As someone who delivers video systems and RF downlinks for drones and helicopters I see four kinds of artifacts in that video:
1) Yes, rolling shutter artifacts appear to be there, but they're very minor (i.e. distortion in the young man's face in the lower left of the first few frames). It appears that the camera is mounted on a gyro stabilized platform. Overall, I suspect that this may even be a full-frame chip, and what appear to be rolling shutter artifacts are actually due to the high compression. Rolling shutter artifacts are very, very annoying and not tolerated well by most users so rolling shutter video chips are going out of style.
2) Lost/corrupted packets. I'm guessing that this is a VOIP system using UDP packets, and you can see some glitches in rows of pixels, like at 0:13 above the horizon to the left. These are often accompanied by 3) and seem to be a predecessor of 4).
3) Compression artifacts. This is probably MPEG-4 of some kind, and you can see the bit rate is rather low because of the blockiness and persistence of bad blocks caused by lost/corrupted packets. The bit rate is low most likely because the RF link won't support a higher one...
4) Lost Link artifacts. These are the most obvious ones, and run from brief ones less than a frame long, which produce the top-down partial-screen "wipes" to ones that last several frames or even several seconds, which look like full-frame "wipe" edits. These are almost certainly caused by loss of radio link from the drone to the ground. The recording software isn't substituting blank pixels or frames, it's just picking up where it left off when it gets the video stream back. Aesthetically, it's probably the best way to go, but if you're collecting something you expect may need to be forensic evidence, it does inconveniently make the video look like it's been edited.
If I were called in to testify on this video clip, I'd say my opinion is that the wipes are caused solely by loss of link, but the video could have purposefully been edited to appear that way.
As for why it jumps so much? His RF Link sucks. Either he's not orienting his antennas correctly (calibrate your magnetometers if you're using gimbaled antennas! Your fixed omnis should stay vertical!) or he's using very high gain omnis at too short a range, or both. Higher gain omnis have deeper nulls at zenith and nadir. (It may seem tempting to the layman, but you don't point your ground station omni at the aircraft - if you're gonna actively aim the antenna, then it should stay perpendicular to your drone.) Finally, he's probably operating in the 2.5GHz ISM band, which in a suburban area like that is probably quite noisy with WiFi and microwave oven interference. Switch to a 5GHz system, it may still be noisy, but at least you don't have all that energy from a magnetron in every home and business spewing radiation intended for hot pockets, leftover mac and cheese, and that fish somebody brings every day for lunch.
Giving up my ability to mod this thread to respond to this tripe.
When I have mod points, I give them first to posts from accounts that carry Karma. ACs don't have Karma, so using a mod point on an AC post seems like a waste. On the rare occasion that an AC post adds value to the discussion, I will give them a +1.
I don't have a facebook account, and my unused Google+ account was taken over by my under-13 son so he could post his minecraft video captures on YouTube. It's not about elitism, but about Karma.
And I do peruse at 0, even when I don't have mod points because ACs are often entertaining.
I don't communicate with other people with mod points, but I expect that most of us operate the same way.
If there's any decay in the community it's from people who post offtopic crap to complain about other people not thinking like they do, or not liking what they like, or to inject politics into a thread. Or from those who come to a thread when it's over a day old and downmod comments that don't agree with their political views so that when the thread gets locked, those posts get archived at -1.
I believe they would. I worked for American Rocket Company in 1989. They developed hybrid engine IP that SpaceDev now owns.
Anyhow, in the late 80's the owners of what would become AmRoc decided to go into the launch business and build a single stage suborbital proof of concept vehicle. Oxidizer was helium pressurized LOX tank and steered by the injected fuel vector control (60% Hydrogen Peroxide, just a few gallons). It needed a guidance system. I was a new grad hired to help obtain it, and do some of the wiring and testing.
The vendor was in Boulder CO. I forget their name. The name no longer exists because AmRoc's chief competitor, Orbital Sciences Corporation sabotaged AmRoc's avionics contract. How? On the eve of our CDR with this Boulder company, all of the employees quit, except for the two owners and a single tech who'd started the company with them. Why did they quit? Orbital Sciences Corp (now Orbital ATK, after they acquired Alliance earlier this year) hired every one of them out from under their feet promising to open a Boulder office.
