Sound recording method and device

• US 9,930,467 B2
• Filed: 03/02/2016
• Issued: 03/27/2018
• Est. Priority Date: 10/29/2015
• Status: Active Grant

• Current Assignee: Xiaomi Inc. (Xiaomi Corp.)
• Original Assignee: Xiaomi Inc. (Xiaomi Corp.)
• Inventors: Shi, Runyu, Xiong, Dawei, Li, Weishan
• Primary Examiner(s): Mei, Xu
• Application Number:
  US15/058,673
• Publication Number:
  US 20170127207A1
• Time in Patent Office: 755 Days
• Field of Search: 381307, 381 26, 381 27, 381 91, 381 92, 381122, 381 97, 381 17- 19
• CPC Class Codes: H04R 1/326 for microphones H04R1/34 and H04R1/40 take precedence
• CPC Class Codes: H04R 2430/20 Processing of the output signals of the acoustic transducers of an array for obtaining a desired directivity characteristic H04R2203/12 takes precedence
• CPC Class Codes: H04R 2499/11 Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04S 2400/01 Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved
• CPC Class Codes: H04S 2400/05 Generation or adaptation of centre channel in multi-channel audio systems
• CPC Class Codes: H04S 2400/07 Generation or adaptation of the Low Frequency Effect [LFE] channel, e.g. distribution or signal processing
• CPC Class Codes: H04S 2400/09 Electronic reduction of distortion of stereophonic sound systems
• CPC Class Codes: H04S 2400/13 Aspects of volume control, not necessarily automatic, in stereophonic sound systems
• CPC Class Codes: H04S 2400/15 Aspects of sound capture and related signal processing for recording or reproduction
• CPC Class Codes: H04S 5/005 of the pseudo five- or more-channel type, e.g. virtual surround
• CPC Class Codes: H04S 7/307 Frequency adjustment, e.g. tone control H04S7/301 takes precedence

Abstract

A sound recording method and device are provided in the field of multimedia processing. The method is applied in a mobile terminal including three microphones, including: acquiring three channels of sound signals collected by the three microphones; calculating a central channel signal, a left channel signal, a right channel signal, a rear left channel signal and a rear right channel signal in a multi-channel surround audio system according to the three channels of sound signals; calculating a bass channel signal in the multi-channel surround audio system according to the three channels of sound signals; and combining the above signals to obtain a sound signal of the multi-channel surround audio system.

Claims

1. A sound recording method, comprising:

acquiring, by a mobile terminal comprising three microphones, three channels of sound signals collected by the three microphones, wherein the three microphones comprise a first microphone representative of a central channel direction of a multi-channel surround audio system, a second microphone representative of a rear left channel direction of the multi-channel surround audio system, and a third microphone representative of a rear right channel direction of the multi-channel surround audio system;

calculating, by the mobile terminal, a central channel signal, a left channel signal, a right channel signal, a rear left channel signal, and a rear right channel signal in the multi-channel surround audio system according to the three channels of sound signals, by;

using a first sound signal collected by the first microphone as the central channel signal;

using a second sound signal collected by the second microphone as the rear left channel signal;

using a third sound signal collected by the third microphone as the rear right channel signal;

performing a first weighted average on amplitudes of the first sound signal and the second sound signal at the same moment to obtain a fourth sound signal and using the fourth sound signal as the left channel signal; and

performing a second weighted average on amplitudes of the first sound signal and the third sound signal at the same moment to obtain a fifth sound signal and using the fifth sound signal as the right channel signal;

calculating, by the mobile terminal, a bass channel signal in the multi-channel surround audio system according to the three channels of sound signals; and

combining, by the mobile terminal, the central channel signal, the left channel signal, the right channel signal, the rear left channel signal, the rear right channel signal, and the bass channel signal to obtain a sound signal of the multi-channel surround audio system.

2. The method of claim 1, wherein the calculating the bass channel signal in the multi-channel surround audio system according to the three channels of sound signals comprises:

averaging amplitudes of the three channels of sound signals at the same moment to obtain an average sound signal; and

performing a low-pass filtering on the average sound signal to obtain the bass channel signal.

3. The method of claim 1, further comprising:

performing a noise-reduction processing to the three channels of sound signals.

