Added JPEG support

2 files changed, 185 insertions, 3 deletions

diff --git a/libcore/imageloader.c b/libcore/imageloader.c
index bb88b70..527e5d6 100644
--- a/libcore/imageloader.c
+++ b/libcore/imageloader.c
@@ -1,7 +1,6 @@
 #include "../config.h"
 #include "helpers.h"
 #include "imageloader.h"
-//#include <math.h>
 #include <string>
 #include <dirent.h>
 #include <iostream>
@@ -69,6 +68,8 @@ bool cImageLoader::LoadImage(const char *fullpath) {
         importer = new cImageImporterPNG;
     else if (endswith(fullpath, ".svg"))
         importer = new cImageImporterSVG;
+    else if (endswith(fullpath, ".jpg"))
+        importer = new cImageImporterJPG;
     else
         return false;
 
@@ -209,3 +210,137 @@ void cImageImporterSVG::GetImageSize(int &width, int &height) {
         height = dim.height;
     }
 }
+
+//
+// Image importer for JPG
+//
+
+cImageImporterJPG::cImageImporterJPG() {
+    cinfo = NULL;
+}
+
+cImageImporterJPG::~cImageImporterJPG() {
+    if (cinfo) {
+        jpeg_destroy_decompress(cinfo);
+        free(cinfo);
+        fclose(infile);
+    }
+}
+
+bool cImageImporterJPG::LoadImage(const char *path) {
+    if (cinfo) {
+        jpeg_destroy_decompress(cinfo);
+        free(cinfo);
+        fclose(infile);
+        cinfo = NULL;
+    }
+
+    // Open input file
+    if ((infile = fopen(path, "rb")) == NULL) {
+        if (config.debugImageLoading)
+            dsyslog("skindesigner: Can't open %s", path);
+        return false;
+    }
+
+    // We set up the normal JPEG error routines, then override error_exit.
+    struct my_error_mgr jerr;
+    cinfo = (j_decompress_ptr)malloc(sizeof(struct jpeg_decompress_struct));
+    cinfo->err = jpeg_std_error(&jerr.pub);
+    jerr.pub.error_exit = my_error_exit;
+    jerr.pub.output_message = my_output_message;
+    // Establish the setjmp return context for my_error_exit to use.
+    if (setjmp(jerr.setjmp_buffer)) {
+        // If we get here, the JPEG code has signaled an error.
+        jpeg_destroy_decompress(cinfo);
+        free(cinfo);
+        fclose(infile);
+        cinfo = NULL;
+        return false;
+    }
+
+    // Now we can initialize the JPEG decompression object.
+    jpeg_create_decompress(cinfo);
+
+    // Step 2: specify data source (eg, a file)
+    jpeg_stdio_src(cinfo, infile);
+
+    // Step 3: read file parameters with jpeg_read_header()
+    (void) jpeg_read_header(cinfo, TRUE);
+    return true;
+}
+
+void cImageImporterJPG::DrawToCairo(cairo_t *cr) {
+    if (!cinfo)
+        return;
+
+    unsigned char *bmp_buffer = NULL;
+
+    // Re-establish error handling
+    struct my_error_mgr jerr;
+    cinfo->err = jpeg_std_error(&jerr.pub);
+    jerr.pub.error_exit = my_error_exit;
+    jerr.pub.output_message = my_output_message;
+    if (setjmp(jerr.setjmp_buffer)) {
+        jpeg_destroy_decompress(cinfo);
+        free(cinfo);
+        fclose(infile);
+        free(bmp_buffer);
+        cinfo = NULL;
+        return;
+    }
+
+    // Step 4: set parameters for decompression
+    cinfo->out_color_space = JCS_EXT_ARGB;
+
+    // Step 5: Start decompressor
+    (void) jpeg_start_decompress(cinfo);
+
+    // Bytes per row in output buffer
+    int row_stride = cinfo->output_width * cinfo->output_components;
+
+    // Allocate buffer
+    unsigned long bmp_size = row_stride * cinfo->output_height;
+    bmp_buffer = (unsigned char*)malloc(bmp_size);
+
+    // Step 6: while (scan lines remain to be read)
+    while (cinfo->output_scanline < cinfo->output_height) {
+        unsigned char *buffer_array[1];
+        buffer_array[0] = bmp_buffer + (cinfo->output_scanline) * row_stride;
+        jpeg_read_scanlines(cinfo, buffer_array, 1);
+    }
+
+    // Step 7: Finish decompression
+    (void)jpeg_finish_decompress(cinfo);
+    fclose(infile);
+
+    // --> At this point we have raw RGB data in bmp_buffer
+
+    // Create new Cairo surface from our raw image data
+    cairo_surface_t *surface;
+    surface = cairo_image_surface_create_for_data(bmp_buffer,
+                                                  CAIRO_FORMAT_ARGB32,
+                                                  cinfo->output_width,
+                                                  cinfo->output_height,
+                                                  row_stride);
+
+    // Draw surface to Cairo
+    if (surface) {
+        cairo_set_source_surface(cr, surface, 0, 0);
+        cairo_paint(cr);
+        cairo_surface_destroy(surface);
+    }
+
+    // Cleanup. In this "ImageImporter" we clean up everything in "DrawToCairo"
+    // as I'm not really sure whether we are able to draw a second time.
+    free(bmp_buffer);
+    jpeg_destroy_decompress(cinfo);
+    free(cinfo);
+    cinfo = NULL;
+}
+
+void cImageImporterJPG::GetImageSize(int &width, int &height) {
+    if (cinfo) {
+        width = cinfo->image_width;
+        height = cinfo->image_height;
+    }
+}
diff --git a/libcore/imageloader.h b/libcore/imageloader.h
index 6caf19f..e90f459 100644
--- a/libcore/imageloader.h
+++ b/libcore/imageloader.h
@@ -1,10 +1,10 @@
 #ifndef __NOPACITY_IMAGELOADER_H
 #define __NOPACITY_IMAGELOADER_H
 
