Method and apparatus for multipoint conferencing

A controller to control a multimedia multipoint conference, the conference including a plurality of participants, each participant being a multimedia terminal device that includes the controller and one or more codecs, the controller comprising:

• At least one processor, wherein the controller further comprises:
• means for receiving from each other participant information on its codec capabilities as part of a terminal capabilities exchange between the participants;
• means for ascertaining if there is a set of codec output characteristics for all participants such that each participant's codec capabilities can be simultaneously met without any media stream from one participant to the other participants needing to be decoded and re-encoded en route to the other participants, and if so, determining, in cooperation with the other participant or participants, the codec output characteristics for all participants that simultaneously meet each participant's codec capabilities without any decoding and re-encoding being needed, the codec output characteristics including one or both of a codec type and a bit rate;
• means for sending instructions to the participants to set each participant's respective one or more codec(s) to the respective determined codec output characteristics;
• after each participant's one or more codecs are set to the respective codec output characteristics, means for receiving a media stream from one or more of the other participants, the media stream from any particular other participant being encoded at the determined codec output characteristics for the particular other participant;
• and
• means for passing the received media streams to each other participant, the determined codec output characteristics being such that the received media streams may be passed to each participant without any en-route decoding and re-encoding of any of the media stream, and without any participant needing to carry out video mixing to generate its output video stream,
• wherein Multipoint Control Unit (MCU) functionality is carried out by the participants operating jointly and cooperatively to jointly determine how to communicate with each other without any transcoding, with no single terminal or device necessarily needing to act as a Multipoint Controller (MC), such that no distinct MCU device or functionality is needed for conferencing between the participants;
• wherein if the means for ascertaining ascertains that there are not codec output characteristics that simultaneously meet the codec capabilities of all participants, then ascertaining whether there is a subset of participants and a first set of codec output characteristics that simultaneously meet the codec capabilities of all members of the subset;
• wherein if such a subset and first set of common codec output characteristics exist, directing the subset members to communicate using the common codec output characteristics;
• and directing those participants whose codec characteristics cannot be met by a common set of codec output characteristics shared by more than one participant to communicate via an (MCU), the MCU including one or more Multipoint Processors (MPs) that can decode, scale, and re-encode streams as necessary to meet the codec requirements of the participants.

A computer readable storage medium storing computer-executable instructions that when executed by processors of a processing system in a plurality of participants of a multimedia multipoint conference, cause the participants to implement a method of controlling the multimedia multipoint conference, the conference including the plurality of participants, each a multimedia terminal device that includes one or more codecs, the method comprising:

• receiving from each other participant information on its codec capabilities as part of a terminal capabilities exchange between the participants;
• ascertaining if there is a set of codec output characteristics for all participants such that each participant's codec capabilities can be simultaneously met without any media stream from one participant to the other participants needing to be decoded and re-encoded en route to the other participants, and if so, determining, in cooperation with the other participant or participants, the codec output characteristics for all participants that simultaneously meet each participant's codec capabilities without any decoding and re-encoding being needed, the codec output characteristics including one or both of a codec type and a bit rate;
• sending instructions to the participants to set each participant's respective one or more codecs to the respective determined codec output characteristics;
• after each participant's one or more codecs are set to the respective codec output characteristics, receiving a media stream from one or more of the other participants, the media stream from any particular other participant being encoded at the determined codec output characteristics for the particular other participant;
• and
• passing the received media streams to each participant, the determined codec output characteristics being such that the received media streams may be passed to each participant without en-route decoding and re-encoding of any of the media stream, and without any participant needing to carry out video mixing to generate its output video stream,
• wherein Multipoint Control Unit (MCU) functionality is carried out by the participants operating jointly and cooperatively to jointly determine how to communicate with each other without any transcoding, with no single terminal or device necessarily needing to act as a Multipoint Controller (MC), such that no distinct MCU device or functionality is needed for conferencing between the participants;
• wherein if the step of ascertaining ascertains that there are not codec output characteristics that simultaneously meet the codec capabilities of all participants, the method includes:
• ascertaining whether there is a subset of participants and a first set of codec output characteristics that simultaneously meet the codec capabilities of all members of the subset;
• if such a subset and first set of common codec output characteristics exist, directing the subset members to communicate using the common codec output characteristics;
• and directing those participants whose codec characteristics cannot be met by a common set of codec output characteristics shared by more than one participant to communicate via an (MCU), the MCU including one or more Processors (MPs) that can decode, scale, and re-encode streams as necessary to meet the codec requirements of the participants.

A controller to control a multimedia multipoint conference, the conference including a plurality of participants, each a multimedia terminal that includes one or more codecs, the controller being on a first participant of the participants, the controller comprising:

• a processor;
• memory coupled to the processor;
• and
• a network interface device coupled to the processor, the network interface device for communicating via a network with the participants,
• wherein the processor is programmed to receive messages from and send messages to the other participants via the network interface device, including receiving from each other participant information on its codec capabilities as part of a terminal capabilities exchange between the participants,
• wherein the processor is programmed further to ascertain if there is a set of codec output characteristics for all participants such that each participant's codec capabilities can be simultaneously met without any media stream from one participant to the other participants needing to be decoded and re-encoded en route to the other participants, and if so, determining, in cooperation with the other participant or participants, the codec output characteristics for all participants that simultaneously meet each participant's codec capabilities without any decoding and re-encoding being needed, the codec output characteristics including one or both of a codec type and a bit rate;
• wherein the processor is programmed further to send instructions to the participants via the network interface device to set each participant's respective one or more codec(s) to the respective determined codec output characteristics,
• wherein the processor is programmed further to receive a media stream from one or more of the other participants via the network interface device after each participant's one or more codecs are set to the respective codec output characteristics, the media stream from any particular other participant being encoded at the determined codec output characteristics for the particular other participant, and
• wherein the processor is programmed further to pass the received media streams to each other participant via the network interface device, the determined codec output characteristics being such that the received media streams may be passed to each participant without any en-route decoding and re-encoding of any of the media stream, and without any participant needing to carry out video mixing to generate its output video stream,
• wherein Multipoint Control Unit (MCU) functionality is carried out by the participants operating jointly and cooperatively to jointly determine how to communicate with each other without any transcoding, with no single terminal or device necessarily needing to act as a Multipoint Controller (MC), such that no distinct MCU device or functionality is needed for conferencing between the participants;
• wherein if the processor ascertains that there are not codec output characteristics that simultaneously meet the codec capabilities of all participants, ascertaining whether there is a subset of participants and a first set of codec output characteristics that simultaneously meet the codec capabilities of all members of the subset;
• if such a subset and first set of common codec output characteristics exist, directing the subset members to communicate using the common codec output characteristics;
• and directing those participants whose codec characteristics cannot be met by a common set of codec output characteristics shared by more than one participant to communicate via an (MCU), the MCU including one or more Multipoint Processors (MPs) that can decode, scale, and re-encode streams as necessary to meet the codec requirements of the participants.