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Video Stabilization in Linux

2012/10/27 / Jer / 0 Comments

The left is the unstabilized video. Right right was stabilized using the vid.stab plug-ins in transcode.

I use a few different processes for getting ride of the camera jitter from when hand-held shots, but I needed quicker methods for when I have a ton of videos to process.

I found that vid.stab has some plug-ins for transcode that are working great for me. I followed the instructions here and then used the commands below to encode my videos. Other than some of the quick jumps in the stabilized videos, the results are great (and fast). I’m noticing the jumps occur when objects in the background are being revealed, so I’ll have to fiddle with this in the future to see how I can clean these up.
transcode -J stabilize=shakiness=8:show=1,preview -i mvi_3816.mov -y null,null -o dummy

transcode -J transform=smoothing=60 -i mvi_3816.mov -y xvid -o mvi_3816_stable.avi

UFlycam Steadicam and SynthEyes

2012/02/09 / Jer / 0 Comments

Now that I have things balanced out, I did a quick test with the new rig. I’d say it worked out nicely, though the extra weight that the clamp adds is basically doubled because I have to counter balance everything at the bottom. This makes the horizontal rotation a bit stiff. However, a quick pass through Syntheyes cleaned things up.

Now I can simulate the first-person perspective of a spirit flying through the loft!

U-Flycam – Steadicam

2012/01/31 / Jer / 0 Comments

About a month ago I purchased a steadicam from Ebay called the U-Flycam. This think is almost 1/10th the cost of most steadicam units, though you do get what you pay for.

For general running around, it works pretty well, but the more I use it, the more I am beginning to realize how many things can be improved. Here are some ideas that other Youtube users have.

First thing I noted was the cheap construction of the mounting device for the camera. Spokes me out a little bit, as I can picture this lever just breaking off. This guy just replaced the whole mounting unit with a quick release plate from Cullman.

I spent a few hours today trying to get my unit balanced with my Canon 60D. The big issue is that my camera is too light. I’ve used bolts and wing nuts in order to add weights to the top, but they are too close to the center pivot. This guy moved the center of gravity up, by raising the camera with a block of wood.

Besides the weights, I also noticed that the universal joint is pretty cheaply made and although one axis can be adjusted, the other axis cannot. The pivot is slightly off, and since this is very close to the balancing center, even a few millimeters throws it off. So, for example, even if it’s balanced, when I twist the handle by turning, every get’s wonky again. I guess I should consider replacing the u-joint with something better, like one of these babies. Or, I could just follow this guy’s DIY handle assembly. Wait a minute, I want to use a gimbal, not a universal joint.

$100 for the U-Flycam, plus $40 shipping, $6 for misc bolts, plus probably another $50 – $100 for more parts to get this rig working the way I’d like. Or, I could just invested a few thousand in this full body unit. HAH! Oh, but this reminds me that I need to find a way to control the sled. Or get all steampunk and build a suit myself from PVC piping like this DIY project.

Besides the hours of playing around, I did come across a reminder to make sure and get as fast a shutter as I can get, to reduce motion blur, assuming that is the look I am going for.

Canon 10-22mm EF-S Wide Angle

2012/01/20 / Jer / 0 Comments

I finally got my U-Fly steadicam unit balanced, but now I see that my 24mm lens is not going to cut it, for filming architecture. 24mm is pretty wide, but not when dealing with the crop of my 60D. D’oh!

So, I’m considering the Canon EF-S 10-22mm, which looks like it will capture exactly what I need. It’s not as fast as the Canon EF 14mm f/2.8 ($1800) lens but, at less than $800, I think it will have to do. Though, it’s going to have to wait awhile as it’s a tad outside my budget, at the moment.

Multimedia Travel Bag

2011/03/28 / Jer / 0 Comments

Lately I find myself running around with my camera, some lenses, an Olympus sound recorder, laptop & notebook. It’s probably a good idea for me to start looking at something that will accommodate all this stuff.

This video review is giving me some ideas.

*update*

I bought this bag and am very happy with it!

Digital Cameras Write Speed on SDHC Memory Cards

2011/02/21 / Jer / 6 Comments

I recently purchased some Patriot 32GB 10speed SDHC cards for my Canon 60D. I was excited to see some improvements over my current 16GB 4Speed card… but I was sadly mistaken.

Problem Symptoms

I can only record a few seconds before I get a “Movie recording has been stopped automatically” message. Apparently I’m not the only person experiencing this problem. This may be an issue with the 60D, as it seems that SanDisk & PNY users are experiencing the same issue on their 32GB 10Speed cards.

The problem is intermittent. When it occurs, you can see the SD write status light on the camera flashing, but then the flashing will temporarily hold. At this point, you’ll see the buffer bar pop up on the LCD. Sometimes it will stall here, or continue. If you are still recording after 4-5 seconds, you’re golden and it should continue on for minutes of recording.

