The original HD version is stored on Vimeo at http://vimeo.com/10718228 .

A smaller version for Mac users is at
http://www.vu-la.com/ANHA/ANHA_AWC_small.m4v .

A similar version in Windows Media 9 format is at
http://www.vu-la.com/ANHA/ANHA_AWC_small.wmv .

Click on the one that you want and it should download.

Windows users who want to try the Mac version can download Apple Quicktime for Windows at
http://www.apple.com/quicktime/download .

cr/30

Here is my answer…

If you are shooting 24P, the 720P compression algorithm is based on 60 frames and the 1080 one is based on 30 frames, even though you are only using 24. So more bits are dedicated to the compression of one frame in 1080 than are in 720. This is significant because the amount of information contained in the two is only marginally different, with the difference being a small horizontal advantage for 1080. The potential 33% in additional H resolution does not even start to compare to the 100% increase in the number of bits per frame available.

Here’s how it works…

Although the total number of pixels is higher in a true 1920 x 1080 frame, the useful resolution is about the same in 1080P and 720P in an HVX200 because the sensors are based on a 960 x 540 array. With offset sampling, Panasonic claims to gain up to 50% in effective resolution. Reality puts you at close to 1280 x 720, or close to the 720P limits, and the 1080P mode can’t give you any more out of the camera, although it is a pretty good conversion from 720P.

The situation for recording is a bit different, and as Adam pointed out, DVCProHD only allows you 960 horizontal samples in 720P but 1280 in 1080, so that’s where you might gain up to 33% in horizontal resolution, up to the theoretical camera limit. The vertical limit is about the same for both because you can’t get much more than 720 lines, even with the offset sampling.

In 720P/24 recording, DVCProHD applies the 100Mb/60 frame encode to each frame, even if you will throw away 36 of them somewhere in the workflow for 24P recording. There is no standard for a 100 Mb/24 frame mode, even though you are only using 40% of the frames. That is why there is no visual difference between a 24PN stream or a 24P/60 stream after pull-down removal.

In 1080P24/30 recording, the ratio is 100Mb/30 or twice the per-frame data rate, hence the compression advantage in the two frames with roughly the same information content (or at least, within 33%.) And in real scenes, the difference is probably much less than 33% most of the time.

Note that the argument still works for 720P60 versus 1080i30 recording. It’s the 60/30 ratio and the similar information content that matter. The vertical resolution may be reduced more for 1080i because of the interlace issue, while the horizontal might still be a bit higher, so the information content may be even closer between the two formats.

The bottom line should be milder compression artifacts on challenging material in 1080 than in 720 and, of course, the visual difference would be more noticeable on progressive originals. In compression, the character of the content determines the ultimate quality of the system output, so you might or might not agree with this analysis, depending on your material. Tricky stuff, this messing with eyeballs and brains…

cr/30

The Jackson Hole presentation issues were caused by bad timing. I got new Macs with the latest operating system (Snow Leopard - 10.6) and Final Cut Studio 3 (FCP7), but the AJA Io HD I/O device didn’t yet have a driver that worked under Snow Leopard. We ended up using an older machine with OS 10.5 and FCP7 and that got us through the show but it was still a bit flaky. The new driver is out now and all seems stable. In software compatibility, timing is everything.

I have been using Final Cut for quite a while, and the biggest headache has been Apple changing the port structure on its laptops. With no ExpressCard slots on most of the new MacBook Pros, disk I/O can be a problem. USB has never been especially stable on Macs and they even took the Firewire port off of the MacBook Pros for a version, until they caught so much hell that they had to put it back on. When i bought the mate to the Io HD, i had to step back in time a year and a half to find a 15″ MacBook Pro with an ExpressCard slot.

I have also been evaluating a copy of Premiere for use with P2 cameras. Adobe is a company that is working to improve its user interface and compatibility but it does not seem to have as much flexibility for the new CoDecs as i had hoped. I think that it is stronger in the integration with the other Adobe apps but not yet a better editing solution than FCP for most of us. Adobe Encore does seem to be the app of choice for authoring BluRay. There are some issues across the board with h.264 encoded BluRays so most people are sticking with MPEG2 and that works really well when encoded with either Apple Compressor or Sorenson Squeeze.

