# 240Hz HDMI cable??



## Gasturbine (May 9, 2008)

I decided to get my speakers off the stands, and fish the wire to wall mount. I went to the local Best Buy to get some wire and stuff, and the attendant was asking me what I was doing, what equipment I had...just making friendly chit chat. When he ask which set I had, I told him I had a Vizio 240Hz LED. He then said, "Didnt it suck to change out all your HDMI cables?".

I told him I wasnt sure what he was talking about, and he told me HDMI cables are rated to the hertz of the signal it was carrying. He could see I was skeptical, so he said "Here...let me show you".

Sure enough, he showed me 3 different 4' Monster cables, and on the front of the box, each said "Up to 120Hz", Up to 240Hz", "3D capable". And of course, each was priced higher than the last...$39, $59, and $79 respectively.

My question is, is this really an issue, or an attempt to make you spend more money? While I know there are "quality" and "cheap" HDMI cables, I thought the bandwidth capability was the same. 

I mean, I can still tell the difference in quick action (sports mostly) that my set is "faster" than my other friends 120Hz set...but am I really bottle necking like Best Buy says?


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## takeshi (Jul 22, 2010)

Gasturbine said:


> Sure enough, he showed me 3 different 4' Monster cables, and on the front of the box, each said "Up to 120Hz", Up to 240Hz", "3D capable".


Always consider the source. Monster's (the name itself is a clue given their track record) offerings do not prove anything other than they are trying to milk consumers for as much as possible. There's no such thing as 120Hz or 240Hz HDMI cable. Your TV set upconverts to 120 or 240Hz. Your devices do not output at 120 or 240. It's all marketing.

The valid types of HDMI cables are listed here:
http://www.hdmi.org/learningcenter/trademark_logo_pub.aspx


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## jrtroo (Feb 4, 2008)

Glad you did not fall for this. I like the subtlety of the question- HDMI cables could hardly be easier to plug/unplug, even if it were it necessary. It is not. If you ever DO need cables, go to monoprice.com, not monster. I'll split the difference in price with you. 

Don't let this guy sell you a car, you could end up with undercoating, extended warranty, tinted windows, upgraded wheels, and a fuzzy steering wheel.


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## Joe01880 (Feb 8, 2009)

Gasturbine said:


> I told him I wasnt sure what he was talking about, and he told me HDMI cables are rated to the hertz of the signal it was carrying. He could see I was skeptical, so he said "Here...let me show you".


If he was just trying to scam you in to buying new cables he knew exactly what he was talking about. If he really believes the crap spewing out of his mouth then he had no idea what he was talking about



Gasturbine said:


> My question is, is this really an issue, or an attempt to make you spend more money? While I know there are "quality" and "cheap" HDMI cables, I thought the bandwidth capability was the same.


It was a case of complete and utter B/S, if in doubt, buy a high dollar cable, bring it home and hook it up, then after you feel silly for doing it, return it with the knowledge that you know more then most Best Buy sales people. Im sure after he tried to sell you new cables he went to his second job pumping gas or picking up dog poo or selling used cars.


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## lrhorer (Aug 31, 2003)

Sometimes I wish every lie told by a salesman could garner a year in prison. The prisons would be full of people - I use the term loosely - serving 10,000 year sentences, though.

HDMI video is an uncompressed digital stream whose bandwidth is related to only two things: the number of pixels and the page update rate. The highest bit rate is encountered with 1080p / 60 Hz signals. If your TV takes a 1080p / 60Hz signal, then it requires the highest bit rate HDMI currently supports, which is something over 3 Gigbits / sec.

OTOH, a 240Hz TV does not support a 1080p / 240Hz signal, as there is no such thing, and never will be. Anything over 60 Hz is a waste, since the human eye simply cannot register any changes in the visual field faster than 1/60th of a second. So why 240Hz TVs, then? Is that, too a scam? No, it isn't. 120Hz is the smallest number that is evenly divisible by all the standard video rates, including 24Hz, 30 Hz, and 60 Hz. If a TV has a native frame rate that is not a precise multiple of the input rate, then internally the signals frame rate has to be converted to something the display can handle, inevitably producing artifacts in the video, most notably jitter or flicker. These effects can be covered by using phosphors with relatively long fade periods (or an LED driver that emulates the effect), but the result then is streaking and ghosting of high velocity images. OTOH, with a 120Hz display rate, the input can be readily upscaled to 120Hz without any 1/2 or 1/3 perod offsets, and the picture is bright and crisp without flicker, jitter, streaking, or ghosting no matter what the input frame rate or what the action in the scene. Now, does that make 240Hz better than 120Hz? Perhaps. Actually, 120Hz should be good enough, but there is some suggestion the extra speed helps reduce the artifacts even further. It may be true, but certainly at least 120Hz is required for the best performance at all video rates.


