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CuriosityStream and Nebula streaming services

I know this post is a little outside the typical theme, but I wanted to write about CuriosityStream and Nebula since I was unable to find many reviews of the services.

I like “edutainment” content in moderation when I’m not able to dedicate attention to reading the corresponding Wikipedia article(s). On YouTube, these are channels like Mustard, Paper Skies, and Wendover.

Some of these creators pitch Nebula as an alternative streaming service with exclusive content not available on YouTube. Since the annual subscription is quite cheap, I thought I would take a subscription and see what it has to offer.

Unfortunately for the channels I am interested in, there are little to no exclusive videos present on Nebula:

Paper Skies: YouTube and Nebula videos
Mustard: YouTube and Nebula videos

Mustard’s channel has only 3 videos on Nebula that have not been posted to YouTube. Some of the “Nebula Original” videos have since been posted to YouTube (and since they’re historical topics, the fact that they’re reposted to YouTube later is of little consequence).

Wendover: YouTube and Nebula videos

Wendover’s Nebula channel has a small number of Nebula exclusive videos. Of the 100 Wendover videos available on Nebula, 12 are not present on YouTube.

But the point of writing a blog post is not only to comment on the lack of original content available on Nebula. Let us talk about Nebula’s content security. There is none.

As far as I can tell, the only thing preventing you from downloading any Nebula exclusive video is guessing the video title:${CHANNEL}-${VIDEO_TITLE}/manifest/c7ef54597481957ca15459cf648a81e58734d0f3cb296f2197bb69a4db085374.m3u8

To obtain the video title, just replace whitespace and punctuation with the hyphen character. For the Mustard channel video “This Plane Tried To Do The Impossible: The Caproni Transaero” you would end up with the video title “this-plane-tried-to-do-the-impossible-the-caproni-transaero”

There are some videos which don’t conform to this scheme exactly, such as the Nebula exclusive movie “Alaska’s Silent Summer” by Wendover. In this case, the manifest URL simply uses the first word of the video title.

If anyone wanted to determine the manifest URL for the Nebula exclusive Mustard video “The Ugliest Plane Ever Built” it wouldn’t require more than a few guesses, given the above information.

The manifest is served by a CDN, and works without authentication so it’s trivial to guess the manifest URL to use with youtube-dl. Enjoy 👍

CuriosityStream is a slightly different matter. The content I looked at appeared to be content produced for television which was relicensed for distribution by CuriosityStream. An example of this would be the ARTE series Happiness is on the Plate, or the BBC series Mumbai Railway which I could not find available on any open content distribution platform (like YouTube).

If you enjoy television productions which have a limited distribution, then a subscription to CuriosityStream might be for you.

CuriosityStream at least varies the hash of their content manifest files, so you cannot simply guess the URL to obtain the content. However, CuriosityStream are not using any form of DRM, so with an account you can obtain an offline copy of the content using youtube-dl.

The real meaning of 10^9

I recently bought a 128GB USB mass storage device from Amazon here in Germany. The price I paid for this unbelievable amount of storage in my pocket? Just 22 Euros.

As you maybe know from a previous article, I’m never exactly pleased when I buy a storage device and find out that the manufacturer is actually selling less capacity than they’re advertising. Rather than turn this into another rant, I’d like to start a discussion with storage manufacturers about what 10^9 means.

First, some definitions:

Gigabyte: 1,000,000,000 bytes is the actual number of bytes in a “gigabyte” which has historically had the acronym “GB” shown.

And when you think about it, it makes sense. Recall your SI units, where you have kilo (1,000), mega (1,000,000), giga (1,000,000,000), tera (1,000,000,000,000), peta (1,000,000,000,000,000)… you get the point.

Gibibyte: 1,073,741,824 bytes. This is the number of bytes in “GiB” which is what computers typically operate in, because it’s a power of 2 (2^30).

So, why the confusion? Well, when you buy a computer with 8 “GB” of RAM, you’re actually buying a computer with 8 GiB of RAM. But, for historical reasons, it’s much more common to see electronics advertised with “GB” instead of “GiB” (although in recent years things seem to be changing, at least on the software side).