I recently went to an Avid Media Composer 4 demo. Avid is working hard to clean up their image of having a mish-mash of code and hardware. The new version actually seems to deal with most CoDecs natively and at least makes a pretty good attempt to merge clips with different frame rates. I have my doubts about how that will work from an aesthetic standpoint but they have certainly come a long way and they give you several options for dealing with motion conversion of each clip. It also seems to manage metadata better than most other apps and that will become more important as people get used to entering data before shoots and as cameras make it easier to update the data in the field.

On the minus side, if you don’t already have Avid software and a fast PC, expect to put out some change. They also don’t support third party hardware so you will need to buy an Avid I/O device. All-in-all, it’s not a cheap proposition but it looks much better than previous versions.

Some of my news clients are using Edius and they seem to like it. I haven’t had a chance to work with it very much because it is a Windows app, but folks who use it seem satisfied.

The only absolute in the NLE world seems to be that each app is a moving target. Just about the time that i get comfortable with one workflow, some vendor comes out with a new camera, record medium and CoDec, and we go back to the starting gate, needing more processing power and a new approach. And, of course, the third party solutions keep coming along to make life easier, or deal with more metadata, or give us more capability, and there are more toys to spend money on. If you want to keep your productivity high, you will continue to be the gerbil on the exercise wheel.

Ain’t technology fun?

Cheers.

cr/30

I also produce and present the Awards show, and mange the technical operations during the weeklong event. I have worked with the Jackson Hole staff for over a decade and look forward to learning more about natural history program production and enjoying the Tetons again this year.

For more information about Jackson Hole, go to www.jhfestival.org.

Each EAD2009 event is organized by a group or individual around the Basin during Atchafalaya Month, October, 2009, and is designed to raise awareness of the need to conserve one of America’s greatest natural resources, our largest remaining river overflow swamp and south Louisiana’s flood protection way. For more information, go to www.EAD2009.info.

VU/LA is donating event organization, web site development and maintenance services, and print design and placement services for EAD2009.

cr/30

The rapid developments in digital technology make the answer different every time i try to explain it. Resolution of electronic cameras now rivals film cameras, although the highest quality digital cameras still cost 10 to 50 times as much as most of us are willing to pay for a camera. And good quality glass still defines the quality of still and motion pictures. How much you are willing to pay still determines how good your pictures will be.

Camera sensitivity is also improving, along with the dynamic range, the contrast that can be captured without losing dark and highlight details. And color reproduction and color control are getting better as well. You can now do things in-camera that were unheard of a few years ago, and the camera is often the best place to do those things because you usually have more information in the camera than you ever have after you save the picture to a card or disc.

These improvements are showing up in both motion and still cameras, and often the distinction is blurred between the two as more motion cameras also shoot stills and now many still cameras now shoot motion sequences.

The biggest distinction between shooting still and motion is the length of the exposure. Motion capture limits the length of each exposure to the time between the frames in the sequence, so a 30 frame per second clip is limited to a shutter speed of 1/30 second. That is a pretty long exposure and most scenes are shot with a shorter exposure to reduce the motion blur as objects move in the scene or the camera moves across a static scene. However, as in still shooting, longer exposures gather more light so there is a trade-off and if there is little movement to capture, a slow shutter can produce a cleaner and/or brighter image. For static scenes, still cameras can use even longer exposures to improve image quality even more.

Conversely, the improvement in sensitivity in electronic cameras and sensors allows shorter shutter speeds for moving scenes and reduces motion blur and image noise in still and motion shots.

Another continuing improvement is in the density of the storage media for cameras. For still cameras, that means more and larger files can be stored between off-loads. As processing speeds in cameras has improved, larger files with more resolution and RAW files without potentially degrading image compression can be recorded for later processing.

For motion cameras, higher quality video compression can be used, providing fewer compromises in image quality and more flexibility in post production because we can deliver more bits from the field into the editing system. However, newer compression schemes do not come without costs. Advanced compression schemes require higher performance processors, so even though your bit rate may be as low or lower than a previous version with lower quality, you may not be able to make use of it without upgrading your computing hardware.