In this thread, a user recommends using a special SD Formatter, which is specifically designed to comply with SD & SDHC standards. What’s the difference between this and a standard Windows format? Well, we’re about to find out. According to memin1857’s posting:

Sd cards are flash devices just like ssd’s. By using it (filling it with data) it will get slow by time. Because overwrites to sectors will be slow compared to fresh sectors as sd controller does not know actually which sectors are free when you delete files.
By formatting with the above utility and setting erase: ON it will instruct sd controller to release all charge from all flash cells so future writes will be much faster. (On par the day you bought your sd card)
This is comparable to MANUALLY TRIMMING an SSD.

NOTE: Do not confuse Overwrite ERASE with Flash ERASE. Overwrite ERASE is just overwriting sectors with zeroes so data is not recoverable but may not necessarily make your card faster, a real Flash ERASE is a command sent to the controller and will make your card freshly fast in short time. (discharging all sectors is a quick operation compared to overwriting them with null data) Also do not confuse with quick format. ERASE:ON is what you want for performance. (Smaller, older sd cards OR some sd card reader/controllers may not support real ERASE function, you will be notified by the format tool if this is the case

THIS IS AN HARDWARE ISSUE, NOT LOGICAL/SOFTWARE.

This may also fix if hardware sectors do not align with logical sectors. This will affect performance.
You may have trouble finding a configuration that can do flash erase.

Conclusion: Formatting with this tool may enhance your sd card performance and there are no negative affects. Worst case senario is you get do benefit.

I tried the SD Formatter, but am having the same results. However, I was unable to get the “Erase” option to work on my Sony VAIO laptop. This funky movie recording stopping problem seems identical as when I use the Windows formatting.

I am attaching 4 text files which show the resulting recording sessions on the 3 unique Patriot 32GB cards of the same type.

videoSessions_02_cardA.txt – Repeating test on first card. Attempting to record full 30 second sessions (file sizes greater than 175MB). Red marks auto-stopped recordings.

02/22/2011 09:09 AM       176,652,568 MVI_1156.MOV
02/22/2011 09:10 AM       177,215,652 MVI_1157.MOV
02/22/2011 09:10 AM       178,358,460 MVI_1158.MOV
02/22/2011 09:11 AM       176,667,328 MVI_1159.MOV
02/22/2011 09:11 AM        31,602,912 MVI_1160.MOV
02/22/2011 09:11 AM       178,501,696 MVI_1161.MOV
02/22/2011 09:12 AM        26,168,012 MVI_1162.MOV
02/22/2011 09:12 AM        32,185,552 MVI_1163.MOV
02/22/2011 09:12 AM        31,843,188 MVI_1164.MOV
02/22/2011 09:12 AM        21,323,728 MVI_1165.MOV
02/22/2011 09:12 AM        32,406,284 MVI_1166.MOV
02/22/2011 09:13 AM        32,109,836 MVI_1167.MOV
02/22/2011 09:13 AM        32,208,380 MVI_1168.MOV
02/22/2011 09:13 AM       177,901,300 MVI_1169.MOV

videoSessions_03_cardB.txt – Testing a unique second card. Attempting to record full 30 second sessions (file sizes greater than 61MB). Red marks auto-stopped recordings.

02/22/2011 09:22 AM        61,924,480 MVI_1192.MOV
02/22/2011 09:23 AM        62,234,256 MVI_1193.MOV
02/22/2011 09:23 AM        62,047,496 MVI_1194.MOV
02/22/2011 09:23 AM        62,473,264 MVI_1195.MOV
02/22/2011 09:23 AM        26,144,048 MVI_1196.MOV
02/22/2011 09:23 AM        32,028,496 MVI_1197.MOV
02/22/2011 09:24 AM        32,117,764 MVI_1198.MOV
02/22/2011 09:24 AM        62,037,244 MVI_1199.MOV
02/22/2011 09:24 AM        26,262,360 MVI_1200.MOV
02/22/2011 09:24 AM        32,228,560 MVI_1201.MOV
02/22/2011 09:24 AM        32,203,492 MVI_1202.MOV
02/22/2011 09:24 AM        32,324,280 MVI_1203.MOV

videoSessions_04_cardC.txt – Testing a third card. Attempting to record full 10 second sessions (file sizes greater than 58MB). Red marks auto-stopped recordings. Lens cap was on during these sessions.

