COMBINATION DEVICE, TELECOMMUNICATION SYSTEM, AND COMBINING METHOD

• US 20110029113A1
• Filed: 02/04/2010
• Published: 02/03/2011
• Est. Priority Date: 02/04/2009
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Hai Shan, Zhong, Zhou, Huan, Ishikawa, Tomokazu, Chong, Kok Seng, Norimatsu, Takeshi
• Granted Patent: US 8,504,184 B2
• Time in Patent Office: Days
• US Class Current: 700/94
• CPC Class Codes: G10L 19/008 Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing
• CPC Class Codes: H04M 3/56 Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities video conference systems H04N7/15

Abstract

A combination device (305) according to the present invention includes: a detection unit (501) that detects active coded bitstreams that are effective coded bitstreams from a plurality of coded bitstreams (116) within a predetermined time period; a first combining unit (504) that combines, from a plurality of downmix sub-streams (115) included in the coded bitstreams (116), only downmix sub-streams (115) included in the active coded bitstreams so as to generate a combined downmix sub-stream (121); and a second combining unit (506) that combines, from a plurality of parameter sub-streams (113) included in the coded bitstreams (116), only parameter sub-streams (113) included In the active coded bitstreams so as to generate a combined parameter sub-stream (122).

Claims

1. A combination device that combines a plurality of coded bitstreams transmitted from a plurality of sites, the plurality of coded bitstreams each including a downmix sub-stream and a parameter sub-stream, the downmix sub-stream being generated by down-mixing a plurality of input audio signals, and the parameter sub-stream being to be used to reconstruct the plurality of input audio signals from the downmix sub-stream, said combination device comprising:

a detection unit configured to detect an active coded bitstream from the plurality of coded bitstreams within a predetermined time period, the active coded bitstream being a coded bitstream that is effective;

a first combining unit configured to combine, from among a plurality of downmix sub-streams, only plural downmix sub-streams included in plural active coded bitstreams, so as to generate a combined downmix sub-stream;

a second combining unit configured to combine, from among a plurality of parameter sub-streams, only plural parameter sub-streams included in the plural active coded bitstreams, so as to generate a combined parameter sub-stream; and

a transmission unit configured to transmit, to the plurality of sites, a combined bit stream that includes the combined downmix sub-stream and the combined parameter sub-stream.

2. The combination device according to claim 1,

wherein said first combining unit includes:

a decoding unit configured to decode, from among the plurality of downmix sub-streams, only the plural downmix sub-streams included in the plural active coded bitstreams, so as to generate plural decoded downmix sub-streams;

an adding unit configured to add the plural decoded downmix sub-streams together so as to generate at least one intermediate combined downmix sub-stream; and

a coding unit configured to code the at least one intermediate combined downmix sub-stream so as to generate at least one combined downmix sub-stream.

3. The combination device according to claim 1,

wherein said first combining unit is configured to combine, for each of the plurality of sites, downmix sub-streams transmitted from the plurality of sites except the each of the plurality of sites, from among the plural downmix sub-streams included in the plural active coded bitstreams, so as to generate a combined downmix sub-stream to be transmitted to the each of the plurality of sites,

said second combining unit is configured to combine, for each of the plurality of sites, parameter sub-streams transmitted from the plurality of sites except the each of the plurality of sites, from among the plural parameter sub-streams included in the plural active coded bitstreams, so as to generate a combined parameter sub-stream to be transmitted to the each of the plurality of sites,

said transmission unit is configured to transmit, to the each of the plurality of sites, a combined bitstream that includes the combined downmix sub-stream and the combined parameter sub-stream, and

when a number of inactive coded bitstreams is two or more, the inactive coded bitstreams being coded bitstreams other than the plurality of active coded bitstreams in the plurality of coded bitstreams,

(1) said first combining unit is configured to combine the plural downmix sub-streams included in all of the plural active coded bitstreams so as to generate a common combined downmix sub-stream,

(2) said second combining unit is configured to combine the plural parameter sub-streams included all of the plural active coded bitstreams so as to generate a common combined parameter sub-stream, and

(3) said transmission unit is configured to transmit a common combined bitstream that includes the common combined downmix sub-stream and the common combined parameter sub-stream, to sites which transmit the inactive coded bitstreams that are two or more.