And it worked. Instead of a custom designed flight computer, gyros, telemetry, data acquisition and etc., we got an avionics system made from secondhand Japanese gyros, engineering model electronics left at the Boulder shop, and the rest from the Omega catalog. Furthermore, only two gyros were available, and in that case, the Z-axis is the only choice to go uninstrumented. Which meant that the flight profile would have to rely on a simple timer schedule: when to start steering away from vertical, when to separate payload, etc. And when to pull the umbilical cord.
All of these things contributed to the failure mode: which was that the LOX valve (a 2.5" gate valve) became encased in ice after frost from the previous day's rehearsal/test pooled around the valve and then refroze when the LOX was filled on launch day. It actually opened about 10%... enough to light the engine. And the person in charge of manually pulling the umbilicals (a payload customer, not an employee) jumped the gun and didn't wait for visual verification of liftoff... so no command could be given to close the valve and turn off the engine. As a result, the rocket sat on the pad and idled, the timer ran up to the moment when the thrust vector Peroxide started flowing... and the X and Y accelerometers saw no response... so more peroxide flowed. Until it pooled in the flame bucket and caught fire.
We sent a nice big black cloud over Santa Maria that day. You can read about it here. But we did prove how safe a hybrid is: if it had been a solid engine or liquid fueled rocket, there would have been a very large explosion. Instead we effectively had a tire fire.
Amroc laid off 90% of its employees within 2 months. Closed its doors and sold its IP to Westinghouse a couple of years after that. Westinghouse later sold it to SpaceDev. And some very happy very well paid engineers in Boulder Colorado earned some very bad karma.
Do I think that Orbital ATK would pay a third party vendor to skimp a little on Acceptance Testing of critical structural components made for SpaceX?
As a former aerospace systems engineer (now RF systems engineer), I found that that is certainly how the US Government and their Prime Contractors treat their suppliers. Every process in place is there to make sure you're not lying about something, cutting a corner, or inflating expenses. And the depressing thing is that every one of them is there to prevent recurrence of a dishonesty that actually took place in the past.
So even if you are one of those vendors that acts in good faith, and believes that a quality product is the best advertising, and that if your project is paid for by tax money then you're ethically obligated to do the best job possible, you get treated exactly like the asshole who made the decision to make a few extra bucks profit by not properly verifying the workmanship on a major structural component for a vehicle that he knew would eventually be manned.
And as an engineer, I know that most engineers want to act in good faith. Some are inept or inexperienced but they still have good faith. The problem lies in management. Once you get the lawyers and bean counters involved is when asshole decisions like that get made.
There are only so many eyeball seconds to go around.
In the US: 300 million x 24 hours per day x 3600 seconds per hour x 0.66 waking hour fudge factor equals only 17 Billion eyeball seconds ever day.
Clearly, that's not enough. If it were, then we wouldn't be assaulted by ads competing for our attention every second of every day. Therefore it must be a common pool resource.
And whoever learns how to project ads onto the insides of closed eyelids and access that lost 8.5 Billion eyeball seconds will make a fortune!
He probably didn't get "aggressive" just got pissed off. I'd wager money he never once used a threatening word or gesture, that he merely expressed outrage, like any of us would. This then becomes inflated into "unacceptable behavior." I've seen it over and over again:
1) Individual attracts attention of police for something innocuous, like having too much melanin, excess hair, non-conformist attire, etc.
2) Law Enforcement Authority (LEA, either public officer or private security) observes individual and waits for them to do something objectionable, however minor (broken taillight, liberating electricity, sitting on sidewalk).
3) LEA then has something they can inflate into "probable cause" or "reasonable suspicion" to detain or arrest individual. Any witnesses at trial will be posed a question whose honest answer will uphold the LEA's account of the incident.
4) Individual has expected reaction, namely, becomes outraged that they were selectively enforced.
5) Individual expresses outrage, either verbally or gesturally. No explicit threat is needed, just behavior other than calm subservience.
6) LEA then has something they can inflate into "aggressive behavior," "resisting arrest," or even "fear for the safety of myself or others." Again, any witnesses at trial will be posed a question whose honest answer will uphold the LEA's account of the incident.
7) Individual then goes to jail, often after being physically beaten. The likelihood of the beating is directly proportional to the melanin concentration / length of hair / degree of nonconformity present at phase 1).
Phase 5 is where most people screw up. In police states like the US and UK are becoming, the police get very offended if you don't respect their ahthoritah. Even talking back can get you beaten and thrown in jail, especially if your melanin concentrations are too high.
we can't send corporations to jail, cause if we did that they'd want other rights too...