Then there are differences in camera sensors. Most motion cameras before 2008 had CCD image sensors and prism optics for high quality RGB image capture, but this year, CMOS sensors have started to become popular. They can give you more sensitivity and offer promise for more improvements, but they also have some side effects that can be annoying, depending on your type of shooting.

Most CMOS cameras are provided with a “rolling shutter” to simplify sensor design and the rolling shutter can create image “artifacts” (unwanted effects) that may be distracting. Flash pictures may show up on only part of a frame, depending on when in the exposure time that it happens. Pans may have a skewing look because the top and bottom of the frame are scanned out at different times during the pan.

Whether these problems affect you depends on whether you shoot events where strobe photography is plentiful and whether you often pan across objects with vertical lines. The improved sensitivity of the camera may make up for any new issues created by the new technology.

The first thing that will help you get the most out of your camera is to get it into as manual a mode as possible. Cheaper cameras may not have much of a manual mode, but you can probably still convince the camera to favor one variable over another. It’s just a matter of understanding what the auto modes mean.

Portrait modes usually use longer exposure times to get more depth of field (focus separation between foreground and background) and cleaner images at the expense of motion blur. So if you can put your camera on a tripod, portrait mode may be good for static shots.

Sports modes usually shorten the exposure to freeze action and assume that you will have enough light to get an acceptable image.

Scenic modes may assume enough light and a wide lens angle so that motion blur and depth of field are not issues.

In a manual mode, you may be able to directly change the shutter speed and/or the aperture settings to experiment with different effects. You may also be able to adjust the sensitivity of the camera to light - the ISO setting - to change the amount of video noise or graininess in the images for the same image brightness.

Once you get the images to your computer, there is almost as much range in processing software as there is in cameras. Most cameras  come with some specialized software, and there are consumer and professional application programs, which can allow you to make big changes in image look, with or without serious side effects.

One thing to keep in mind when you are deciding how to capture and store your images is the amount of correction that you want to be able to apply in your processing software. Some cameras now allow you to store images with 16 bits of information per color, instead of the older 8-bit formats. JPEGs usually only provide 8 bits. That means only 256 shades of gray between black and white. That is just about enough for the human visual system to think that the shades are continuous but not necessarily enough to allow big changes in contrast or color. If you change too much, steps may become visible in smooth areas like clouds. Sixteen bits per color allow 256 steps between each 8-bit step or level, allowing for much greater changes without visible image problems.

A similar thing is happening in video cameras but 16 bits per color are more than most video systems can handle, higher quality video cameras provide recordings with 10 bits per color, still four steps between every 8-bit step - a big help in post production.

So how much camera and how much processing do you need? That depends on what you will use the stills or video for. If you are going to a movie screen in a big theater, you had better think about using high definition video at 1920 x 1080 pixels per frame and you will probably want to be compatible with current movie standards of 24 frames per second.

Shooting 24 frames requires that you pay attention to camera pan and tilt rates or you will end up with blurry or jumpy clips, depending on your shutter speed. Most 24 frame video is shot at 1/48 sec shutter speed, just like film cameras, to achieve a good compromise between motion blur and motion “judder” the effect caused by moving the camera across a background or having an object jump across the frame in visible steps.

If you are planning to show your movies on a smaller screen, you might want to use the lower resolution high definition standard of 1280 x 720 pixels at up to 60 frames per second. The 60 frame version gives you superb motion reproduction and allows excellent slow motion shooting, at the expense of bigger files and longer transfer times from the camera.

If your main interest is in web tv, then your may not want to bother with HD at all. You can get faster load times and adequate results with cheaper processing hardware (computer) and software (editing program) if you stick to standard definition video (20th century television).

And don’t forget that all of your images are now on digital media so you can’t go back to an original tape if your disk drive crashes. So make backup copies of all of your computer data, especially your images and video clips.

cr/30

And the new MacBook Pros that came out last year didn’t have Firewire (IEEE1394) ports on them. Apple drove us to Firewire from SCSI a decade ago; now they want to take it away? That went over like a lead balloon and Firewire ports are back.

