Video transmission system, transmission apparatus, display apparatus, video transmission method, and recording medium

A transmission apparatus that is included in a video transmission system and transmits a video stream, the video transmission system including a display apparatus that is separate from the transmission apparatus, receives the video stream, and displays a video represented by the video stream, and a controller,

• the transmission apparatus comprising:
• an encoder that performs encoding of a first video stream to generate a second video stream, the encoding causing a first bit rate of the first video stream to be a second bit rate lower than or equal to the first bit rate;
• and
• a transmitter that divides the second video stream into a plurality of transmission packets and transmits a plurality of packets including the plurality of transmission packets to the display apparatus via a network, wherein
• the controller:
• (i) controls the encoding performed by the encoder to reduce the second bit rate by a predefined amount or reduce the second bit rate at a transmission rate of a certain proportion, when a determination result of whether packet loss has occurred in the display apparatus indicates an occurrence of packet loss;
• and
• (ii) causes the transmitter to transmit a plurality of dummy packets, along with the plurality of transmission packets, to the display apparatus via the network, when the determination result indicates that packet loss has not occurred for a predetermined time.

A display apparatus included in a video transmission system, the video transmission system including a transmission apparatus and a controller, the display apparatus being separate from a transmission apparatus, receiving a video stream, and displaying a video represented by the video stream,

• the display apparatus comprising:
• a receiver that receives a plurality of packets including a plurality of transmission packets from the transmission apparatus via a network;
• a decoder that generates a second video stream from the plurality of transmission packets and decodes a video for display from the second video stream;
• a display that displays the video for display;
• and
• a determiner that determines whether packet loss has occurred, based on the plurality of packets received by the receiver, wherein
• the plurality of transmission packets are generated by the transmission apparatus by dividing the second video stream of a second bit rate lower than or equal to a first bit rate, the second video stream being generated through encoding of a first video stream of the first bit rate, and
• the controller:
• (i) controls the encoding performed by the transmission apparatus to reduce the second bit rate by a predefined amount or reduce the second bit rate at a transmission rate of a certain proportion, when a determination result of the determiner indicates that packet loss has occurred;
• and
• (ii) causes the transmission apparatus to transmit a plurality of dummy packets, along with the plurality of transmission packets, to display apparatus via the network, when the determination result indicates that packet loss has not occurred for a predetermined time.

A video transmission method for a video transmission system, the video transmission system including a transmission apparatus that transmits a video stream, a display apparatus that is separate from the transmission apparatus and that receives the video stream and displays a video represented by the video stream, and a controller, the video transmission method comprising:

• by the transmission apparatus:
• performing encoding of a first video stream to generate a second video stream, the encoding causing a first bit rate of the first video stream to be a second bit rate lower than or equal to the first bit rate;
• and
• dividing the second video stream into a plurality of transmission packets and transmitting a plurality of packets including the plurality of transmission packets to the display apparatus via a network,
• by the display apparatus:
• receiving the plurality of packets;
• generating the second video stream from the plurality of transmission packets and decoding a video for display from the second video stream;
• displaying the video for display;
• and
• determining whether packet loss has occurred, based on the plurality of packets received, and
• by the controller:
• (i) controlling the encoding performed by the transmission apparatus to reduce the second bit rate by a predefined amount or reduce the second bit rate at a transmission rate of a certain proportion, when a determination result of the display apparatus indicates an occurrence of packet loss;
• and
• (ii) causing the transmission apparatus to transmit a plurality of dummy packets, along with the plurality of transmission packets, to the display apparatus via the network, when the determination result indicates that packet loss has not occurred for a predetermined time.