Classified media quality of experience

Abstract

A method for reporting a streaming quality is shown, wherein at least one continuous media stream is streamed to a client (601), and wherein the streaming is controlled by a protocol (109) that is operated between the client (601) and a server (600), the method including selecting at least one quality metric and a quality metrics class from a pre-defined set of at least two quality metrics classes, and reporting to the server (600) the quality of the streaming based on the at least one selected quality metric and the selected quality metrics class. The protocol (109) is preferably a Real-time Streaming Protocol (RTSP) in combination with a Session Description Protocol (SDP) in the context of the 3GPP Packet-Switched Streaming Service (PSS). Also shown is a computer program, a computer program product, a system, a client, a server and a protocol.

1 . A method for receiving streaming media content, comprising:
 sending, from a client device to a server, a protocol message requesting streaming media;   negotiating, by the client device with the server, a quality metrics class to be used in determining a quality of streaming of at least one media stream received from the server, the negotiated quality metrics class being selected from a pre-defined set of at least two quality metrics classes each defining a different set of rules for judging whether a frame of a media stream is a good frame, wherein the negotiating is according to a protocol that defines a quality metrics class field within at least one of its protocol data units, wherein the quality metrics class field is capable of identifying each quality metrics class of the pre-defined set of at least two quality metrics classes;   receiving the at least one media stream from the server;   determining whether reducing the frequency of re-buffering events would improve the quality of streaming based on a defined frequency for re-buffering events and on at least one quality metric that is at least partially based on judging whether at least one or more frame[s] of the at least one received media stream is a good frame according to rules corresponding to the negotiated quality metrics class;   determining whether reducing the frequency of re-buffering events would improve the quality of streaming based on a defined frequency for re-buffering events and on at least one quality metric that is at least partially based on judging whether at least one or more frame[s] of the at least one received media stream is a good frame according to rules corresponding to the negotiated quality metrics class;   in response to determining that reducing the frequency of re-buffering events would improve the quality of streaming, transmitting a feedback message to the server, the feedback message for causing the server to enhance a data rate of receiving the at least one media stream.   
     
     
         2 . The method of  claim 1  wherein the quality metrics class field is comprised in a header section of the at least one protocol data unit. 
     
     
         3 . The method of  1 , wherein the set of rules defined by at least one of the quality metrics classes comprises:
 judging, to be a good frame, the earlier of:
 a completely received I-frame of the at least one media stream; or 
 the N-th completely received frame of the at least one media stream after last frame error or loss, wherein the integer N is either signaled or defaults to ∞ in case of a video frame or to 1 in case of an audio frame; and 
   judging a frame of the at least one media stream following a good frame to be a good frame, if the frame is completely received, and otherwise judging the frame and all subsequent frames until the next good frame to be corrupted.   
     
     
         4 . The method of  claim 1 , wherein the set of rules defined by at least one of the quality metric classes comprises judging a coded frame of the at least one media stream to be a good frame according to an error tracking algorithm. 
     
     
         5 . The method of  claim 4 , wherein the set of rules defined by at least one of the quality metrics classes comprises:
 judging an intra-coded frame of the at least one media stream to be a good frame, if it is completely received, and to be a corrupted frame otherwise; or   judging a predictively coded frame of the at least one media stream to be a good frame, if it is completely received and if all its prediction reference samples belong to good frames, and to be a corrupted frame otherwise.   
     
     
         6 . The method of  claim 1 , wherein the set of rules defined by at least one of the quality metrics classes comprises judging a coded frame of the at least one media stream to be a good frame according to a decoding quality evaluation algorithm. 
     
     
         7 . The method of  claim 6 , wherein the set of rules defined by at least one of the quality metrics classes comprises:
 judging an intra-coded frame of the at least one media stream to be a good frame, if it is completely received, and to be a corrupted frame otherwise; or   judging a predictively coded frame of the at least one media stream to be a good frame, if it is completely received and all of its prediction reference samples belong to good frames, or if at least a part of the frame is completely received, all prediction reference samples of the completely received parts of the frame belong to good frames, and all concealed parts' of the frame are considered as good;   wherein:
 concealed parts of the frame are obtained by applying an error concealment algorithm to lost or erroneous parts of a decoded version of the frame; and 
 the concealed parts are considered as good if an average boundary difference between the concealed parts and surrounding completely received and decoded parts of the frame is below a threshold. 
   
     
     
         8 . The method of  claim 1 , wherein streaming of the media stream is controlled by a Real-time Streaming Protocol RTSP in combination with a Session Description Protocol SDP in the context of a Packet-Switched Streaming Service PSS of a third generation mobile communications system. 
     