4. A mobile terminal, comprising:

three microphones;

a processor; and

a memory for storing instructions executable by the processor;

wherein the processor is configured to;

acquire three channels of sound signals collected by the three microphones, wherein the three microphones comprise a first microphone representative of a central channel direction of a multi-channel surround audio system, a second microphone representative of a rear left channel direction of the multi-channel surround audio system, and a third microphone representative of a rear right channel direction of the multi-channel surround audio system;

calculate a central channel signal, a left channel signal, a right channel signal, a rear left channel signal, and a rear right channel signal in a multi-channel surround audio system according to the three channels of sound signals, by;

using a first sound signal collected by the first microphone as the central channel signal;

using a second sound signal collected by the second microphone as the rear left channel signal;

using a third sound signal collected by the third microphone as the rear right channel signal;

performing a first weighted average on amplitudes of the first sound signal and the second sound signal at the same moment to obtain a fourth sound signal and using the fourth sound signal as the left channel signal; and

performing a second weighted average on amplitudes of the first sound signal and the third sound signal at the same moment to obtain a fifth sound signal and using the fifth sound signal as the right channel signal;

calculate a bass channel signal in the multi-channel surround audio system according to the three channels of sound signals; and

combine the central channel signal, the left channel signal, the right channel signal, the rear left channel signal, the rear right channel signal, and the bass channel signal to obtain a sound signal of the multi-channel surround audio system.

5. The mobile terminal claim 4, wherein the processor is further configured to:

average amplitudes of the three channels of sound signals at the same moment to obtain an average sound signal; and

perform a low-pass filtering on the average sound signal to obtain the bass channel signal.

6. The mobile terminal of claim 4, wherein the processor is further configured to:

perform a noise-reduction processing to the three channels of sound signals.

7. A non-transitory readable storage medium comprising instructions which, when executed by a mobile terminal comprising a processor and three microphones, cause the mobile terminal to perform acts comprising:

acquiring three channels of sound signals collected by the three microphones, wherein the three microphones comprise a first microphone representative of a central channel direction of a multi-channel surround audio system, a second microphone representative of a rear left channel direction of the multi-channel surround audio system, and a third microphone representative of a rear right channel direction of the multi-channel surround audio system;

calculating a central channel signal, a left channel signal, a right channel signal, a rear left channel signal, and a rear right channel signal in the multi-channel surround audio system according to the three channels of sound signals, by;

using a first sound signal collected by the first microphone as the central channel signal;

using a second sound signal collected by the second microphone as the rear left channel signal;

using a third sound signal collected by the third microphone as the rear right channel signal;

performing a first weighted average on amplitudes of the first sound signal and the second sound signal at the same moment to obtain a fourth sound signal and using the fourth sound signal as the left channel signal; and

performing a second weighted average on amplitudes of the first sound signal and the third sound signal at the same moment to obtain a fifth sound signal and using the fifth sound signal as the right channel signal;

;

calculating a bass channel signal in the multi-channel surround audio system according to the three channels of sound signals; and

combining the central channel signal, the left channel signal, the right channel signal, the rear left channel signal, the rear right channel signal, and the bass channel signal to obtain a sound signal of the multi-channel surround audio system.

8. The non-transitory readable storage medium of claim 7, wherein the calculating the bass channel signal in the multi-channel surround audio system according to the three channels of sound signals comprises:

averaging amplitudes of the three channels of sound signals at the same moment to obtain an average sound signal; and

performing a low-pass filtering on the average sound signal to obtain the bass channel signal.

9. The non-transitory readable storage medium of claim 7, wherein the instructions, when executed by the mobile terminal, further cause the mobile terminal to perform an act of performing a noise-reduction processing to the three channels of sound signals.

10. A sound recording method, comprising:

acquiring, by a mobile terminal comprising three microphones, three channels of sound signals collected by the three microphones, wherein the three microphones are dispersedly disposed with respect to an origin point;

calculating, by the mobile terminal, a central channel signal, a left channel signal, a right channel signal, a rear left channel signal, and a rear right channel signal in a multi-channel surround audio system according to the three channels of sound signals, by;

for a sound channel in the multi-channel surround audio system, acquiring two channels of sound signals collected by two microphones nearest to the sound channel, and

separating out a sound signal corresponding to the sound channel from the two channels of sound signals according to a phase difference of arrival corresponding to the sound channel,

wherein the phase difference of arrival is a difference between initial phase angles of sound from the sound channel when arriving at the two microphones respectively;

calculating, by the mobile terminal, a bass channel signal in the multi-channel surround audio system according to the three channels of sound signals; and

combining, by the mobile terminal, the central channel signal, the left channel signal, the right channel signal, the rear left channel signal, the rear right channel signal, and the bass channel signal to obtain a sound signal of the multi-channel surround audio system.

