Function convert_to_yuv10_mt 

pub(crate) fn convert_to_yuv10_mt(
    src: &[u8],
    src_stride: usize,
    width: usize,
    height: usize,
    rgba_input: bool,
    i444: bool,
    full_range: bool,
    y_buf: &mut [u16],
    u_buf: &mut [u16],
    v_buf: &mut [u16],
    strides: (usize, usize),
    bands: usize,
)

Convert a packed BGRA/RGBA buffer to planar 10-bit YUV (4:2:0 or 4:4:4) in 16-bit samples, for the software encoders’ 10-bit sessions, across up to bands threads as convert_to_yuv_mt splits them.

The 10-bit samples are computed from the 8-bit source directly rather than widened from an 8-bit conversion, so the two bits the encoder gains carry the precision an 8-bit Y, Cb, Cr rounds away. The matrix is BT.709 at full_range or limited range, and a 4:2:0 chroma sample is the conversion of the mean of its 2x2 block, which sites it at the block’s center as the 8-bit conversion does. strides are in samples.