US 11,743,561 B2
Image display device, lip-sync correction method thereof, and image display system
In Sun Song, Seoul (KR); and Young Do Kwon, Seoul (KR)
Assigned to LG ELECTRONICS INC., Seoul (KR)
Appl. No. 17/764,062
Filed by LG ELECTRONICS INC., Seoul (KR)
PCT Filed Sep. 25, 2019, PCT No. PCT/KR2019/012455
§ 371(c)(1), (2) Date Mar. 25, 2022,
PCT Pub. No. WO2021/060578, PCT Pub. Date Apr. 1, 2021.
Prior Publication US 2022/0377437 A1, Nov. 24, 2022
Int. Cl. H04N 21/8547 (2011.01); H04N 21/439 (2011.01)
CPC H04N 21/8547 (2013.01) [H04N 21/439 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A lip-sync correction method of an image display device, the method comprising:
receiving an audio delay measurement command from a user;
transmitting an audio detection command to a remote control device and outputting a pre-stored test signal to an external speaker;
calculating an audio delay value by comparing an audio signal received from the remote control device with the test signal;
correcting a decoding time stamp of an image signal on the basis of the audio delay value;
storing a lip-sync table related to lip-sync values respectively corresponding to external input sources;
correcting the lip-sync values respectively corresponding to the input sources on the basis of the audio delay value,
wherein the correcting of the decoding time stamp corrects the decoding time stamp on the basis of the corrected lip-sync value; and
delaying buffering of a compressed frame and a decoding time point of the compressed frame on the basis of the corrected decoding time stamp.