Then, this year, the ExpressCard slots, only a few years old, are gone and replaced by SD card slots. Pardon me, but i have not seen SD cards of any variety that provide anything other than storage. Yeah, cool, you can boot from one, but i can do that from a bus-powered USB drive, when i need to. Apple claims that not more than 10% of us actually used the Express Cards. I guess that means that they expect that 10% to buy 17″ MacBook Pros, the only model with the expansion slot still available.

By the way, the demise of the Express Card slots means that Apple has now done to Sony what they did to Panasonic by removing the CardBus slots. Sony went to the SxS card instead of the P2 card. A lot of good it has done them now. Eventually everyone will go to SD cards, just in time for Apple to find a new standard. That’s the great thing about standards - we have so many of them. (I obviously did not make that up.)

Well, i have a MacBook, which has no expansion slot either. It has USB2 and Firewire 400. I have used it with an IOHD box to capture Apple ProRes and it works, if just barely. It really should be a little faster to meet the system requirements, but the software loads so i use it.

Aside: It’s kinda like the helicopter shoot that i did in New York in the early days of HD. The camera controls and recorders were so big that we needed a Sikorsky helo and a Honda generator to make it work. Yeah, that’s right, a gas generator on a helicopter with the exhaust pointed out an open door. The pilot was a well-known Viet Nam veteran and his idea of weight and balance was to lift off and see if he could keep both the front and back off the ground. We did the shoot and it worked.

Running software these days is kinda like that. We load it up on the best machine that we have available and see if we can keep the machine from crashing and the software from giving us error messages. For video capture, that means no dropped frames.

There are two issues with capturing HD video.

One is the CPU speed - advanced CoDecs (the video compression methods) require more powerful processors than the old DV family ones that we got used to. One way around that is to get an external hardware accellerator, like the IOHD for ProRes. There are a few others that have different mixes of capability but the IOHD is the leader for Mac users. It’s like having a capture and display card plus an external format converter and frame sync, all working with a laptop. Pretty cool.

The other issue is the one that most of us are familiar with - disk performance. Before we had DVCProHD, we were pretty much limited to building RAID arrays for desktop machines with fast disk interface cards. I managed to squeeze four 250GB SATA drives into a dual processor G5 in the days before extra disk bays and got about 700GB of useful, albeit non-redundant, 8-bit, uncompressed HD storage. When we got DVCProHD, we were able to transfer via Firewire from first, tape decks, then cameras, directly to external disks, using laptops. CardBus slots, then ExpressCard slots provided us with the extra, isolated busses that we needed to capture and record at the same time.

But the MacBook, and now most of the MacBook Pros, put us back in the mode of trying to use USB2, which is marginal for disk storage, or coming up with another scheme.

One other scheme is good old Ethernet. While we were looking the other way, a lot of systems, including my trusty old MacBook, got a boost up to Gigabit Ethernet. So i decided to do some tests, and i found that with a fast USB2 drive, i could get about 26MB/sec write speed on the AJA System Test. With a Firewire 400 interface to the same drive, i could get above 30 MB/sec, not bad, but only about 240 Mbps, which is marginal for reliable Apple ProResHQ at 220 Mbps. But when i connected my old G5 to my MacBook via Gig-E and mounted the RAID from the MacBook, i got over 50 MB/s - much more comfortable numbers.

So i got online and found that there are quite a few options for Network Attached Storage using Gig-E interfaces and RAIDed drives. One is the “Intel SS4200-E NAS GETH EXT-HD 4 BAY SATA EMC SS4200-ENA”, which PCMall has for about $240 without drives. This unit uses up to four field replaceable SATA drives and auto configures to a RAID 1 mirror with two drives or a RAID 5 parity set with four drives. You can also manually configure it for a RAID 1/0 fast mirror if you rather. This looks like a good deal and claims to work with the naked Hitachi SATA drives that i use for my backup system. I often find 500 GB or 1 TB drives for $80 to $150.

So the moral of this story is to not forget to look at all the options. Ethernet is not known for its robustness as a capture medium but giving it enough headroom just might make it practical. I plan to give it a try. I’ll let you know how it works out.