Some smart executive at a storage company long ago figured out that if they were advertising products as having 1 GB of capacity, that was actually 10^9 bytes, not 2^30 bytes, and they could increase profits if they started selling devices which were only 1,000,000,000 bytes instead of 1,073,741,824 bytes. That’s like 7% less storage!!!.jpg

The celebration probably looked something like this

And in fact, storage manufacturers have been quite clear about this for a long time. They state quite clearly, in small print, on the back of the box or at the bottom of their product webpage, that the actual size of a Gigabyte is really 1,000,000,000 bytes. So, when you plug that shiny new storage device into your computer, and see 119.2GiB, well that’s just you failing to do the math to account for the difference between 10^9 and 2^30.

In fact, many manufacturers have support pages dedicated to outraged people who buy a device and haven’t read the fine print. Here is the SanDisk website explaining device capacity:

I am not here trying to argue that electronics manufacturers should advertise storage devices advertised in GiB. They’re correctly advertising the capacity of the devices in Gigabytes, the SI unit. It would probably help SanDisk even more if on their website they used the appropriate definition for 2^30, which is Gibibyte. But as I said, consumers have gotten used to reading “GB” so when they see “GiB” they don’t understand what the difference is.

I know, I can hear you thinking right now “Okay, so what? Get to the point already, you’ve been droning on for over 400 words. Hey, are you paid by the word?”

First, I make no money from this website. And second, I said this was a discussion, not a rant. In a discussion, you must provide context and frame the problem. Otherwise it’s just blatent complaining.

Remember that SanDisk page (pictured above) where they helpfully explained the difference between a Gigabyte and Gibibyte for us? Well, I didn’t show you the whole page. Here is what is written directly after the screenshot pictured above explaining a gibibyte:

So, basically what SanDisk is telling us here is that the actual size of the device isn’t even the advertised capacity multiplied by 10^9 bytes, it’s actually less. This is basically the legal equivalent of them saying “trust us, it really has 128,000,000,000 bytes inside, but you can’t use them all.”

Somehow, our governments have decided that this kind of advertising is legal.

I went back and looked at the page where I bought the product. It might shock you, dear reader, but there was no fine bullet point in the specifications saying “actual user storage less”:

This is understandable. If people saw “actual user storage less” mentioned in the product advertisement, they would probably be suspicious of the amount of storage they were actually buying, and sales would suffer.

I thought I would go look at other retailers to see if “actual user storage less” was mentioned anywhere on their websites. Here is the same product listed on

What about

Okay, so the companies selling these devices aren’t overly eager to include this fine print, which SanDisk actually includes on their website. In small text, at the bottom of the page:

I emailed SanDisk about this to ask why the “actual user storage less” wasn’t mentioned on any retailers website, and they responded:

While I disagree with their reply, I understand that retailers have some freedoms in how they advertise a product. However, with this in mind, I am sure that a small army of SanDisk lawyers would co-sign a cease and desist letter if I started advertising their products in any way which they determined was harming their brand value. But then something curious happened…


SanDisk claims that they don’t have any control over how retailers advertise their product, but then they state that these companies are “authorised distributors and resellers.”

Given the incredibly high percentage of counterfeit products being sold these days under the label of a well known brand, it’s clear that manufacturers need a trustworthy outlet to sell their goods, or consumers might begin to doubt the quality of their brand. That’s the economic impact of “electronics priacy” [PDF].

Managing your supply chain and maintaining your brand image costs companies millions, if not billions, of dollars every year. It’s serious business. People go to jail for importing and selling counterfeit products.

So, when a company claims that they have no control over how their product is advertised, I find that a bit difficult to believe. Legally they may not have an obligation to require retailers mention “actual user storage less” but morally and ethically they should ensure that their retailers do not advertise their product in a misleading way.

SanDisk is selling a “128GB” USB stick, which has a raw capacity of ~125GB (116GiB):

They also mention in small text, on the back of the package, that “actual user storage less.” Too bad they didn’t state this anywhere on the actual retail page.

