EFM+ data decoding method with error detection function in optical drive system

Abstract

The invention relates to an EFM+ data decoding method used in an optical drive system, which is characterized by comprising the following steps: adding a third step between a second step for deserializing and a fourth step in which an RS decoding unit is sent into an audio-video demodulation unit after error detection and error correction, wherein the third step is used for performing a first judgment on whether the input first data accords with an EFM+ modulation rule; if the input first data accords with the EFM+ modulation rule, looking up a table to finish EFM+ decoding, and entering the fourth step; if the input first data does not accord with the EFM+ modulation rule, returning to the second step, and then entering the third step to perform a second judgment; if the input first dataaccords with the EFM+ modulation rule according to the second judgment, looking up the table to finish the EFM+ decoding, and then entering the fourth step; if the input first data does not accord with the EFM+ modulation rule according to the second judgment, returning to the first step, and then entering the third step after the first step and the second step to perform a third judgment; if theinput first data accords with the EFM+ modulation rule according to the third judgment, looking up the table to finish the EFM+ decoding, and then entering the fourth step; if the input first data does not accord with the EFM+ modulation rule according to the third judgment, adjusting the first data to make the first data accord with the EFM+ modulation rule, then looking up the table to finish the EFM+ decoding, and entering the fourth step. The EFM+ data decoding method can simply and effectively improve the accuracy and the reliability for reading data, and has a practical value.

Description

technical field [0001] The invention relates to an optical disc drive, which is an EFM+ data decoding method with error detection function used in the optical disc drive system. The table look-up decoding method that needs to be used in the process of disc data readout, especially the data demodulation after 8 to 16 (Eight to Fourteen Modulation plus) modulation and encoding used in DVD (Digital Video Disc) discs, referred to as EFM+ data decoding code method. Background technique [0002] In order to increase the reliability of optical disc data reading, user information must be converted into a physical expression form suitable for storage on the medium before storage. CD-ROM converts 8-bit data into 14-bit channel code, which is called 8 to 14 modulation coding, recorded as EFM (Eight to Fourteen Modulation); DVD-ROM converts 8-bit data into 16-bit channel code, called 8 to 16 (Eight to Fourteen Modulation plus) modulation coding, referred to as EFM+ coding, the red lig...

AI Technical Summary

Problems solved by technology

[0008] However, due to the higher and higher reading speed of optical discs, and the characteristics of optical discs that are easy to scratch, 16-bit data that does not conform to the above EFM+ modulation rules are prone to appear in the process of reading data and data processing from optical discs.

If these data are not properly processed, only the RS decoding unit performs EFM+ decoding, and it is easy to make mistakes

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