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Old 14th October 2017, 20:06   #13  |  Link
iwod
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Join Date: Apr 2002
Posts: 756
Quote:
Originally Posted by pandy View Post
But when we compare x264 and x265 then increasing complexity of the JET looks quite unpleasant... I know that overall trend is to use more threads but still - increasing computational complexity (exponentially) quickly become serious issue.
Those 64x and 16x are just worse case scenario a bit exaggerated figures.
In 80 when MPEG-1 (and later 2) was born every 2 - 3 years CPU computational power was almost doubled, now we observe severe stagnation on this - rarely new CPU's are providing more than 20% processing gain...
Yes, and it also happens the world have moved to Mobile, and we dont use CPU to do decoding anymore, in most cases we are doing Hardware accelerated decoding with Specific Hardware or DSP, and it also happen they are 10x more efficient at doing so.

But i do understand the concern. If I remember x265 started off being 5x to 10x slower then x264. And the reference encoder were very slow.

I am mainly concerned about two things,

1. Real Time Encoding, that is if you are encoding a live sports like Football Match, I think we are running into some limitation there in regards to Speed / Bitrate and Quality.

2. Decoding: As benwaggoner mentioned, the decoding complexity hasn't increased much, MPEG-2 -> HEVC is only 4x per pixel, which is very little increase in that space when we had 10 - 20x computation power. What has increased though is we moved from 480P to 4K, that is ~20x Pixels.

Unless 3D, VR, or some other Killer Apps comes in, JET or AV2 will properly be the last video codec improvement we see. Pretty much like Audio Codec, bandwidth increase in 5G will means most of those bitrate saving being less of a concern.
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