Digital signal multiplexing method and apparatus, digital signal transmission method and apparatus, digital signal recording method and apparatus and recording medium

• US 6,414,970 B1
• Filed: 01/22/1999
• Issued: 07/02/2002
• Est. Priority Date: 01/26/1998
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Tahara, Katsumi, Yasuda, Mikita, Negishi, Shinji
• Primary Examiner(s): Patel, Ajit
• Assistant Examiner(s): Tsegaye, Saba
• Application Number:
  US09/235,786
• Time in Patent Office: 1,257 Days
• Field of Search: 370/503, 370/513, 370/537, 370/510, 370/538, 370/539, 370/540, 370/541, 370/244, 370/394, 370/468, 370/474, 370/517, 370/516, 370/498
• US Class Current: 370/510
• CPC Class Codes: H04N 21/23406 involving management of server-side video buffer
• CPC Class Codes: H04N 21/23608 Remultiplexing multiplex streams, e.g. involving modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/2365 Multiplexing of several video streams
• CPC Class Codes: H04N 21/4344 Remultiplexing of multiplex streams, e.g. by modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/4347 Demultiplexing of several video streams
• CPC Class Codes: H04N 21/44004 involving video buffer management, e.g. video decoder buffer or video display buffer

Abstract

A digital signal multiplexing method and apparatus in which plural degree-one multiplexed streams produced on time-divisionally multiplexing a bitstream of one or more digital signals are received and are time-divisionally multiplexed to generate a degree two multiplexed stream. Specifically, plural degree-one multiplexed streams are received, and the received degree-one multiplexed streams are time-divisionally multiplexed based on a repetitive pattern associated with the bitrate of the respective degree-one multiplexed streams to generate a degree two multiplexed stream. The time reference value attached to the degree two multiplexed stream is corrected based on the reference clocks not synchronized with the system clocks of the degree-one multiplexed streams. A pre-set volume of the dummy data is multiplexed if the corrected time reference value becomes larger than the time reference value attached to the degree-one multiplexed streams.

Claims

1. A digital signal multiplexing apparatus in which degree-one multiplexed streams are received from a plurality of degree-one multiplexers and in which the received degree-one multiplexed streams are time-divisionally multiplexed to generate a degree two multiplexed stream, said degree-one multiplexed streams being a time-divisionally multiplexed bitstream of one or more digital signals having a time reference value attached thereto, comprising:

reception means for receiving a plurality of degree-one multiplexed streams from said degree-one multiplexers;

multiplexing means for time-divisionally multiplexing the received degree-one multiplexed streams based on a repetitive pattern associated with a bitrate of the degree-one multiplexed streams to generate the degree two multiplexed stream; and

time reference value correction means for operating based on asynchronous reference clocks not synchronized with reference clocks for operating the degree-one multiplexers and for correcting the time reference value appended to said degree two multiplexed stream;

said multiplexing means multiplexing a pre-set quantity of dummy data if the time reference value corrected by said time reference value correction means becomes larger than the time reference value attached to the degree-one multiplexed streams by the degree-one multiplexers by a value larger than a pre-set value.

2. The digital signal multiplexing apparatus according to claim 1 wherein said reception means receives from the respective degree-one multiplexers the degree-one multiplexed streams of a bitrate lower than a bitrate assigned on the basis of a repetitive pattern for multiplexing by said multiplexing mean (assigned bitrate).

3. The digital signal multiplexing apparatus according to claim 2 wherein said reception means receives from the respective degree-one multiplexers the degree-one multiplexed streams of a bitrate represented by

4. The digital signal multiplexing apparatus according to claim 1 wherein said multiplexing means time-divisionally multiplexes the respective received degree-one multiplexed streams after lapse of delay exceeding the maximum delay time of the degree-one multiplexed streams generated by said reception memories.

5. The digital signal multiplexing apparatus according to claim 1 wherein said reception memories receive a transport stream prescribed by ISO13818-1 and wherein said multiplexing means generates a transport stream provided in ISO13818-1.

6. The digital signal multiplexing apparatus according to claim 5 wherein said time reference value correction means corrects a program clock reference (PCR) value attached to a transport stream prescribed by ISO13818-1.

7. The digital signal multiplexing apparatus according to claim 5 wherein said multiplexing means multiplexes a null packet prescribed in ISO13818-1.

