ext/image_intensities/jpeg.c in image_intensities-1.0.2 vs ext/image_intensities/jpeg.c in image_intensities-1.0.3

@@ -1,71 +1,60 @@
-#include <stdio.h>
-#include <stdint.h>
-#include <stdlib.h>
 #include <stddef.h>
+#include <stdlib.h>
+#include <turbojpeg.h>
 #include <fcntl.h>
-#include <string.h>
-#include <jpeglib.h>
-#include <setjmp.h>
+#include <unistd.h>
+#include <sys/mman.h>
 
 #include "definitions.h"
 
-struct my_error_mgr {
-    struct jpeg_error_mgr pub;
-    jmp_buf setjmp_buffer;
-};
-
-static void my_error_exit(j_common_ptr cinfo)
-{
-    struct my_error_mgr *myerr = (struct my_error_mgr *) cinfo->err;
-    longjmp(myerr->setjmp_buffer, 1);
-}
-
 raster_data read_jpeg_file(const char *file_name)
 {
-    struct jpeg_decompress_struct cinfo;
-    struct my_error_mgr jerr;
-    FILE *file;
-    JSAMPARRAY buffer;
-    int row_stride;
-
     raster_data data = {};
+    tjhandle decompressor = NULL;
+    void *input = NULL;
+    off_t size = 0;
+    int fd = -1;
+    int error = 0;
+    int jpegSubsamp;
 
-    file = fopen(file_name, "rb");
-    if (file == NULL) {
-        data.error = 1;
-        return data;        
+    fd = open(file_name, 0);
+    if (fd < 0) {
+        error = 1;
+        goto cleanup;
     }
 
-    cinfo.err = jpeg_std_error(&jerr.pub);
-    jerr.pub.error_exit = my_error_exit;
+    if ((size = lseek(fd, 0, SEEK_END)) < 0) {
+        error = 1;
+        goto cleanup;
+    }
 
-    if (setjmp(jerr.setjmp_buffer)) {
-        jpeg_destroy_decompress(&cinfo);
-        fclose(file);
+    if ((input = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0)) == NULL) {
+        error = 1;
+        goto cleanup;
+    }
 
-        return data;
+    if ((decompressor = tjInitDecompress()) == NULL) {
+        error = 1;
+        goto cleanup;
     }
 
-    jpeg_create_decompress(&cinfo);
-    jpeg_stdio_src(&cinfo, file);
-    jpeg_read_header(&cinfo, TRUE);
-    jpeg_start_decompress(&cinfo);
+    if ((tjDecompressHeader2(decompressor, input, size, &data.width, &data.height, &jpegSubsamp)) < 0) {
+        error = 1;
+        goto cleanup;
+    }
 
-    data.width  = cinfo.output_width;
-    data.height = cinfo.output_height;
-    data.pixels = malloc(cinfo.output_components * cinfo.output_width * cinfo.output_height);
+    data.pixels = malloc(data.width * data.height * sizeof(rgb_pixel));
 
-    row_stride = cinfo.output_width * cinfo.output_components;
-    buffer = (*cinfo.mem->alloc_sarray)((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);
-
-    for (size_t i = 0; cinfo.output_scanline < cinfo.output_height; ++i) {
-        jpeg_read_scanlines(&cinfo, buffer, 1);
-        memcpy(&data.pixels[i * cinfo.output_width], buffer[0], row_stride);
+    if ((tjDecompress2(decompressor, input, size, (uint8_t *) data.pixels, data.width, 0, data.height, TJPF_RGB, TJFLAG_FASTDCT)) < 0) {
+        error = 1;
+        goto cleanup;
     }
 
-    jpeg_finish_decompress(&cinfo);
-    jpeg_destroy_decompress(&cinfo);
-    fclose(file);
+cleanup:
+    if (decompressor) tjDestroy(decompressor);
+    if (input) munmap(input, size);
+    if (fd >= 0) close(fd);
 
+    data.error = error;
     return data;
 }