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In defense of 'flicks' (or how I learned to stop worrying and love 705600000)

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Re: In defense of 'flicks' (or how I learned to stop worrying and love 705600000)

#21

Post by slimscsi »

333c wrote: post #18
slimscsi wrote: post #16

Earlier quoted context omitted.

Thanks for the comment. For the record, I am very aware of iee 754, And I am aware that some numbers that have infinite repetition in decimal can have an exact representation. I actually thought about pointing that out. However I decided that it didn't add much to the post. It was written for more of a general audience and diving into those details, while would make the post more technically correct, would not actual…

The issues of "repeating decimal" and exact representation as a floating point number are orthogonal. Because the mantissa in a floating point number (which is fixed width) is in base 2, only fractions with denominators that are powers of two can be exactly represented. This means that simple base-10 decimals like 0.1 cannot be exactly represented by a float. For this reason it's at least a bit misleading to talk abo…

Thanks again for the refresher. But again I am keenly aware for how floating point works. As for audience, this is not a hacker new exclusive. It just happens to be here rite now. It will probably make rounds in other forums as well. If you want to write an post an article on how floating point works. I’ll be happy to read it!

Re: In defense of 'flicks' (or how I learned to stop worrying and love 705600000)

#22

Post by 333c »

saagarjha wrote: post #20
slimscsi wrote: post #16

Earlier quoted context omitted.

Thanks for the comment. For the record, I am very aware of iee 754, And I am aware that some numbers that have infinite repetition in decimal can have an exact representation. I actually thought about pointing that out. However I decided that it didn't add much to the post. It was written for more of a general audience and diving into those details, while would make the post more technically correct, would not actual…

I don't want to come off as combative, but I would argue that a correction would add quite a bit to the post. What you have is straight-up incorrect and wouldn't even take that much effort to fix. "For a computer to store the decimal representation a number that repeats forever would require an infinite amount of memory, so the number is approximated" would be correct and it's just a couple words more.

I agree. This is a small change that makes the statement true.

Re: In defense of 'flicks' (or how I learned to stop worrying and love 705600000)

#23

Post by pg_is_a_butt »

333c wrote: post #15

> The number result is 0.008333333333 with the 3 repeating forever. For a computer to store a number that repeats forever would require an infinite amount of memory This is very much not true, as I'm sure other HN readers will notice. The number is rational (it's equivalent to 1/120). Now, it is true that a floating point number may not be able to represent it exactly, but by no means does this number require "infini…

I got hung up on this too... so entirely wrong, I can't even bother wasting my time continuing reading.

For a contradictory example, even with an infinite amount of memory, a computer cannot store the floating point number .1

Re: In defense of 'flicks' (or how I learned to stop worrying and love 705600000)

#24

Post by anonymfus »

In real modern video files every frame has its own timecode, and mobile phones typically record with variable framerate when these timecodes are placed highly irregularly (the reason can be a lack of performance or an attempt to sync with light source of the different frequency than camera's settings). Any new video editing software is expected to deal with such files, and flicks are useless here.

Re: In defense of 'flicks' (or how I learned to stop worrying and love 705600000)

#25

Post by [deleted] »

333c wrote: post #15

> The number result is 0.008333333333 with the 3 repeating forever. For a computer to store a number that repeats forever would require an infinite amount of memory This is very much not true, as I'm sure other HN readers will notice. The number is rational (it's equivalent to 1/120). Now, it is true that a floating point number may not be able to represent it exactly, but by no means does this number require "infini…

[deleted]

Re: In defense of 'flicks' (or how I learned to stop worrying and love 705600000)

#26

Post by nanis »

slimscsi wrote: post #16
333c wrote: post #15

> The number result is 0.008333333333 with the 3 repeating forever. For a computer to store a number that repeats forever would require an infinite amount of memory This is very much not true, as I'm sure other HN readers will notice. The number is rational (it's equivalent to 1/120). Now, it is true that a floating point number may not be able to represent it exactly, but by no means does this number require "infini…

Thanks for the comment. For the record, I am very aware of iee 754, And I am aware that some numbers that have infinite repetition in decimal can have an exact representation. I actually thought about pointing that out. However I decided that it didn't add much to the post. It was written for more of a general audience and diving into those details, while would make the post more technically correct, would not actual…

There are uncountably infinite real numbers and countably infinite rational numbers, so we cannot represent all of them using a {0, 1}^n where n is a finite number. No matter which numbers you can exactly represent, there will always be uncountably many real numbers which are not exactly representable, and, conversely, the set of real numbers exactly representable using a finite number of bits will have measure zero.