8. A method for multiplexing digital signals comprising:

receiving degree-one multiplexed streams from a plurality of degree-one multiplexers, said degree-one multiplexed streams being a time-divisionally multiplexed bitstream of one or more digital signals having a time reference value attached thereto;

time-divisionally multiplexing received degree-one multiplexed streams based on a repetitive pattern associated with the bitrate of respective degree-one multiplexed streams to generate a degree two multiplexed stream;

correcting the time reference value attached to the time reference value attached to the degree two multiplexed stream based on asynchronous reference clocks not synchronized with reference clocks for operating said degree-one multiplexers; and

multiplexing a pre-set volume of dummy data if the corrected time reference value exceeds the time reference value attached to the degree-one multiplexed streams by more than a predetermined value.

9. The method for multiplexing digital signals according to claim 8 wherein the degree-one multiplexed streams of a bitrate lower than the bitrate assigned based on the repetitive pattern for multiplexing (assigned bitrate).

10. The digital signal multiplexing method according to claim 9 wherein the degree-one multiplexed streams of a bitrate represented by

  (CrMIN/CpMAX)XP

are received from the respective degree-one multiplexers, where CrMIN is the minimum value of the rating of the reference clocks for operating said time reference value correction means, CpMAX is the minimum value of the rating of the reference clocks for operating said degree-one multiplexers and P is the assigned bitrate.

11. The digital signal multiplexing method according to claim 8 wherein the respective received degree-one multiplexed streams are time-divisionally multiplexed after lapse of delay exceeding the maximum delay time of the degree-one multiplexed streams generated by reception.

12. The digital signal multiplexing method according to claim 8 wherein a transport stream prescribed by ISO13818-1 is received and wherein a transport stream provided in ISO13818-1 is generated.

13. The digital signal multiplexing method according to claim 12 wherein a program clock reference (PCR) value attached to a transport stream prescribed by ISO13818-1 is corrected.

14. The digital signal multiplexing method according to claim 12 wherein said multiplexing means multiplexes a null packet prescribed in ISO13818-1 as dummy data.

15. An apparatus for transmitting digital signals comprising:

a plurality of degree-one multiplexers for time-divisionally multiplexing a bitstream of one or more digital signals and for attaching a time reference value to generate a plurality of degree-one multiplexed streams; and

a degree-two multiplexing device including reception means for receiving plural degree-one multiplexed streams from said degree-one multiplexers, multiplexing means for time-divisionally multiplexing the received degree-one multiplexed streams based on a repetitive pattern associated with the bitrate of respective degree-one multiplexed streams to generate a degree two multiplexed stream, time reference value correcting means for correcting the time reference value attached to the degree two multiplexed stream based on asynchronous reference clocks not synchronized with reference clocks adapted for operating said degree-one multiplexers and transmission means for transmitting the degree two multiplexed stream generated by said multiplexing means, said degree-two multiplexing device multiplexing a pre-set volume of the dummy data when the time reference value corrected by said time reference value correction means becomes larger than the time reference value attached to the degree-one multiplexed streams by the degree-one multiplexers by a value larger than a pre-set value.

16. The digital signal transmitting apparatus according to claim 15 wherein each degree-one multiplexer generates a degree-one multiplexed stream at a bitrate lower than the bitrate assigned based on the repetitive pattern for multiplexing (assigned bitrate).

17. The digital signal transmitting apparatus according to claim 15 wherein the degree-one multiplexed streams of a bitrate represented by

  (CrMIN/CpMAX)XP

are generated by the degree-one multiplexers, where CrMIN is the minimum value of the rating of the reference clocks for operating said time reference value correction means, CpMAX is the minimum value of the rating of the reference clocks for operating said degree-one multiplexers and P is the assigned bitrate.

18. The digital signal transmitting apparatus according to claim 15 wherein the respective received degree-one multiplexed streams are time-divisionally multiplexed by the multiplexing means of said degree-two multiplexer after lapse of delay exceeding the maximum delay time of the degree-one multiplexed streams generated by reception.

19. A digital signal transmitting method comprising:

time-divisionally multiplexing a bitstream of one or more digital signals by pre-set reference clocks and attaching a time reference value for generating a plurality of degree-one multiplexed streams;

receiving said degree-one multiplexed streams;

time-divisionally multiplexing the received degree-one multiplexed streams, based on a repetitive pattern associated with the bitrate of each degree-one multiplexed stream, to generate a degree two multiplexed stream;

correcting the time reference value attached to the degree two multiplexed stream based on reference clocks not synchronized with the reference clocks adapted for generating each degree-one multiplexed stream for transmitting the degree two multiplexed stream; and

transmitting the degree two multiplexed stream, on which are multiplexed a pre-set volume of the dummy data, if the corrected time reference value has become than the time reference value attached to the degree-one multiplexed streams by the degree-one multiplexers by a value larger than a pre-set value.

