CODEWITHSUNDEEP
imagerust
Joel Imbergamo
Joel Imbergamo

Reputation: 369

Decoding an image from binary in rust

I am playing with the youtube api and I would like to download the thumbnails and process them. I've managed to download them in binary doing a simple http request and I can save them as a .jepec file. What I would like to do is not having to save the image as a file and parse the binary directly into an image all in memory to avoid leaving files behind. Any idea on hat do I need to do to accompish this?

Here is my code:

#[tokio::main(flavor = "current_thread")]
async fn main() {
    let res = reqwest::get("https://i.ytimg.com/vi/dQw4w9WgXcQ/hqdefault.jpg")
        .await
        .unwrap();
    let bytes: Bytes = res.bytes().await.unwrap();

    let _ = fs::write("img.jpeg", bin.clone()); // this saves the image correctly

    let img = ????::from(bytes); // help here

}

Upvotes: 1

Views: 1238

Answers (1)

Mac O'Brien
Mac O'Brien

Reputation: 2917

You can use the jpeg_decoder crate:

use jpeg_decoder::Decoder;

let mut decoder = Decoder::new(&*bytes);
let pixels = decoder.decode().expect("jpeg decoding failed");
let info = decoder.info().unwrap(); // image metadata

If you call decode() from an async function, you should do so in a blocking task using tokio::spawn_blocking, as decode() is not itself async.

Upvotes: 2

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