Struct LosslessEncoder 

pub struct LosslessEncoder { /* private fields */ }

Streaming lossless (modular) encoder.

Accepts pixel rows incrementally via push_rows, then encodes on finish. This allows callers to free source pixel buffers as rows are pushed, rather than materializing the entire image in memory before encoding.

use jxl_encoder::{LosslessConfig, PixelLayout};

let mut enc = LosslessConfig::new()
    .encoder(800, 600, PixelLayout::Rgb8)?;

for chunk in source_rows.chunks(row_bytes * 100) {
    enc.push_rows(chunk, 100)?;
}

let jxl_bytes = enc.finish()?;

Implementations

impl LosslessEncoder

pub fn with_icc_profile(self, data: &[u8]) -> Self

Attach an ICC color profile.

pub fn with_exif(self, data: &[u8]) -> Self

Attach EXIF data.

pub fn with_xmp(self, data: &[u8]) -> Self

Attach XMP data.

pub fn with_source_gamma(self, gamma: f32) -> Self

Specify that source pixels use a custom gamma transfer function.

pub fn with_color_encoding(self, ce: ColorEncoding) -> Self

Override the color encoding written to the JXL header.

pub fn with_intensity_target(self, nits: f32) -> Self

Set the peak display luminance in nits for HDR content.

pub fn with_min_nits(self, nits: f32) -> Self

Set the minimum display luminance in nits.

pub fn with_intrinsic_size(self, width: u32, height: u32) -> Self

Set the intrinsic display size.

pub fn rows_pushed(&self) -> u32

Number of rows pushed so far.

pub fn height(&self) -> u32

Total expected height.

pub fn push_rows(&mut self, pixels: &[u8], num_rows: u32) -> Result<()>

Push pixel rows into the encoder.

pixels must contain exactly width * num_rows * bytes_per_pixel bytes. Rows are deinterleaved into per-channel planes immediately, so the caller can free the source buffer after this call returns.

pub fn finish(self) -> Result<Vec<u8>>

Encode the accumulated pixels and return the JXL bytes.

All rows must have been pushed via push_rows before calling this. Returns an error if the image is incomplete.

pub fn finish_with_stats(self) -> Result<EncodeResult>

Encode and return JXL bytes together with EncodeStats.

pub fn finish_into(self, out: &mut Vec<u8>) -> Result<EncodeResult>

Encode, appending to an existing buffer.

pub fn finish_to(self, dest: impl Write) -> Result<EncodeResult>

Encode, writing to a std::io::Write destination.