AUDIO SYNCHRONIZATION METHOD FOR BLUETOOTH SPEAKERS

• US 20160098244A1
• Filed: 01/05/2015
• Published: 04/07/2016
• Est. Priority Date: 10/03/2014
• Status: Active Grant

• Current Assignee: Airoha Technology Corporation (MediaTek, Inc.)
• Original Assignee: Airoha Technology Corporation (MediaTek, Inc.)
• Inventors: HSIEH, KUEN-RONG, SU, I-FENG, LIN, JHANG-LIANG, CHIU, SHENG-YO
• Granted Patent: US 9,817,629 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G06F 3/165 Management of the audio stream, e.g. setting of volume, audio stream path
• CPC Class Codes: H04N 21/43637 involving a wireless protocol, e.g. Bluetooth, RF or wireless LAN [IEEE 802.11] arrangements for wireless networking or broadcasting of information in indoor or near-field type systems H04B10/114
• CPC Class Codes: H04R 2227/005 Audio distribution systems for home, i.e. multi-room use
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication

Abstract

An audio synchronization method for Bluetooth speakers is disclosed. The Bluetooth speakers comprise a first Bluetooth speaker and a second Bluetooth speaker transmitting digital audio packets by Bluetooth communication. The method comprises steps of: fetching the sample counts of the first Bluetooth speaker and the second Bluetooth speaker at the first timing; and adjusting the sample rate of the second Bluetooth speaker according to the sample counts of the first Bluetooth speaker and the second Bluetooth speaker. By using the method of the present invention, the sample counts are checked periodically to keep the Bluetooth speakers audio synchronized.

Claims

1. An audio synchronization method for Bluetooth speakers, wherein the Bluetooth speakers comprise a first Bluetooth speaker and a second Bluetooth speaker, the first Bluetooth speaker and the second Bluetooth speaker transmit digital audio packets by Bluetooth communication, wherein the method comprises the steps of:

fetching sample counts of the first Bluetooth speaker and the second Bluetooth speaker at a first timing; and

adjusting a sample rate of the second Bluetooth speaker according to the sample counts of the first Bluetooth speaker and the second Bluetooth speaker.

2. The method as claimed in claim 1, further comprising a step of comparing the sample counts of the first Bluetooth speaker and the second Bluetooth speaker of the first timing.

3. The method as claimed in claim 1, wherein the first Bluetooth speaker is a master and the second Bluetooth speaker is a slave.

4. The method as claimed in claim 1, further comprising a step of fetching the sample counts of the first Bluetooth speaker and the second Bluetooth speaker at the same timing.

5. The method as claimed in claim 1, further comprising a step of synchronizing the clocks of the first Bluetooth speaker and the second Bluetooth speaker.

6. The method as claimed in claim 5, further comprising a step of pairing the second Bluetooth speaker with the first Bluetooth speaker, such that the first Bluetooth speaker and the second Bluetooth speaker use the same clock.

7. The method as claimed in claim 6, further comprising a step of defining the first timing according to the clock.

8. The method as claimed in claim 1, wherein each of the first Bluetooth speaker and the second Bluetooth speaker comprises:

a buffer for temporarily storing the digital audio packets;

a decoder connected to the buffer for decoding samples of the digital audio packets;

a sample rate adjusting unit connected to the decoder for adjusting the sample rate; and

a DAC connected to the sample rate adjusting unit for converting the samples to an analog audio signal.

9. The method as claimed in claim 8, further comprising steps of:

fetching the sample counts of the first Bluetooth speaker and the second Bluetooth speaker at the first timing; and

adjusting the sample rate of the second Bluetooth speaker according to the sample counts of the first Bluetooth speaker and the second Bluetooth speaker of the first timing.

10. The method as claimed in claim 9, further comprising a step of comparing the sample counts of the first Bluetooth speaker and the second Bluetooth speaker of the first timing.

11. The method as claimed in claim 1, wherein the digital audio packets comprises a plurality of packets, each packet comprises a sequence number for labeling an amount of the samples before the packet.

12. An audio synchronization method for Bluetooth speakers, wherein the Bluetooth speakers comprise a first Bluetooth speaker and a second Bluetooth speaker, the first Bluetooth speaker and the second Bluetooth speaker transmit digital audio packets by Bluetooth communication, wherein the method comprises steps of:

fetching a first sample count of the first Bluetooth speaker at a first timing;

transmitting the first timing and the first sample count to the second Bluetooth speaker;

fetching a second sample count of the second Bluetooth speaker of the first timing; and

adjusting a sample rate of the second Bluetooth speaker according to the first sample count and the second sample count.

13. The method as claimed in claim 12, further comprising a step of comparing the first sample count and the second sample count.

14. The method as claimed in claim 12, further comprising a step of synchronizing clocks of the first Bluetooth speaker and the second Bluetooth speaker.

15. The method as claimed in claim 14, further comprising a step of defining the first timing according to the clock.

16. The method as claimed in claim 12, wherein the digital audio packets comprise a plurality of packets, each packet comprises a sequence number labeling an amount of samples before the packet.