Netflix Encode Optimisation

[muon]

Was reading this last week and thought others may be interested.

http://techblog.netflix.com/2015/12/per-title-encode-optimization.html

I wouldn't have thought to do this. Would have just done a fixed ladder.

For Maths nerds, the efficient frontier can be depicted as below.

 

[muon]

On freeview that would be statistical multiplexing.

https://en.wikipedia.org/wiki/Statistical_time_division_multiplexing

You can see slightly delayed data on it below.

http://en.digitalbitrate.com/dtv.php?liste=1&live=9&lang=en&mux=BBCA

Change the mux (multiplex) to check the HD ones, BBCB for example.

 

[muon]

Something else interesting now is Adaptive Bit Rate Optimisation although I don't think Netflix use it. Basically in an online stream you have several layers of different bit rates typically chunked into 10 second segments and the player picks the highest bit rate based on your bandwidth. What ABRO does is it strips out a higher bit rate chunk if a lower bit rate chunk is of the same perceived quality resulting in you and the service using less bandwidth.

http://techblog.netflix.com/2016/12/more-efficient-mobile-encodes-for.html

Using it for mobiles now. Kind of makes sense there as people care about data usage on mobiles.

Per-chunk encode optimization

In our parallel encoding pipeline, the video source is split up into a number of chunks, each of which is processed and encoded independently. For our AVCMain encodes, we analyze the video source complexity to select bitrates and resolutions optimized for that title. Whereas our AVCMain encodes use the same average bitrate for each chunk in a title, the mobile encodes optimize the bitrate for each individual chunk based on its complexity (in terms of motion, detail, film grain, texture, etc). This reduces quality fluctuations between the chunks and avoids over-allocating bits to chunks with less complex content.