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## Jonathan_S (Oct 23, 2001)

lrhorer said:


> HDMI video is an uncompressed digital stream whose bandwidth is related to only two things: the number of pixels and the page update rate. The highest bit rate is encountered with 1080p / 60 Hz signals. If your TV takes a 1080p / 60Hz signal, then it requires the highest bit rate HDMI currently supports, which is something over 3 Gigbits / sec.


Isn't HDMI 1.4a about 3 Gbit/sec per channel; but about 8 Gbit/sec total (plus overhead)?

Doesn't change your point though, 240hz TV's don't need special '240hz HDMI cables'


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## HomieG (Feb 17, 2003)

Jonathan_S said:


> Isn't HDMI 1.4a about 3 Gbit/sec per channel; but about 8 Gbit/sec total (plus overhead)?
> 
> Doesn't change your point though, *240Ghz *TV's don't need special '*240Ghz* HDMI cables'


Should not need to worry about blur with 240Ghs (gigahertz) 

The 3Gb/s / 8Gb/s are the data rate. Not the refresh rate of the screen/display.


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## GBL (Apr 20, 2000)

The only thing to look for is a "standard" and "high speed" designation on the actual cable connectors. Also, it mostly matters only for longer (more then 6') cables.



> *Q. What is the difference between a "Standard" HDMI cable and a "High-Speed" HDMI cable?
> *
> Recently, HDMI Licensing, LLC announced that cables would be tested as Standard or High-Speed cables.
> 
> ...


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## ghuido (May 9, 2007)

Everytime a Best Buy Emp comes over while at the store, I say "I'm good". I once saw a Best Buy person try to explain the TIVO to someone. I had to step in. I felt sorry for the person.


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## shwru980r (Jun 22, 2008)

I like to ask the salesman to set up side by side comparison on two TVs of the same model so I can judge for myself. When they refuse, I mention that the high profit margin on these cables would seem to warrant a side by side comparison display, unless there really is no perceivable difference. After all, they have displays of various TVs so you can compare the picture, why not the cables, since I think they make more money selling the cable than they do the actual TV.


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## rage777 (Aug 19, 2006)

I *think *you also need a high speed HDMI cable if you want ARC.


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## Joe01880 (Feb 8, 2009)

rage777 said:


> I *think *you also need a high speed HDMI cable if you want ARC.


wow, i wish someone would have told me that before i used my old cables on my H/T system with ARC and HDMI control...which work fine


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## lrhorer (Aug 31, 2003)

Jonathan_S said:


> Isn't HDMI 1.4a about 3 Gbit/sec per channel; but about 8 Gbit/sec total (plus overhead)?


Yeah, that's right.


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## lrhorer (Aug 31, 2003)

HomieG said:


> The 3Gb/s / 8Gb/s are the data rate. Not the refresh rate of the screen/display.


Correct, but the two are directly related. A 1920 x 1080 screen consists of 2,073,600 pixels. At a color depth of 8 bits by 3 colors, that is a data set of 49,766,400 bits per page. At 60 pages per second, that equates to 2,985,984,000 bits per second. There has been talk of developing TVs with 10 bit color depth or even 12. At 10 bits per color, the rate would be 3.7 Gbps and at 12 it would be nearly 4.5 Gbps.

Of course, the audio add a bit on top of that, but even 32 bit audio times 7 full channels times a 48 KHz sampling rate is only about 10 Mbps if it were not compressed, which it is.


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## d_anders (Oct 12, 2000)

Cables and accessories are Best Buy's french fries and soda....that's where all their margin comes in...which is why they have their own brands besides Monster, because they can have them made even cheaper and make even more money.

All accessories can be purchased so much cheaper online.

Best Buy is a big Radio Shack with some added services, and is only good for convenience and for peace of mind purchases on larger items (TV's, Stereos, etc.) where you may want to easily return or fix and item (i.e., extended warranty). That convenience comes with a premium, which at times I'm willing to pay...

Best Buy's model with Geek Squad with installation services is where their sweet spot is for a non-tech oriented buying public...or for more expensive installations...home theatres, car stereo installations, etc...More tech integration with home installs, is where they could find growth...providing the economy overall improves...


