4K codecs - the good, the big and the ugly. Part 1

There can be little doubt that there is going to be a huge increase in the demand for 4K footage over the next few years and much of that early demand will have to satisfied by stock material. Currently broadcasters can turn to an enormous library of SD and HD material compiled over decades of shooting, but that won't cut the mustard when intercut with newly acquired 4K footage.

Which is good news for those of us who are planning on making our own library of high quality 4K stock shots. One question I would love to answer is which flavour of 4K will be the choice of stock libraries and I really hope that the big boys can come to some sort of agreement here, because uploading four different versions of a 4K clip is not a quick process.

Now H.265 has been announced and I think this will become the bookies favourite even though its younger cousin H.264 is not currently stock libraries first choice for progressive footage. But efficient as H.265 is, it's unlikely to be a good format to edit with for reasons I won't go into here. This means any stock footage will have to be transcoded to another format or codec before editing.

So I ran some tests on existing codecs using a 4K clip from a time lapse within Adobe After Effects to see if any of them would be good enough to host on the web and edit with natively. Here is a still from the sequence. 

The One Tower, St Georges Wharf, Vauxhall, London

The crane on the tall building behind Vauxhall Bridge was unfortunately hit by a helicopter in January 2013 in case it looks familiar - you can see a 1080p version of the time lapse here. I chose this clip because of the complexity of the image with lots of vertical and horizontal lines and a lot of detail in the sky and water.

Here are the codec candidates:

Avid DNxHD - works on Mac and PC and the codec is free.
BlackMagic codec - great quality but probably too big and not widely used.
Cineform - again works on Mac and PC but you need the Premium version of Cineform Studio to create files and this is $299.
Photo JPEG - An old codec, with good compatibility. Currently the choice of many stock companies but not the most efficient of compression choices.
TIFF - Using LZW compression should give a perfect image but with file sizes to match. Also tried a QT using TIFF.
Animation - Not used so much any more but moving between editing and graphics tools is used to be the king. Huge differences in file size depending on the compression ratio.
MPEG A & B - Had their day I think and largely used only for interlaced  
ProRes - A really great codec but will not play well (if at all) on PCs, which really is a ridiculous situation. If it did this would be numero uno. I'm working on a PC so couldn't produce any test results. Pah!

I created a 4K (4096x2304) 1 second clip in each format at two or three compression settings (75%, 90% & 100% where possible) to look at file size and quality. Here are the results:

File sizes of  1 second 4K clip in various codecs 

The TIFF sequence adds up to 288 MB for the 25 frames. 

Unsurprisingly the uncompressed or lossless compression codecs are significantly larger than the lossy compressed versions. The embedded TIFF QTs were significantly larger than the sequence of stills using the LZW lossless compression and the TIFF sequence would still be a good way to exchange between editing and graphic systems.

The lossy compression codecs start with Cineform (100% quality) at 126 MB for a 1 second clip. Bearing in mind that the maximum  length of a clip on iStock is 30 seconds and you could end up with a files of 3.78 GB! At 75% quality it would be a mere 1.8 GB

The tests showed that DNxHD 444 10 bit was almost the same size at 100%, 90% and 75%. Somewhat surprisingly it made little difference on MJPEG codecs whether 75% or 90% compression was chosen. But Cineform at 100% jumped up to 126 MB - almost double the 90% file size, which shows remarkably efficient compression if the quality stands up.

Photo JPEG and MPEG4 also showed a big difference between 75% and 90% and a 30 second clip at the higher compression (75% quality) would be just over 1 GB in size.

In Part 2 of this blog I look at the picture quality of the smaller files to see whether they have a future as a 4K stock format.

The evangelists and agnostics of 4K video

One of the best things about editing TV programmes is that you get to see them in the best quality possible straight out of the edit suite. With a broadcaster approved monitor and a fast computer the pictures often look great - the only thing that would make them better is watching them from a comfy sofa - perks of an executive producer, not a humble editor.

At home I have Sky HD which is pretty good and Freeview which isn't. I also have a powerful computer which plays out my 4K timelapses in Cineform QuickTime and suddenly everything before looks inadequate. I don't have a 4K monitor but the detail on a decent HD TV is amazing - you can almost smell the congestion zone in some of my London shots.

But not everybody thinks 4K is a necessary step for the future. Philip Bloom has this to say:

"8K is the future. Not 4k. Now don’t get me wrong – 4k is smashing, but the difference between 2K (essentially full HD) and 4k is not the leaps and bounds that we had from SD to HD. Not to my old eyes, and by the time we all have 8K, won’t see a bloody thing but THIS is the progress leap that will make the difference."

But for Jim Jannard the founder of Red the release of new 4K Sony cameras is confirmation that 4K will be as big as HD:

"Sony has come to the party. God love them. The F65 is a true 4K camera (although not 8K as it is advertised). The F5 and F55 are 4K cameras soon to be released. There are 4K display panels being released. 4K projectors. The world is finally coming to its senses. We predicted this 6 years ago. Now it is here" 

Now Philip Bloom and Jim Jannard have rarely sung from the same hymn sheet but I expected cordiality over this one. I have seen material projected in 4K from the Canon 1D C and the Canon C500 and it looks pretty fantastic but then it had the best post production money can buy so it should. 

It is over 6 years since Sky launched HD transmission in the UK so I feel we are due an upgrade and 8K is just too far removed from practicality, but material is being filmed, edited and shown in 4K right now. It is the near future and I feel every TV production company should start to look to that future.

Time - it’s never running at the right speed

Of all the various ways of measuring things, Time is generally the most important or critical, at least it is to me. Size doesn't matter, distance can be reduced or extended by speed and volume can be altered, sometimes by the flick of a dial. But Time, that little four letter word that I have given a capital "T", has a mind of its own and will never change, despite the best efforts of the Large Hadron Collider scientists.

Twenty-four hours a day, Time rules my world; where I have to be, what I have to do, what has to be finished, deadlines. I can't change these. I ask for one more minute to finish editing a piece and if I get it I lose a minute from the next Time period. The producer tells me we are on air in five minutes and EVS need the cut in three. I need six, but somehow I finish in four and we get to air. Yes! I beat Time, kind of.

So with all these Time pressures, why on earth do I love making Time lapse sequences? Because, let's face it, the world looks much better when slowed right down or sped right up. It's boring at normal speed, that's so everyday, so dull. In slow motion you can see things missed in real Time. Footage from the Phantom Flex or Hi-Mo cameras analyse movement in a beautiful and intriguing way.Timelapses truncate Time and let you see in thirty seconds what took hours or even days to actually happen. You can't comprehend that as a human, so to see a flower opening, a bridge being built or even the view from the highest building in the world (see Philips Bloom's fabulous film) is a miracle because it manipulates Time.

So I am bored of the speed at which I live and want to control it and if I can't become a Time Lord, then timelapse photography is the closest I am likely to get.To see some of my attempts to control Time go to my Vimeo site at http://vimeo.com/pukkatv/videos