Pseudo multi-channel play-back apparatus
Compressed audio data for 5.1 channels stored in the DVD-ROM 11 A is read by the AC-3 decoder 12 of a pseudo multi-channel stereo play-back apparatus and, after expansion, stored temporarily in a buffer 13 , channel by channel. Among stored audio data stored in the buffer 13 , audio data for left and right channels and for a front center channel are then subjected to the phase transformation. Audio data for left and right front channels are mixed with the phase transformed audio data by first and second mixing circuits 21 and 22 and mixed audio data are converted into analog audio signals by first and second D/A converters. The apparatus is capable of pseudo reproduction of the multi-channel audio signals stored in a recording medium such as a DVD-ROM by two channel play-back with an excellent sound effect which is not obtainable by usual two-channel play-back systems.
1. A pseudo multi-channel play-back apparatus comprising:
a memory for temporarily storing first and second digital audio signals:
a phase control circuit for controlling a phase of said first digital audio signal;
a mixing circuit for mixing said first digital audio signal transformed by said phase control circuit with said second digital audio signal that has not been input to said phase control circuit; and
a D/A converter for converting an output of said mixing circuit into an analog sound signal.
2. A pseudo multi-channel play-back apparatus according to claim 1 , wherein said first digital audio signal includes a digital audio signal for a first channel and a digital audio signal for a second channel, and
wherein said second digital audio signal includes a digital audio signal for a third channel, and
wherein said mixing circuit mixes digital audio signals for the first and second channels transformed by said phase control circuit and the digital audio signal for the third channel stored in said memory.
3. A pseudo multi-channel play-back apparatus according to claim 2 , wherein said mixing circuit mixes the digital audio signal for the third channel and the digital audio signal for the first channel while giving respective digital audio signals a space transmission characteristic which represents a play-back sound field.
4. A pseudo multi-channel play-back apparatus according to claim 2 , wherein said second digital audio signal further includes a digital audio signal for a fourth channel, and
wherein said mixing circuit mixes digital audio signals for the first and second channels transformed by said phase control circuit and the digital audio signals for the third and fourth channels stored in said memory.