4. The combination device according to claim 1,

wherein, when a number of the plural active coded bitstreams is two, said transmission unit is configured to (i) transmit, without a combining process, a first coded bitstream that is one of the plural active coded bitstreams to a site transmitting a second coded bitstream that is other one of the plural active coded bitstreams, and to (ii) transmit the second coded bitstream to a site transmitting the first coded bitstream without a combining process.

5. The combination device according to claim 1,

wherein, when a number of the plural active coded bitstreams is one, said transmission unit is configured to transmit, without a combining process, the active coded bitstream to the plurality of sites except a site transmitting the active coded bitstream.

6. The combination device according to claim 1,

wherein said detection unit is configured to detect the active coded bitstream based on information included in each of the plurality of parameter sub-streams.

7. The combination device according to claim 1,

wherein said first combining unit is configured to combine the plural downmix sub-streams included in all of the plural active coded bitstreams so as to generate a single combined downmix sub-stream,

said second combining unit is configured to combine the plural parameter sub-streams included in all of the plural active coded bitstreams so as to generate a single combined parameter sub-stream, and

said transmission unit is configured to transmit, to each of the plurality of sites, a single combined bitstream that includes the single combined downmix sub-stream and the single combined parameter sub-stream.

8. The combination device according to claim 7, further comprising

an additional information generation unit configured to generate, for each of active sites which have transmitted the plural active coded bitstreams, additional information to be used to specify a signal component from signal components in the single combined bitstream, the signal component corresponding a corresponding one of the plural active coded bitstreams which has been transmitted from the each of active sites,

wherein said transmission unit is configured to transmit the additional information to the each of active sites.

9. The combination device according to claim 8,

wherein said additional information generation unit is configured to generate the additional information for each of the active sites, the additional information being to be used to specify a parameter from parameters included in the single combined parameter sub-stream, the parameter corresponding to a corresponding one of the plural parameter sub-streams which has been transmitted from the each of the active sites.

10. The combination device according to claim 1,

wherein said second combining unit includes

a parameter basis unifying unit configured to convert different parameter presentation bases of the plural parameter sub-streams to a single unified parameter presentation basis, and generate plural unified parameters based on the single unified parameter presentation basis, when the plural parameter sub-streams are expressed by the different parameter presentation bases, and

said second combining unit is configured to combine the plural unified parameters so as to generate the combined parameter sub-stream.

11. The combination device according to claim 10, further comprising

a parameter basis selection unit configured to select the single unified parameter presentation basis from a plurality of parameter presentation bases, based on a current bit rate available for transmission from said combination device to the plurality of sites.

12. The combination device according to claim 10, further comprising

a parameter basis selection unit configured to select the single unified parameter presentation basis from a plurality of parameter presentation bases, based on a bit cost indicating the number of bits of the combined parameter sub-stream.

13. The combination device according to claim 2,

wherein each of the plural downmix sub-stream is generated by down-mixing the plurality of input audio signals, transformed into a spectrum domain, and coded,

said decoding unit is configured to decode the plural downmix sub-streams to generate the plural decoded downmix sub-streams in the spectrum domain, and

said adding unit is configured to add the plural decoded downmix sub-streams in the spectrum domain together so as to generate the at least one intermediate combined downmix sub-stream.

14. The combination device according to claim 13,

wherein said first combining unit further includes

a scaling unit configured to scale the at least one intermediate combined downmix sub-stream so that spectrum power of the plural decoded downmix sub-streams is preserved in the at least one intermediate combined downmix sub-stream, and

said coding unit is configured to code the at least one intermediate combined downmix sub-stream scaled by said scaling unit so as to generate the combined downmix sub-stream.

15. The combination device according to claim 13,

wherein said second combining unit includes:

an inverse quantization unit configured to inversely quantize the plural parameter sub-streams so as to generate plural inversely-quantized parameters;

a parameter combining unit configured to combine the plural inversely-quantized parameters so as to generate a combined parameter;

a parameter update unit configured to update a part of parameters included in the combined parameter so as to generate a updated parameter; and

a quantization unit configured to quantize (a) a parameter except the part of parameters included in the combined parameter and (b) the updated parameter so as to generate the combined parameter sub-stream.

16. A telecommunication system comprising:

a plurality of sites each including a coding device that generates a coded bitstream that includes a downmix sub-stream and a parameter sub-stream, the downmix sub-stream being generated by down-mixing a plurality of input audio signals, and the parameter sub-stream being to be used to reconstruct the plurality of input audio signals from the downmix sub-stream; and

the combination device according to claim 1 which combines a plurality coded bitstreams including the coded bitstream which are transmitted from said plurality of sites so as to generate a combined bitstream, and transmits the combined bitstream to each of said plurality of sites,

wherein each of said plurality of sites further includes a decoding device that decodes the combined bitstream to generate output audio signals.

17. A telecommunication system comprising:

a plurality of sites each including a coding device that generates a coded bitstream that includes a downmix sub-stream and a parameter sub-stream, the downmix sub-stream being generated by down-mixing a plurality of input audio signals, and the parameter sub-stream being to be used to reconstruct the plurality of input audio signals from the downmix sub-stream; and

the combination device according to claim 8 which combines a plurality of coded bitstreams including the coded bitstream which are transmitted from said plurality of sites so as to generate a combined bitstream, and transmits the combined bitstream to each of said plurality of sites,

wherein each of said plurality of sites further includes a decoding device that decodes the combined bitstream to generate output audio signals, and

said decoding device generates, based on the additional information, the output audio signals from which a signal component is removed from signal components in the single combined bitstream, the signal component corresponding to the coded bitstream transmitted from a corresponding one of said plurality of sites which includes said decoding device.

18. A combining method of combining a plurality of coded bitstreams transmitted from a plurality of sites, the plurality of coded bitstreams each including a downmix sub-stream and a parameter sub-stream, the downmix sub-stream being generated by down-mixing a plurality of input audio signals, and the parameter sub-stream being to be used to reconstruct the plurality of input audio signals from the downmix sub-stream, said combining method comprising:

detecting an active coded bitstream from the plurality of coded bitstreams within a predetermined time period, the active coded bitstream being a coded bitstream that is effective;

combining, from among a plurality of downmix sub-streams, only plural downmix sub-streams included in plural active coded bitstreams including the active bitstream, so as to generate a combined downmix sub-stream;

combining, from among a plurality of parameter sub-streams, only plural parameter sub-streams included in the plural active coded bitstreams, so as to generate a combined parameter sub-stream; and

transmitting, to each of the plurality of sites, a combined bit stream that includes the combined downmix sub-stream and the combined parameter sub-stream.

19. A non-transitory computer-readable recording medium for use in a computer, the recording medium having a computer program recorded thereon for causing the computer to execute the combining method according to claim 18.

20. An integrated circuit that combines a plurality of coded bitstreams transmitted from a plurality of sites, the plurality of coded bitstreams each including a downmix sub-stream and a parameter sub-stream, the downmix sub-stream being generated by down-mixing a plurality of input audio signals, and the parameter sub-stream being to be used to reconstruct the plurality of input audio signals from the downmix sub-stream, said integrated circuit comprising:

a detection unit configured to detect an active coded bitstream from the plurality of coded bitstreams within a predetermined time period, the active coded bitstream being a coded bitstream that is effective;

a first combining unit configured to combine, from among a plurality of downmix sub-streams, only plural downmix sub-streams included in plural active coded bitstreams including the active bitstream, so as to generate a combined downmix sub-stream;

a second combining unit configured to combine, from among a plurality of parameter sub-streams, only plural parameter sub-streams included in the plural active coded bitstreams, so as to generate a combined parameter sub-stream; and

a transmission unit configured to transmit, to each of the plurality of sites, a combined bit stream that includes the combined downmix sub-stream and the combined parameter sub-stream.