Bluetooth synchronization method and Bluetooth synchronization system

A Bluetooth synchronization method applied to an audio sender, wherein the audio sender comprises a Bluetooth dongle and an application processor (AP), the method comprising:

• acquiring a Bluetooth synchronization point from the Bluetooth dongle;
• converting the Bluetooth synchronization point into an AP synchronization point of the AP according to a clock map of the Bluetooth dongle and the AP, wherein
• converting the Bluetooth synchronization point into the AP synchronization point of the AP according to the clock map of the Bluetooth dongle and the AP comprises:
• converting the Bluetooth synchronization point into the AP synchronization point of the AP by using a transfer function written as:
• Sa
• =
• (
• S
• ⁢
• b
• -
• Y
• ⁢
• b
• ⁢
• n
• )
• ×
• D
• L
• +
• (
• Sb
• -
• Ybn
• )
• +
• Yan
• ;
• and
• processing an original audio data having a first duration to generate an unencoded audio data having a predetermined second duration to an encoder, wherein the first duration is determined according to the AP synchronization point;
• wherein the Bluetooth dongle and the AP have different clock sources, Sa is the AP
• synchronization point of the AP, Sb is the Bluetooth synchronization point acquired from the Bluetooth dongle, Yan is a latest running time of the AP on the clock map, Ybn is a latest running time of the Bluetooth dongle on the clock map, L is a predetermined interval determined based on a system clock of the AP, D is an average normalization factor acquired according to a plurality of running times of the Bluetooth dongle and a plurality of running times of the AP recorded in the clock map;
• and
• wherein the audio sender is configured to play the original audio data having the first duration at a target synchronization point, and the target synchronization point is generated by delaying a predetermined presentation delay from the AP synchronization point.

A Bluetooth synchronization system comprising:

• a Bluetooth dongle;
• and
• an application processor (AP) coupled to the Bluetooth dongle;
• wherein the AP is configured to perform the following steps:
• acquiring a Bluetooth synchronization point and decoded audio data according to an isochronous data packet from the Bluetooth dongle;
• acquiring a plurality of running times of the Bluetooth dongle periodically;
• acquiring a plurality of running times of the AP periodically;
• acquiring an average normalization factor according to the plurality of running times of the Bluetooth dongle and the plurality of running times of the AP;
• converting the Bluetooth synchronization point into an AP synchronization point of the AP according to a clock map of the Bluetooth dongle and the AP, wherein the AP is configured to convert the Bluetooth synchronization point into the AP synchronization point of the AP by using a transfer function written as:
• Sa
• =
• (
• S
• ⁢
• b
• -
• Y
• ⁢
• b
• ⁢
• n
• )
• ×
• D
• L
• +
• (
• Sb
• -
• Ybn
• )
• +
• Yan
• ;
• and
• processing the decoded audio data to generate playback-ready audio data according to the AP synchronization point;
• wherein the Bluetooth dongle and the AP are within an audio receiver of the Bluetooth synchronization system, and have different clock sources, the clock map is configured to record the plurality of running times of the Bluetooth dongle and the plurality of running times of the AP, Sa is the AP synchronization point of the AP, Sb is the Bluetooth synchronization point acquired from the Bluetooth dongle, Yan is a latest running time of the AP on the clock map, Ybn is a latest running time of the Bluetooth dongle on the clock map, L is a predetermined interval determined based on a system clock of the AP, and D is the average normalization factor.