[Ethereum] Can we mint 5 gigabyte video NFTs

blockchainerc-1155erc-721nft

What is the maximum size of NFTs on the Ethereum blockchain (ERC-721 or ERC-1155 tokens)?

crypto art NFTs on the Ethereum blockchain already contain JPG/PNG files that are about 5 MB large, and sometimes even motion graphics in MP4 format about 50 MB large, so why not full-length hour-long movies wrapped inside an NFT?

Is this impossible to do on the Ethereum blockchain, or would a whole separate company and blockchain be required to support that digital video ecosystem?

Best Answer

I'll come at this from a slightly different direction...

The current price of ETH is ~$1500.

The Yellow Paper states that storing a 256-bit (32-byte) word costs 20,000 gas.

Average gas price is currently ~100 Gwei. That's 100 x 20,000 Gwei per 32 bytes, which is 2,000,000 Gwei, which is 0.002 ETH, which is $3.

1 GB is 1,073,741,824 bytes, so there are 33,554,432 32-byte words. As above, each of these words costs $3, so each GB costs (3 * 33554432) = $100,663,296 at current prices.

5 MB would therefore cost ~$503,316.

Clearly the base cost of an NFT - before any abstract value has been applied - is not the price shown above, so NFT's can't actually be storing the associated picture or movie data on the blockchain.

If you look at the spec for EIP-1155 you'll see it defines an image field in the token's metadata:

"image": {
            "type": "string",
            "description": "A URI pointing to a resource with mime type image/* representing the asset to which this token represents. Consider making any images at a width between 320 and 1080 pixels and aspect ratio between 1.91:1 and 4:5 inclusive."
        },

If we look at a real example, in this case by calling the CryptoKitty (an ERC-721 token) API, we see the following:

-> https://public.api.cryptokitties.co/v1/kitties/1

{
  "id": 1,
  "name": "Flying Kitten",
  "bio": "哎呀妈呀！! 本喵爬不更名，坐不改姓，就叫 #{name}！我的表哥是喵星球鼎鼎大名的多啦A梦。 不是什么太高调的事，不过本喵确实和汤姆猫有过相交之情。 本喵和你是不是上辈子见过呀？",
  "image_url": "https://img.cryptokitties.co/0x5328276603d169165d0f71ca67ccc89c45027df3/1.png",
  "image_url_cdn": "https://img.cn.cryptokitties.co//0x5328276603d169165d0f71ca67ccc89c45027df3/1.png",
  "image_url_png": "https://img.cryptokitties.co/0x5328276603d169165d0f71ca67ccc89c45027df3/1.png",
  "image_path": "",
  "generation": 0,

And so we see the image files are stored off-chain.

Can we mint 5 gigabyte video NFTs?

Yes, given that they're stored off-chain...

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