Systems, methods, and media for controlling delivery of content
Methods, systems, and computer readable media for controlling delivery of content are provided. In some embodiments, a system for controlling delivery of content is provided. The system includes processing circuitry configured to: transmit, to a server, a plurality of requests for blocks of the content; while at least some of the plurality of requests are still outstanding: detect a change of a service characteristic of a connection between the system and the server; determine a preferred number of outstanding requests; and cancel at least some of the requests from the plurality that are still outstanding based on the preferred number and a count of the requests from the plurality that are still outstanding.
1. A method for controlling delivery of content, the method comprising:
transmitting, to a server, a plurality of requests for blocks of the content;
while an actual number of outstanding requests is at least one:
measuring a latency of a connection between a system and the server, wherein the latency includes a time differential between a transmission of a request for a block of content from the system to the server and receipt of a first network packet associated with the block of content at the system;
measuring a bandwidth of the connection between the system and the server, wherein the bandwidth includes a size of the block divided by a time differential between the receipt of the first network packet and receipt of a last network packet associated with the block of content;
detecting a change of a service characteristic of the connection between the system and the server, where the service characteristic is based on the latency and the bandwidth;
determining a preferred number of outstanding requests based upon the service characteristic and the size of the block of content; and
adjusting the actual number of outstanding requests based on the preferred number and a count of the requests from the plurality that are still outstanding.
2. The method of claim 1 , wherein determining the preferred number of requests is evaluated using the following expression:
preferred
number
of
requests
=
⌈
t
latency
t
transmission
⌉
+
1
where t latency is the latency and t transmission is a transmission time.
3. The method of claim 2 , wherein the transmission time is evaluated using the following expression:
t
transmission
=
block
size
bandwidth
where block size is the size of the requested block of content and bandwidth is the bandwidth.
4. The method of claim 1 , wherein the plurality of requests for blocks of content are transmitted using an Open Systems Interconnect (OSI) application-layer protocol.
5. The method of claim 1 , wherein each block of content in the plurality of requested blocks of content is a fragment of a larger content file.
6. The method of claim 1 , wherein the content is streaming content.
7. The method of claim 6 , wherein the streaming content is from a live performance.
8. The method of claim 1 , wherein adjusting the actual number of outstanding requests comprises cancelling at least one request of the outstanding requests.
9. The method of claim 1 , wherein adjusting the actual number of outstanding requests comprises transmitting a set of one or more requests.
10. The method of claim 1 further comprising:
determining whether an underflow condition has occurred; and
when an underflow condition has occurred, reducing the number of outstanding requests in response to the underflow condition.
11. The method of claim 1 further comprising:
determining whether a buffer level exceeds a threshold; and
when the buffer level exceeds the threshold, reducing the number of outstanding requests in response to the threshold being exceeded.
12. A non-transitory machine readable medium containing processor instructions for controlling delivery of content, where execution of the instructions by a processor causes the processor to perform a process that comprises:
transmitting, to a server, a plurality of requests for blocks of the content;
while an actual number of outstanding requests is at least one:
measuring a latency of a connection between a system and the server, wherein the latency includes a time differential between a transmission of a request for a block of content from the system to the server and receipt of a first network packet associated with the block of content at the system;
measuring a bandwidth of the connection between the system and the server, wherein the bandwidth includes a size of the block divided by a time differential between the receipt of the first network packet and receipt of a last network packet associated with the block of content;
detecting a change of a service characteristic of the connection between the system and the server, where the service characteristic is based on the latency and the bandwidth;
determining a preferred number of outstanding requests based upon the service characteristic and the size of the block of content; and
adjusting the actual number of outstanding requests based on the preferred number and a count of the requests from the plurality that are still outstanding.
13. The non-transitory machine readable medium of claim 12 , wherein determining the preferred number of requests is evaluated using the following expression:
preferred
number
of
requests
=
⌈
t
latency
t
transmission
⌉
+
1
where t latency is the latency and t transmission is a transmission time.
14. The non-transitory machine readable medium of claim 13 , wherein the transmission time is evaluated using the following expression:
t
transmission
=
block
size
bandwidth
where block size is the size of the requested block of content and bandwidth is the bandwidth.
15. The non-transitory machine readable medium of claim 12 , wherein the plurality of requests for blocks of content are transmitted using an Open Systems Interconnect (OSI) application-layer protocol.
16. The non-transitory machine readable medium of claim 12 , wherein each block of content in the plurality of requested blocks of content is a fragment of a larger content file.
17. The non-transitory machine readable medium of claim 12 , wherein the content is streaming content.
18. The non-transitory machine readable medium of claim 17 , wherein the streaming content is from a live performance.
19. The non-transitory machine readable medium of claim 12 , wherein adjusting the actual number of outstanding requests comprises cancelling at least one request of the outstanding requests.
20. The non-transitory machine readable medium of claim 12 , wherein adjusting the actual number of outstanding requests comprises transmitting a set of one or more requests.