MPEG decoder and optical video disc player using the same

• US 5,995,709 A
• Filed: 02/26/1997
• Issued: 11/30/1999
• Est. Priority Date: 12/27/1996
• Status: Expired due to Fees

• Current Assignee: Victor Company of Japan Limited (JVC Kenwood Corporation)
• Original Assignee: Victor Company of Japan Limited (JVC Kenwood Corporation)
• Inventors: Tsuge, Kenji
• Primary Examiner(s): Chevalier, Robert
• Application Number:
  US08/806,415
• Time in Patent Office: 1,007 Days
• Field of Search: 386/95, 386/46-52, 386/4, 386/83, 386/92, 348/468, 348/589, 348/600
• US Class Current: 386/244
• CPC Class Codes: H04N 5/85 on discs or drums
• CPC Class Codes: H04N 9/8042 involving data reduction
• CPC Class Codes: H04N 9/8233 the additional signal being a character code signal

Abstract

A system for inserting text data (e.g., closed caption data) contained In a user data or image data of an MPEG stream into the scanning line H21 of the Image signal recovered from the MPEG stream through a simplified process. In case of text data in the user data, the image data is decoded compressed image data on the video-CD is expended and stored as video data in the first memory location, and the closed caption data in the user data area is NRZ-modulated and stored in the second memory location. The caption data is read out of the second memory location and output to a bit map pixel data channel during a period of H21 of the output video data stream, and the video data Is read out of the first memory location and output to an video pixel data channel in the periods after H22 of the output video data stream. Thus, the two data are multiplexed on a bus.

Claims

1. A method, used in an MPEG decoder which receives a data stream including MPEG-coded data which contains closed caption (CC) data in a user data area as character codes (in a user data mode) or in a picture data area as NRZ-converted pixel data (in an MPEG mode) and at least outputting an MPEG-decoded video data stream, for inserting the CC data in the scanning line H21, the method comprising the steps of:

storing MPEG-decoded video data in said MPEG-decoded video data stream in a first memory area for storing a frame of video data read by a horizontal scanning line of data for each horizontal scanning period;

in response to a determination that said CC data is in said user data mode, executing the following steps of;

converting said CC data in said user data area into NRZ-converted CC data;

storing said NRZ-converted CC data in a second memory area;

in a period of a horizontal scanning line H21 (hereinafter, referred to simply as "H21"), outputting said NRZ-converted CC data from said second memory area to a bit map pixel data channel of a video output processor;

in each of the horizontal scanning periods after H21, outputting the contents of the next line of said first memory area to a video pixel data channel of said video output processor, and

in response to a determination that said CC data is in said MPEG mode executing the following steps of;

in a period of said line H21 outputting the contents of the first line of said first memory area;

in each of the horizontal scanning periods after H21, outputting the contents of the next line of said first memory area; and

excluding at least said line H21 from vertical interpolation target.

2. A method, used in an MPEG decoder which receives a data stream including MPEG-coded data which contains closed caption (CC) data in picture data as NRZ-converted pixel data (in an MPEG mode) and at least outputting an MPEG-decoded video data stream, for inserting the CC data in the scanning line H21, the method comprising the steps of:

storing MPEG-decoded video data in said MPEG-decoded video data stream in a first memory area for storing a frame of video data which is to be read by a horizontal scanning line of data at a time; and

in response to a determination that the current frame contains said CC data in said MPEG mode, executing the following steps of;

in a period of said line H21, outputting the contents of the first line of said first memory area;

in each of the horizontal scanning periods after H21, outputting the contents of the next line of said first memory area; and

excluding at least said line H21 from vertical interpolation target.

3. A method as defined in claim 2, wherein said step of excluding at least said line H21 comprises the step, started by each of vertical sync signals, of clearing vertical interpolation coefficients for a first field.

4. A method as defined in claim 2, wherein said step of excluding at least said line H21 comprises the step, executed in case when it is found in a horizontal sync interrupt routine that the current frame has said CC data of said MPEG mode, of making the lines H21 and H22 monochrome.

5. A system, used in an MPEG decoder which receives a data stream including MPEG-coded data which contains closed caption (CC) data in a user data area as character codes (in a user data mode) or in picture data as NRZ-converted pixel data (in an MPEG mode) and at least outputting MPEG-decoded video data, for inserting the CC data in the scanning line H21, the system comprising:

first memory means for storing a frame of said MPEG-decoded video data which is to be read by a horizontal scanning line of data at a time;

means for converting said CC data in said user data area into NRZ-converted CC data;

second memory means for storing said NRZ-converted CC data;

means for outputting said NRZ-converted CC data from said second memory area to a bit map pixel data channel in a period of a horizontal scanning line H21 (hereinafter, referred to simply as "line H21");

means operative in said user data mode for outputting the contents of the next line of said first memory means to a video pixel data channel in each of the horizontal scanning periods after H21;

means operative in said MPEG mode for outputting the contents of the first line of said first memorv means in a period of said line H21;

means operative in said MPEG mode for outputting the contents of the next line of said first memory means in each of the horizontal scanning periods after H21; and

means operative in said MPEG mode for excluding at least said line H21 from vertical interpolation target.

6. A system as defined in claim 5, wherein all said means other than said first and said second memory means are realized as a single integrated circuit (IC).

