Multi-channel audio reproducing device
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorYoshiichi Tanaka
Life of this patent
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Abstract
A multi-channel audio reproducing device of a type converting, from digital to analog, multi-channel audio data whose channels are different in sampling frequency by using DACs fewer in number than the channels, and reproducing the same. A decoding part executes sampling frequency conversion with respect to the audio data in at least one channel so that a sampling frequency thereof coincides with that of the other channels. A DAC part converts, from digital to analog in a time sharing manner, the audio data in the plurality of channels equalized in sampling frequency.
Claims20
A multi-channel audio reproducing device for reproducing multi-channel audio data recorded on a recording medium and obtained by encoding audio data in a plurality of channels sampled at different sampling frequencies, said multi-channel audio reproducing device comprising:
- a reading means for reading out the multi-channel audio data from the recording medium;
- a decoding means for decoding the multi-channel audio data read by said reading means;
- a DAC means for converting, from digital to analog, the audio data in each of the channels obtained after the decoding by said decoding means;
- and
- an LPF means for extracting, from an audio signal in each of the channels obtained after the D/A conversion by said DAC means, any component equal to or lower than a cutoff frequency which is assigned in accordance with a sampling frequency of each of the audio signals, and outputting the same as an analog audio signal for every channel;
- wherein said decoding means includes a sampling frequency converting means for executing sampling frequency conversion with respect to the audio data in at least one channel obtained by the decoding so that a sampling frequency thereof coincides with that of the other channels;
- and
- wherein said DAC means includes a digital to analog converter for converting, from digital to analog in a time sharing manner, the audio data in the plurality of channels equalized in sampling frequency through the sampling frequency conversion.
A DVD audio reproducing device for reproducing multi-channel audio data, recorded on a DVD, obtained by encoding audio data in a plurality of channels sampled at different sampling frequencies, said DVD audio reproducing device comprising:
- a reading means for reading out the multi-channel audio data from the DVD;
- a decoding means for decoding the multi-channel audio data read by said reading means;
- a DAC means for converting, from digital to analog, the audio data in each of the channels obtained after the decoding by said DAC means;
- and
- an LPF means for extracting, from an audio signal in each of the channels obtained after the D/A conversion by said DAC means, any component equal to or lower than a cutoff frequency assigned in accordance with a sampling frequency of each of the audio signals, and outputting the same in a form of an analog audio signal for every channel;
- wherein said decoding means includes a sampling frequency converting means for executing sampling frequency conversion with respect to the audio data in at least one channel obtained by the decoding so that a sampling frequency thereof coincides with that of the other channels;
- and
- said DAC means includes a digital to analog converter for converting, from digital to analog in a time sharing manner, audio data in the plurality of channels equalized in sampling frequency through the sampling frequency conversion.
A DVD audio reproducing device for reproducing six-channel audio data, recorded on a DVD, obtained by encoding audio data in six channels sampled at different sampling frequencies, said DVD audio reproducing device comprising:
- a reading means for reading out the six-channel audio data from the DVD:
- a decoding means for decoding the six-channel audio data read from said reading means;
- a DAC means for converting, from digital to analog, the audio data in each of the channels obtained after the decoding by said decoding means;
- and
- an LPF means for extracting, from an audio signal in each of the channels obtained after the D/A conversion by said DAC means, any component equal to or lower than a cutoff frequency assigned in accordance with a sampling frequency of each of the audio signals, and outputting the same in a form of an analog audio signal for every channel;
- wherein said decoding means includes a sampling frequency converting means for executing sampling frequency conversion with respect to the audio data in three channels obtained by the decoding so that each sampling frequency thereof coincides with that of three other channels;
- and
- said DAC means includes three digital to analog converters for converting, from digital to analog in a time sharing manner, the audio data in three channels equalized in sampling frequency through the sampling frequency conversion.
A method of reproducing multi-channel audio obtained by encoding audio data in a plurality of channels sampled at different sampling frequencies, said method comprising:
- decoding the multi-channel audio data;
- converting, from digital to analog, the audio data in each of the channels obtained by decoding the multi-channel audio data;
- and
- extracting, from an audio signal in each of the channels obtained by decoding the multi-channel audio data, a component equal to or lower than a cutoff frequency assigned in accordance with a sampling frequency of each of the audio signals, and outputting the same in a form of an analog audio signal for every channel;
- wherein in said decoding, sampling frequency conversion is executed with respect to the audio data in at least one channel obtained by decoding so that a sampling frequency thereof coincides with that of the other channels;
- and
- wherein in said converting, the audio data in the plurality of channels equalized in sampling frequency through the sampling frequency conversion is converted from digital to analog in a time sharing manner.
