84 lines
2.5 KiB
Markdown
84 lines
2.5 KiB
Markdown
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# GIF en- and decoding library [](https://github.com/image-rs/image-gif/actions)
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GIF en- and decoder written in Rust ([API Documentation](https://docs.rs/gif/)).
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# GIF encoding and decoding library
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This library provides all functions necessary to de- and encode GIF files.
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## High level interface
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The high level interface consists of the two types
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[`Encoder`](https://docs.rs/gif/*/gif/struct.Encoder.html) and [`Decoder`](https://docs.rs/gif/*/gif/struct.Decoder.html).
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### Decoding GIF files
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```rust
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// Open the file
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use std::fs::File;
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let input = File::open("tests/samples/sample_1.gif").unwrap();
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// Configure the decoder such that it will expand the image to RGBA.
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let mut options = gif::DecodeOptions::new();
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options.set_color_output(gif::ColorOutput::RGBA);
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// Read the file header
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let mut decoder = options.read_info(input).unwrap();
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while let Some(frame) = decoder.read_next_frame().unwrap() {
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// Process every frame
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}
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```
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### Encoding GIF files
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The encoder can be used to save simple computer generated images:
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```rust
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use gif::{Frame, Encoder, Repeat};
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use std::fs::File;
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use std::borrow::Cow;
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let color_map = &[0xFF, 0xFF, 0xFF, 0, 0, 0];
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let (width, height) = (6, 6);
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let beacon_states = [[
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0, 0, 0, 0, 0, 0,
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0, 1, 1, 0, 0, 0,
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0, 1, 1, 0, 0, 0,
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0, 0, 0, 1, 1, 0,
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0, 0, 0, 1, 1, 0,
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0, 0, 0, 0, 0, 0,
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], [
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0, 0, 0, 0, 0, 0,
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0, 1, 1, 0, 0, 0,
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0, 1, 0, 0, 0, 0,
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0, 0, 0, 0, 1, 0,
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0, 0, 0, 1, 1, 0,
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0, 0, 0, 0, 0, 0,
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]];
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let mut image = File::create("target/beacon.gif").unwrap();
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let mut encoder = Encoder::new(&mut image, width, height, color_map).unwrap();
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encoder.set_repeat(Repeat::Infinite).unwrap();
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for state in &beacon_states {
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let mut frame = Frame::default();
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frame.width = width;
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frame.height = height;
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frame.buffer = Cow::Borrowed(&*state);
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encoder.write_frame(&frame).unwrap();
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}
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```
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[`Frame::from_*`](https://docs.rs/gif/*/gif/struct.Frame.html) can be used to convert a true color image to a paletted
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image with a maximum of 256 colors:
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```rust
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use std::fs::File;
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// Get pixel data from some source
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let mut pixels: Vec<u8> = vec![0; 30_000];
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// Create frame from data
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let frame = gif::Frame::from_rgb(100, 100, &mut *pixels);
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// Create encoder
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let mut image = File::create("target/indexed_color.gif").unwrap();
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let mut encoder = gif::Encoder::new(&mut image, frame.width, frame.height, &[]).unwrap();
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// Write frame to file
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encoder.write_frame(&frame).unwrap();
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```
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