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## mr.unnatural (Feb 2, 2006)

The moral to this story is this: "Never ask a Best Buy drone questions about the products they sell because they clearly have no clue what they're talking about."

I once made the mistake about asking about the new series 2 Tivos that were coming out. The BB salesperson said they'd be out soon and that they were now called "UltimateTV." I tried to explain that they weren't made by Tivo, but he insisted I was wrong. In fact, he became quite adamant about it.

I don't recall the last time I set foot in a Best Buy. After seeing one of their group rituals on YouTube I've been afraid of becoming one of their human sacrifices to appease the electronic gods.

The good news is that you might be able to find some great deals when they all go out of business, because that's where they're heading, at least according to Wall Street.


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## ggieseke (May 30, 2008)

And another moral is "do your research".

I bought my latest TV there but it took walking two salesmen through their own website to get the advertised price.

Anyone who buys cables of any kind from BB has money to burn or just doesn't pay attention. $25 for a CAT-5 3' ethernet patch cable is insane when monoprice will sell it to you for around a buck is crazy, but they keep pulling it off. Don't get me started on "Geek Squad's" pricing.


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## lrhorer (Aug 31, 2003)

mr.unnatural said:


> The moral to this story is this: "Never ask a Best Buy drone questions about the products they sell because they clearly have no clue what they're talking about."


Boy, you got that right. Even asking them where something is in the store or whether it is in stock is liable to get a wrong answer.



mr.unnatural said:


> I don't recall the last time I set foot in a Best Buy. After seeing one of their group rituals on YouTube I've been afraid of becoming one of their human sacrifices to appease the electronic gods.


Not at all. I frequently go to Best Buy for several reasons.

1. Time. Although I can usually find an item online cheaper, sometimes I do not wish to wait 4 - 5 days or more for it to arrive. If a hard drive in one of my arrays fails on a Saturday or Sunday evening, for example, I will jump into my car and head to the BestBuy for a replacement. Yes, it costs perhaps $5 more than online, but it is not wise to allow an array to sit for 5 days in a degraded state. If the cost differential is not excessive, I'll take small hit on my wallet.

2. Return policy. Best Buy's return policy is generally more lenient than online merchants. If I am uncertain of the exact nature of a device I am purchasing, Best Buy may provide a better safety net without any concern of shipping, re-stocking fees, etc.

3. Warranty service. If something purchased at Best Buy fails during its warranty period, one may simply take the device back for immediate exchange at no extra cost. With online services, one is generally out at least the one way freight cost, and it is likely to be several days or even weeks before the item shows up on one's doorstep.

Of course the cost of providing these conveniences is the reason BestBuy is usually a bit more expensive than online vendors. OTOH, sometimes BB will have overstock sales that compete with the online vendor's prices, and I have had very good luck purchasing floor models at significant discounts from BB.


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## lrhorer (Aug 31, 2003)

ggieseke said:


> And another moral is "do your research".


:up::up::up:



ggieseke said:


> Anyone who buys cables of any kind from BB has money to burn or just doesn't pay attention.


Or perhaps is in a hurry. I needed a 10' USB cable double-quick a few Sundays ago. Altex electronics is closed on Sunday, and of course an online vendor was out of the question. Oddly enough, I found one at BestBuy for a reasonable price. It wasn't in the electronics section, however. It was in the musical instrument section. For the most part, however, you are perfectly correct. Buying cables at BestBuy is foolish.


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## Worf (Sep 15, 2000)

It pays to walk around - the cheap cables will be where people are expected to be cheap. I.e., never by the TVs. Look near the game consoles and accessories (gamers are cheapskates). The cables that are the most expensive will be where you expect them to be - USB cables near computer accessories will be 200% more expensive than the same cable elsewhere (say, game consoles or musical instruments).


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## aaronwt (Jan 31, 2002)

Best Buys policy is different now for most items. It used to be that they would do an exchange if an item was defective while under the warranty. But now they will try to repair it first instead of just exchanging it for a new one or giving Best Buy credit toward a new one.

Of course if still within the first 60 days they will replace it since you have sixty days to return an item now. AT least with the reward zone program I'm in.


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## agredon (Jul 26, 2011)

Anything above 60 Hz is a gimmick because there are not and probably never will be anything broadcast at more than 60 Hz. Why do you need to redraw the same frame 4 times?


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## randyb359 (Jan 3, 2009)

agredon said:


> Anything above 60 Hz is a gimmick because there are not and probably never will be anything broadcast at more than 60 Hz. Why do you need to redraw the same frame 4 times?


cables higher than 60 Hz are a gimmick because the signal going in is only 60 Hz. The higher refresh rates are generated by the TV and do make motion appear smother.


