Dynamic delay equalization for media transport
Systems and methods of the present disclosure provide for dynamic delay equalization of related media signals in a media transport system. Methods include receiving a plurality of related media signals, transporting the related media signals along different media paths, calculating uncorrected propagation delays for the media paths, and delaying each of the related media signals by an amount related to the difference between the longest propagation delay (of the uncorrected propagation delays) and the uncorrected propagation delay of the related media signal/media path. Calculating the uncorrected propagation delays and delaying the related media signals may be performed in response to a change to the propagation delay of at least one of the related media signals/media paths. Additionally or alternatively, calculating the uncorrected propagation delays and delaying the related media signals may be performed while transporting the related media signals.
1. A method, comprising:
receiving, by a first edge output device at a first egress of a first media path, a first upstream delay signal from a first edge input device at a first ingress of the first media path;
determining, by the first edge output device, a first uncorrected propagation delay from the first ingress to the first egress based upon the first upstream delay signal;
receiving, by a second edge output device at a second egress of a second media path, a second upstream delay signal from a second edge input device at a second ingress of a second media path;
determining, by the second edge output device, a second uncorrected propagation delay from the second ingress to the second egress based upon the second upstream delay signal;
determining a target propagation delay, by the first edge output device and the second edge output device, that is at least as large as a maximum of the first uncorrected propagation delay and the second uncorrected propagation delay.
2. The method of claim 1 , comprising:
interconnecting, by a network fabric, the first media path from the first edge input device to the first edge output device; and
interconnecting the second media path from the second edge input device to the second edge output device.
3. The method of claim 1 , comprising:
exchanging, by the first edge output device and the second edge output device, the first uncorrected propagation delay and the second uncorrected propagation delay; and
determining, by each of the first edge output device and the second edge output device, the maximum of the first uncorrected propagation delay and the second uncorrected propagation delay as the target propagation delay.
4. The method of claim 1 , comprising:
receiving, by the first edge output device, the second uncorrected propagation delay from the second edge output device;
determining, by the first edge output device, the maximum of the first uncorrected propagation delay and the second uncorrected propagation delay as the target propagation delay; and
sending, by the first edge output device, the target propagation delay to the second edge output device.
5. The method of claim 1 , comprising:
delaying, by a first dynamic delay element of the first media path, a first media signal from the first edge input device based upon a first delay command;
delaying, by a second dynamic delay element of the second media path, a second media signal from the second edge input device based upon a second delay command;
commanding, by the first edge output device, the first dynamic delay element to delay the first media signal by a difference between the target propagation delay and the first uncorrected propagation delay; and
commanding, by the second edge output device, the second dynamic delay element to delay the second media signal by a difference between the target propagation delay and the second uncorrected propagation delay.
6. The method of claim 5 , comprising:
commanding, by the first edge output device, the first dynamic delay element to delay the first media signal an amount of delay related to a value by which the second uncorrected propagation delay exceeds the first uncorrected propagation delay; and
commanding, by the second edge output device, the second dynamic delay element to delay the second media signal an amount of delay related to a value by which the first uncorrected propagation delay exceeds the second uncorrected propagation delay.
7. The method of claim 5 , wherein a plurality of ingresses includes the first ingress and the second ingress, wherein a plurality of egresses includes the first egress and the second egress, and wherein the plurality of media signals includes the first media signal and the second media signal.
8. The method of claim 7 , wherein each of the plurality of media signals has an uncorrected propagation delay and wherein the target propagation delay is a maximum of the uncorrected propagation delays of the plurality of media signals.
9. The method of claim 5 , comprising transmitting, by the first edge input device and the second edge input device, the first media signal from the first egress.
10. The method of claim 9 , comprising transmitting the second media signal from the second egress with a relative propagation delay of less than 20 ms.
11. A non-transitory computer readable storage medium comprising instructions that when executed by a processor cause the processor to perform:
receiving, by a first edge output device at a first egress of a first media path, a first upstream delay signal from a first edge input device at a first ingress of the first media path;
determining, by the first edge output device, a first uncorrected propagation delay from the first ingress to the first egress based upon the first upstream delay signal;
receiving, by a second edge output device at a second egress of a second media path, a second upstream delay signal from a second edge input device at a second ingress of a second media path;
determining, by the second edge output device, a second uncorrected propagation delay from the second ingress to the second egress based upon the second upstream delay signal;
determining a target propagation delay, by the first edge output device and the second edge output device, that is at least as large as a maximum of the first uncorrected propagation delay and the second uncorrected propagation delay.
12. The non-transitory computer readable storage medium of claim 11 , wherein the instructions further cause the processor to perform:
interconnecting, by a network fabric, the first media path from the first edge input device to the first edge output device; and
interconnecting the second media path from the second edge input device to the second edge output device.
13. The non-transitory computer readable storage medium of claim 11 , wherein the instructions further cause the processor to perform:
exchanging, by the first edge output device and the second edge output device, the first uncorrected propagation delay and the second uncorrected propagation delay; and
determining, by each of the first edge output device and the second edge output device, the maximum of the first uncorrected propagation delay and the second uncorrected propagation delay as the target propagation delay.
14. The non-transitory computer readable storage medium of claim 11 , wherein the instructions further cause the processor to perform:
receiving, by the first edge output device, the second uncorrected propagation delay from the second edge output device;
determining, by the first edge output device, the maximum of the first uncorrected propagation delay and the second uncorrected propagation delay as the target propagation delay; and
sending, by the first edge output device, the target propagation delay to the second edge output device.
15. The non-transitory computer readable storage medium of claim 11 , wherein the instructions further cause the processor to perform:
delaying, by a first dynamic delay element of the first media path, a first media signal from the first edge input device based upon a first delay command;
delaying, by a second dynamic delay element of the second media path, a second media signal from the second edge input device based upon a second delay command;
commanding, by the first edge output device, the first dynamic delay element to delay the first media signal by a difference between the target propagation delay and the first uncorrected propagation delay; and
commanding, by the second edge output device, the second dynamic delay element to delay the second media signal by a difference between the target propagation delay and the second uncorrected propagation delay.
16. The non-transitory computer readable storage medium of claim 15 , wherein the instructions further cause the processor to perform:
commanding, by the first edge output device, the first dynamic delay element to delay the first media signal an amount of delay related to a value by which the second uncorrected propagation delay exceeds the first uncorrected propagation delay; and
commanding, by the second edge output device, the second dynamic delay element to delay the second media signal an amount of delay related to a value by which the first uncorrected propagation delay exceeds the second uncorrected propagation delay.
17. The non-transitory computer readable storage medium of claim 15 , wherein a plurality of ingresses includes the first ingress and the second ingress, wherein a plurality of egresses includes the first egress and the second egress, and wherein the plurality of media signals includes the first media signal and the second media signal.
18. The non-transitory computer readable storage medium of claim 17 , wherein each of the plurality of media signals has an uncorrected propagation delay and wherein the target propagation delay is a maximum of the uncorrected propagation delays of the plurality of media signals.
19. The non-transitory computer readable storage medium of claim 15 , wherein the instructions further cause the processor to perform;
transmitting, by the first edge input device and the second edge input device, the first media signal from the first egress.
20. The non-transitory computer readable storage medium of claim 19 , wherein the instructions further cause the processor to perform;
transmitting the second media signal from the second egress with a relative propagation delay of less than 20 ms.