Umm... clearly they want all of the rights and none of the obligations or liabilities. Even the biggest corporate penalties ever, the Deepwater Horizon fines levied against BP, are not any worse in the context of the companies earnings than a good spanking would be to an 8 year old. How is this justice, when the amount of damage they caused (workers killed, cleanup costs, fishery collapses, etc.) that would have put an individual person in jail for life?
The Lifehacker article describes the process, but fails to provide a link to an actual tone, and the site referenced in plaintext no longer has the tone.
That's actually a rather good analogy because in the early days of automobiling, you had to know how to fix and maintain a car in order to operate one, either for work or for pleasure. And they were very simple machines that had a rather low barrier to learning how to maintain.
Then later on, as cars got more complex, it became a pleasure to work on them, partly because overcoming the growing barrier was itself rewarding, and it came with a social cache.
Gradually, though, we've come to the point where even the most technically gifted people have to take their car to a mechanic for anything but basic maintenance, and the barrier to being a mechanic is now so high that few people do it as a hobby.
For the automobile, this process took over a century. Personal computers and programming have progressed this entire gamut since I first sat down at a computer in 1977. (A DEC printer terminal in a high school janitor closet, connected to the city hall mainframe. The account I had access to had a program called STARTREK.BAS. You can guess the rest... and remember, it was a printer terminal.)
Slashdot Mirror
As someone who delivers video systems and RF downlinks for drones and helicopters I see four kinds of artifacts in that video:
1) Yes, rolling shutter artifacts appear to be there, but they're very minor (i.e. distortion in the young man's face in the lower left of the first few frames). It appears that the camera is mounted on a gyro stabilized platform. Overall, I suspect that this may even be a full-frame chip, and what appear to be rolling shutter artifacts are actually due to the high compression. Rolling shutter artifacts are very, very annoying and not tolerated well by most users so rolling shutter video chips are going out of style.
2) Lost/corrupted packets. I'm guessing that this is a VOIP system using UDP packets, and you can see some glitches in rows of pixels, like at 0:13 above the horizon to the left. These are often accompanied by 3) and seem to be a predecessor of 4).
3) Compression artifacts. This is probably MPEG-4 of some kind, and you can see the bit rate is rather low because of the blockiness and persistence of bad blocks caused by lost/corrupted packets. The bit rate is low most likely because the RF link won't support a higher one...
4) Lost Link artifacts. These are the most obvious ones, and run from brief ones less than a frame long, which produce the top-down partial-screen "wipes" to ones that last several frames or even several seconds, which look like full-frame "wipe" edits. These are almost certainly caused by loss of radio link from the drone to the ground. The recording software isn't substituting blank pixels or frames, it's just picking up where it left off when it gets the video stream back. Aesthetically, it's probably the best way to go, but if you're collecting something you expect may need to be forensic evidence, it does inconveniently make the video look like it's been edited.
If I were called in to testify on this video clip, I'd say my opinion is that the wipes are caused solely by loss of link, but the video could have purposefully been edited to appear that way.
As for why it jumps so much? His RF Link sucks. Either he's not orienting his antennas correctly (calibrate your magnetometers if you're using gimbaled antennas! Your fixed omnis should stay vertical!) or he's using very high gain omnis at too short a range, or both. Higher gain omnis have deeper nulls at zenith and nadir. (It may seem tempting to the layman, but you don't point your ground station omni at the aircraft - if you're gonna actively aim the antenna, then it should stay perpendicular to your drone.) Finally, he's probably operating in the 2.5GHz ISM band, which in a suburban area like that is probably quite noisy with WiFi and microwave oven interference. Switch to a 5GHz system, it may still be noisy, but at least you don't have all that energy from a magnetron in every home and business spewing radiation intended for hot pockets, leftover mac and cheese, and that fish somebody brings every day for lunch.
You just slashdotted Dilbert.
That's an accomplishment.
Opened this thread to find out this very answer myself. Leaving disappointed.
I suspect, however, that a Stingray is involved, and I don't mean the Chevy.
Less amateur than not knowing how to select the plaintext URL, use your right mouse button and left click "Open Link in New Tab," actually.
the unintentionally funny parts of the movie
As in, a bald guy with white lips shouting, "Bring me the rod!"
I instantly barked out a good laugh at that one, which made others in the audience "get it," and in a few moments half the theater was cracking up.
