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dev-null-undefinedandClaude
14e0d12813
`embedded_preview_srgb` (the loupe stand-in and the grid thumbnail of an unedited raw) decoded the largest embedded JPEG whatever the size asked for: a 512 px thumbnail of a Sony A7R VI ARW decoded its 9984 x 6656 JPEG (5.6 MB) although the file holds a 1616 x 1080 one (0.3 MB). `lightcraft_raw::embedded_preview_covering(bytes, min_edge)` returns the smallest of a TIFF-based raw's JPEGs whose long edge is at least `min_edge` and that is a copy of the largest one: aspect ratio within 1 % (not a letterboxed thumbnail of another shape) and the same number of components (not the grey semantic masks of an iPhone ProRAW DNG); else the largest, as `embedded_preview`. The colour-space handling stays in `decode_raw_preview` (a `covering` argument); an unsupported raw's editing source and the camera-look fit keep the largest JPEG, so a source never depends on its size level. On 120 raws of every make in the corpus at 256 / 512 / 1600 px: wherever the largest JPEG is still chosen the output is identical byte for byte; where a smaller one is (Sony, Nikon, Panasonic, Adobe DNG) orientation matches, the size is equal or 1-2 px off, mean difference <= 4.7 / 255. - Rebased onto #1020: its plan route (`preview_window` -> `planned_preview`) now takes the box size and picks with `embedded_preview_covering` too, so a TIFF raw read through the sparse plan gets the whole file's JPEG. Co-Authored-By: Claude <[email protected]>
50 lines
2.1 KiB
Rust
50 lines
2.1 KiB
Rust
//! Opt-in test of the embedded-preview read path on a **real file the user has** — typically one on a
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//! network share, which is where reading only the header instead of the whole raw matters:
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//!
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//! LC_PREVIEW_RAW="/run/user/1000/gvfs/smb-share:.../DSCF0001.RAF" \
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//! cargo test --release -p lightcraft-engine --test preview_read -- --ignored --nocapture
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//!
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//! It reports what the preview cost and fails when the read is not the small part of the file the
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//! header path promises. Skipped without `LC_PREVIEW_RAW` (there is no committed raw fixture: media
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//! is never committed, see AGENTS.md).
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use std::time::Instant;
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#[test]
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#[ignore = "needs LC_PREVIEW_RAW pointing at a real raw file"]
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fn a_preview_reads_only_the_header_and_the_preview() {
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let Ok(path) = std::env::var("LC_PREVIEW_RAW") else {
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eprintln!("skipped: set LC_PREVIEW_RAW=<path to a raw file>");
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return;
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};
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let file_len = std::fs::metadata(&path).expect("the file exists").len();
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assert!(file_len > 0, "empty file");
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let started = Instant::now();
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let window = lightcraft_engine::files::preview_window(&path, usize::MAX)
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.expect("the file reads")
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.expect("it carries an embedded preview the header can point at");
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let elapsed = started.elapsed();
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let (_, preview, read) = window;
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let frac = read.fraction();
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println!(
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"preview of {path}\n read {} of {} bytes ({:.1} %) in {:.2} s{}",
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read.read,
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read.total,
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frac * 100.0,
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elapsed.as_secs_f64(),
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if read.planned {
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" [plan]"
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} else if read.header_path {
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" [header path]"
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} else {
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" [whole file]"
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}
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);
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assert!(read.header_path, "the header or the plan must answer for a raw whose preview is not the whole file");
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assert_eq!(read.total, file_len, "the report covers the whole file");
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assert!(frac < 0.5, "a preview must not cost most of the file: read {} of {} bytes", read.read, read.total);
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assert!(preview.starts_with(&[0xff, 0xd8]), "the preview bytes are a JPEG: {:?}", preview.get(..4));
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}
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