing. An encoding scheme provides significantly lower computational demand, by deriving the spatial parameters and output downmixes from the coincident microphone array signals and the coincident-to-surround channel-coefficients matrix, instead of the multi-channel signals.
Claims20
A method for MPEG Surround spatial audio encoding of coincident surround sound recordings, the scheme comprising:
- conducting time-frequency subband analysis filtering of time-domain coincident microphone array signals producing a plurality of subband-domain coincident microphone array signals;
- determining microphone signal energy and cross-correlation parameters for each of a plurality of MPEG Surround parameter bands, said bands associated with each of the plurality of subband-domain coincident microphone array signals, forming a plurality of parameter band values;
- determining required spatial parameters based on the plurality of parameter band values and a plurality of subband-domain coincident-to-surround channel coefficients, said subband-domain coincident-to-surround channel coefficients being in a matrix that maps the subband-domain coincident microphone array signals to subband-domain multi-channel surround signals;
- and
- downmixing the plurality of subband-domain coincident-to-surround channel coefficients through a spatial encoding tree to derive a plurality of output-downmix channel coefficients.
A method for encoding coincident surround sound recordings, the method comprising deriving spatial parameters and output downmixes from a coincident microphone signal array and a coincident-to-surround channel coefficent matrix.
A computer system for encoding coincident surround sound recordings the computer system comprising:
- a machine capable of executing instructions embodied as software;
- and
- a plurality of software portions, wherein
- one of said software portions is configured to conduct time-frequency subband analysis filtering of time-domain coincident micro-phone array signals producing a plurality of subband-domain coincident microphone array signals;
- one of said software portions is configured to determine microphone signal energy and cross-correlation parameters for each of a plurality of MPEG Surround parameter bands forming a plurality of parameter band values;
- one of said software portions is configured to determine required spatial parameters based on the plurality of parameter band values and a plurality of subband-domain coincident-to-surround channel coefficients, said subband-domain coincident-to-surround channel coefficients being in a matrix that maps the subband-domain coincident microphone array signals to subband-doman multi-channel surround signals;
- and
- one of said software portions is configured to downmix the plurality of subband-domain coincident-to-surround channel coefficients through a spatial encoding tree to derive a plurality of output-downmix channel coefficients.
A computer-readable storage medium tangibly embodying a program of instructions executable by a machine wherein said program of instruction comprises a plurality of program codes for encoding coincident surround sound recordings, said program of instructions comprising program code for deriving spatial parameters and output downmixes from a coincident microphone signal array and a coincident-to-surround channel-coefficient matrix.
Dependencies are inferred from the claim text.