add jpg2if

3 files changed, 123 insertions, 7 deletions

diff --git a/Makefile b/Makefile
index be04259..5187f6b 100644
--- a/Makefile
+++ b/Makefile
@@ -3,10 +3,10 @@
 
 include config.mk
 
-SRC = png2if.c if2png.c
+SRC = png2if.c if2png.c jpg2if.c
 OBJ = ${SRC:.c=.o}
 
-all: options png2if if2png
+all: options png2if if2png jpg2if
 
 options:
 	@echo imagefile build options:
@@ -20,23 +20,28 @@ options:
 
 ${OBJ}: config.mk
 
+jpg2if: jpg2if.o
+	@echo CC -o $@
+	@${CC} -o $@ jpg2if.o ${LDFLAGS} ${JPEG_LIBS}
+
 png2if: png2if.o
 	@echo CC -o $@
-	@${CC} -o $@ png2if.o ${LDFLAGS}
+	@${CC} -o $@ png2if.o ${LDFLAGS} ${PNG_LIBS}
 
 if2png: if2png.o
 	@echo CC -o $@
-	@${CC} -o $@ if2png.o ${LDFLAGS}
+	@${CC} -o $@ if2png.o ${LDFLAGS} ${PNG_LIBS}
 
 clean:
 	@echo cleaning
-	@rm -f png2if if2png ${OBJ}
+	@rm -f png2if if2png jpg2if ${OBJ}
 
 install: all
 	@echo installing executable files to ${DESTDIR}${PREFIX}/bin
 	@mkdir -p ${DESTDIR}${PREFIX}/bin
-	@cp -f png2if if2png ${DESTDIR}${PREFIX}/bin
+	@cp -f png2if if2png jpg2if ${DESTDIR}${PREFIX}/bin
 	@chmod 755 ${DESTDIR}${PREFIX}/bin/png2if
+	@chmod 755 ${DESTDIR}${PREFIX}/bin/jpg2if
 	@chmod 755 ${DESTDIR}${PREFIX}/bin/if2png
 
 uninstall:
diff --git a/config.mk b/config.mk
index b6af2cf..2763f09 100644
--- a/config.mk
+++ b/config.mk
@@ -4,7 +4,9 @@
 PREFIX = /usr/local
 
 # libs
-LIBS = -lpng
+LIBS =
+PNG_LIBS = -lpng
+JPEG_LIBS = -ljpeg
 
 # flags
 CFLAGS = -std=c90 -ansi -pedantic -Wall -Wextra -Os
diff --git a/jpg2if.c b/jpg2if.c
new file mode 100644
index 0000000..7b19171
--- /dev/null
+++ b/jpg2if.c
@@ -0,0 +1,109 @@
+/* See LICENSE file for copyright and license details. */
+#include <arpa/inet.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <setjmp.h>
+#include <jpeglib.h>
+#include "arg.h"
+
+char *argv0;
+
+static jmp_buf setjmp_buffer;
+
+static void
+usage(void)
+{
+	fprintf(stderr, "usage: %s\n", argv0);
+	exit(EXIT_FAILURE);
+}
+
+METHODDEF(void)
+if_jpeg_error(j_common_ptr cinfo)
+{
+	/* Always display the message. */
+	/* We could postpone this until after returning, if we chose. */
+	(*cinfo->err->output_message) (cinfo);
+
+	/* Return control to the setjmp point */
+	longjmp(setjmp_buffer, 1);
+}
+
+int
+main(int argc, char *argv[])
+{
+	struct jpeg_decompress_struct cinfo;
+	struct jpeg_error_mgr jerr;
+	uint32_t width, height, val_be;
+	size_t jpeg_row_len;
+	int status = EXIT_FAILURE;
+	JSAMPARRAY buffer; /* output row buffer */
+
+	ARGBEGIN {
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc != 0)
+		usage();
+
+	/* load jpeg */
+	cinfo.err = jpeg_std_error(&jerr);
+
+	jerr.error_exit = if_jpeg_error;
+	/* Establish the setjmp return context for my_error_exit to use. */
+	if (setjmp(setjmp_buffer)) {
+		/* If we get here, the JPEG code has signaled an error.
+		* We need to clean up the JPEG object, close the input file, and return. */
+		goto cleanup;
+	}
+
+	jpeg_create_decompress(&cinfo);
+	jpeg_stdio_src(&cinfo, stdin);
+
+	jpeg_read_header(&cinfo, TRUE);
+
+	/* change output for imagefile */
+	cinfo.output_components = 4;          /* # of color components per pixel */
+	cinfo.out_color_space = JCS_EXT_RGBA; /* colorspace of input image */
+
+	jpeg_start_decompress(&cinfo);
+	jpeg_row_len = cinfo.output_width * cinfo.output_components;
+
+	/* Make a one-row-high sample array that will go away when done with image */
+	buffer = (*cinfo.mem->alloc_sarray)
+	         ((j_common_ptr) &cinfo, JPOOL_IMAGE, jpeg_row_len, 1);
+
+	width = cinfo.image_width;
+	height = cinfo.image_height;
+
+	/* write header with big endian width and height-values */
+	fprintf(stdout, "imagefile");
+	val_be = htonl(width);
+	fwrite(&val_be, sizeof(uint32_t), 1, stdout);
+	val_be = htonl(height);
+	fwrite(&val_be, sizeof(uint32_t), 1, stdout);
+
+	while (cinfo.output_scanline < cinfo.output_height) {
+		/* jpeg_read_scanlines expects an array of pointers to scanlines.
+		 * Here the array is only one element long, but you could ask for
+		 * more than one scanline at a time if that's more convenient. */
+		(void)jpeg_read_scanlines(&cinfo, buffer, 1);
+
+		/* write data */
+		if (fwrite(buffer[0], 1, jpeg_row_len, stdout) != jpeg_row_len) {
+			fprintf(stderr, "fwrite() failed\n");
+			goto cleanup;
+		}
+	}
+	jpeg_finish_decompress(&cinfo);
+	status = EXIT_SUCCESS;
+
+cleanup:
+	jpeg_destroy_decompress(&cinfo);
+
+	return status;
+}