At this point, anyone who is sane will do the math and ask the question “You received 2.2% less capacity than was advertised. Why have you wasted your time writing about this?” and that’s because I’m scared of the precedent this is setting.

It’s true, it’s seemingly pointless to sit here and discuss the missing 2.2%. But 10 years ago, you would spend a lot of money to buy a USB stick which was 2GB. Even now, most people pay phone companies tens of dollars per month to transfer 3GB over 3G or LTE, or $90 per month if you’re unlucky enough to own a smartphone in Canada:

So even though as a percentage, it’s relatively small, it a not-insignificant amount of capacity that’s missing. If this was a 1TB device, you would be missing 23GB, and this is even before we get into Giga versus Gibi and formatting…

When I buy a device where the primary function is storage, I expect to be buying a device which can contain $CAPACITY * 10^9 bytes of data. This is important for things like data recovery. If I need to make an exact duplicate of the data on a storage device which is 128GB, I don’t want to have to worry about buying a device from a specific manufacturer, model, or serial number range to be able to store the data. This isn’t swapping the PCB on a broken hard drive, it’s just buying a simple storage device!

I’m scared of what message we’re sending to manufacturers when we allow them to sell us products with vague statements like “actual user storage less” and what it means for the future of the industry.

If I buy a smartphone which has 16GB of space, I expect to be able to use less, because the primary function of a smartphone is to be a pocket computer. I understand that capacity is required for the operating system, and that the actual capacity available to me will be less than the advertised amount.

But to buy a device whose sole purpose is to store data, and have that device provide less capacity than advertised. That’s scary, not for the 2.2% that I can’t use today, but because tomorrow it might be 5%, and in 10 years 20%.

Why is the capacity less? Perhaps they’re using NAND which doesn’t have space over provisioned for error correction and wear levelling, allowing them to fit a few more on a wafer. Or maybe the chips have bad regions which they’ve mapped around, meaning you get a slightly smaller capacity. I doubt we’ll ever get an explanation apart from “actual user storage less.”

SanDisk isn’t the only manufacturer doing this, but they’re certainly the worst offender that I’ve found. Recently I purchased some 16GB micro SDHC cards from Transcend, and they’re 0.5% under capacity as well. Luckily I have found that Samsung’s EVO line appears to at least provide the advertised capacity in 10^9 bytes. But, how much longer until everyone clues in to the get out of jail free card that is “actual user storage less” and starts selling devices under the 10^9 capacity?

The moral of the story here is: complaining on the internet is useless. Vote with your wallet. Return anything which is not actually 10^9 bytes of capacity, and rate it accordingly to warn other users. I’m not going to support a brand which, in my opinion, allows retailers to advertise their products in misleading ways. Besides, the performance sucked (4.5MB/s sequential write). You get what you pay for.

From Amazon with love: not quite 32GB micro SD cards

I needed more space in my tablet and phone, so I went to everyone’s favourite online merchant, Amazon, and purchased two SanDisk 32GB Class 10 micro SDHC cards.

Now, if you haven’t bought SanDisk micro SD cards lately, let me warn you now, the silk screen looks horrible. At first I thought they were counterfeit, it’s that bad. I wonder if the guys at SanDisk did some research to see how shitty they could make the silk screen and not have it appear in cell phone photos. My potato camera phone has just enough noise that it’s difficult to tell just how bad the SanDisk logo looks, but it’s awful.

My camera phone isn't the greatest, but these cards look just blurry and noisy in reality

My camera phone isn’t the greatest, but these cards look just as blurry and noisy in reality

But a bad silk screen can be overlooked if the cards themselves still function, which brings me to my next point:

[38853.623229] scsi 9:0:0:0: Direct-Access     Generic- SD/MMC           1.00 PQ: 0 ANSI: 0 CCS
[38854.311664] sd 9:0:0:0: [sdb] 60367872 512-byte logical blocks: (30.9 GB/28.7 GiB)
[38854.312801] sd 9:0:0:0: [sdb] Write Protect is off
[38854.312812] sd 9:0:0:0: [sdb] Mode Sense: 03 00 00 00
[38854.313898] sd 9:0:0:0: [sdb] No Caching mode page found
[38854.313917] sd 9:0:0:0: [sdb] Assuming drive cache: write through
[38854.329950]  sdb: sdb1
[38854.333772] sd 9:0:0:0: [sdb] Attached SCSI removable disk

