Method and interworking network node for enabling bit rate adaption in media streaming
A network node and a method therein for transferring a media stream are disclosed. The network node ( 110 ) transfers (A 010 ) a media stream from a first device ( 111 ) to at least a second device ( 112 ), wherein the first device ( 111 ) supports bit rate adaptation based on Temporary Maximum Media Stream Bitrate Request, “TMMBR”, feedback and the second device ( 112 ) supports bit rate adaptation based on Self-Clocked Rate Adaptation for Multimedia, “SCReAM”, feedback. The network node ( 110 ) receives (A 020 ) SCReAM feedback from the second device ( 112 ). Furthermore, the network node ( 110 ) derives (A 030 ) at least one rate control message from the SCReAM feedback. Moreover, the network node ( 110 ) determines (A 040 ), based on said at least one rate control message, a recommended bit rate to be recommended for use by the first device ( 111 ) when encoding the media stream. Then, the network node ( 110 ) sends (A 050 ) a TMMBR message to the first device ( 111 ), wherein the TMMBR message indicates the recommended bit rate. A corresponding computer program and a carrier therefor are also disclosed.
1. A method, the method comprising a network node:
transferring a media stream from a first device to at least a second device, wherein the first device supports bit rate adaptation based on a Temporary Maximum Media Stream Bitrate Request (TMMBR) message and the second device supports bit rate adaptation based on Self-Clocked Rate Adaptation for Multimedia (SCReAM) feedback;
receiving SCReAM feedback from the second device;
deriving at least one rate control message from the SCReAM feedback;
determining, based on the at least one rate control message, a recommended bit rate to be recommended for use by the first device when encoding the media stream; and
sending the TMMBR message to the first device, wherein the TMMBR message indicates the recommended bit rate.
2. The method of claim 1 , wherein the SCReAM feedback is received within a time interval, wherein a duration of the time interval is dependent on bandwidth between the network node and the first device.
3. The method of claim 1 :
wherein the media stream has a current bit rate; and
wherein the determining of the recommended bit rate further is based on the current bit rate.
4. The method of claim 1 :
wherein the determining of the recommended bit rate comprises aggregating the at least one rate control message into an aggregated bit rate; and
wherein the determining of the recommended bit rate further is based on the aggregated bit rate.
5. The method of claim 4 , wherein the at least one rate control message comprises at least two rate control messages.
6. A network node, comprising:
processing circuitry;
memory containing instructions executable by the processing circuitry whereby the network node is operative to:
transfer a media stream from a first device to at least a second device, wherein the first device supports bit rate adaptation based on a Temporary Maximum Media Stream Bitrate Request (TMMBR) message and the second device supports bit rate adaptation based on Self-Clocked Rate Adaptation for Multimedia (SCReAM) feedback;
receive SCReAM feedback from the second device;
derive at least one rate control message from the SCReAM feedback;
determine, based on the at least one rate control message, a recommended bit rate to be recommended for use by the first device when encoding the media stream; and
send the TMMBR message to the first device, wherein the TMMBR message indicates the recommended bit rate.
7. The network node of claim 6 , wherein the instructions are such that the network node is operative to receive the SCReAM feedback within a time interval, wherein a duration of the time interval is dependent on bandwidth between the network node and the first device.
8. The network node of claim 6 :
wherein the media stream has a current bit rate; and
wherein the instructions are such that the network node is operative to determine the recommended bit rate based on the current bit rate.
9. The network node of claim 6 , wherein the instructions are such that the network node is operative to:
aggregate the at least one rate control message into an aggregated bit rate; and
determine the recommended bit rate based on the aggregated bit rate.
10. The network node of claim 9 , wherein the at least one rate control message comprises at least two rate control messages.
11. A non-transitory computer readable recording medium storing a computer program product for controlling a network node, the computer program product comprising software instructions which, when run on processing circuitry of the network node, causes the network node to:
transfer a media stream from a first device to at least a second device, wherein the first device supports bit rate adaptation based on a Temporary Maximum Media Stream Bitrate Request (TMMBR) message and the second device supports bit rate adaptation based on Self-Clocked Rate Adaptation for Multimedia (SCReAM) feedback;
receive SCReAM feedback from the second device;
derive at least one rate control message from the SCReAM feedback;
determine, based on the at least one rate control message, a recommended bit rate to be recommended for use by the first device when encoding the media stream; and
send the TMMBR message to the first device, wherein the TMMBR message indicates the recommended bit rate.