BITRATE SWITCHING AT PICTURE LEVEL FOR VIDEO DISTRIBUTION
Systems and methods for bitrate switching are described herein to improve the video distribution for users having different available bandwidth. Embodiments described herein improve the bitrate switching granularity and bitrate adaptation capabilities of a video delivery system.
1 . A system for bitrate switching, the system comprising:
a plurality of encoders jointly configured with the same GOP structure and the same resolution, wherein the plurality of encoders generate N streams of different bitrates in ascending order relative to the bitrate;
a rate selector that receives a request for a segment from a player and selects a bitrate for the segment or a fragment of the segment; and
a rate analyzer that sends bitrate data about the player to the rate selector to select the bitrate for the segment or the fragment of the segment;
wherein the rate selector receives the segment or the fragment of the segment from an edge server and sends the segment in a selected bitrate to the player.
2 . The system of claim 1 wherein the rate selector selects different fragments of the segment to reconstruct the segment.
3 . The system of claim 1 wherein the plurality of encoders stream the same segment to the edge server at different bitrates.
4 . The system of claim 1 wherein the rate selector switches between different bitrate streams to select fragments to make up the requested segment for the player.
5 . The system of claim 1 wherein the encoders/packagers generate streams corresponding to bitrate ladders.
6 . The system of claim 1 wherein the rate selector sends the segment in CMAF-LLC format in the selected bitrate to the player.
7 . The system of claim 1 wherein the rate analyzer is implemented either at the edge side or at the player side.
8 . The system of claim 1 wherein bitrate selection is implemented by the rate selector at the edge server.
9 . The system of claim 1 wherein the edge server receives the segment in CMAF-LLC format for all bitrates.
10 . The system of claim 1 wherein bitrate selection is implemented by the rate selector at the origin server location.
11 . The system of claim 1 wherein all streams corresponding to all the possible bitrates are conveyed until the edge server.
12 . The system of claim 1 wherein for the CMAF-LLC format, each sub-GOP wrapped in a fragment is separated with a MOOF delimiter.
13 . The system of claim 1 wherein, after initializing the bitrate, the segments corresponding to a maximal acceptable bitrate are pushed to the player, wherein the maximal acceptable bitrate is obtained from data computed by the rate observer.
14 . The system of claim 1 wherein the rate selector is implemented at the edge server, wherein all streams corresponding to all the possible bitrates are conveyed to the edge server.
15 . The system of claim 1 wherein the encoders generate N streams of the segment at different bitrates.
16 . The system of claim 1 wherein the encoders generate N streams of chunks or fragments of the segment at different bitrates.
17 . A method for bitrate switching, the method comprising:
jointly configuring a plurality of encoders with the same GOP structure, the same resolution;
generating, by the plurality of encoders, N streams in ascending order relative to the bitrate;
receiving a request for a segment from a player;
sending bitrate data about the player;
selecting a bitrate for the segment or a fragment of the segment using the bitrate data; and
receiving the segment or the fragment of the segment from an edge server;
sending the segment in a selected bitrate to the player.