Apparatus and method for converting control information

Abstract

picture and speech communication between plural terminals connected to different networks, such as a circuit-switched network and IP network. A converting apparatus 400 for control information or media information for picture/speech communications is provided across first and second terminals 301, 302 connected to respective different types of networks. Converting apparatus 400 includes control information converter 420, transcoder 450 and ability information converter 460. In case the ability information extracted from the decoding information, received from the first terminal 301, is not coincident to the ability information extracted from the call control information received from the second terminal 302, it is further checked whether or not there is picture format size coincidence. If the picture format size coincidence persists in one direction, processing is carried out for converting part of the decoding information or the control information, without causing the operations of the transcoder. In case there is no picture format size coincidence, the transcoder 450 is booted to convert the bitstream.

Description

This is MPEF-4 MPEG-4 standard, contained in the decoding information, received from the first terminal 100, and changes the so retrieved information into the description of, e.g., SDP prescribed in the IETF RFC, by way of conversion into call control information, to output the so produced information to the second transmitting/receiving unit 130. This second transmitting/receiving unit 130 sends the resulting call control information to the second terminal 150.

The second terminal 150 extracts the ability information, set forth in the description of the SDP, from the call control information, received from the second transmitting/receiving unit 130, and determines whether or not the so extracted information contains the ability information the second terminal is able to receive. If the extracted information contains the ability information the second terminal 150 is able to receive, the second terminal returns a response signal of that effect to the converting apparatus 210. If the ability information, obtained from the call control information, does not contain the ability information the second terminal is able to receive, the second terminal returns a negative response.

If an affirmative response is received from the second terminal 150, the control information converter 215 of the converting apparatus 210 converts the affirmative response into a form that permits the first terminal 100 to receive the response. The converting apparatus then sends the so produced affirmative response to the first terminal. By the above processing, a negotiation of the ability information is carried out between the second terminal 150 and the first terminal 100 (as a whole, generally, in the direction from the first to the second terminal).

The negotiation of the ability information in a direction from the second terminal 150 to the first terminal 100 is carried out in a similar manner to that in the direction from the first terminal 100 towards the second terminal 150 described above.

Thus, even if, in the communication between two different networks, the format of the ability information of one of two terminals involved in the communication differs from that of the counterpart side terminal, such as when the format of the first-stated terminal is DCI and that of the second-stated terminal is SDP, the communication can be established by interposing the converting apparatus configured for converting the control information.

A third embodiment of the present invention, including a converter (transcoder) in the converting apparatus, will now be explained. The components of the second embodiment which are the same as those of the first embodiment are omitted in the explanation for simplicity. FIG. 3 depicts a block diagram showing the configuration of an apparatus for converting the control information according to a third embodiment of the present invention. Specifically, FIG. 3 shows a converting apparatus 300, arranged between a first terminal 301 and a second terminal 302. In the following explanation, it is again assumed that the first terminal 301 is connected to a circuit-switched network and the second terminal 302 is connected to an IP network.

The converting apparatus 300 includes a control information converter 320, a transcoder 350, first transmitting/receiving units 120, 121 and second transmitting/receiving units 130, 131. The converting apparatus 300 receives the decoding information, such as DCI of the MPEG-4 standard, using, e.g., the ITU-TH. 245 standard, while receiving the call control information, such as the SDP information prescribed by IETF RFC, from the second terminal 302.

The transcoder (converter) 350 is made up by a picture transcoder and a speech transcoder.

In the above configuration, the control information converter 320 extracts the first ability information, pertinent to, e.g., a codec, mounted on the first terminal 301, from the decoding information received from the first terminal 301, while extracting the second ability information, pertinent to, e.g., a codec, mounted on the second terminal 301, from the call control information received from the second terminal 302.

The control information converter 320 then determines whether or not the first ability information and the second ability information coincide with each other. If the first ability information and the second ability information do not coincide with each other, the control information converter causes the transcoder (converter) 350 to be booted. Depending on the state of non-coincidence of the ability information, the transcoder (converter) 350 performs processing by the picture transcoder and/or by the speech transcoder.