I suspect that by that point, most people had realized that the movie was terribly bad, and needed some real entertainment.
Giving up my ability to mod this thread to respond to this tripe.
When I have mod points, I give them first to posts from accounts that carry Karma. ACs don't have Karma, so using a mod point on an AC post seems like a waste. On the rare occasion that an AC post adds value to the discussion, I will give them a +1.
I don't have a facebook account, and my unused Google+ account was taken over by my under-13 son so he could post his minecraft video captures on YouTube. It's not about elitism, but about Karma.
And I do peruse at 0, even when I don't have mod points because ACs are often entertaining.
I don't communicate with other people with mod points, but I expect that most of us operate the same way.
If there's any decay in the community it's from people who post offtopic crap to complain about other people not thinking like they do, or not liking what they like, or to inject politics into a thread. Or from those who come to a thread when it's over a day old and downmod comments that don't agree with their political views so that when the thread gets locked, those posts get archived at -1.
I believe they would. I worked for American Rocket Company in 1989. They developed hybrid engine IP that SpaceDev now owns.
Anyhow, in the late 80's the owners of what would become AmRoc decided to go into the launch business and build a single stage suborbital proof of concept vehicle. Oxidizer was helium pressurized LOX tank and steered by the injected fuel vector control (60% Hydrogen Peroxide, just a few gallons). It needed a guidance system. I was a new grad hired to help obtain it, and do some of the wiring and testing.
The vendor was in Boulder CO. I forget their name. The name no longer exists because AmRoc's chief competitor, Orbital Sciences Corporation sabotaged AmRoc's avionics contract. How? On the eve of our CDR with this Boulder company, all of the employees quit, except for the two owners and a single tech who'd started the company with them. Why did they quit? Orbital Sciences Corp (now Orbital ATK, after they acquired Alliance earlier this year) hired every one of them out from under their feet promising to open a Boulder office.
And it worked. Instead of a custom designed flight computer, gyros, telemetry, data acquisition and etc., we got an avionics system made from secondhand Japanese gyros, engineering model electronics left at the Boulder shop, and the rest from the Omega catalog. Furthermore, only two gyros were available, and in that case, the Z-axis is the only choice to go uninstrumented. Which meant that the flight profile would have to rely on a simple timer schedule: when to start steering away from vertical, when to separate payload, etc. And when to pull the umbilical cord.
All of these things contributed to the failure mode: which was that the LOX valve (a 2.5" gate valve) became encased in ice after frost from the previous day's rehearsal/test pooled around the valve and then refroze when the LOX was filled on launch day. It actually opened about 10%... enough to light the engine. And the person in charge of manually pulling the umbilicals (a payload customer, not an employee) jumped the gun and didn't wait for visual verification of liftoff... so no command could be given to close the valve and turn off the engine. As a result, the rocket sat on the pad and idled, the timer ran up to the moment when the thrust vector Peroxide started flowing... and the X and Y accelerometers saw no response... so more peroxide flowed. Until it pooled in the flame bucket and caught fire.
We sent a nice big black cloud over Santa Maria that day. You can read about it here. But we did prove how safe a hybrid is: if it had been a solid engine or liquid fueled rocket, there would have been a very large explosion. Instead we effectively had a tire fire.
Amroc laid off 90% of its employees within 2 months. Closed its doors and sold its IP to Westinghouse a couple of years after that. Westinghouse later sold it to SpaceDev. And some very happy very well paid engineers in Boulder Colorado earned some very bad karma.
Do I think that Orbital ATK would pay a third party vendor to skimp a little on Acceptance Testing of critical structural components made for SpaceX?
Why yes. Yes I do.
After the doge meme's 15 minutes of internet fame, your sentence actually much parses.
"the vendor is a lying bastard"
As a former aerospace systems engineer (now RF systems engineer), I found that that is certainly how the US Government and their Prime Contractors treat their suppliers. Every process in place is there to make sure you're not lying about something, cutting a corner, or inflating expenses. And the depressing thing is that every one of them is there to prevent recurrence of a dishonesty that actually took place in the past.
So even if you are one of those vendors that acts in good faith, and believes that a quality product is the best advertising, and that if your project is paid for by tax money then you're ethically obligated to do the best job possible, you get treated exactly like the asshole who made the decision to make a few extra bucks profit by not properly verifying the workmanship on a major structural component for a vehicle that he knew would eventually be manned.
