Struct GifDecoder 

pub struct GifDecoder<S>
where
    S: Source,
{ /* private fields */ }

Decodes a GIF stream.

Decoder presents the first frame; GifDecoder::next_frame walks the rest. See the crate docs for why the split is where it is.

Implementations

impl<S> GifDecoder<S>

where S: Source,

pub fn new(source: S, limits: Limits) -> Result<GifDecoder<S>, PixelsError>

Parse the header and logical screen descriptor, reading nothing more.

Errors

Returns PixelsError::Malformed for a bad signature or screen descriptor, or PixelsError::LimitExceeded if the canvas exceeds limits.

pub const fn screen(&self) -> Screen

The logical screen descriptor.

pub fn next_frame(&mut self) -> Result<Option<Frame>, PixelsError>

Decode the next frame, compositing it onto the canvas.

Returns None once the stream’s trailer is reached. Each frame carries the whole canvas, because that is what a viewer draws — a frame’s own rectangle is meaningless without what it was composited onto.

Errors

Returns PixelsError::Malformed for a malformed block or a frame that does not fit its canvas, or PixelsError::Io on source failure.

Trait Implementations

impl<S> Debug for GifDecoder<S>

where S: Debug + Source,

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<S> Decoder for GifDecoder<S>

where S: Source + Debug,

fn source_info(&self) -> SourceInfo

Palette, the first frame’s interlace, the screen’s background colour and comment extensions. XMP is not read.

fn descriptor(&self) -> ImageDescriptor

The shape of the image, known after the header is parsed.

fn capability(&self) -> DecodeCapability

What this decoder can produce without a full decode.

fn animation(&self) -> Option<Animation>

The source’s animation, if it has more than one frame.

fn read_row(&mut self, out: &mut [u8]) -> Result<(), PixelsError>

Decode the next row, top to bottom, into out.

fn orientation(&self) -> Orientation

How the stored image must be turned to display upright, as its metadata declares.

fn pages(&self) -> u32

How many pages the source document holds, at least 1.

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

The embedded ICC colour profile, if the file carries one.

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

The embedded EXIF block, if the file carries one: the TIFF-structured bytes from the byte-order mark (II or MM), without the Exif\0\0 identifier a JPEG wraps it in.

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

The embedded XMP packet, if the file carries one: the XML as stored, from <?xpacket or <x:xmpmeta.

fn read_region( &mut self, region: Region, out: &mut TileMut<'_>, ) -> Result<(), PixelsError>

Decode an arbitrary region into out.

fn reduced_descriptor(&self, target: (u32, u32)) -> Option<ImageDescriptor>

What this decoder would produce if asked for target or larger, when the format lets it reach that size more cheaply than a full decode.

fn reduce_to(&mut self, descriptor: ImageDescriptor) -> Result<(), PixelsError>

Commit to producing descriptor, which Decoder::reduced_descriptor must have returned.