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## agredon (Jul 26, 2011)

randyb359 said:


> cables higher than 60 Hz are a gimmick because the signal going in is only 60 Hz. The higher refresh rates are generated by the TV and do make motion appear smother.


The TV only receives 60 frames (or half-frames for interlaced video) each second. Unless it can calculate the intermediate frames from the current and next frame in better than real-time [and I doubt any consumer-grade product, much less a TV has the horsepower to do that], all its doing is redrawing the same frame 4 times. Motion cannot be smoother if there is no motion. Any additional smoothness you're seeing is purely a Placebo effect.

As for the framerate part (mentioned a few posts above), I had never heard that before...but it would seem to make sense, at least for native 1080p24 content, but I've never seen anything other than 480i30, 720p60, and 1080i30 used on TV (24p content is converted to 30i before broadcast). Since 60 is a multiple of both, this would only seem to be an issue for Blu-Ray and perhaps some on-Demand content. It would have no effect on the smoothness of a football game or other sporting event as the manufacturer's regularly claim.


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## Worf (Sep 15, 2000)

Incorrect, 120/240 Hz refresh TVs DO interpolate frames. It doesn't take much video processing power to do that these days. It just goes into "input lag" - when input lag is 16ms, that's 1 frame of lag. But these faster TVs can have easily 33/66ms lag (2-4 frames)

It's why if you leave the frame interpolation mode on (rather than frame-repeat), the highest frame-interpolation settings will produce a very trippy image during fast motion (e.g., drumming). It's something to see for a few minutes just to see how wacky it gets. Try it with a 24fps video source of fast action if you really want some wild times.

Of course, then any reasonable person goes and disables frame interpolation and sets it to frame-repeat mode so you don't get such trippy movies.

My favorite is to see a musician drumming. Watch the drumsticks.


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## randyb359 (Jan 3, 2009)

agredon said:


> The TV only receives 60 frames (or half-frames for interlaced video) each second. Unless it can calculate the intermediate frames from the current and next frame in better than real-time [and I doubt any consumer-grade product, much less a TV has the horsepower to do that], all its doing is redrawing the same frame 4 times. Motion cannot be smoother if there is no motion. Any additional smoothness you're seeing is purely a Placebo effect.
> 
> As for the framerate part (mentioned a few posts above), I had never heard that before...but it would seem to make sense, at least for native 1080p24 content, but I've never seen anything other than 480i30, 720p60, and 1080i30 used on TV (24p content is converted to 30i before broadcast). Since 60 is a multiple of both, this would only seem to be an issue for Blu-Ray and perhaps some on-Demand content. It would have no effect on the smoothness of a football game or other sporting event as the manufacturer's regularly claim.


It does trick the mind into seeing smother motion. TV itself is a mind trick as there is no actual motion on the screen and the old TVs never even had an entire picture at one time.


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## randyb359 (Jan 3, 2009)

agredon said:


> The TV only receives 60 frames (or half-frames for interlaced video) each second. Unless it can calculate the intermediate frames from the current and next frame in better than real-time [and I doubt any consumer-grade product, much less a TV has the horsepower to do that], all its doing is redrawing the same frame 4 times. Motion cannot be smoother if there is no motion. Any additional smoothness you're seeing is purely a Placebo effect.
> 
> As for the framerate part (mentioned a few posts above), I had never heard that before...but it would seem to make sense, at least for native 1080p24 content, but I've never seen anything other than 480i30, 720p60, and 1080i30 used on TV (24p content is converted to 30i before broadcast). Since 60 is a multiple of both, this would only seem to be an issue for Blu-Ray and perhaps some on-Demand content. It would have no effect on the smoothness of a football game or other sporting event as the manufacturer's regularly claim.


It does trick the mind into seeing smoother motion. TV itself is a mind trick as there is no actual motion on the screen and the old TVs never even had an entire picture at one time.


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## unitron (Apr 28, 2006)

randyb359 said:


> It does trick the mind into seeing smother motion. TV itself is a mind trick as there is no actual motion on the screen and the old TVs never even had an entire picture at one time.


Motion pictures themselves are a mind trick and don't really move.


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## lrhorer (Aug 31, 2003)

Well, the film does. 

