Video transmission system, video transmission method and video transmitter
A video transmission system includes a video transmitter for storing a packet of video data in a transmitting buffer and transmitting the packet stored in the transmitting buffer, a video receiver for receiving the packet, and an estimation unit for estimating a characteristic of a transmission line between the video transmitter and the video receiver from an arrival time of each packet in the video receiver. The video transmitter transmits a packet at a timing specified from an inverse characteristic of a characteristic of the transmission line.
1. A video transmission system comprising:
a video transmitter, comprising one or more processors, configured to store a packet of video data in a transmitting buffer and transmit the packet stored in the transmitting buffer;
a video receiver, comprising one or more processors, configured to receive the packet; and
an estimation unit, comprising one or more processors, configured to estimate a characteristic of a transmission line between the video transmitter and the video receiver from an arrival time of each packet in the video receiver, wherein
the characteristic is estimated from a delay jitter of each packet,
the estimation unit specifies a delay jitter pattern from the delay jitters corresponding to packets in a packet group, and
the video transmitter is configured to:
determine an adjusted transmission timing by adjusting a regular transmission timing determined based on a constant packet transmission interval with a timing change that is determined based on the estimated characteristic of the transmission line, and transmit the packet at the adjusted transmission timing.
2. The video transmission system according to claim 1 , wherein
the video transmitter is configured to transmit the packet of the video data to each of a first transmission line and a second transmission line,
the video receiver is configured to complement the video data using the packet received from each of the first transmission line and the second transmission line,
the estimation unit is configured to estimate the characteristic from an arrival time difference between a packet received from the first transmission line and a packet received from the second transmission line, and
the video transmitter is configured to transmit a packet to a transmission line having an early arrival time after a time in accordance with the arrival time difference has elapsed after the packet is transmitted to a transmission line having a late arrival time.
3. The video transmission system according to claim 2 , wherein
each of the video transmitter and the video receiver is implemented by a program for realizing respective functions, in hardware of the same specification including an FPGA, wherein
the video transmitter has a transmitting buffer and the video receiver has a first receiving buffer to store a packet received from the first transmission line, a second receiving buffer to store a packet received from the transmission line, and a buffer size of the transmitting buffer and a total buffer size of the first receiving buffer and the second receiving buffer are the same.
4. A video transmission method comprising:
storing, by a video transmitter, a packet of video data in a transmitting buffer and transmitting the packet stored in the transmitting buffer;
receiving, by a video receiver, the packet;
estimating, by a computer, a characteristic of a transmission line between the video transmitter and the video receiver from an arrival time of each packet in the video receiver, wherein the characteristic is estimated from delay jitter of each packet, and the characteristic is a delay jitter pattern specified from delay jitter corresponding to packets in a packet group; and
determining, by the video transmitter, an adjusted transmission timing by adjusting a regular transmission timing determined based on a constant packet transmission interval with a timing change that is determined based on the estimated characteristic of the transmission line, and transmitting, by the video transmitter, the packet at the adjusted transmission timing.
5. A video transmitter comprising:
a transmitting buffer configured to store a packet of video data;
a transmitting unit, comprising one or more processors, configured to transmit the packet stored in the transmitting buffer to the video receiver; and
a control unit, comprising one or more processors, configured to receive a characteristic of a transmission line between the video transmitter and the video receiver estimated from an arrival time of each packet, from the video receiver, determine an adjusted transmission timing by adjusting a regular transmission timing determined based on a constant packet transmission interval with a timing change that is determined based on the estimated characteristic of the transmission line, and perform control of transmitting, by the transmitting unit, the packet at the adjusted transmission timing, wherein the characteristic is estimated from delay jitter of each packet, and the characteristic is a delay jitter pattern specified from delay jitter corresponding to packets in a packet group.
6. The video transmission system according to claim 2 , wherein
the video transmitter is configured to transmit packets to each of the first transmission line and the second transmission line so that the packets having the same sequence numbers arrive at the video receiver at the same time; and
the video receiver is configured to integrate two packets to which the same sequence number is attached, compensate the video data using the integrated packets, and reproduce the video data.