Method and device for error analysis of optical disc

• US 7,861,141 B2
• Filed: 02/17/2006
• Issued: 12/28/2010
• Est. Priority Date: 10/21/2005
• Status: Expired due to Fees

• Current Assignee: MediaTek, Inc.
• Original Assignee: MediaTek, Inc.
• Inventors: Chen, Hsin-cheng, Hsueh, Ching-wen
• Primary Examiner(s): CHAUDRY, MUJTABA M
• Application Number:
  US11/357,323
• Publication Number:
  US 20070094573A1
• Time in Patent Office: 1,775 Days
• Field of Search: 714/762, 714/768, 714/769
• US Class Current: 714/769
• CPC Class Codes: G11B 20/1816 Testing
• CPC Class Codes: G11B 20/1833 by adding special lists or symbols to the coded information G11B20/1806, G11B20/1866 take precedence
• CPC Class Codes: G11B 20/1866 by interleaving G11B20/1809 takes precedence
• CPC Class Codes: G11B 2020/10796 address data
• CPC Class Codes: G11B 2020/1823 wherein a flag is set when errors are detected or qualified
• CPC Class Codes: G11B 2020/1846 using a picket code, i.e. a code in which a long distance code [LDC] is arranged as an array and columns containing burst indicator subcode [BIS] are multiplexed for erasure decoding

Abstract

A method and device for error analysis particularly adoptable for a recording medium such as an optical disc are disclosed. The present invention executes an encoding-like operation such as an interleaving operation to error flags during reproducing data from the optical disc, so as to obtain number and distribution of the errors on the disc.

Claims

1. A method for obtaining error information of an optical disc, comprising:

receiving error flags corresponding to data recorded on the optical disc, wherein the data is recorded in accordance with a recording sequence;

writing the error flags to an error buffer in a format of an error flag map;

reading the error flags from the error buffer according to a sequence corresponding to the recording sequence; and

using the error flags read from the error buffer to obtain information about errors of the optical disc.

2. The method of claim 1, further comprising:

receiving no-solution flags; and

writing the no-solution flags to the error buffer;

wherein when an error flag is read from the error buffer, a corresponding no-solution flag is also read from the error buffer.

3. The method of claim 1, wherein an error flag indicates if a codeword of the data has an error, and wherein a corresponding no-solution flag indicates if the error cannot be solved.

4. The method of claim 1, wherein using the error flags to obtain the information comprises counting the error flags.

5. The method of claim 1, wherein the information about the errors of the optical disc comprises a distribution of the errors.

6. The method of claim 1, wherein the information about the errors of the optical disc comprises a symbol error rate (SER).

7. The method of claim 1, wherein the information about the errors of the optical disc comprises a random symbol error rate (RSER).

8. The method of claim 1, wherein the optical disc is selected from a group consisting of a Blu-ray disc, an HD-DVD, a CD, a DVD+, a DVD-, and a DVD-RAM.

9. The method of claim 1, wherein the method is performed in connection with reproduction of the data on the optical disc;

wherein during the reproduction of the data a data bit stream read from the optical disc is demodulated into ECC cluster format;

wherein an ECC cluster comprises M rows×

N columns of data;

wherein x long distance code (LDC) groups are extracted from the ECC cluster to form an LDC cluster;

wherein y burst indicator subcode (BIS) groups are extracted from the ECC cluster to form a BIS cluster;

wherein the LDC cluster is mapped to an LDC block;

wherein the LDC block comprises multiple codewords and each codeword comprises multiple data bytes and multiple parity bytes;

wherein writing the error flags to the error buffer comprises writing an error flag E_R,L of a data byte C_R,L or a parity byte P_R,L of the LDC block to the error buffer as;

for row Q=2×

R+mod(L,2) 0≦

Q≦

M−

1

for column P=div(L,2) 0≦

P≦

N−

y−

1;

wherein R and L are respectively row and column numbers of the LDC block; and

wherein Q and P are respectively row and column numbers of the LDC cluster.

10. The method of claim 9, wherein the error flags are written to an array in the error buffer;

wherein the array has a left side and a right side;

wherein reading the error flags from the error buffer according to the sequence that corresponds to the recording sequence comprises shifting each of the error flags over mod(3×

div(Q,

     2), N−

y) units in a left direction; and

wherein the error flags that are shifted out of the left side of the array are re-filled in the array from the right side.

11. The method of claim 2, wherein the method is performed in connection with reproduction of the data on the optical disc;

wherein during the reproduction of the data a data bit stream read from the optical disc is demodulated into ECC cluster format;

wherein multiple long distance code (LDC) groups are extracted from the ECC cluster to form an LDC cluster;

wherein the LDC cluster is mapped to an LDC block;

wherein the LDC block comprises multiple codewords;

wherein a relationship between the error flag E_q,p and the corresponding no-solution flag NS_w is expressed as w=2×

p+mod(q,

     2);

wherein q and p are respectively row and column numbers of the LDC cluster; and

wherein w is a codeword of the LDC block.