Live timing for dynamic adaptive streaming over HTTP (DASH)

A client device for receiving information for streaming of media data, the client device comprising:

• a clock;
• and
• one or more processors configured to:
• receive a media presentation description (MPD) for media content, wherein the MPD includes data indicative of wall-clock times at which the client device can retrieve segments of the media content from a source device, wherein the data indicates a synchronization method by which the client device is to synchronize the wall-clock times with the clock, and wherein the synchronization method indicated by the MPD comprises one of network time protocol (NTP), HTTP Time Protocol (HTP), or HTTP,
• prior to retrieving any of the segments, synchronize the clock with the wall-clock times using the method indicated by the MPD,
• wherein when the synchronization method comprises NTP, the MPD includes data indicative of network addresses for one or more NTP servers, and wherein the one or more processors are configured request a time from at least one of the NTP servers, and
• wherein when the synchronization method comprises HTP or HTTP, the MPD includes data indicative of network addresses for one or more HTTP servers, and wherein the one or more processors are configured to request the time from at least one of the HTTP servers;
• determine, from the MPD, a time at which a segment of the segments of the media content can be retrieved;
• and
• request the segment of the media content from the source device when the synchronized clock indicates that a current time is equal to or greater than the time at which the segment can be retrieved.

A non-transitory computer-readable storage medium having stored thereon instructions that, when executed, cause a processor of a client device to:

• receive a media presentation description (MPD) for media content, wherein the MPD includes data indicative of wall-clock times at which the client device can retrieve segments of the media content from a source device, wherein the data indicates a synchronization method by which the client device is to synchronize the wall-clock times with a clock of the client device, and wherein the synchronization method indicated by the MPD comprises one of network time protocol (NTP), HTTP Time Protocol (HTP), or HTTP;
• prior to retrieving any of the segments, synchronize the clock of the client device with the wall-clock times using the method indicated by the MPD,
• wherein when the synchronization method comprises NTP, the MPD includes data indicative of network addresses for one or more NTP servers, and wherein the instructions that cause the processor to synchronize the clock comprise instructions that cause the processor to request a time from at least one of the NTP servers, and
• wherein when the synchronization method comprises HTP or HTTP, the MPD includes data indicative of network addresses for one or more HTTP servers, and wherein the instructions that cause the processor to synchronize the clock comprise instructions that cause the processor to request the time from at least one of the HTTP servers;
• determine, from the MPD, a time at which a segment of the segments of the media content can be retrieved;
• and
• request the segment of the media content from the source device when the synchronized clock indicates that a current time is equal to or greater than the time at which the segment can be retrieved.

A method of signaling information for streaming of media data, the method comprising:

• generating data for a media presentation description (MPD) for media content, wherein the MPD includes data indicative of wall-clock times at which a client device can retrieve segments of the media content from a source device, wherein the generated data indicates a synchronization method by which the client device is to synchronize the wall-clock times with a clock of the client device, and wherein the synchronization method indicated by the MPD comprises one of network time protocol (NTP), HTTP Time Protocol (HTP), or HTTP,
• wherein when the synchronization method comprises NTP, generating the data for the MPD comprises generating the data to indicate that the synchronization method comprises NTP and to indicate network addresses for one or more NTP servers from which to request data for synchronizing the clock of the client device with the wall-clock times;
• wherein when the synchronization method comprises HTP, generating the data for the MPD comprises generating the data to indicate that the synchronization method comprises HTP and to indicate network addresses for one or more HTTP servers from which to request data for synchronizing the clock of the client device with the wall-clock times;
• wherein when the synchronization method comprises HTTP, generating the data comprises generating the data to indicate that the synchronization method comprises HTTP and to indicate the network addresses for the one or more HTTP servers from which to request data for synchronizing the clock of the client device with the wall-clock times;
• and outputting the MPD.