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Falsehoods programmers believe about video

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Re: Falsehoods programmers believe about video

#91

Post by grkjusdgf »

Shendare wrote: post #87
tantalor wrote: post #74

Earlier quoted context omitted.

Okay, so how are subtitles different?

Subtitles are simply translations of speech or text into another language, and are generally (though not always) center aligned near the bottom of the frame.

This is wrong. Subtitles and closed captions serve the same purpose and the terms are largely interchangeable. It's an Americanism to associate subtitles specifically with translations or closed captions specifically with EIA-608.

The essential function of subtitles and closed captions is to enable a viewer to read dialogue (or contextual audio elements) without needing to either hear or understand the audio. It may be in the same language or not.

As one example, in some Chinese markets TV and movies are all subtitled in Chinese, not (primarily) for the deaf, but because the standard Chinese subtitles are intelligible to readers whose only spoken language is a mutually unintelligible dialect.

Re: Falsehoods programmers believe about video

#92

Post by tehwalrus »

mysterypie wrote: post #55
kibwen wrote: post #32

Earlier quoted context omitted.

That's what the marketing department may believe, but in reality that's super creepy. Let's not pretend that I'm on a friendly first-name basis with corporations, or that in reality I'm anything more than an autogenerated numeric ID in a database as far as the corporation is concerned. Furthermore, nobody but my mother calls me by my real first name, and this holds for half of my cohort. And why does any company thin…

> nobody but my mother calls me by my real first name, and this holds for half of my cohort Really? I've been assuming that addressing people by first name--even people you've just met--is now the default, at least for the United States and Canada. Are you in the USA/Canada, by the way? I know that it used to be rude to address someone by their first name unless you knew them well. You had to say, Mr. last-name or Mr…

I really really dont like being called "Joseph" in long form. I know there are some Matthews, Benjamins and a Sybille who agree...

Re: Falsehoods programmers believe about video

#93

Post by kdeldycke »

inopinatus wrote: post #8
unscaled wrote: post #5

Earlier quoted context omitted.

This unfortunately follows the conventions of the genre called "Falsehood programmers believe about X": http://spaceninja.com/2015/12/08/falsehoods-programmers-beli... I honestly think this genre is horrible and counterproductive, even though the writer's intentions are good. It gives no examples, no explanations, no guidelines for proper implementations - just a list of condescending gotchas, showing off the superio…

Perhaps there is scope for a list of Falsehoods Programmers Believe About Falsehoods Programmers Believe.

Love that idea! Please help me compile a list there: https://github.com/kdeldycke/kevin-deldycke-blog/blob/master... :)

Re: Falsehoods programmers believe about video

#95

Post by DonHopkins »

deadmutex wrote: post #65
CoolGuySteve wrote: post #44

Earlier quoted context omitted.

It's also missing the most common error I see: conflating subtitles with closed captions. Closed captions are positioned on the screen to indicate who's talking, have descriptive audio for sound effects, and should be in a high contrast easy to read font (most people with hearing deficiencies also have problems seeing, ie: out of date prescriptions for both hearing aids and eye glasses). As far as I know, QuickTime d…

AFAIK, The YouTube implementation does all of those. Here is a demo: https://www.youtube.com/watch?v=BbqPe-IceP4 Please do not spread falsehoods. Disclamer: I work at YouTube.

The falsehood you're spreading is that youtube closed captioning is consistently usable for everyone by default.

This is how my subtitles / closed captions have looked for me on youtube for a year or so now [1] (on up-to-date Mac Chrome). The font is extremely small and blurry and practically transparent, and there is a horrible background color, which is usually yellow until a week or so ago, but has now changed to green for Christmas.

All I want for Christmas is readable YouTube text. I'm so glad YouTube is trying to keep up with the season's festivities by changing the background color of their absolutely unreadable text from yellow to green, but shouldn't they try to make the text readable by default somehow instead? Maybe a point size larger than 10 points, and a transparency higher than 10 percent, and a neutral or at least less nauseating background color?

Do all users have different randomly selected fonts and point sizes and colors? Why does it change randomly without any user intervention? Is this some sort of a/b/.../z testing? Get it together, YouTube!

