Dynamic buffering and synchronization of related media streams in packet networks
Mechanisms are disclosed for using two or more buffers, at a common receiving node, to reduce the effects of jitter, packet loss, and/or packet latency and/or synchronize different types of packets. Specifically, the two or more buffers can be used to temporarily store packets from different media streams that have a common timestamp and/or sequence number. Characteristics of the two or more buffers can then be independently controlled to accommodate the different media streams.
1. A method, comprising:
(a) receiving, at a common receiving node, first and second packets, the first and second packets having common packet durations as well as at least one of common timestamps and common sequence numbers, the first packet being received in a first media stream and the second packet being received in a second different media stream; (b) writing, by a processor, the first packet to a first buffer; (c) writing, by the processor, the second packet to a second buffer; and (d) selecting, by a control module, at least one of (i) a time to read each of the first and second packets from the first and second buffers, respectively, and (ii) which of the first and second packets to read, wherein, in (ii), only one of the first and second packets is used to fill a gap in a data stream; and wherein the first and second packets have common source and destination address pairs, wherein a payload of the first packet has a first level of compression, wherein a payload of the second packet has a second level of compression, wherein the first level of compression is less than the second level of compression, and wherein the payload types of the first and second packets are the same; and wherein the first packet is transmitted over a packet-switched network and the second packet is transmitted over a circuit-switched network, wherein (ii) is selected, wherein the first packet is read from a first queue corresponding to the first buffer and the second packet is not read from a second queue corresponding to the second buffer, and wherein the second packet is removed from the second queue at substantially the same time that the first packet is read from the first queue.
2. The method of claim 1 , wherein (i) is selected, wherein the first and second packets have common source and destination address pairs, and wherein the first and second packets have different types of media payloads.
3. The method of claim 1 , wherein (ii) is selected, wherein the first and second packets have common source and destination address pairs, wherein payloads of the first and second packets have differing levels of compression, and wherein the first and second packets have a common type of media payload.
4. A non-transitory computer readable medium encoded with instructions that, when executed, perform the steps of claim 1 and wherein the computer readable medium is in communication with the processor.
5. A system, comprising:
an input operable to receive first and second packets, the first and second packets having common packet durations and common timestamps and/or sequence numbers, the first packet being received in a first media stream, the second packet being received in a second different media stream;
a processor operable to write the first packet to a first buffer and write the second packet to a second buffer; and
a control module operable to determine at least one of (i) a time to read each of the first and second packets from the first and second buffers, respectively, and (ii) which of the first and second packets to read, wherein, in (ii), only one of the first and second packets is used to fill a gap in a data stream; and
wherein the first and second packets have common source and destination address pairs, wherein a payload of the first packet has a first level of compression, wherein a payload of the second packet has a second level of compression, wherein the first level of compression is less than the second level of compression, and wherein the payload types of the first and second packets are the same; and
wherein the first packet is transmitted over a packet-switched network and the second packet is transmitted over a circuit-switched network, wherein (ii) is selected, wherein the first packet is read from the first buffer and the second packet is not read from the second buffer, and wherein the second packet is removed from the second buffer at substantially the same time that the first packet is read from the first buffer.
6. The system of claim 5 , wherein (i) is selected, wherein the first and second packets have common source and destination address pairs and wherein the first and second packets have different types of media payloads.
7. The system of claim 5 , wherein (ii) is selected, wherein the first and second packets have common source and destination address pairs, wherein payloads of the first and second packets have differing levels of compression, and wherein the first and second packets have a common type of media payload.
8. The system of claim 5 , wherein the control module resizes, while at least one of the first and second buffers is occupied, the at least one of the first and second buffers, said resizing being a function of at least one of a state of a network over which the first and/or second packets are transmitted, a time to process the first and/or second packets, relative occupancies of the first and second buffers, time varying user requirements, and time varying application requirements.