     
         9 . The method of  claim 8 , wherein the SDP comprises at least one SDP attribute that defines at least one quality metrics class field, wherein the quality metrics class field is capable of identifying each quality metrics class of the pre-defined set of at least two quality metrics classes. 
     
     
         10 . The method of  claim 9 , wherein the RTSP is used to negotiate a quality metrics class with the server to which the quality of the streaming is reported at least partially based on the SDP attribute. 
     
     
         11 . The method according to  claim 10 , wherein the RTSP uses a DESCRIBE method for the negotiation. 
     
     
         12 . A client device, comprising:
 one or more communications interface for communicating with a server; and   one or more processing modules operable to:
 transmit to the server a protocol message requesting streaming media, 
 negotiate, with the server, a quality metrics class to be used in determining a quality of streaming from the server, the negotiated quality metrics class being selected from a pre-defined set of at least two quality metrics classes each defining a different set of rules for judging whether a frame of the at least one media stream is a good frame, wherein negotiating is according to a protocol that defines a quality metrics class field within at least one of its protocol data units, wherein the quality metrics class field is capable of identifying each quality metrics class of the pre-defined set of at least two quality metrics classes, 
 receive the at least one media stream from the server, 
 determine whether reducing a frequency of re-buffering events would improve the quality of streaming based on a defined frequency for re-buffering events and on at least one quality metric that is at least partially based on judging whether at least one or more frame[s] of the at least one received media stream is a good frame according to rules corresponding to the negotiated quality metrics class, 
 in response to determining that reducing the frequency of re-buffering events would improve the quality of streaming, transmitting a feedback message to the server, the feedback message for causing the server to enhance a data rate of receiving the at least one media stream, 
 and receive the at least one media stream from the server at the enhanced data rate. 
   
     
     
         13 . The client device of  claim 12 , wherein the quality metrics class field is comprised in a header section of the at least one protocol data unit. 
     
     
         14 . The client device of  12 , wherein the set of rules defined by at least one of the quality metrics classes comprises:
 judging, to be a good frame, the earlier of:
 a completely received I-frame of the at least one media stream; or 
 the N-th completely received frame of the at least one media stream after last frame error or loss, wherein the integer N is either signaled or defaults to ∞ in case of a video frame or 1 in case of an audio frame; and 
   judging a frame of the at least one media stream following a good frame to be a good frame, if the frame is completely received, and otherwise judging the frame and all subsequent frames until the next good frame to be corrupted.   
     
     
         15 . The client device of  claim 12 , wherein the set of rules defined by at least one of the quality metric classes comprises judging a coded frame of the at least one media stream to be a good frame according to an error tracking algorithm. 
     
     
         16 . The client device of  claim 15 , wherein the set of rules defined by at least one of the quality metrics classes comprises:
 judging an intra-coded frame of the at least one media stream to be a good frame, if it is completely received, and to be a corrupted frame otherwise; or   judging a predictively coded frame of the at least one media stream to be a good frame, if it is completely received and if all its prediction reference samples belong to good frames, and to be a corrupted frame otherwise.   
     
     
         17 . The client device of  claim 12 , wherein the set of rules defined by at least one of the quality metrics classes comprises judging a coded frame of the at least one media stream to be a good frame according to a decoding quality evaluation algorithm. 
     
     
         18 . The client device of  claim 17 , wherein the set of rules defined by at least one of the quality metrics classes comprises:
 judging an intra-coded frame of the at least one media stream to be a good frame, if it is completely received, and to be a corrupted frame otherwise; or   judging a predictively coded frame of the at least one media stream to be a good frame, if it is completely received and all of its prediction reference samples belong to good frames, or if at least a part of the frame is completely received, all prediction reference samples of the completely received parts of the frame belong to good frames, and all concealed parts' of the frame are considered as good;   wherein:
 concealed parts of the frame are obtained by applying an error concealment algorithm to lost or erroneous parts of a decoded version of the frame; and 
 the concealed parts are considered as good if an average boundary difference between the concealed parts and surrounding completely received and decoded parts of the frame is below a threshold. 
   
     
     
         19 . The client device of  claim 12 , wherein streaming of the media stream is controlled by a Real-time Streaming Protocol RTSP in combination with a Session Description Protocol SDP in the context of a Packet-Switched Streaming Service PSS of a third generation mobile communications system. 
     
     
         20 . The client device of  claim 19 , wherein the SDP comprises at least one SDP attribute that defines at least one quality metrics class field, wherein the quality metrics class field is capable of identifying each quality metrics class of the pre-defined set of at least two quality metrics classes. 
     
     
         21 . The client device of  claim 20 , wherein the RTSP is used to negotiate a quality metrics class with the server to which the quality of the streaming is reported at least partially based on the SDP attribute. 
     
     
         22 . The client device according to  claim 21 , wherein the RTSP uses a DESCRIBE method for the negotiation.