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libwebp

Function WebPDecodeYUV

Source 
pub fn WebPDecodeYUV(
    data: &[u8],
) -> Result<(u32, u32, u32, u32, WebpYuvBox), WebPSimpleError>
Expand description

Decodes WebP images pointed to by data to Y’UV format[^1].

[^1] Also named Y’CbCr. See: http://en.wikipedia.org/wiki/YCbCr

§Return value

It retuns a tuple with the following data in this order:

  • width
  • height
  • stride
  • uv_stride
  • a WebpYuvBox which contains the pointers to the Y, U and V planes.

The dimension of the U and V planes are both (width + 1) / 2 and (height + 1)/ 2. The Y buffer has a stride returned as stride, while U and V have a common stride returned as uv_stride.

§Errors

Returns Err if data doesn’t contain a valid WebP image.

§Examples

use libwebp::WebPDecodeYUV;

let data: &[u8];

let (width, height, stride, uv_stride, buf) =
    WebPDecodeYUV(data).expect("Invalid WebP data");
assert!(width <= stride);
assert!((width + 1) / 2 <= uv_stride);
assert_eq!(buf.y().len(), stride as usize * height as usize);
assert_eq!(buf.u().len(), uv_stride as usize * ((height as usize + 1) / 2));
assert_eq!(buf.v().len(), uv_stride as usize * ((height as usize + 1) / 2));
eprintln!(
    "top-left pixel: yuv({}, {}, {})",
    buf.y()[0],
    buf.u()[0],
    buf.v()[0],
)