7. A system as defined in claim 5, wherein all said means other than said first and said second memory means are incorporated in said MPEG decoder.

8. A system, operating with an MPEG decoder which receives a data stream including MPEG-coded data which contains closed caption (CC) data in picture data as NRZ-converted pixel data (in an MPEG mode) and at least outputting MPEG-decoded video data, for inserting the CC data in the scanning line H21, the system comprising:

memory means for storing a frame of said MPEG-decoded video data in a first memory area which is to be read by a horizontal scanning line of data at a time;

means operative in said MPEG mode for outputting the contents of the first line of said first memory area in a period of said line H21;

means operative in said MPEG mode for outputting the contents of the next line of said first memory area in each of the horizontal scanning periods after H21; and

means operative in said MPEG mode for excluding at least said line H21 from vertical interpolation target.

9. A system as defined in claim 8, wherein said means for excluding at least said line H21 comprises:

means activated by each of vertical sync signals for clearing vertical interpolation coefficients for a first field of a picture.

10. A system as defined in claim 8, wherein said means for excluding at least said line H21 comprises:

means, activated in case when it is found in a horizontal sync interrupt routine that the current frame has said CC data of said MPEG mode, for making the lines H21 and H22 monochrome.

11. A system for receiving a data stream including MPEG-coded data which contains CC data in a user data or MPEG mode and at least outputting an MPEG-decoded video data stream which contains the CC data in the scanning line H21 in a form of NRZ-converted pixel data, the system being connected to a RAM having at least a first memory area for storing a frame of video data which is to be read by a horizontal scanning line of data at a time and a second memory area, the system comprising:

means for accessing said RAM;

means for receiving said data stream from the outside;

control means for MPEG-decoding said MPEG-coded data in said data stream, storing MPEG-decoded video data in said first area through said RAM accessing means and extracting said CC data in said user data area; and

means having a video pixel data channel and a bit map pixel data channel for combining a first data stream received via said video pixel data channel and a second data stream received via said bit map pixel data channel Into a single data stream;

said control means comprising;

means for converting said extracted CC data and storing NRZ-converted CC data in said second memory area through said RAM access means;

means for outputting said NRZ-converted CC data from said second memory area to said bit map pixel data channel in a period of a horizontal scanning line H21 (hereinafter, referred to simply as "line H21"); and

means operative in said user data mode for outputting the contents of the next line of said first memory means to a video pixel data channel in each of the horizontal scanning periods after H21.

12. A system as defined in claim 11, wherein said control means further comprises:

means operative in said MPEG mode for outputting the contents of the first line of said first memory means in a period of said line H21; and

means operative in said MPEG mode for outputting the contents of the next line of said first memory means in each of the horizontal scanning periods after H21.

13. A system as defined in claim 12, wherein said control means further comprises means operative in said MPEG mode for excluding at least said line H21 from vertical interpolation target.

14. A system as defined in claim 13, wherein said means for excluding at least said line H21 comprises:

means activated by each of vertical sync signals for clearing vertical interpolation coefficients for a first field of a picture.

15. A system as defined in claim 13, wherein said means for excluding at least said line H21 comprises:

means, activated in case when it is found in a horizontal sync interrupt routine that the current frame has said CC data of said MPEG mode, for making the lines H21 and H22 monochrome.

16. A system as defined in claim 11, wherein means for receiving said data stream from the outside and control means are realized as a single integrated circuit (IC).

17. A video-CD player capable of inserting CC data contained in a user data mode or am MPEG mode as NRZ-converted pixel data in an MPEG-coded data recorded on a video-CD into the scanning line H21 of a video signal reproduced from the video-CD;

the video-CD player comprising;

means for playing said video-CD and providing an MPEG-coded data stream;

means for MPEG decoding said MPEG-coded data stream and providing a video data and said CC data;

first memory means for storing a frame of said video data which is to be read by a horizontal scanning line of data at a time;

means for NRZ-converting said CC data into NRZ-converted CC data;

second memory means for storing said NRZ-converted CC data;

means having a video pixel data channel and a bit map pixel data channel for combining a first data stream received via said video pixel data channel and a second data stream received via said bit map pixel data channel into a single data stream;

means for outputting said NRZ-converted CC data from said second memory area to said bit map pixel data channel in a period of a horizontal scanning line H21; and

means operative in said user data mode for outputting the contents of the next line of said first memory means to said video pixel data channel in each of the horizontal scanning periods after H21.

18. A video-CD player as defined in claim 17, further comprising:

means operative in said MPEG mode for outputting the contents of the first line of said first memory means in a period of said line H21; and

means operative in said MPEG mode for outputting the contents of the next line of said first memory means in each of the horizontal scanning periods after H21.

19. A system as defined in claim 18, further comprising means operative in said MPEG mode for excluding at least said line H21 from vertical interpolation target.

20. A system as defined In claim 19, wherein said means for excluding at least said line H21 comprises:

means activated by each of vertical sync signals for clearing vertical interpolation coefficients for a first field of a picture.

21. A system as defined in claim 19 wherein said means for excluding at least said line H21 comprises:

means, activated in case when it is found in a horizontal sync interrupt routine that the current frame has said CC data of said MPEG mode, for making the lines H21 and H22 monochrome.