Disk /dev/sdb: 28.8 GiB, 30908350464 bytes, 60367872 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00000000

Device     Boot Start      End  Sectors  Size Id Type
/dev/sdb1        8192 60367871 60359680 28.8G  c W95 FAT32 (LBA)

28.7GiB?! What the hell? I know storage manufacturers have redefined a gigabyte to be 1,000,000,000 bytes (1 billion bytes) instead of 1,073,741,824 bytes (1024^3) but this is some next level math happening here.

For comparison, here is a Transcend 32GB Class 10 micro SDHC card:

[38782.491351] scsi 7:0:0:0: Direct-Access     Generic- SD/MMC           1.00 PQ: 0 ANSI: 0 CCS
[38783.265974] sd 7:0:0:0: [sdb] 61831168 512-byte logical blocks: (31.6 GB/29.4 GiB)
[38783.267091] sd 7:0:0:0: [sdb] Write Protect is off
[38783.267099] sd 7:0:0:0: [sdb] Mode Sense: 03 00 00 00
[38783.268192] sd 7:0:0:0: [sdb] No Caching mode page found
[38783.268197] sd 7:0:0:0: [sdb] Assuming drive cache: write through
[38783.273707]  sdb: sdb1
[38783.277183] sd 7:0:0:0: [sdb] Attached SCSI removable disk

Disk /dev/sdb: 29.5 GiB, 31657558016 bytes, 61831168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x000db221

Device     Boot Start      End  Sectors  Size Id Type
/dev/sdb1        2048 61831167 61829120 29.5G  c W95 FAT32 (LBA)

29.4GiB is a lot closer to what we expect from a 32GB (32,000,000,000 byte) card. The precise number is 29.80232GiB, but okay, it’s not much less.

So the SanDisk card is a about 700MB smaller than the Transcend. That alone was enough to make me apply for an RMA…


A Class 10 SD card is defined as having at least 10MB/s sequential write performance. Since we already know these cards over-advertise their capacity, what is the performance like?

Card 1

Card 1

Card 1 makes it past the Class 10 specification, averaging a sequential write speed of 11.7MB/s using H2testw with a fresh FAT filesystem. Not great, but at least it’s within specifications.

Card 2

Card 2

Card 2 however, barely makes it past Class 4. With an average write speed of only 5.55MB/s, this card is just abysmal.

What about read speeds? Well, Amazon claims up to 48MB/s (megabytes per second) reading speed:


Card 1 managed a semi-respectable 18.2MB/s read speed. Card 2 however, was just awful and couldn’t give more than 7.2MB/s read speed.

Back to Amazon you go, shitty SanDisk SD cards. Next time I am going to buy Transcend, and from now on I’ll be testing any cards I buy to make sure they:
A) Are actually the advertised capacity
B) Meet the minimum specifications for their advertised Class
C) Can be read in all my devices, unlike these cards which wouldn’t read at all in my MacBook Pro

Testing method:
Both cards were tested in a Dell Venue 8 Pro running Windows 8.1.

I would have liked to have tested their raw speed using dd in Linux, but unfortunately my MacBook Pro would not read the cards at all! dmesg was full of SD sector and command errors when I put the cards in the reader.

Edit (26.07.2015): I bought Transcend cards from Amazon, and again they were not true 32GB cards. My old Transcend card was made in Taiwan, whereas all the “32GB” cards I have gotten from Amazon this year are made in China.

It makes me wonder if SanDisk and Transcend have licensed an ODM to produce cards for them, and then stuck their silk screen on the cards. I suspect this because both the SanDisk and Transcend cards I received identified themselves as SL32G cards, whereas my Taiwan manufactured Transcend identifies as USD.

For the time being, I have ceased to purchase 32GB microSDHC cards from Amazon until I can find a brand that sells a card that is actually 32GB.