-#define X_DISPLAY_MISSING
-
 #include <cairo.h>
 #include <librsvg/rsvg.h>
+#include <jpeglib.h>
+#include <setjmp.h>
 #include <vdr/osd.h>
 #include <vdr/tools.h>
 
@@ -44,6 +44,53 @@ private:
     RsvgHandle *handle;
 };
 
+// Image importer for JPG
+
+#if BITS_IN_JSAMPLE != 8
+  #error libjpeg-turbo has to be compiled with 8-bit samples!
+#endif
+#ifndef JCS_EXTENSIONS
+  #error libjpeg-turbo with JCS_EXTENSIONS required!
+#endif
+
+struct my_error_mgr {
+  struct jpeg_error_mgr pub; // "public" fields
+  jmp_buf setjmp_buffer;     // for return to caller
+};
+
+METHODDEF(void)
+my_error_exit(j_common_ptr cinfo) {
+    // cinfo->err really points to a my_error_mgr struct, so coerce pointer
+    my_error_mgr *myerr = (my_error_mgr*) cinfo->err;
+
+    // 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(myerr->setjmp_buffer, 1);
+}
+
+METHODDEF(void)
+my_output_message(j_common_ptr cinfo) {
+    char buf[JMSG_LENGTH_MAX];
+    cinfo->err->format_message(cinfo, buf);
+    dsyslog("skindesigner: libjpeg error: %s", buf);
+}
+
+class cImageImporterJPG : public cImageImporter {
+public:
+    cImageImporterJPG();
+    ~cImageImporterJPG();
+    bool LoadImage(const char *path);
+    void DrawToCairo(cairo_t *cr);
+    void GetImageSize(int &width, int &height);
+private:
+    j_decompress_ptr cinfo;
+    FILE *infile;
+};
+
+
 
 class cImageLoader {
 private: