Codec converter, gateway device, and codec converting method

• US 8,085,809 B2
• Filed: 02/06/2009
• Issued: 12/27/2011
• Est. Priority Date: 04/23/2008
• Status: Active Grant

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Inoishi, Mitsuru
• Primary Examiner(s): Mui, Gary
• Application Number:
  US12/366,841
• Publication Number:
  US 20090268755A1
• Time in Patent Office: 1,054 Days
• Field of Search: 370/401, 370465-467, 370474-476, 370/412, 370/513
• US Class Current: 370/466
• CPC Class Codes: H04L 65/103 in the network
• CPC Class Codes: H04L 65/765 intermediate

Abstract

A codec converter includes: a plurality of codec converting units each configured to convert first encoded media data encoded using a first encoding mode into second encoded media data encoded using a second encoding mode different from the first encoding mode; a media data extracting unit configured to extract input-encoded media data from an input packet, and to generate conversion information that identifies a desired format conversion; a resource allocation unit configured to route the input-encoded media data to a selected one of the plurality of codec converting units based on the conversion information; and a packet reassembling unit configured to receive output-encoded media data from the selected one of the plurality of codec converting units, and to assemble the output-encoded media data into an output packet. Each of the plurality of codec converting units selects a different pair of first and second encoding modes.

Claims

1. A codec converter comprising:

a plurality of separate codec converting units each configured to convert first encoded media data encoded using a first encoding mode into second encoded media data encoded using a second encoding mode different from the first encoding mode;

a media data extracting unit configured to extract input-encoded media data from an input packet, and to generate conversion information that identifies a desired format conversion;

a resource allocation unit configured to route the input-encoded media data to a selected one of the plurality of separate codec converting units based on the conversion information; and

a packet reassembling unit configured to receive output-encoded media data from the selected one of the plurality of separate codec converting units, and to assemble the output-encoded media data into an output packet,

wherein the plurality of separate codec converting units are arranged in parallel between the resource allocation unit and the packet reassembling unit,

wherein the first encoding mode is chosen from a plurality of possible encoding modes,

wherein the second encoding mode is chosen from the plurality of possible encoding modes, and

wherein each of the plurality of separate codec converting units selects a different pair of first and second encoding modes.

2. The codec converter, as recited in claim 1,

wherein each of the plurality of separate codec converting units shares a common encoding mode as one of the first and second encoding modes.

3. The codec converter, as recited in claim 1, wherein each of the plurality of separate codec converting units further comprises:

a decoder configured to decode the first encoded media data to provide decoded media data; and

an encoder configured to encode the decoded media data into the second encoded media data,

wherein the decoded media data is directly input to the encoder.

4. The codec converter, as recited in claim 1, further comprising:

a network buffer placed between the media data extracting unit and the resource allocation unit, configured to temporarily store the input-encoded media data before the input-encoded media data is provided to the resource allocation unit, to adjust a jitter of the media data.

5. The codec converter, as recited in claim 1,

wherein the plurality of possible encoding modes includes at least two of:

an ITU-T G.711 codec mode, an ITU-T G.722 codec mode, an enhanced variable rate codec (EVRC) mode, and an adaptive multi-rate (AMR) codec mode.

6. The codec converter, as recited in claim 1,

wherein the plurality of separate codec converting units comprise one or more digital signal processors.

7. The codec converter, as recited in claim 1,

wherein each of the plurality of separate codec converting units is configured to simultaneously convert signals on a plurality of channels.

8. The codec converter, as recited in claim 1, further comprising

a management element containing one or more management tables,

wherein each of the one or more management tables includes management data relating to the plurality of separate codec converting units, and

wherein the resource allocation unit uses the management data to route the input-encoded media data to the selected one of the plurality of separate codec converting units.

9. A gateway device provided at a network border between a plurality of networks, the gateway device comprising the codec converter according to claim 1,

wherein the plurality of networks each employ a corresponding one of a plurality of network encoding modes chosen from the plurality of possible encoding modes, and

wherein the codec converter is configured to buffer signals between the plurality of networks.

10. A gateway device provided at a network border between a plurality of networks according to claim 9,

wherein each of the plurality of separate codec converting units further comprises:

a decoder configured to decode the first encoded media data to provide decoded media data; and

an encoder configured to encode the decoded media data into the second encoded media data, and

wherein the decoded media data is directly input to the encoder.

11. A codec converter comprising:

a plurality of separate codec converting units, each including a decoder for decoding first encoded media data using a first codec mode to generate decoded media data, and an encoder, which is associated with the decoder, for encoding the decoded media data using a second codec mode, which is different from the first codec mode, to generate second encoded media data, an output of the decoder being directly connected to an input of the encoder;

a media data extracting unit for extracting input media data from an input packet and generating channel identification information for identifying a communication channel of the packet corresponding to the extracted input media data;

a network buffer for temporarily storing the extracted input media data to adjust jitter of the buffered input media data;

an information managing unit for storing management information identifying a correspondence between the channel identification information and the plurality of separate codec converting units;

a resource allocation unit for allocating the buffered input media data to one of the plurality of separate codec converting units corresponding to the channel identification information of the media data; and

a packet reassembling unit for assembling the second encoded media data output from the one of the separate codec converting units into a packet.

12. The codec converter, as recited in claim 11,

wherein each of the plurality of separate codec converting units shares a common encoding mode as one of the first and second codec modes.

13. The codec converter, as recited in claim 11,

wherein the plurality of separate codec converting units comprise one or more digital signal processors.

14. The codec converter, as recited in claim 11,

wherein each of the plurality of separate codec converting units is configured to simultaneously convert signals on a plurality of channels.

15. A gateway device provided at a network border between a plurality of networks, the gateway device comprising the codec converter according to claim 11,

wherein the plurality of networks each employ a corresponding one of a plurality of network codec modes chosen from a plurality of possible codec modes, and

wherein the codec converter is configured to buffer signals between the plurality of networks.

16. The codec converter, as recited in claim 15,

wherein the plurality of possible codec modes includes at least two of:

an ITU-T G.711 codec mode, an ITU-T G.722 codec mode, an enhanced variable rate codec (EVRC) mode, and an adaptive multi-rate (AMR) codec mode.

17. A codec converting method, including:

extracting media data from an input packet in a media data extracting unit;

generating channel identification information in the media data extracting unit to identify a communication channel of the input packet based on the extracted media data;

receiving channel identification information in an information managing unit;

managing stored information in the information managing unit regarding which channel identification information corresponds to which of the plurality of separate codec converting units;

adjusting a jitter of the extracted media data in a network buffer after storing the extracted media data;

allocating the jitter adjusted media data to one of the plurality of separate codec converting units based on the stored information;

decoding the jitter adjusted media data in a decoder of a codec converting unit to generate decoded media data;

encoding the decoded media data in an encoder of the codec converting unit output from the corresponding decoder to generate converted media data; and

assembling the converted media data into an output packet in a packet reassembling unit,

wherein the encoder uses a second codec mode, which is different from a first codec mode used by the decoder.

18. The codec converting method of claim 17,

wherein the channel identification information includes an internal session number identifying a selected one of the separate codec converting units used to generate the extracted media data.

19. The codec converting method of claim 17,

wherein the stored information includes information regarding the first and second codec modes, information regarding the capacity of each of the plurality of codec converting units, and information regarding the current status of the plurality of codec converting units.

20. The codec converting method of claim 17,

wherein the first and second codec modes each comprise one of:

an ITU-T G.711 codec mode, an ITU-T G.722 codec mode, an enhanced variable rate codec (EVRC) mode, and an adaptive multi-rate (AMR) codec mode.