Re: In defense of 'flicks' (or how I learned to stop worrying and love 705600000)

#27

Post by kragen »

saagarjha wrote: post #20
slimscsi wrote: post #16

Earlier quoted context omitted.

Thanks for the comment. For the record, I am very aware of iee 754, And I am aware that some numbers that have infinite repetition in decimal can have an exact representation. I actually thought about pointing that out. However I decided that it didn't add much to the post. It was written for more of a general audience and diving into those details, while would make the post more technically correct, would not actual…

I don't want to come off as combative, but I would argue that a correction would add quite a bit to the post. What you have is straight-up incorrect and wouldn't even take that much effort to fix. "For a computer to store the decimal representation a number that repeats forever would require an infinite amount of memory, so the number is approximated" would be correct and it's just a couple words more.

Agreed.

Re: In defense of 'flicks' (or how I learned to stop worrying and love 705600000)

#28

Post by kragen »

slimscsi wrote: post #17
kazinator wrote: post #14

> That is 367.5 times more audio samples than video frames. Okay, but an audio sample is not comparable to a frame of video, which by itself means something to the viewer. (But, on the other hand which probably doesn't differ much from the previous or next one, especially at 120 Hz). An audio sample is sort of more comparable to a pixel.

Its comparing 1 dimensional space to 2 demential space. So, any comparison is gong to be a little hand wavy. But temporally, I believe the comparison is apt.

> Its comparing 1 dimensional space to 2 demential space

Although I love the coinage "2 demential space", I think you mean "comparing one-dimensional space [audio] to three-dimensional space [video]". A two-dimensional signal might be a still image or a temporal sequence of samples from a one-dimensional array of sensors, such as those in a single slice of a CT machine or a linear MIMO antenna array. A video signal is three-dimensional, not two-dimensional, and probably not "2 demential" either.

Re: In defense of 'flicks' (or how I learned to stop worrying and love 705600000)

#29

Post by slimscsi »

anonymfus wrote: post #24

In real modern video files every frame has its own timecode, and mobile phones typically record with variable framerate when these timecodes are placed highly irregularly (the reason can be a lack of performance or an attempt to sync with light source of the different frequency than camera's settings). Any new video editing software is expected to deal with such files, and flicks are useless here.

I’m not sure I’d agree here. RTPM is probably the most popular live streaming protocol, and it typically has huge variations in instantaneous frames rates. However it’s time base is hard coded to 1/1000. Which means it can’t even accurately represent 30fps. Flicks would be at least a massive improvement here. And even given variable frame rate, a time base must be chosen in advance, so flicks is at least as good as any other value.

Re: In defense of 'flicks' (or how I learned to stop worrying and love 705600000)

#30

Post by slimscsi »

kragen wrote: post #28
slimscsi wrote: post #17

Earlier quoted context omitted.

Its comparing 1 dimensional space to 2 demential space. So, any comparison is gong to be a little hand wavy. But temporally, I believe the comparison is apt.

> Its comparing 1 dimensional space to 2 demential space Although I love the coinage "2 demential space", I think you mean "comparing one-dimensional space [audio] to three-dimensional space [video]". A two-dimensional signal might be a still image or a temporal sequence of samples from a one-dimensional array of sensors, such as those in a single slice of a CT machine or a linear MIMO antenna array. A video signal i…

Including pixel intensity, you are correct. Infact it has thee planes, so you could even call it 9 demential If you break it down that way.
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