SYSTEM AND METHOD FOR PROVIDING ERROR RESILIENCE, RANDOM ACCESS AND RATE CONTROL IN SCALABLE VIDEO COMMUNICATIONS
First Claim
1. A video communication system comprising:
- a communication network,a conferencing server disposed in the network and linked to at least one receiving and at least one transmitting endpoint by at least one communication channel each over the communication network,at least one endpoint that transmits coded digital video using a scalable video coding format, andat least one receiving endpoint that is capable of decoding a digital video signal coded in a scalable video coding format supporting temporal scalability and at least one of spatial and quality scalability,wherein the scalable video coding format for spatial scalability includes a base spatial and at least one spatial enhancement layer, for quality scalability includes a base quality layer at least one quality enhancement layer, and for temporal scalability includes a base temporal layer and at least one temporal enhancement layer, wherein the base temporal layers and enhancement temporal layers are interlinked by a threaded picture prediction structure for at least one of the spatial or quality scalability layers,and wherein the conferencing server is configured to selectively eliminate or modify portions of the input video signals received from transmitting endpoints that correspond to layers higher than the base spatial or quality layer, prior to creating the output video signal that is forwarded to the at least one receiving endpoint, so that use of lower spatial or quality layer data is signaled or explicitly coded in the output video signal for use in decoding pictures at resolutions higher than the base spatial or quality layer.
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Accused Products
Abstract
Systems and methods for error resilient transmission, rate control, and random access in video communication systems that use sealable video coding are provided. Error resilience is obtained by using information from low resolution layers to conceal or compensate loss of high resolution layer information. The same mechanism is used for rate control by selectively eliminating high resolution layer information from transmitted signals, which elimination can be compensated at the receiver using information from low resolution layers. Further, random access or switching between low and high resolutions is also achieved by using information from low resolution layers to compensate for high resolution spatial layer packets that may have not been received prior to the switching time.
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Citations
40 Claims
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1. A video communication system comprising:
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a communication network, a conferencing server disposed in the network and linked to at least one receiving and at least one transmitting endpoint by at least one communication channel each over the communication network, at least one endpoint that transmits coded digital video using a scalable video coding format, and at least one receiving endpoint that is capable of decoding a digital video signal coded in a scalable video coding format supporting temporal scalability and at least one of spatial and quality scalability, wherein the scalable video coding format for spatial scalability includes a base spatial and at least one spatial enhancement layer, for quality scalability includes a base quality layer at least one quality enhancement layer, and for temporal scalability includes a base temporal layer and at least one temporal enhancement layer, wherein the base temporal layers and enhancement temporal layers are interlinked by a threaded picture prediction structure for at least one of the spatial or quality scalability layers, and wherein the conferencing server is configured to selectively eliminate or modify portions of the input video signals received from transmitting endpoints that correspond to layers higher than the base spatial or quality layer, prior to creating the output video signal that is forwarded to the at least one receiving endpoint, so that use of lower spatial or quality layer data is signaled or explicitly coded in the output video signal for use in decoding pictures at resolutions higher than the base spatial or quality layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A video communication system comprising:
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a communication network, one endpoint that transmits coded digital video using a scalable video coding format, and at least one receiving endpoint that is capable of decoding a digital video signal coded in a scalable video coding format supporting temporal scalability and at least one of spatial and quality scalability, wherein the scalable video coding format for spatial scalability includes a base spatial and at least one spatial enhancement layer, for quality scalability includes a base quality layer at least one quality enhancement layer, and for temporal scalability includes a base temporal layer and at least one temporal enhancement layer, wherein the base temporal layers and enhancement temporal layers are interlinked by a threaded picture prediction structure for at least one of the spatial or quality scalability layers, and wherein the transmitting endpoint is configured to selectively eliminate or modify portions of its coded video signal that correspond to layers higher than the base spatial or quality layer, prior to creating the output video signal that is forwarded to the at least one receiving endpoint, so that use of lower spatial or quality layer data is signaled or explicitly coded in the output video signal for use in decoding pictures at resolutions higher than the base spatial or quality layer. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
wherein the data is further appropriately scaled to the desired target resolution when explicitly coded in the output video signal that is transmitted to the one or more receiving endpoints.
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13. The system of claim 11, wherein the transmitting endpoint is configured to encode transmitted media as frames in a threaded coding structure having a number of different temporal levels, wherein a subset of the frames (“
- R”
) is particularly selected for reliable transport and includes at least the frames of the lowest temporal layer in the threaded coding structure and such that the decoder can decode at least a portion of received media based on a reliably received frame of the type R after packet loss or error and thereafter is synchronized with the encoder, and wherein the transmitting endpoint selectively eliminates portions of the input video signals received from transmitting endpoints that correspond to layers higher than the base spatial or quality layer in non-R frames only, prior to creating the output video signal that is transmitted to the at least one receiving endpoint.
- R”
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14. The system of claim 11, wherein the transmitting endpoint is further configured to control the transmission rate of the output video signal that is transmitted to the at least one receiving endpoint so that the retained portions of its input video signal that correspond to layers higher than the base spatial or quality layer do not adversely affect the smoothness of the output bit rate.
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15. The system of claim 11, wherein the selective elimination or modification by the transmitting endpoint is performed according to desired output bit rate requirements.
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16. The system of claim 11, wherein the at least one receiving endpoint is configured to display the decoded output picture at a desired spatial resolution that falls in between an immediately lower and an immediately higher spatial layer provided by the received coded video signal.