As an example, a case where the first ability information and the second ability information are not coincident with each other, such that the picture transcoder is booted, will now be explained. The transcoder (converter) 350 effects stream conversion so that a video stream encoded for compression by one of the terminals will become decodable by the counterpart side terminal. The transcoder then outputs the so converted stream. For example, assume that the H.263 video codec and the MPEG-4 video codec are mounted on the second terminal 302 and on the first terminal 301, respectively. The picture transcoder transcodes the H.263 stream, received from the second terminal 302 over the second transmitting/receiving unit 131, into the MPEG-4 stream, and outputs the so produced MPEG-4 stream to the first terminal 301 over the first transmitting/receiving unit 121.

With the present embodiment, described above, the converter(s) (at least one of the picture transcoder and the speech transcoder) is booted in case the first ability information and the second ability information are not coincident with each other, so that, even if the two terminals differ from each other as to the ability, such as that of the codec, it is possible for the two terminals to have picture/speech communication with each other.

A fourth embodiment of the present invention, including a converter (transcoder) in the converting apparatus, will now be explained. The components of the fourth embodiment which are the same as those of the first to the third embodiments are omitted in the explanation for simplicity. FIG. 4 depicts a block diagram showing the configuration of an apparatus for converting the control information according to the fourth embodiment of the present invention. Specifically, FIG. 4 shows a converting apparatus 400, arranged between a first terminal 301 and a second terminal 302. In the following explanation, it is assumed again that the first terminal 301 is connected to a circuit-switched network and the second terminal 302 is connected to an IP network, as in the previous embodiments.

The converting apparatus 400 includes a control information converter 420, a transcoder 450, an ability information converter 460, first transmitting/receiving units 120, 121 and second transmitting/receiving units 130, 131. The converting apparatus receives decoding information, such as DCI of the MPEG-4 standard, from the first terminal 301, using, e.g., the ITU-TH. 245 standard, while receiving call control information, such as the SDP information prescribed by IETF RFC, from the second terminal 302.

In the above configuration, the control information converter 420 extracts the first ability information, pertinent to, e.g., a codec, mounted on the first terminal 301, from the decoding information received from the first terminal 301, while extracting the second ability information, pertinent to, e.g., a codec, mounted on the second terminal 302, from the call control information received from the second terminal 302.

The control information converter 420 then verifies whether or not the first ability information and the second ability information coincide with each other. If the two information do not coincide with each other, the control information converter 420 further checks whether or not the two terminals coincide with each other as to the picture format size and, depending on the result of check, performs the following processing.

First, in case the picture format size in one of the direction from the first terminal 301 to the second terminal 302 and the direction vice versa is not coincident, but the picture format size in the other direction is coincident, only the transcoder 450 for the non-coincident direction, here the picture transcoder, is booted to convert the picture stream. As for the direction of coincidence in the picture format size, a necessary part of the DCI of decoding information or control information (for example, a part of the level information) or a necessary part of the DCI in the picture stream, is converted by the ability information converter 460 and output.

Thus, with the present embodiment, in case the ability information received from the first terminal is not coincident with that received from the second terminal, but the picture size is coincident in one of the two directions, part of the decoding information or control information or part of the decoding information in the picture stream is converted, in place of performing the converter operation, as long as the direction of the picture size coincidence is concerned. Hence, the volume of calculations may be decreased as compared to the case of the third embodiment in which processing through the converter is necessarily carried out.

A fifth embodiment of the present invention, including a converter (transcoder), in the converting apparatus, will now be explained. The components of the fifth embodiment which are the same as those of the first to the fourth embodiments are omitted in the explanation for simplicity. FIG. 5 depicts a block diagram showing the configuration of an apparatus for converting the control information according to the fifth embodiment of the present invention. Specifically, FIG. 5 shows a converting apparatus 500, arranged between a first terminal 301 and a second terminal 302. In the following explanation, it is assumed that the first terminal 301 is connected to a circuit-switched network and the second terminal 302 is connected to an IP network, as in the previous embodiments.