02/22/2011 09:36 AM        58,113,676 MVI_1228.MOV
02/22/2011 09:36 AM        60,127,292 MVI_1229.MOV
02/22/2011 09:36 AM        60,470,144 MVI_1230.MOV
02/22/2011 09:36 AM        60,958,272 MVI_1231.MOV
02/22/2011 09:36 AM        31,874,880 MVI_1232.MOV
02/22/2011 09:37 AM        61,413,000 MVI_1233.MOV
02/22/2011 09:37 AM        26,051,140 MVI_1234.MOV
02/22/2011 09:37 AM        31,969,860 MVI_1235.MOV
02/22/2011 09:37 AM        31,953,048 MVI_1236.MOV
02/22/2011 09:37 AM        62,914,432 MVI_1237.MOV
02/22/2011 09:37 AM        62,286,076 MVI_1238.MOV
02/22/2011 09:38 AM        25,760,912 MVI_1239.MOV
02/22/2011 09:38 AM        61,450,564 MVI_1240.MOV
02/22/2011 09:38 AM        26,067,636 MVI_1241.MOV
02/22/2011 09:38 AM        31,970,588 MVI_1242.MOV
02/22/2011 09:38 AM        31,785,792 MVI_1243.MOV
02/22/2011 09:38 AM        60,489,452 MVI_1244.MOV

I find it interesting how, on a freshly formatted card, I’m able to record exactly 4 full sessions. On the fifth session, the recording stops recording automatically after 4-5 seconds. After 5 sessions, I start to get intermittent failing sessions.

Another detail that I should note: On successful recording sessions that follow a failed session, the buffer bar will pop up and display 2 bars before the bar disappears and the session continues to record as normal. This behavior is consistent on recordings that follow a failed recording session.

My Advice

First, avoid 32 GB cards if you have a Canon 60D. If you have already purchased a few cards (like myself), make sure you have some freshly formatted cards on hand. When the time comes to records some critical moments, just pop in a fresh card and you should get a few good recording sessions before things start failing.

If anyone has better luck with this, please let me know.

**UPDATE**
In the comments Henry Levenson wrote,

The issue with the movie stopping automatically with the 60D has to due with the buffer capacity of the SD card used and the info transfer rate which has to be equal or > than 40 MB/second. If the transfer rate is slower or the buffer capacity for video’s on the card is exceeded.

If this is true, it leaves me wondering just how useful the speed rating of the card is. Henry’s explanation will potentially disappoint many 32GB SD card owners.
Thanks Henry!

Taking Video w/ Digital SLR Cameras

2011/02/04 / Jer / 0 Comments

I am upgrading my DSLR for video.
A pleasant situation occurred that put me in possession of a Nikon D300. I LOVE this camera, but it’s making me a bit of a snob when it comes to image quality. Please keep in mind that I am NOT a professional photographer, but I can recognise washed out colors and artifacting when I see it. This camera has neither.

So that brings me to the point of this little post. I currently have a JVC Everio HD camcorder and a Sony MiniDV. I love my Sony because it is feature rich (i.e. time lapse video & night vision) and has been very reliable till recently. Since I’m working with tape, it sometimes gives me some digital artifacts. Also, due to the mechanical moving parts, it’s not as light as my JVC and the battery life is about 1/5th that of modern camcorders.

I’m seriously thinking about purchasing a DSLR that takes digital video. Some key things that I am focusing on is the quality of video taken in low lighting conditions, weight, price and the severity of rolling shutter.

Big questions I’m asking myself is do I want to consolidate? Can I find a single camera that would replace my Nikon D300 camera, my JVC and Sony camcorders? Something that takes pictures as good as my D300 (“good enough”), yet can record video and be relatively light weight.

The D5000 has video capabilities and seems very comparable to the D300, though is about half the price ($700). This article compares the ISO quality of the Nikon cameras. From what I can see, the D5000 is approaching “good enough”.

This article compares the the latest offerings from Canon, including video examples of the rolling shutter. They recommend the Canon 7d ($1500 USD) for those on a budget. Gizmodo also has a good articles showing the 7d’s capabilities.

Comparision
The Canon 7d and the Nikon D300 are both around 2 lbs. The D5000 is about 1.25 pounds.

This forum thread seems to be doing a great job of doing a comparison breakdown of the Canon 7d vs the Nikon D300.

A perfect example of rolling shutter. Notice the vertical lines bending as the camera moves side to side?

What about video on the cameras vs the camcorders? Do the camcorders also suffer from rolling shutter? Most do not. Most camcorders use CCD sensors (Charge-Coupled Devices), while digital cameras, including the famous Red cam, use CMOS sensors. According to Wikipedia, “CCDs use what is referred to as global shutters which take a single snapshot representing a point of time and do not suffer from these motion artifacts.” Therefore, camcorders using CCDs don’t suffer from this bendy rolling shutter effect.

Conclusion
I’m going to hang onto my D300 and look into purchasing a better camcorder that will be a good substitute for my JVC and Sony. This article discusses how I can record video from my D300 using an attached PC.

*Update*
I decided to purchase a Canon 60D for video and have sold my D300. I have manual lenses for my Canon for video and everything is looking great. The manual focus is helping train my imperfect eyes as well as building respect for nice “glass”. The rolling shutter effect has not caused me any issues with my 3D tracking using Syntheyes, so far. A review of my Canon D60 is overdue.

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