Channel hiatus correction method and HDMI device
A channel hiatus correction method for an HDMI device is provided. A recovery code from scrambled data of the stream is obtained. A liner feedback shift register (LFSR) value of channels of the HDMI port is obtained based on the recovery code and the scrambled data of the stream. The stream is de-scrambled according to the LFSR value of the channels of the HDMI port. Video data is displayed according to the de-scrambled stream.
1. A channel hiatus correction method for a high-definition multimedia interface (HDMI) device, comprising:
obtaining a stream from a source device through an HDMI port of the HDMI device;
obtaining a recovery code from scrambled data of the stream, wherein the recovery code is leading guard band data, trailing guard band data, or preamble data from the source device;
obtaining a linear feedback shift register (LFSR) value of channels of the HDMI port based on the recovery code and the scrambled data of the stream;
de-scrambling the stream according to the LFSR value of the channels of the HDMI port; and
displaying video data according to the de-scrambled stream.
2. The channel hiatus correction method as claimed in claim 1 , wherein the stream is a transition minimized differential signaling (TMDS) stream and is free of character of a scrambler synchronization control period (SSCP).
3. The channel hiatus correction method as claimed in claim 1 , wherein obtaining the LFSR value of channels of the HDMI port based on the recovery code and the scrambled data of the stream further comprises:
performing an exclusive-OR (XOR) operation on the scrambled data of the stream and the recovery code.
4. The channel hiatus correction method as claimed in claim 1 , wherein obtaining the stream from the source device through the HDMI port of the HDMI device further comprises:
enabling the HDMI port of the HDMI device to receive the stream when disabling another port of the HDMI device.
5. The channel hiatus correction method as claimed in claim 1 , wherein obtaining the stream from the source device through the HDMI port of the HDMI device further comprises:
receiving the stream when the source device is plugged into the HDMI port of the HDMI device.
6. The channel hiatus correction method as claimed in claim 1 , wherein obtaining the LFSR value of the channels of the HDMI port based on the recovery code and the scrambled data of the stream further comprises:
obtaining a first LFSR value of one of the channels when the LFSR value is equal to the first LFSR value; and
obtaining a second LFSR value and a third LFSR value of the remaining channels,
wherein the second and third LFSR values correspond to the first LFSR value.
7. The channel hiatus correction method as claimed in claim 6 , wherein the first, second and third LFSR values are obtained based on an LFSR generator polynomial with different seed values.
8. The channel hiatus correction method as claimed in claim 1 , further comprising:
obtaining the recovery code according to a previous stream,
wherein the previous stream comprises character of the SSCP.
9. A high-definition multimedia interface (HDMI) device, comprising:
an HDMI interface, comprising a plurality of HDMI ports;
a controller coupled to the HDMI interface and configured to obtain a stream from a source device through a first HDMI port of HDMI ports, and comprising:
a channel hiatus corrector configured to obtain a linear feedback shift register (LFSR) value of channels of the first HDMI port based on scrambled data of the stream and a recovery code, wherein the recovery code is leading guard band data, trailing guard band data, or preamble data from the source device; and
a de-scrambler configured to de-scramble the stream according to the LFSR value of channels of the first HDMI port; and
a display device coupled to the controller, and configured to display video data according to the de-scrambled stream.
10. The HDMI device as claimed in claim 9 , wherein the stream is a transition minimized differential signaling (TMDS) stream and is free of character of a scrambler synchronization control period (SSCP).
11. The HDMI device as claimed in claim 9 , wherein the channel hiatus corrector is configured to perform an exclusive-OR (XOR) operation on the scrambled data of the stream and the recovery code, so as to obtain the LFSR value.
12. The HDMI device as claimed in claim 9 , wherein the controller is configured to enable the first HDMI port of the HDMI interface after disabling a second HDMI port of the HDMI ports in the HDMI interface, so as to receive the stream from the source device through the first HDMI port.
13. The HDMI device as claimed in claim 9 , wherein the controller is configured to receive the stream when the source device is plugged into the first HDMI port of the HDMI interface.
14. The HDMI device as claimed in claim 9 , wherein the controller is configured to obtain a first LFSR value of one of the channels when the LFSR value is equal to the first LFSR value, and obtain a second LFSR value and a third LFSR value of the remaining channels, wherein the second and third LFSR values correspond to the first LFSR value.
15. The HDMI device as claimed in claim 14 , wherein the first, second and third LFSR values are obtained based on an LFSR generator polynomial with different seed values.
16. The HDMI device as claimed in claim 9 , wherein the controller is configured to obtain the recovery code according to a previous stream, and the previous stream comprises character of the SSCP.