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17. The system of claim 11, wherein the at least one receiving endpoint is further configured to operate the decoding loop of the immediately higher spatial layer at the desired spatial resolution by scaling all coded data of the immediately higher spatial layer to the desired spatial resolution, and wherein the resultant drift is eliminated by using at least one of:
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periodic intra pictures, periodic use of intra base layer mode, full resolution decoding of at least the lowest temporal layer of the immediately higher spatial layer.
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18. The system of claim 11, wherein the scalable video coding format is further configured with at least one of:
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periodic intra pictures; periodic intra macroblocks; and threaded picture prediction, in order to avoid drift when the higher than the base spatial or quality layer'"'"'s coded information that is modified or eliminated corresponds to the base temporal layer.
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19. The system of claim 11, wherein the receiving endpoint is further configured to operate at least one decoding loop for spatial or quality layers higher than the target spatial or quality layer for at least the base temporal layer, so that when the at least one receiving endpoint switches target layers it can immediately display decoded pictures at the new target layer resolution.
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20. A method for video communication over a communication network, having a conferencing server disposed therein and linked to at least one receiving and at least one transmitting endpoint by at least one communication channel each over the communication network, the at least one endpoint transmitting coded digital video using a scalable video coding format, and the at least one receiving endpoint capable of decoding a digital video signal coded in a scalable video coding format supporting temporal scalability and at least one of spatial and quality scalability, wherein the scalable video coding format for spatial scalability includes a base spatial and at least one spatial enhancement layer, for quality scalability includes a base quality layer at least one quality enhancement layer, and for temporal scalability includes a base temporal layer and at least one temporal enhancement layer, wherein the base temporal layers and enhancement temporal layers are interlinked by a threaded picture prediction structure for at least one of the spatial or quality scalability layers,
the method comprising: at the conferencing server, selectively eliminating or modifying modify portions of the input video signals received from transmitting endpoints that correspond to layers higher than the base spatial or quality layer prior to creating the output video signal that is forwarded to the at least one receiving endpoint, so that use of lower spatial or quality layer data is signaled or explicitly coded in the output video signal for use in decoding pictures at resolutions higher than the base spatial or quality layer. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 39)
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30. A video communication method comprising:
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a communication network, one endpoint that transmits coded digital video using a scalable video coding format, and at least one receiving endpoint that is capable of decoding a digital video signal coded in a scalable video coding format supporting temporal scalability and at least one of spatial and quality scalability, wherein the scalable video coding format for spatial scalability includes a base spatial and at least one spatial enhancement layer, for quality scalability includes a base quality layer at least one quality enhancement layer, and for temporal scalability includes a base temporal layer and at least one temporal enhancement layer, wherein the base temporal layers and enhancement temporal layers are interlinked by a threaded picture prediction structure for at least one of the spatial or quality scalability layers, and wherein the transmitting endpoint is configured to selectively eliminate or modify portions of its coded video signal that correspond to layers higher than the base spatial or quality layer, prior to creating the output video signal that is forwarded to the at least one receiving endpoint, so that use of lower spatial or quality layer data is signaled or explicitly coded in the output video signal for use in decoding pictures at resolutions higher than the base spatial or quality layer. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 40)
wherein the data is further appropriately scaled to the desired target resolution when explicitly coded in the output video signal that is transmitted to the one or more receiving endpoints.
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32. The method of claim 30, further comprising, at the transmitting endpoint encoding transmitted media as frames in a threaded coding structure having a number of different temporal levels, wherein a subset of the frames (“
- R”
) is particularly selected for reliable transport and includes at least the frames of the lowest temporal layer in the threaded coding structure and such that the decoder can decode at least a portion of received media based on a reliably received frame of the type R after packet loss or error and thereafter is synchronized with the encoder, and wherein the transmitting endpoint selectively eliminates or modifies portions of its input video signal that correspond to layers higher than the base spatial or quality layer in non-R frames only, prior to creating the output video signal that is transmitted to the at least one receiving endpoint.
- R”
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33. The method of claim 30, further comprising, at the transmitting endpoint controlling the transmission rate of the output video signal that is transmitted to the at least one receiving endpoint so that the retained portions of its input video signal that correspond to layers higher than the base spatial or quality layer do not adversely affect the smoothness of the output bit rate.
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34. The method of claim 30, further comprising, at the transmitting endpoint performing the selective elimination or modification according to desired output bit rate requirements.
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35. The method of claim 30, further comprising, at the at least one receiving endpoint displaying the decoded output picture at a desired spatial resolution that falls in between an immediately lower and an immediately higher spatial layer provided by the received coded video signal.
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36. The method of claim 35, further comprising, at the at least one receiving endpoint operating the decoding loop of the immediately higher spatial layer at the desired spatial resolution by scaling all coded data of the immediately higher spatial layer to the desired spatial resolution, and wherein the resultant drift is eliminated by using at least one of:
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periodic intra pictures, periodic use of intra base layer mode, full resolution decoding of at least the lowest temporal layer of the immediately higher spatial layer.
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37. The method of claim 30, wherein the scalable video coding format is further configured with at least one of:
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periodic intra pictures; periodic intra macroblocks; and threaded picture prediction, in order to avoid drift when the higher than the base spatial or quality layer'"'"'s coded information that is modified or eliminated corresponds to the base temporal layer.
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38. The method of claim 30, further comprising, at the receiving endpoint operating at least one decoding loop for spatial or quality layers higher than the target spatial or quality layer for at least the base temporal layer, so that when the at least one receiving endpoint switches target layers it can immediately display decoded pictures at the new target layer resolution.
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40. A non-transitory computer readable medium comprising a set of executable instructions to direct a processor to perform the method in claim 30.
Specification