Struct JxlDecoder 

pub struct JxlDecoder<State: JxlState> { /* private fields */ }

High level API using the typestate pattern to forbid invalid usage.

Implementations

impl<S: JxlState> JxlDecoder<S>

pub fn frame_index(&self) -> Option<&FrameIndexBox>

Returns the parsed frame index box, if the file contained one.

The frame index box (jxli) is an optional part of the JXL container format that provides a seek table for animated files, listing keyframe byte offsets, timestamps, and frame counts.

pub fn gain_map(&self) -> Option<&GainMapBundle>

Returns a reference to the parsed gain map bundle, if the file contained a jhgm box (ISO 21496-1 HDR gain map).

The gain map codestream is a bare JXL codestream that can be decoded with the same decoder. The ISO 21496-1 metadata blob is stored as raw bytes for the caller to parse.

pub fn take_gain_map(&mut self) -> Option<GainMapBundle>

Takes the parsed gain map bundle, if the file contained a jhgm box. After calling this, gain_map() will return None.

pub fn exif(&self) -> Option<&[u8]>

Returns the raw EXIF data from the Exif container box, if present.

The 4-byte TIFF header offset prefix is stripped; this returns the raw EXIF/TIFF bytes starting with the byte-order marker (II or MM). Returns None for bare codestreams or files without an Exif box.

Note: the Exif box may appear after the codestream in the container. Call this after decoding at least one frame for the most complete results.

pub fn take_exif(&mut self) -> Option<Vec<u8>>

Takes the EXIF data, leaving None in its place.

pub fn xmp(&self) -> Option<&[u8]>

Returns the raw XMP data from the xml container box, if present.

Returns None for bare codestreams or files without an xml box.

Note: the xml box may appear after the codestream in the container. Call this after decoding at least one frame for the most complete results.

pub fn take_xmp(&mut self) -> Option<Vec<u8>>

Takes the XMP data, leaving None in its place.

pub fn rewind(self) -> JxlDecoder<Initialized>

Rewinds a decoder to the start of the file, allowing past frames to be displayed again.

impl JxlDecoder<Initialized>

pub fn new(options: JxlDecoderOptions) -> Self

pub fn process( self, input: &mut impl JxlBitstreamInput, ) -> Result<ProcessingResult<JxlDecoder<WithImageInfo>, Self>>

impl JxlDecoder<WithImageInfo>

pub fn basic_info(&self) -> &JxlBasicInfo

Obtains the image’s basic information.

pub fn embedded_color_profile(&self) -> &JxlColorProfile

Retrieves the file’s color profile.

pub fn output_color_profile(&self) -> &JxlColorProfile

Retrieves the current output color profile.

pub fn set_output_color_profile( &mut self, profile: JxlColorProfile, ) -> Result<()>

Specifies the preferred color profile to be used for outputting data. Same semantics as JxlDecoderSetOutputColorProfile.

pub fn current_pixel_format(&self) -> &JxlPixelFormat

Retrieves the current pixel format for output buffers.

pub fn set_pixel_format(&mut self, pixel_format: JxlPixelFormat)

Specifies pixel format for output buffers.

Setting this may also change output color profile in some cases, if the profile was not set manually before.

pub fn process( self, input: &mut impl JxlBitstreamInput, ) -> Result<ProcessingResult<JxlDecoder<WithFrameInfo>, Self>>

pub fn flush_pixels( &mut self, buffers: &mut [JxlOutputBuffer<'_>], ) -> Result<()>

Draws all the pixels we have data for. This is useful for i.e. previewing LF frames.

Note: see process for alignment requirements for the buffer data.

pub fn has_more_frames(&self) -> bool

impl JxlDecoder<WithFrameInfo>

pub fn skip_frame( self, input: &mut impl JxlBitstreamInput, ) -> Result<ProcessingResult<JxlDecoder<WithImageInfo>, Self>>

Skip the current frame.

pub fn frame_header(&self) -> JxlFrameHeader

pub fn num_completed_passes(&self) -> usize

Number of passes we have full data for.

pub fn flush_pixels( &mut self, buffers: &mut [JxlOutputBuffer<'_>], ) -> Result<()>

Draws all the pixels we have data for.

Note: see process for alignment requirements for the buffer data.

pub fn process<In: JxlBitstreamInput>( self, input: &mut In, buffers: &mut [JxlOutputBuffer<'_>], ) -> Result<ProcessingResult<JxlDecoder<WithImageInfo>, Self>>

Guarantees to populate exactly the appropriate part of the buffers. Wants one buffer for each non-ignored pixel type, i.e. color channels and each extra channel.

Note: the data in buffers should have alignment requirements that are compatible with the requested pixel format. This means that, if we are asking for 2-byte or 4-byte output (i.e. u16/f16 and f32 respectively), each row in the provided buffers must be aligned to 2 or 4 bytes respectively. If that is not the case, the library may panic.