fix(#2): proper JPEG output via libraw_dcraw_make_mem_image + image crate

Cargo.toml

@@ -7,6 +7,7 @@ edition = "2024"
 libraw-sys = "0.1.1"
 image = "0.24"
 clap = { version = "4.0", features = ["derive"] }
+libc = "0.2"
 
 [[bin]]
 name = "photo_editor"

src/main.rs

@@ -1,8 +1,10 @@
 use clap::Parser;
+use image::{DynamicImage, ImageBuffer, Rgb};
 use libraw_sys::*;
 use std::ffi::CString;
-use std::os::raw::c_int;
+use std::os::raw::{c_int, c_size_t};
 use std::path::{Path, PathBuf};
+use std::ptr::null_mut;
 
 /// Resolve and sanitize a user-provided path.
 /// - Resolves to absolute path via canonicalize (or parent canonicalization for output)
@@ -195,9 +197,42 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         .unwrap_or("jpg")
         .to_lowercase();
 
-    let output_cstr = CString::new(output_path.to_string_lossy().as_bytes())
-        .map_err(|_| "Output path contains null bytes, cannot process".into())?;
-    let ret = unsafe { libraw_dcraw_ppm_tiff_writer(lr, output_cstr.as_ptr()) };
+    let ret = if ext == "jpg" || ext == "jpeg" {
+        // Use libraw_dcraw_make_mem_image + image crate for proper JPEG encoding
+        let mut imgdata: *mut std::os::raw::c_uchar = null_mut();
+        let mut imgsize: c_size_t = 0;
+        let ret = unsafe { libraw_dcraw_make_mem_image(lr, &mut imgdata, &mut imgsize) };
+        if ret != LIBRAW_SUCCESS {
+            ret
+        } else {
+            let width = unsafe { (*(*lr).internal_data).imgdata.idata.width } as u32;
+            let height = unsafe { (*(*lr).internal_data).imgdata.idata.height } as u32;
+            let bytes = unsafe { std::slice::from_raw_parts(imgdata, imgsize as usize) };
+            let img = DynamicImage::ImageRgb8(ImageBuffer::<Rgb<u8>, Vec<u8>>::from_raw(
+                width,
+                height,
+                bytes.to_vec(),
+            ).ok_or("Failed to create image from libraw data")?);
+            unsafe {
+                let freedata = *(*lr).internal_data.imgdata.freedata;
+                let freesize = *(*lr).internal_data.imgdata.freesize;
+                if !freedata.is_null() {
+                    libc::free(freedata as *mut std::os::raw::c_void);
+                }
+            }
+            img.save_with_format(&output_path, image::ImageOutputFormat::Jpeg(90))
+                .map_err(|e| {
+                    eprintln!("Error: Failed to write JPEG: {}", e);
+                    "Failed to write JPEG".to_string()
+                })?;
+            LIBRAW_SUCCESS
+        }
+    } else {
+        // For TIFF/PPM, use libraw_dcraw_ppm_tiff_writer
+        let output_cstr = CString::new(output_path.to_string_lossy().as_bytes())
+            .map_err(|_| "Output path contains null bytes, cannot process".into())?;
+        unsafe { libraw_dcraw_ppm_tiff_writer(lr, output_cstr.as_ptr()) }
+    };
 
     if ret != LIBRAW_SUCCESS {
         eprintln!("Error: Failed to write output file. Error code: {}", ret);