A recording medium on which a program for reproducing multi-channel audio data obtained by encoding audio data in a plurality of channels sampled at different sampling frequencies is recorded to be executed in a computer device, the program for realizing an operational environment causing the computer device to perform a method comprising:
- decoding the multi-channel audio data;
- converting, from digital to analog, the audio data in each of the channels obtained by decoding the multi-channel audio data;
- and
- extracting, from an audio signal in each of the channels obtained by decoding the multi-channel audio data, a component equal to or lower than a cutoff frequency assigned in accordance with a sampling frequency of each of the audio signals, and outputting the same in a form of an analog audio signal for every channel;
- wherein in said decoding, sampling frequency conversion is executed with respect to the decoded audio data in at least one channel so that a sampling frequency thereof coincides with that of the other channels;
- and
- wherein in said converting, the audio data in the plurality of channels equalized in sampling frequency through the sampling frequency is converted from digital to analog in a time sharing manner.
A multi-channel audio reproducing device for reproducing multi-channel audio data recorded on a recording medium and obtained by encoding audio data in a plurality of channels sampled at different sampling frequencies, said multi-channel audio reproducing device comprising:
- a reading part operable to read out the multi-channel audio data from the recording medium;
- a decoding part operable to decode the multi-channel audio data read by said reading part;
- a DAC part operable to convert, from digital to analog, the audio data in each of the channels obtained after the decoding by said decoding part;
- and
- an LPF part operable to extract, from an audio signal in each of the channels obtained after the D/A conversion by said DAC part, any component equal to or lower than a cutoff frequency which is assigned in accordance with a sampling frequency of each of the audio signals, and output the same as an analog audio signal for every channel;
- wherein said decoding part includes sampling frequency converting circuit operable to execute sampling frequency conversion with respect to the audio data in at least one channel obtained by the decoding so that a sampling frequency thereof coincides with that of the other channels;
- and
- wherein said DAC part includes a digital to analog converter operable to convert, from digital to analog in a time sharing manner, the audio data in the plurality of channels equalized in sampling frequency through the sampling frequency conversion.
A DVD audio reproducing device for reproducing multi-channel audio data, recorded on a DVD, obtained by encoding audio data in a plurality of channels sampled at different sampling frequencies, said DVD audio reproducing device comprising:
- a reading part operable to read out,the multi-channel audio data from the DVD;
- a decoding part operable to decode the multi-channel audio data read by said reading part;
- a DAC part operable to convert, from digital to analog, the audio data in each of the channels obtained after the decoding by said DAC part;
- and
- an LPF part operable to extract, from an audio signal in each of the channels obtained after the D/A conversion by said DAC part, any component equal to or lower than a cutoff frequency assigned in accordance with a sampling frequency of each of the audio signals, and output the same in a form of an analog audio signal for every channel;
- wherein said decoding part includes a sampling frequency converting circuit operable to execute sampling frequency conversion with respect to the audio data in at least one channel obtained by the decoding so that a sampling frequency thereof coincides with that of the other channels;
- and
- said DAC part includes a digital to analog converter operable to convert, from digital to analog in a time sharing manner, audio data in the plurality of channels equalized in sampling frequency through the sampling frequency conversion.
A DVD audio reproducing device for reproducing six-channel audio data, recorded on a DVD, obtained by encoding audio data in six channels sampled at different sampling frequencies, said DVD audio reproducing device comprising:
- a reading part operable to read out the six-channel audio data from the DVD:
- a decoding part operable to decode the six-channel audio data read from said reading part;
- a DAC part operable to convert, from digital to analog, the audio data in each of the channels obtained after the decoding by said decoding part;
- and
- an LPF part operable to extract, from an audio signal in each of the channels obtained after the D/A conversion by said DAC part, any component equal to or lower than a cutoff frequency assigned in accordance with a sampling frequency of each of the audio signals, and output the same in a form of an analog audio signal for every channel;
- wherein said decoding part includes sampling frequency converting circuit operable to execute sampling frequency conversion with respect to the audio data in three channels obtained by the decoding so that each sampling frequency thereof coincides with that of three other channels;
- and
- said DAC part includes three digital to analog converters operable to convert, from digital to analog in a time sharing manner, the audio data in three channels equalized in sampling frequency through the sampling frequency conversion.
Dependencies are inferred from the claim text.