It might beat buying a big old clunky laptop.

crc/30

“The Rec 709 issue is a bit confusing because I’ve had D.I. houses tell me that they color-correct LOG footage in Rec 709 color space but aren’t changing the gamma or limiting the dynamic range.  So does that mean they are just using Rec 709’s color gamut but not its gamma structure?”

Another poster wrote that there is a big difference between the corrections actually being made to the program and the corrections being made for monitoring purposes. She suggested that for film work, most facilities seldom transfer to Rec 709 color and then go back for a film-out.  That may be true for film work, but most video production ends up in Rec 709 space and the limitations of that format are a big part of the post production process. So i thought i should write a little about the subject.

First, a good summary of Rec 709 can be found on Wikipedia.

Rec 709 specifies several parameters for HD images and some of them interact, so it is sometimes difficult to separate them out without knowing the processes that got you to the image that you are working with.

The transfer characteristics are defined for the RGB signals coming from the sensor and include a “gamma” exponent. They also include a spec for maximum gain at blacks, which is about 4.5x. The slope of the linear 4.5x portion at the low end of the curve turns into the gamma curve (0.45 power function) at a specified value around 10% output video level.

If you manipulate the RGB signals together, then you can change the overall transfer characteristics of the system without affecting the color (other than the brightness of the colors - it is useful from this point on to think about the brightness or lightness of the colors separate from the saturation and hue.)

If you manipulate amplitude of the RGB signals individually, then you change the color balance. If you change the gamma of the individual RGB signals, then you will affect specific colors and shades in unique ways and are probably leaving the realm of standard color references and making purely aesthetic decisions. There are reasons to change individual gamma settings to correct for camera setup problems but those are less common than creative changes.

Once you get past the RGB controls, you may have to deal with the transformation equations into color difference space. Color difference signals represent the same information as RGB, but using one luma (brightness) signal and two color signals, which are derived by removing the luma from each of the red and blue signals. They are supposed to be independent of luma but, because of the way that most cameras work, there is some cross-talk among the channels. Because of this cross-talk, and because the luma signal is composed of different amounts of R, G and B signals, changing the colors may affect the brightness, depending on where you make the changes. Color difference signals may also be sub-sampled in spatial resolution, but that is mostly a different issue. In fact, the filtering process of sub-sampling chroma can subtly affect color contrast because the edges are softened, but that is not usually an obvious problem because we can’t resolve as much color detail as luma.

Also, standard definition (SD) colors conforming to Rec 601 have different brightness levels than those of Rec 709, because the two standards use different amounts of RGB signals to make luma. If you want to see an obvious difference, look at SD color bars next to HD color bars, both viewed in monochrome (chroma turned all the way down.) The yellow, cyan and green bars are brighter in HD and the magenta, red and blue bars are darker than in SD. On a waveform monitor, the bars look odd to someone used to looking at SD bars. There is a big jump down between the green and magenta bars, instead of the even steps in SD.

The effect of the luma equation is probably the biggest difference between SD and HD signals and accounts for the fact that people think that HD has a larger “color gamut” than SD. There is a difference in the gamut because of the choice of slightly different red, green and blue primary color references, but the difference in the luma equations makes real colors look more contrasty, increasing the apparent saturation of an image.

If you keep your signals in RGB through processing, then the luma issues may not be obvious in your system, but if you leave the RGB domain and convert to luma and color difference for display, then some of these issues may surface. And of course, going to film out involves transformations beyond the knowledge of this video engineer, so the accuracy of your simulated display maps can make predictions of film results dead on or way off base.

The bottom line is that the mode of correction can most definitely allow changes in transfer characteristics (gamma) and color representation that appear to be independent, and which may create unnatural effects, because the processes are themselves not natural as we think of traditional grading. They can also be implemented in ways that are essentially irreversible, so archiving intermediate elements and using non-destructive corrections can save a lot of time and money if the product turns out to need upstream changes.

crc/30

Recently, someone asked me what size P2 cards that he should get for his P2 camera. With the new, cheaper, larger cards coming out, the answer is not necessarily the same as it was in the past. Most people would have said, “As big as you can afford.” The answer may be more complicated now. (No, these days, answers seldom get simpler.) He also asked what type of devices were best for transferring P2 cards in the field.