You are correct, of course. The images do not move. The result of displaying a series of slightly different images in quick succession produces an impression of movement due to an effect known as "persistence of vision". The mind fills in the gaps between the individual images, and if the intervals at which the images were taken and played back are sufficiently uniform, and the rate at which the images are produced is sufficiently high, then the picture appears to be moving perfectly smoothly.


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## unitron (Apr 28, 2006)

lrhorer said:


> Well, the film does.
> 
> You are correct, of course. The images do not move. The result of displaying a series of slightly different images in quick succession produces an impression of movement due to an effect known as "persistence of vision". The mind fills in the gaps between the individual images, and if the intervals at which the images were taken and played back are sufficiently uniform, and the rate at which the images are produced is sufficiently high, then the picture appears to be moving perfectly smoothly.


What may not be widely known is that the film doesn't run like tape in a tape recorder, but rather it "jerks" ahead on frame at a time, one every 24th of a second, and half-way through that 1/24 of a second, the shutter briefly closes so that the same frame is actually on the screen twice before the next frame is projected.

That phony 48 frames per second winds up looking smoother than the 24 per second it starts out as before the extra shutter action.


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## Worf (Sep 15, 2000)

The motion blur captured on the film (it's shot at 24fps and the film is exposed 1/24th of a second) also helps make the motion a bit "smoother". It's why computer generated graphics tend to require faster framerates as they don't have motion blur. Sharp edges flickering at 24fps is very jerky, but add motion blur and it smooths out.

Of course, the film look is so associated with movies that using 60fps leads to a "home video" look and even 48fps leads to the "cheesy" look. Hard to tell if it's a cultural thing.


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## lrhorer (Aug 31, 2003)

unitron said:


> What may not be widely known is that the film doesn't run like tape in a tape recorder, but rather it "jerks" ahead on frame at a time, one every 24th of a second, and half-way through that 1/24 of a second, the shutter briefly closes so that the same frame is actually on the screen twice before the next frame is projected.


Correct, again. In most classical projectors, the film was smoothy run into and out of the projector case by steady tension on the film reels, but the film looped around rollers that were able to move back and forth under light tension. As the film frame moved into place, a set of registry pins would pop through the holes in the film edges and stop the film from moving for a bit less than that 1/24 of a second, and then withdraw to allow the film to move to the next frame. Photographic film is of course very light and fairly tough, but stopping even something as low in mass as a 20 square cm piece of film stock that quickly produces a pretty hefty force for something only about .025 mm thick. That is why those of us who grew up in the 1950s and 1960s or earlier were often treated to a sudden temporary interruption of the show at a movie theater when the film broke and had to be hurriedly spliced back together. With advances in the chemistry of the film base material and of projector mechanisms, such events are far rarer these days.


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## Jonathan_S (Oct 23, 2001)

lrhorer said:


> Correct, again. In most classical projectors, the film was smoothy run into and out of the projector case by steady tension on the film reels, but the film looped around rollers that were able to move back and forth under light tension. As the film frame moved into place, a set of registry pins would pop through the holes in the film edges and stop the film from moving for a bit less than that 1/24 of a second, and then withdraw to allow the film to move to the next frame. Photographic film is of course very light and fairly tough, but stopping even something as low in mass as a 20 square cm piece of film stock that quickly produces a pretty hefty force for something only about .025 mm thick. That is why those of us who grew up in the 1950s and 1960s or earlier were often treated to a sudden temporary interruption of the show at a movie theater when the film broke and had to be hurriedly spliced back together. With advances in the chemistry of the film base material and of projector mechanisms, such events are far rarer these days.


A bit further back than than (way before my time), early 50s and before, after a film break instead you'd get to see why projection booths were lined with fire resistant materials and had metal fire shutters over the projector openings.

Nitrate film stock doesn't like coming to a halt in front of (usually) a carbon arc light source. It'd burst into flames from the heat quite quickly.


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## lrhorer (Aug 31, 2003)

Yep. In those days the film base was nitrocellulose. Nitrocellulose is known as "gun cotton", an explosive used in bullet primers. The nitrocellulose composition in old film stock is rather more stable than gun cotton - hitting a film container with a hammer won't make it explode - but it is still self-oxidizing, and so burns easily and rapidly. Being self-oxidizing means it not only can easily burst into flame at elevated temperatures, but it also means it decomposes spontaneously over time even at relatively low temperatures. Unfortunately, this means there are tens of thousands of precious film canisters in storage whose contents are now nothing but dust. Many, many wonderful films made prior to the 1940s have been lost forever. Of course, a huge number of lousy films have also been lost, but even that is a bit sad.


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