I most certainly didn't do anything to configure the closed captions like this. Are there keyboard commands so power users can quickly switch fonts to strange colors and point sizes, that my cats may have pressed when walking on my keyboard?

[1] http://imgur.com/gallery/GOh1t

Re: Falsehoods programmers believe about video

#96

Post by vilya »

gkop wrote: post #73
pedrocr wrote: post #42

Earlier quoted context omitted.

A single uncompressed frame of 1080p video occupies 28MB in RAM, so 1 minute of 24fps video will take up 40GB. If you want to be able to run 4 cores at once it's 3 times that. You won't be doing that any time soon on your laptop or smartphone.

Curious as to your math? My naive thinking is 1920 * 1080 * 8 (generous) bytes is around 16MB.

I think the grandparent post is talking about decoding to RGB with a full 32-bit float per channel, which is 12 bytes per pixel rather than 8. The high precision is needed for HDR and for the extra processing you have to do to the pixels after they're decodeed - motion compensation, gamma correction, etc.

Re: Falsehoods programmers believe about video

#97

Post by Thrillington »

nercht12 wrote: post #67
mysterypie wrote: post #55

Earlier quoted context omitted.

> nobody but my mother calls me by my real first name, and this holds for half of my cohort Really? I've been assuming that addressing people by first name--even people you've just met--is now the default, at least for the United States and Canada. Are you in the USA/Canada, by the way? I know that it used to be rude to address someone by their first name unless you knew them well. You had to say, Mr. last-name or Mr…

I personally don't like the shift, even being in the younger crowd. Calling someone by their first name sounds not only presumptuous but leaves you in an awkward spot of guessing whether to use a nickname (you may heard they've been given) or their full first name. With some coworkers, it's fine 'cause we're on a friendly basis anyways, but if I don't know from Adam, I prefer people don't use my first name. It only l…

Give me a genderless honorific and I'm right there with you. Otherwise, a quick correction to ask for use of a nickname seems easier and less embarrassing all around than presuming gender incorrectly.

Re: Falsehoods programmers believe about video

#98

Post by [deleted] »

deadmutex wrote: post #86
smnscu wrote: post #85

Earlier quoted context omitted.

I have to change my CC settings every damn couple of days because they revert to the same white-on-white 400% bullshit. So thanks for that.

I am not sure, but the screenshot I submitted seems to be the default settings. However, software that is 100% perfect is pretty much impossible to write, and if you think there's a systematic issue, please file a bug, so it can help others in same situation.

[deleted]

Re: Falsehoods programmers believe about video

#99

Post by the8472 »

pedrocr wrote: post #42
the8472 wrote: post #38

Earlier quoted context omitted.

a 1-minute span for I-frames would not be prohibitive for parallel processing that the quotes part was referring to, with a 60-minute video it would still give you 60 segments to process in parallel.

A single uncompressed frame of 1080p video occupies 28MB in RAM, so 1 minute of 24fps video will take up 40GB. If you want to be able to run 4 cores at once it's 3 times that. You won't be doing that any time soon on your laptop or smartphone.

The maximum number of references frames, i.e. how much the Decoded Picture Buffer has to hold, is 16. So even if a GOP is 1 minute long you would have to hold at most 16 pictures in memory to have enough information to stream over that 1-minute segment.

So I still do not see how this would prohibit parallel processing.

Re: Falsehoods programmers believe about video

#100

Post by Thrillington »

smallnamespace wrote: post #83
kibwen wrote: post #62

Earlier quoted context omitted.

I'm explicitly disregarding government websites here, since the government has a legitimate reason to care about my full name (and gets to define what a "legal" name means), and also 99% of the websites that I sign up for are unrelated to the government. There's no reason for a social network to report the names of all its users to a government agency automatically, and I'm skeptical that even my bank would have such…

I don't mean reporting all the names, but for example if you ever transmit payments there is a KYC process, and if you are a bank you must report any suspicious money laundering activity. At the end of the day there are cultural conventions around names, and various agencies use them. I don't see why software should be explicitly culturally neutral, unless your audience is explicitly a global one (and even then, I th…

There is significant engineering cost to implement localization correctly. If you're a bank or in another market where you interact with a government, then you must bear those costs. If not, why not just use an opaque string and spend your engineering dollars on your actual product?
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