20. The digital signal transmitting method according to claim 19 wherein said degree-one multiplexed streams of a bitrate lower than a bitrate assigned on the basis of a repetitive pattern for multiplexing (assigned bitrate) are generated.

21. The digital signal transmitting method according to claim 20 wherein said degree-one multiplexed streams of a bitrate represented by

22. The digital signal transmitting method according to claim 19 wherein said degree-one multiplexed streams are time-divisionally multiplexed after lapse of delay exceeding the maximum delay time generated by transmission of the degree-one multiplexed streams.

23. An apparatus for recording digital signals comprising:

a plurality of degree-one multiplexers for time-divisionally multiplex a bitstream of one or more digital signals and for attaching a time reference value to generate a plurality of degree-one multiplexed streams; and

a degree-two multiplexing device including reception means for receiving degree-one multiplexed streams from said degree-one multiplexers, multiplexing means for time-divisionally multiplexing the received degree-one multiplexed streams based on a repetitive pattern associated with the bitrate of respective degree-one multiplexed streams to generate a degree two multiplexed stream, time reference value correction means for correcting the time reference value attached to the degree two multiplexed stream based on asynchronous reference clocks not synchronized with reference clocks adapted for operating said degree-one multiplexers and recording means for recording the degree two multiplexed stream generated by said multiplexing means on a recording medium, said degree-two multiplexing device multiplexing a pre-set volume of the dummy data when the time reference value corrected by said time reference value correction means becomes larger than the time reference value attached to the degree-one multiplexed streams by the degree-one multiplexers by a value larger than a pre-set value.

24. The digital signal recording apparatus according to claim 23 wherein said degree-one multiplexers generate the degree-one multiplexed streams of a bitrate lower than a bitrate assigned on the basis of a repetitive pattern for multiplexing by said multiplexing mean (assigned bitrate).

25. The digital signal recording apparatus according to claim 24 wherein said degree-one multiplexers generate the degree-one multiplexed streams of a bitrate represented by

26. The digital signal recording apparatus according to claim 23 wherein said multiplexing means of said degree-two multiplexer time-divisionally multiplexes the respective received degree-one multiplexed streams after lapse of delay exceeding the maximum delay time of the degree-one multiplexed streams generated by transmission by said degree-one multiplexers.

27. A digital signal recording method comprising:

time-divisionally multiplexing a bitstream of one or more digital signals by pre-set reference clocks and attaching a time reference value for generating a plurality of degree-one multiplexed streams;

receiving said degree-one multiplexed streams;

time-divisionally multiplexing the received degree-one multiplexed streams, based on a repetitive pattern associated with the bitrate of each degree-one multiplexed stream, to generate a degree two multiplexed stream;

correcting the time reference value attached to the degree two multiplexed stream based on reference clocks not synchronized with the reference clocks adapted for generating each degree-one multiplexed stream for recording the degree two multiplexed stream; and

recording the degree two multiplexed stream, on which are multiplexed a pre-set volume of the dummy data, if the corrected time reference value has become than the time reference value attached to the degree-one multiplexed streams by the degree-one multiplexers by a value larger than a pre-set value.

28. The digital signal recording method according to claim 27 wherein said degree-one multiplexed streams of a bitrate lower than a bitrate assigned on the basis of a repetitive pattern for multiplexing (assigned bitrate) are generated.

29. The digital signal recording method according to claim 28 wherein said degree-one multiplexed streams of a bitrate represented by

30. The digital signal recording method according to claim 27 wherein said degree-one multiplexed streams are time-divisionally multiplexed after lapse of delay exceeding the maximum delay time generated by transmission of the degree-one multiplexed streams.

31. A recording medium having a degree two multiplexed stream recorded thereon, said degree two multiplexed stream being recorded on the recording medium by:

time-divisionally multiplexing a bitstream of one or more digital signals by pre-set reference clocks and attaching a time reference value for generating a plurality of degree-one multiplexed streams;

time-divisionally multiplexing the received degree-one multiplexed streams, based on a repetitive pattern associated with the bitrate of each degree-one multiplexed stream, to generate a degree two multiplexed stream;

correcting the time reference value attached to the degree two multiplexed stream based on reference clocks not synchronized with the reference clocks adapted for generating each degree-one multiplexed stream; and

recording the degree two multiplexed stream on the recording medium;

on the condition that the degree two multiplexed stream is recorded in a state in which a pre-set volume of the dummy data are multiplexed thereon if the corrected time reference value has become than the time reference value attached to the degree-one multiplexed streams by a value larger than a pre-set value.