Add program that demonstrates how to check for the existence of the colorspace extensions
git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@733 632fc199-4ca6-4c93-a231-07263d6284db
diff --git a/Makefile.am b/Makefile.am
index 560af9a..f2219b0 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -73,7 +73,7 @@
endif
bin_PROGRAMS = cjpeg djpeg jpegtran rdjpgcom wrjpgcom tjbench
-noinst_PROGRAMS = tjunittest
+noinst_PROGRAMS = tjunittest jcstest
tjbench_SOURCES = tjbench.c bmp.h bmp.c tjutil.h tjutil.c rdbmp.c rdppm.c \
wrbmp.c wrppm.c
@@ -114,6 +114,9 @@
wrjpgcom_LDADD = libjpeg.la
+jcstest_SOURCES = jcstest.c
+
+jcstest_LDADD = libjpeg.la
dist_man1_MANS = cjpeg.1 djpeg.1 jpegtran.1 rdjpgcom.1 wrjpgcom.1
diff --git a/README-turbo.txt b/README-turbo.txt
index 8b18d4c..327647c 100755
--- a/README-turbo.txt
+++ b/README-turbo.txt
@@ -227,7 +227,7 @@
Setting cinfo.in_color_space (compression) or cinfo.out_color_space
(decompression) to one of these values will cause libjpeg-turbo to read the
red, green, and blue values from (or write them to) the appropriate position in
-the pixel when YUV conversion is performed.
+the pixel when compressing from/decompressing to an RGB buffer.
Your application can check for the existence of these extensions at compile
time with:
@@ -240,7 +240,7 @@
When using the RGBX, BGRX, XBGR, and XRGB colorspaces during decompression, the
X byte is undefined, and in order to ensure the best performance, libjpeg-turbo
can set that byte to whatever value it wishes. If an application expects the X
-byte to be used as an alpha channel, then it should use JCS_EXT_RGBA,
+byte to be used as an alpha channel, then it should specify JCS_EXT_RGBA,
JCS_EXT_BGRA, JCS_EXT_ABGR, or JCS_EXT_ARGB. When these colorspace constants
are used, the X byte is guaranteed to be 0xFF, which is interpreted as opaque.
@@ -249,6 +249,9 @@
#ifdef JCS_ALPHA_EXTENSIONS
+jcstest.c, located in the libjpeg-turbo source tree, demonstrates how to check
+for the existence of the colorspace extensions at compile time and run time.
+
=================================
libjpeg v7 and v8 API/ABI support
=================================
diff --git a/jcstest.c b/jcstest.c
new file mode 100644
index 0000000..98f16da
--- /dev/null
+++ b/jcstest.c
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C)2011 D. R. Commander. All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * - Neither the name of the libjpeg-turbo Project nor the names of its
+ * contributors may be used to endorse or promote products derived from this
+ * software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS",
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* This program demonstrates how to check for the colorspace extension
+ capabilities of libjpeg-turbo at both compile time and run time. */
+
+#include <stdio.h>
+#include <jpeglib.h>
+#include <jerror.h>
+#include <setjmp.h>
+
+#ifndef JCS_EXTENSIONS
+#define JCS_EXT_RGB 6
+#endif
+#if !defined(JCS_EXTENSIONS) || !defined(JCS_ALPHA_EXTENSIONS)
+#define JCS_EXT_RGBA 12
+#endif
+
+static char lasterror[JMSG_LENGTH_MAX] = "No error";
+
+typedef struct _error_mgr {
+ struct jpeg_error_mgr pub;
+ jmp_buf jb;
+} error_mgr;
+
+static void my_error_exit(j_common_ptr cinfo)
+{
+ error_mgr *myerr = (error_mgr *)cinfo->err;
+ (*cinfo->err->output_message)(cinfo);
+ longjmp(myerr->jb, 1);
+}
+
+static void my_output_message(j_common_ptr cinfo)
+{
+ (*cinfo->err->format_message)(cinfo, lasterror);
+}
+
+int main(void)
+{
+ int jcs_valid = -1, jcs_alpha_valid = -1;
+ struct jpeg_compress_struct cinfo;
+ error_mgr jerr;
+
+ printf("libjpeg-turbo colorspace extensions:\n");
+ #if JCS_EXTENSIONS
+ printf(" Present at compile time\n");
+ #else
+ printf(" Not present at compile time\n");
+ #endif
+
+ cinfo.err = jpeg_std_error(&jerr.pub);
+ jerr.pub.error_exit = my_error_exit;
+ jerr.pub.output_message = my_output_message;
+
+ if(setjmp(jerr.jb)) {
+ // this will execute if libjpeg has an error
+ jcs_valid = 0;
+ goto done;
+ }
+
+ jpeg_create_compress(&cinfo);
+ cinfo.input_components = 3;
+ jpeg_set_defaults(&cinfo);
+ cinfo.in_color_space = JCS_EXT_RGB;
+ jpeg_default_colorspace(&cinfo);
+ jcs_valid = 1;
+
+ done:
+ if (jcs_valid)
+ printf(" Working properly\n");
+ else
+ printf(" Not working properly. Error returned was:\n %s\n",
+ lasterror);
+
+ printf("libjpeg-turbo alpha colorspace extensions:\n");
+ #if JCS_ALPHA_EXTENSIONS
+ printf(" Present at compile time\n");
+ #else
+ printf(" Not present at compile time\n");
+ #endif
+
+ if(setjmp(jerr.jb)) {
+ // this will execute if libjpeg has an error
+ jcs_alpha_valid = 0;
+ goto done2;
+ }
+
+ cinfo.in_color_space = JCS_EXT_RGBA;
+ jpeg_default_colorspace(&cinfo);
+ jcs_alpha_valid = 1;
+
+ done2:
+ if (jcs_alpha_valid)
+ printf(" Working properly\n");
+ else
+ printf(" Not working properly. Error returned was:\n %s\n",
+ lasterror);
+
+ jpeg_destroy_compress(&cinfo);
+ return 0;
+}
diff --git a/sharedlib/CMakeLists.txt b/sharedlib/CMakeLists.txt
index 97e06e3..25ddbdf 100755
--- a/sharedlib/CMakeLists.txt
+++ b/sharedlib/CMakeLists.txt
@@ -53,6 +53,9 @@
target_link_libraries(jpegtran jpeg)
set_property(TARGET jpegtran PROPERTY COMPILE_FLAGS "-DUSE_SETMODE")
+add_executable(jcstest ../jcstest.c)
+target_link_libraries(jcstest jpeg)
+
install(TARGETS jpeg cjpeg djpeg jpegtran
ARCHIVE DESTINATION lib
LIBRARY DESTINATION lib