Video streaming

A method of streaming a media sequence from a server to a receiver over a transmission link in a network, comprising:

• (a) receiving, from the server at the receiver over the transmission link in the network, a first encoded sequence, said first encoded sequence representing a media sequence streamed and encoded at a first quality level;
• and
• (b) determining a temporal position in the first encoded sequence at which to switch from transmission of the first encoded sequence to a second encoded sequence while ensuring timely delivery of the sequence,
• wherein the second encoded sequence represents the media sequence encoded at a second quality level, said first quality level being lower than said second quality level;
• and
• wherein said temporal position is dependent on a position when the difference in cumulative bit counts between the second encoded sequence and the first encoded sequence is greater than the predicted throughput over the transmission link multiplied by the difference in a first preload and a second preload, wherein the first preload is the playout duration of data buffered at the receiver needed to deliver the second encoded sequence at the predicted throughput from the current temporal position, and the second preload is the playout duration of data presently buffered at the receiver.

Apparatus for transmitting a media sequence from a server to a receiver over a transmission link in a network, comprising:

• a communication circuit;
• at least one processor and a memory operatively coupled thereto, the at least one processor being programmed to control the apparatus to at least:
• (a) encode a media sequence at first and second quality levels to generate a respective first encoded sequence and second encoded sequence, wherein the first quality level is lower than the second quality level;
• (b) deliver, in connection with the communication circuit, the first encoded sequence to the receiver;
• and
• (c) determine a temporal position in the first encoded sequence at which to switch from transmission of the first encoded sequence to the second encoded sequence while ensuring timely delivery of the media sequence;
• wherein said temporal position is dependent on a position when the difference in cumulative bit counts between the second encoded sequence and the first encoded sequence is greater than the predicted throughput over the transmission link multiplied by the difference in a first preload and a second preload, wherein the first preload is the playout duration of data buffered at the receiver needed to deliver the second encoded sequence at the predicted throughput from the current temporal position, and the second preload is the playout duration of data presently buffered at the receiver.

Apparatus for streaming a media sequence from a server to a receiver over a transmission link in a network, comprising:

• a communication circuit;
• at least one processor and a memory operatively coupled thereto, the at least one processor being programmed to control the apparatus to at least:
• (a) receive, from the server at the receiver over the transmission link in the network, a first encoded sequence, said first encoded sequence representing a media sequence streamed and encoded at a first quality level;
• and
• (b) determine a temporal position in the first encoded sequence at which to switch from transmission of the first encoded sequence to a second encoded sequence while ensuring timely delivery of the sequence,
• wherein the second encoded sequence represents the media sequence encoded at a second quality level, said first quality level being lower than said second quality level;
• and
• wherein said temporal position is dependent on a position when the difference in cumulative bit counts between the second encoded sequence and the first encoded sequence is greater than the predicted throughput over the transmission link multiplied by the difference in a first preload and a second preload, wherein the first preload is the playout duration of data buffered at the receiver needed to deliver the second encoded sequence at the predicted throughput from the current temporal position, and the second preload is the playout duration of data presently buffered at the receiver.