I believe the decision of what size cards to buy should be driven by your expected workflow in the field, so i would deal with the last question first.

There are several approaches to transfer of data from cards, driven by how much you intend to spend for a system and by how many people you expect to have on a P2 shoot.

One way is to have a laptop with a CardBus slot available and have someone transfer cards to hard drives (preferably mirrored hard drives) while the shoot is progressing. CardBus slots are becoming rare so this would probably be a machine that you already have, or you might want to buy an external P2 Drive (PCD20) to handle multiple cards. The P2 Drive with transfer software allows someone to start a batch transfer with several cards and allow it to proceed unattended. The older PCD10 only has a USB2 port but the PCD20 has both IEEE1394 (Firewire) and USB2.

Another way is to use a dedicated machine like a P2 Gear (HPG10) or P2 Portable (HPG20) to transfer cards manually to a hard drive. This gives you a smaller profile in the field, and gives you a separate HD playback station for continuity or script to review takes on a real HD monitor before the cards are erased to recycle. It still allows you to mirror drives if you use a drive enclosure that handles mirroring outside the P2 hardware. This approach transfers one card at a time and does not allow the use of transfer software to optimize the transfer using metadata or add verification to the transfer process.

A variation of the second approach uses the more expensive P2 Mobile (HPM110), which has a larger LCD monitor, six P2 card slots and which can do other things, like support conversion of HDX900 or off-speed Varicam playback to editable clips by removing duplicate frames.

The final approach is to have enough cards to not transfer in the field but to do the transfers at the end of the day in a hotel room or back at the studio.

Once you make the workflow decision, then you should choose the size cards that support that approach. Several smaller cards will allow you to start transferring quicker in the field if that is your approach. Larger cards might end up being cheaper if you want to pile up clips and transfer all at the end of the day.

The new, E-series cards have an estimated 5-year life, based on normal usage, rather about a 10-year life for the older ones, but the new ones are cheaper. At the rate of chip advances, you may want to get new, even cheaper cards in five years, anyway.

cr/30

Both HDLink models contain look-up-tables (LUTs), which provide for control of red, green and blue signals to the monitor. Most LUTs are maps from input to output values for each of the three color signals, but the HDLink gives you a “3D” LUT capability; it allows you to map from any RGB value to any other RGB value, providing some colorimetry control beyond simple color balance.

Actually, there is some trickery going on in this amazing box, as there is in most 3D LUT devices. A full, 10-bit, RGB map from any input to any output would require 30-bits of fast RAM, or about a Gigabyte, plus the computational headache of calculating each of those entries for each change in the LUT.

The trick is to use 16 or 17 values for each of the colors and to interpolate using a fast DSP for the rest of the values. The HDLink uses 16 values, as does the Apple Color app; most of the others use 17. It turns out that 17 makes the values fall in binary increments of 64 levels, but either will work. It is just a bit of a nuisance to have different standards. Apparently, Blackmagic software can convert from 17 points now, so using other standard LUTs will work. It’s not clear to me how Color deals with the discrepancy.

The treat that you get with the HDLink Pro is that the SDI loop-through connector can be programmed to get the corrected signal, making the unit an inline SDI/HD SDI hardware color corrector. The HDLink Utility gives you curve-based correction capability and if you are patient enough, you can build your own LUTs with specific corrections.

Steve Shaw has a LUT builder application that allows you to create a 3D LUT from a grade that you have done to an image by comparing the original to a corrected frame. You can find Steve’s app (for Windows only) at Light Illusion. One problem that i have with that approach is that you need a sophisticated color corrector to get the grade before you can build the LUT.

I have built a prototype correction tool that allows me to map six vector color corrections directly into a 3D LUT and i hope to be able to make it supportable in the near future, but right now, it still requires pasting the LUT results into a template file. It seems to work, but i’ll know how well after a couple more outings with it.

If you have any experience working with LUTs, please comment here or email me. I can use all the help that i can get.

cr/30