What does this HEVC mean for you and me. Well, this codec paves the way for higher resolutions and the ability to hold fairly reasonable mobile streaming of this material.
Samsung launched the S4 which promises to support the HEVC technology. Expect more and more devices over the coming months to be sold supporting HEVC.
What is HEVC exactly???
Well if you have been ripping your Blue Ray or DVD collection in the years gone by you will have probably used the H.264 codec (MP4) or AVC (Advanced Video Coding). HEVC is simply the next step, H.265 will be the next codec to use.
The ITU approved this standardization in April 2013. The ITU oversee the 'H' series of standards which it partners with the SO/IEC Moving Picture Experts Group (MPEG). Both the ITU and MPEG groups have given their approval.
Recommendation ITU-T H.265 represents an evolution of the existing video coding
Recommendations (ITU-T H.261, ITU-T H.262, ITU-T H.263 and ITU-T H.264) and was developed
in response to the growing need for higher compression of moving pictures for various applications
such as Internet streaming, communication, videoconferencing, digital storage media and television
broadcasting. It is also designed to enable the use of the coded video representation in a flexible
manner for a wide variety of network environments. The use of this Recommendation | International
Standard allows motion video to be manipulated as a form of computer data and to be stored on
various storage media, transmitted and received over existing and future networks and distributed on
existing and future broadcasting channels.
You can find the entire ITU pdf on H.265 @ http://www.itu.int/rec/T-REC-H.265-201304-I/en
So now manufacturers will start to make products that support the HEVC standard.
The bit rate savings and increase in picture quality is outstanding. Just take a look at the history from MPEG 2 in 1994.
Back in 2010 a committee known as JVT-VC which represented both MPEG and ITU-T members set about achieving the following brief:
H.265 has to deliver a picture of the same perceived visual quality as H.264 but using only half the transmitted volume of data and therefore half the bandwidth.
Shut up already here comes the Science.......
Like H.264 before it - and all video standards from H.261 on, HEVC is based on the same notion of spotting motion-induced differences between frames, and finding near-identical areas within a single frame. These similarities are subtracted from subsequent frames and whatever is left in each partial frame is mathematically transformed to reduce the amount of data needed to store each frame.
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| Source Elemental Technologies |
When an H.264 frame is encoded, it’s divided into a grid of squares, known as "macroblocks" in the jargon. H.264 macroblocks were no bigger than 16 x 16 pixels, but that’s arguably too small a size for HD imagery and certainly for Ultra HD pictures, so H.265 allows block sizes to be set at up to 64 x 64 pixels, the better to detect finer differences between two given blocks.
H.265 goes further.... H.264 encoders check intra picture similarities in eight possible directions from the source block. H.265 extends this to 33 possible vectors - the better to reveal more subtle pixel block movement. There are also other tricks that H.265 gains to predict more accurately where to duplicate a given block to generate the final frame.
To read more about H.265 I suggest you read the report published by Tony Smith at the The Register. It makes for a good read over a cup tea the Register
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