Rate control in video communication via virtual transmission buffer
AssigneeApple Inc.
InventorsXiaosong ZHOU, Hsi-Jung WU
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Abstract
Embodiments of the present invention provide a video encoding system that may include a coding engine to code an input video signal according to a video compression process, compression of each portion of the input signal performed according to coding parameters assigned to the respective portion. The video encoding system may also include a rate controller to select coding parameters of each portion of the input signal, the rate controller estimating delay of delivery of coded video data by a delivery network according to a leaky bucket modeling process and selecting coding parameters of a portion to be coded based at least in part on the estimated delay.
Claims26
A video encoding system, comprising:
- a coding engine to code an input video signal according to a video compression process, compression of each portion of the input signal performed according to coding parameters assigned to the respective portion;
- a communication manager to receive through a network back-channel indicators of communication delays between the system and a decoder;
- and
- a rate controller to select coding parameters of each portion of the input signal, the rate controller estimating delay of delivery of coded video data by the network according to a leaky bucket modeling process and selecting coding parameters of a portion based at least in part on the estimated delay and the decoder specific delay.
A method of controlling an encoder bit rate in a variable bit rate encoder, comprising:
- receiving a video signal to be encoded;
- calculating a delay period based on a leaky bucket modeling process from a coding rate of an encoder and an estimated delivery rate of a communication network channel;
- receiving, from a decoder, indicators of communication delays between the encoder and a decoder;
- comparing the modeled delay to the received delay indicators;
- and
- coding the video signal using coding parameters selected based on the comparison.
A computer-readable storage medium encoded with a computer-executable instructions for a causing a computer to perform method of coding an input video signal into a compressed bitstream, the method comprising:
- responsive to receiving the input video signal, calculating a first network delay period based on an input rate and output rate of a communication channel, wherein the input rate is the encoder's bit rate;
- receiving a second network delay period from a decoder;
- adjusting the encoder bit rate based at least in part on the first and second network delay periods;
- and
- coding the input video signal into the compressed bitstream at the adjusted encoder bit rate.
Dependencies are inferred from the claim text.