HD in the OR: The AVCHD Video Recording Format

avchdCan we go from this to this?or2.jpg

This post continues my series HD in the OR examining the current and future use of High Definition video in the Operating Room- as well as current and future HD technology.  You can read background on my OR HD testing here.  This was a big week – after working with the Stryker HD system in the OR a few days ago I operated in a new hospital today and walked right into a Linvatec HD system trial.  Review info coming soon.

In this post I want to review the new HD video recording format AVCHD for you and explore if it has a potential space in the OR (sneak peak- the answer is a qualified “yes”).

First a bit of video in the OR history:  One area that is relatively ignored is archiving video.  As I have written before, for years the standard video archive format was simple consumer VHS, and for those of us who wanted the highest possible resolution of our archives- S-VHS.  The use of consumer DV was never really widely adopted in the OR.  I do remember a single Sony DVCAM based recorder that never really made it to widespread installations.  If I recall correctly, it was Karl Storz who offered it briefly.  I really wanted to use this format since it provided higher resolution (500 lines) and native firewire output for direct digital input into my computer for editing.  Our only option for getting the video into these decks was S-video input since none of the major companies offered firewire output on their OR cameras (despite my requests). 

What is AVCHD?  Briefly, AVCHD is a relatively new digital compression and recording format for high definition video being promoted primarily by Panasonic and Sony. 

How is AVCHD Better than Other HD Recoding Options?:  The main difference is that the MPEG-4 technology that fuels AVCHD is roughly twice as efficient as the MPEG-2 technology used in HDV (the other consumer tape based HD recording options).  What this means is that files are 1/2 the size but retain the same high quality.  This compression is so effective that new camcorders have been developed that can directly record HD video in real time to a hard drive or even flash- based memory card (Panosonic has introduced a consumer AVCHD HD recorder that saves to SD cards and Sony one that saves to Memory Sticks).  – And as I keep advocating- if video can be highly compressed and retain quality then wireless systems can be enabled or internet-based recording and archiving options. This is the Holy Grail for the surgeon in terms of documentation- online access  to HD footage from the OR from the office.

Technical Details of The AVCHD Compression Format:  Digitalcontentproducer has reviewed the format. AVCHD stands for Advanced Video Codec High Definition, and it’s based upon the AVC codec, a joint standard of the ITU (International Telecommunications Union) and ISO (International Standardization Organization) groups. It’s also called H.264. AVC/H.264 is an advanced subset of MPEG-4 compression. H.264 is a very hot topic lately in the broadcast and internet video worlds.

AVCHD is Based on the Same Codec Used in Your IPOD: They comment also that while AVCHD is relatively new, AVC is an established standard—particularly in streaming video and it is the primary codec for iPod video. AVC is also starting to displace MPEG-2 in the cable TV and satellite TV markets, and it’s one of the three technologies available for HD DVDs (along with MPEG-2 and Microsoft’s VC1).   Even the Sony PS3 will play it natively.

More Technical Details on The Video Files Produced:  The AVCHD specification itself supports scalable frame sizes from 720×480 up to 1920×1080 in either 4:3 or 16:9 aspect ratios. Like HDV, AVCHD video uses the 4:2:0 sampling format, which is superior to the 4:1:1 used in DV camcorders (less artifact and better color fidelity).  AVCHD uses an MPEG-2 transport stream “wrapper,” and it is scalable up to 18Mbps

What is HDV – Why Not Use It?:  HDV is the first consumer High Definition Video format released. It allowed the recording of HD footage on standard miniDV tapes.  Unfortunately, its MPEG-2 based format still creates huge files and is not compatible with a disk (non-tape) based recording format.  More on this format to follow in upcoming posts… 

The Editing Quagmire: Editing is the current AVCHD shortcoming.  Many software based NLE programs cannot edit AVCHD video leaving the recorded files of limited use in presentations inthe medical world.  I predict this will change in the next 2 years.  Today Vegas 7+ supports AVCHD editing (of course it does as a Sony product since they are backing this format in the consumer realm).   Adobe Premiere still does not support the format and the message board logs are full of people being told by Adobe don’t hold your breath.  Apple Final Cut Pro has announced support on the Mac side.  Third party tools exist to transcode the video to allow any program to edit it but that is a royal pain.  Both Ulead VideoStudio 11 Plus and Pinnacle Studio 11 support AVCHD and even Blu-ray disc burning.  Nero Ultra Edition Enhanced can process it as well.  

Will We See AVCHD In The OR?- My Inside Insight:  I have spoken to several Medical Video device companies and as of today there is no development in this area.  Even a discussion I had with sources in the Medical Imaging Division of Sony would suggest this is not a format being aggressively pursured.  If anyone is could push this technology into the Medical arena it could be Sony.  They have the medical video hardware and the consumer AVCHD technology- and they are globally committed to AVCHD technology and HD medical video.  For now the mainstay of documentation in the OR remains MPEG-2 based DVD recorders for at least the next two years is what you will see. (hint: and next blu-ray - more to come on this soon)

Then What are the OR advantages of AVCHD?

    1. High HD video quality
    2. smallest HD captured video file size
    3. ability to archive in HD not SD
    4. ability to record on removable flash media or a disk drive
    5. ability to edit by surgeon with consumer software
    6. potential for wireless streming and archiving HD systems

Quality Concerns:  All early reviews of the AVCHD HD camcorders have however noted quality flaws when compared with their comparable HDV based tape systems.  The errors seen have been primarily lower light sensitivity and moting artifacts and flaws (as expected with higher compressions codecs).  This concerns me enough to delay upgrading my camcorder and I don’t want them in the OR until it is settled.  The software will need to be tweaked at minimum.

I’ll post a line-up of the consumer AVCHD camcorders next

Then exciting insight from suprise trials this week of the latest HD systems from Stryker and Linvatec.  Details coming from Docinthemachine HD OR system testing.

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