The converting apparatus 500 includes a control information converter 520, an ability information converter 560, first transmitting/receiving units 120, 121 and second transmitting/receiving units 130, 131. The converting apparatus receives decoding information, such as DCI of the MPEG-4 standard, using, e.g., the ITU-TH. 245 standard, while receiving call control information, such as the SDP information prescribed by IETF RFC, from the second terminal 302.

In the above configuration, the control information converter 520 extracts the first ability information, pertinent to, e.g., a codec, mounted on the first terminal 301, from the decoding information received from the first terminal 301, while extracting the second ability information, pertinent to, e.g., a codec, mounted on the second terminal 302, from the call control information received from the second terminal 302.

The control information converter 420 then verifies whether or not the first ability information and the second ability information coincide with each other. If the two information do not coincide with each other, the control information converter further checks whether or not the picture format sizes of the two terminals coincide with each other and, depending on the result of check, performs the following processing.

First, in case the picture format size of the two terminals is coincident as to a direction from the first terminal 301 to the second terminal 302 and as to a direction from the second terminal 302 to the first terminal 301, a necessary part of the DCI of the decoding information or control information, for example, a part of level information, or a necessary part of the DCI in the picture stream, is converted by the ability information converter 560 for both directions, and output.

Thus, with the present embodiment, even in case the ability information received from the first terminal is not coincident with that received from the second terminal, but the picture size is coincident in the two directions, part of the decoding information or control information or part of the decoding information in the picture stream is converted, in place of performing the converter operation, for both the directions, and output. Hence, the volume of calculations may be decreased as compared to the case of the third embodiment in which processing is necessarily through the converter.

In the foregoing, description has been made of several embodiments of the present invention. It should be noted however that, as will be apparent from the principle of the invention, the technical scope of the present invention is not limited to the embodiments described, and that various modifications or substitutions may be made without departing from the scope of the invention which resides in the configuration of providing for the communications between terminals belonging to different sorts of the networks.

It should be noted that other objects, features and aspects of the present invention will become apparent in the entire disclosure and that modifications may be done without departing the gist and scope of the present invention as disclosed herein and claimed as appended herewith.

Also it should be noted that any combination of the disclosed and/or claimed elements, matters and/or items may fall under the modifications aforementioned.

Claims

1. An apparatus for converting control information or of the media information for picture/speech communication between first and second terminals connected to respective different types of networks, comprising:

at least one processor; and

at least one memory device that stores a plurality of instructions, which when executed by the at least one processor, cause the at least one processor to:

receive, from the first terminal through a first type of network, first decoding information;

a converter for effecting converting processing in a first direction for converting convert first decoding information acquired through the first type of network from said first terminal into first call control information;

to output transmit, through a second different type of network, the resulting first call control information to said second terminal; and

receive, from the second terminal through the second different type of network, second call control information;

for effecting converting processing in a second direction for converting convert second call control information acquired through the second different type of network from said second terminal into second decoding information;

to output transmit the resulting second decoding information to said first terminal through the first type of network, wherein

at least Decoder Configuration information DCI is received as the decoding information from said first terminal employing MPEG-4 as a system for encoding a moving picture for compression the first decoding information is Decoder Configuration information (DCI) based on an MPEG-4 standard, and the DCI is converted into the first call control information.

2. A method for converting control information or media information for picture/speech communication between first and second terminals connected to respective different types of networks, comprising:

receiving, from the first terminal through a first type of network, first decoding information;

a first converting step of a converting apparatus, provided between said terminals, for converting the first decoding information, acquired through the first type of network from said first terminal, into first call control information,;

to output transmitting, through a second different type of network, the resulting first call control information to said second terminal; and

receiving, from the second terminal through the second different type of network, second call control information;

a second converting step of said converting apparatus, for converting the second call control information acquired through the second different type of network from said second terminal, into the second decoding information,;

to output transmitting the resulting second decoding information to said first terminal through the first type of network, wherein

at least the Decoder Configuration information DCI is received as the decoding information from said first terminal employing MPEG-4 as a system for encoding a moving picture for compression the first decoding information is Decoder Configuration information (DCI) based on an MPEG-4 standard, and the DCI is converted into the first call control information.