And as an engineer, I know that most engineers want to act in good faith. Some are inept or inexperienced but they still have good faith. The problem lies in management. Once you get the lawyers and bean counters involved is when asshole decisions like that get made.
There are only so many eyeball seconds to go around.
In the US: 300 million x 24 hours per day x 3600 seconds per hour x 0.66 waking hour fudge factor equals only 17 Billion eyeball seconds ever day.
Clearly, that's not enough. If it were, then we wouldn't be assaulted by ads competing for our attention every second of every day. Therefore it must be a common pool resource.
And whoever learns how to project ads onto the insides of closed eyelids and access that lost 8.5 Billion eyeball seconds will make a fortune!
If the proposed completely unregulated system were to indeed come into being, the airwaves would be filled with porn and misinformed rants.
Just like the internet.
Both are very inexpensive to produce.
And none of us paid any attention to the above, of course.
Well played.
He probably didn't get "aggressive" just got pissed off. I'd wager money he never once used a threatening word or gesture, that he merely expressed outrage, like any of us would. This then becomes inflated into "unacceptable behavior." I've seen it over and over again:
1) Individual attracts attention of police for something innocuous, like having too much melanin, excess hair, non-conformist attire, etc.
2) Law Enforcement Authority (LEA, either public officer or private security) observes individual and waits for them to do something objectionable, however minor (broken taillight, liberating electricity, sitting on sidewalk).
3) LEA then has something they can inflate into "probable cause" or "reasonable suspicion" to detain or arrest individual. Any witnesses at trial will be posed a question whose honest answer will uphold the LEA's account of the incident.
4) Individual has expected reaction, namely, becomes outraged that they were selectively enforced.
5) Individual expresses outrage, either verbally or gesturally. No explicit threat is needed, just behavior other than calm subservience.
6) LEA then has something they can inflate into "aggressive behavior," "resisting arrest," or even "fear for the safety of myself or others." Again, any witnesses at trial will be posed a question whose honest answer will uphold the LEA's account of the incident.
7) Individual then goes to jail, often after being physically beaten. The likelihood of the beating is directly proportional to the melanin concentration / length of hair / degree of nonconformity present at phase 1).
Phase 5 is where most people screw up. In police states like the US and UK are becoming, the police get very offended if you don't respect their ahthoritah. Even talking back can get you beaten and thrown in jail, especially if your melanin concentrations are too high.
I always use foo@bar.net. I'm sure the mailhost at bar.net forwards foo's mail right to the black hole.
Most retail monkeys don't get it and think it's a real address.
But the code monkeys know better.
Well, it appears he was right.
we can't send corporations to jail, cause if we did that they'd want other rights too...
Umm... clearly they want all of the rights and none of the obligations or liabilities. Even the biggest corporate penalties ever, the Deepwater Horizon fines levied against BP, are not any worse in the context of the companies earnings than a good spanking would be to an 8 year old. How is this justice, when the amount of damage they caused (workers killed, cleanup costs, fishery collapses, etc.) that would have put an individual person in jail for life?
No, thank you, Princess Projection of Ironica!
The Lifehacker article describes the process, but fails to provide a link to an actual tone, and the site referenced in plaintext no longer has the tone.
But Wikipedia does. The proper tone is IC_SIT.ogg
Don't forget the big pharma lobbyists, too!
Big Mother is SO BIG that when she sits around the house...
There you go.
A-something anyway.
I believe it's pronounced "azz-WEE-pay."
That's actually a rather good analogy because in the early days of automobiling, you had to know how to fix and maintain a car in order to operate one, either for work or for pleasure. And they were very simple machines that had a rather low barrier to learning how to maintain.
Then later on, as cars got more complex, it became a pleasure to work on them, partly because overcoming the growing barrier was itself rewarding, and it came with a social cache.
Gradually, though, we've come to the point where even the most technically gifted people have to take their car to a mechanic for anything but basic maintenance, and the barrier to being a mechanic is now so high that few people do it as a hobby.
For the automobile, this process took over a century. Personal computers and programming have progressed this entire gamut since I first sat down at a computer in 1977. (A DEC printer terminal in a high school janitor closet, connected to the city hall mainframe. The account I had access to had a program called STARTREK.BAS. You can guess the rest... and remember, it was a printer terminal.)
Sounds like the GP's assessment was rather accurate then. Both the part you emphasized and the final modifying clause.