11. The method of claim 10, wherein the separating out the sound signal corresponding to the sound channel from the two channels of sound signals according to the phase difference of arrival corresponding to the sound channel comprises:

filtering a first channel of sound signal in the two channels of sound signals according to the phase difference of arrival corresponding to the sound channel to obtain first filtering data, filtering a second channel of sound signal in the two channels of sound signals according to the phase difference of arrival corresponding to the sound channel to obtain second filtering data; and

exacting a same portion in the first filtering data and the second filtering data as the sound signal corresponding to the sound channel.

12. The method of claim 10, further comprising:

performing a noise-reduction processing to the three channels of sound signals.

13. A mobile terminal, comprising:

three microphones;

a processor; and

a memory for storing instructions executable by the processor;

wherein the processor is configured to;

acquire three channels of sound signals collected by the three microphones, wherein the three microphones are dispersedly disposed with respect to an origin point;

calculate a central channel signal, a left channel signal, a right channel signal, a rear left channel signal, and a rear right channel signal in a multi-channel surround audio system according to the three channels of sound signals, by;

for a sound channel in the multi-channel surround audio system, acquiring two channels of sound signals collected by two microphones nearest to the sound channel, and

separating out a sound signal corresponding to the sound channel from the two channels of sound signals according to a phase difference of arrival corresponding to the sound channel,

wherein the phase difference of arrival is a difference between initial phase angles of sound from the sound channel when arriving at the two microphones respectively;

calculate a bass channel signal in the multi-channel surround audio system according to the three channels of sound signals; and

combine the central channel signal, the left channel signal, the right channel signal, the rear left channel signal, the rear right channel signal, and the bass channel signal to obtain a sound signal of the multi-channel surround audio system.

14. The mobile terminal of claim 13, wherein the processor is further configured to:

filter a first channel of sound signal in the two channels of sound signals according to the phase difference of arrival corresponding to the sound channel to obtain first filtering data, and filter a second channel of sound signal in the two channels of sound signals according to the phase difference of arrival corresponding to the sound channel to obtain second filtering data; and

exact a same portion in the first filtering data and the second filtering data as the sound signal corresponding to the sound channel.

15. The mobile terminal of claim 13, wherein the processor is further configured to:

perform a noise-reduction processing to the three channels of sound signals.

16. A non-transitory readable storage medium comprising instructions which, when executed by a mobile terminal comprising a processor and three microphones, cause the mobile terminal to perform acts comprising:

acquiring three channels of sound signals collected by the three microphones, wherein the three microphones are dispersedly disposed with respect to an origin point;

calculating a central channel signal, a left channel signal, a right channel signal, a rear left channel signal, and a rear right channel signal in a multi-channel surround audio system according to the three channels of sound signals, by;

for a sound channel in the multi-channel surround audio system, acquiring two channels of sound signals collected by two microphones nearest to the sound channel, and

separating out a sound signal corresponding to the sound channel from the two channels of sound signals according to a phase difference of arrival corresponding to the sound channel,

wherein the phase difference of arrival is a difference between initial phase angles of sound from the sound channel when arriving at the two microphones respectively;

calculating a bass channel signal in the multi-channel surround audio system according to the three channels of sound signals; and

combining the central channel signal, the left channel signal, the right channel signal, the rear left channel signal, the rear right channel signal, and the bass channel signal to obtain a sound signal of the multi-channel surround audio system.

17. The non-transitory readable storage medium of claim 16, wherein the instructions, when executed by the mobile terminal, further cause the mobile terminal to perform acts of:

filtering a first channel of sound signal in the two channels of sound signals according to the phase difference of arrival corresponding to the sound channel to obtain first filtering data, and filtering a second channel of sound signal in the two channels of sound signals according to the phase difference of arrival corresponding to the sound channel to obtain second filtering data; and

exacting a same portion in the first filtering data and the second filtering data as the sound signal corresponding to the sound channel.

18. The non-transitory readable storage medium of claim 16, wherein the instructions, when executed by the mobile terminal, further cause the mobile terminal to perform an act of performing a noise-reduction processing to the three channels of sound signals.