Video compression is not understood well enough throughout the whole stack yet.<p>I recently got a 1080p projector for home use, so now movies / TV series in my home are viewed on a 100" screen. Content is mostly from Netflix and Amazon Prime Video.<p>Netflix does a really good job with encoding. I cannot say the same for Amazon Prime Video; even with their exclusive (in UK) offerings, like American Gods or Mr Robot, the quality of the encode is quite poor when viewed on a big screen. Banding, shimmering blocky artifacts on subtle gradients, insufficient bit budget for dimly lit scenes - once you become aware of the issues, it becomes really distracting.<p>OTOH a really big screen is a fantastic ad for high quality high bitrate content. Anything less than 2GB/hour is noticeably poor.
Remember when we did this ugly <i>interlacing</i> thing, so that we could get a higher (50/60fps) framerate?<p>When did we decide that 24/25/30fps was good enough? Now we have a Blu-Ray standard that cannot handle greater than 30fps, and media corporations that are unwilling to release content via any other medium.<p>Put that together with ever-increasing resolutions, and the amount of pixels something moves across from one frame to the next becomes greater, and video looks more and more choppy.<p>Franky, this is a <i>much</i> bigger problem than NTSC ever was. Even with content (The Hobbit, Billy Lynn's Halftime Walk) being created at higher framerates, users have no way to get the content outside of a specialized theater because the Blu-Ray standard cannot handle it, and because people seem to honestly believe that higher framerates look <i>bad</i>.<p>I suppose we can only hope that creators take better advantage of digital mediums that <i>do not</i> have such moronic, and frankly harmful, arbitrary limitations.
looks like this contains a bunch of creative commons (CC-BY-SA) content ripped from wikipedia without proper attribution. please add the missing attribution<p><a href="https://it.wikipedia.org/wiki/File:Pixel_geometry_01_Pengo.jpg" rel="nofollow">https://it.wikipedia.org/wiki/File:Pixel_geometry_01_Pengo.j...</a><p><a href="https://en.wikipedia.org/wiki/Chroma_subsampling#/media/File:Colorcomp.jpg" rel="nofollow">https://en.wikipedia.org/wiki/Chroma_subsampling#/media/File...</a><p>etc
It's interesting to note
that the architecture of the first ISO codec MPEG (1)
is almost identical to the one we have today H.265
That codec was standardised in the late 90s
So this design has carried through for about 20 years.
Most of the changes relate to the targeted parameters
such as frame size, frame rate and bitrate.
Only the last step 264 --> 265 seems to have added new features.<p>This is a very well written introduction
Xiph.org wrote fascinating stuff about video compression when working on their next-generation codec, Daala <a href="https://xiph.org/daala/" rel="nofollow">https://xiph.org/daala/</a>
This was also food for whiteboards in the show silicon valley. Compare: <a href="https://github.com/leandromoreira/digital_video_introduction/blob/master/i/thor_codec_block_diagram.png" rel="nofollow">https://github.com/leandromoreira/digital_video_introduction...</a><p>with:
<a href="http://imgur.com/a/Sne89" rel="nofollow">http://imgur.com/a/Sne89</a>
The frequency of 60/1001 Hz and the situation where we are stuck with it basically forever is a shame upon the entire profession of video engineers.
This is awesome. I work in the VOD space, specifically in content protection and this is great reference guide. I've been meaning to write a similar guide for DRM.
first example interlacing image is wrong, shows running dogo with simulated division into scan lines, but does not take into account timing difference - that was one of the mayor sources of deinterlacing artifacts. Alternating fields are 1/60 second apart in time.<p><a href="http://www.onlinevideo.net/2011/05/learn-the-basics-of-deinterlacing-your-online-videos/" rel="nofollow">http://www.onlinevideo.net/2011/05/learn-the-basics-of-deint...</a>
I believe the next step in video compression will be more on smarts like object tracking och object recognition.<p>Machine learning becoming more and more popular will probably help :)