[Personalrobots-commit] SF.net SVN: personalrobots: [91] pkg/trunk/image_utils

[<mor...@us...>]

Revision: 91
          http://personalrobots.svn.sourceforge.net/personalrobots/?rev=91&view=rev
Author:   morgan_quigley
Date:     2008-04-04 09:45:35 -0700 (Fri, 04 Apr 2008)

Log Message:
-----------
a header to wrap jpeg compression / decompression

Added Paths:
-----------
    pkg/trunk/image_utils/include/
    pkg/trunk/image_utils/include/image_utils/
    pkg/trunk/image_utils/include/image_utils/jpeg_wrapper.h

Added: pkg/trunk/image_utils/include/image_utils/jpeg_wrapper.h
===================================================================
--- pkg/trunk/image_utils/include/image_utils/jpeg_wrapper.h	                        (rev 0)
+++ pkg/trunk/image_utils/include/image_utils/jpeg_wrapper.h	2008-04-04 16:45:35 UTC (rev 91)
@@ -0,0 +1,128 @@
+#ifndef IMAGE_UTILS_JPEG_WRAPPER_H
+#define IMAGE_UTILS_JPEG_WRAPPER_H
+
+#include "ijg_libjpeg/ros_jpeg_mutex.h"
+extern "C"
+{
+#include "jpeglib.h"
+}
+
+class JpegWrapper
+{
+public:
+  JpegWrapper() 
+  : raster_width(0), raster_height(0), raster(NULL),
+    raster_alloc_size(0)
+  {
+    cinfo.err = jpeg_std_error(&jerr);
+    jpeg_create_compress(&cinfo);
+    dinfo.err = jpeg_std_error(&jerr);
+    jpeg_create_decompress(&dinfo);
+  }
+
+  ~JpegWrapper()
+  {
+    jpeg_destroy_compress(&cinfo);
+    jpeg_destroy_decompress(&dinfo);
+    if (raster)
+      delete[] raster;
+  }
+
+  inline int width()  { return raster_width; }
+  inline int height() { return raster_height; }
+  inline int raster_size() { return 3 * raster_width * raster_height; }
+  inline uint8_t *get_raster() { return raster; }
+
+  bool decompress_jpeg_buf(char *data, uint32_t data_len)
+  {
+    ros_jpeg_mutex_lock();
+    jpeg_buffer_src(&dinfo, data, data_len);
+    jpeg_read_header(&dinfo, TRUE);
+    jpeg_start_decompress(&dinfo);
+    if (dinfo.output_components != 3)
+    {
+      printf("woah! this jpeg buffer doesn't have three components.\n");
+      return false;
+    }
+    raster_width = dinfo.output_width;
+    raster_height = dinfo.output_height;
+    realloc_raster_if_needed();
+    int row_stride = raster_width * 3;
+    JSAMPROW row_pointer[1];
+    while (dinfo.output_scanline < dinfo.output_height)
+    {
+      row_pointer[0] = (JSAMPROW)&raster[dinfo.output_scanline * row_stride];
+      jpeg_read_scanlines(&dinfo, row_pointer, 1);
+    }
+    jpeg_finish_decompress(&dinfo);
+    ros_jpeg_mutex_unlock();
+    return true;
+  }
+protected:
+  uint8_t *raster;
+  int raster_width, raster_height;
+  int raster_alloc_size;
+  jpeg_compress_struct cinfo;
+  jpeg_decompress_struct dinfo;
+  jpeg_error_mgr jerr;
+
+  static void buffer_dest_init(j_compress_ptr cinfo) { }
+  static void buffer_source_init(j_decompress_ptr cinfo) { }
+  static boolean buffer_source_fill(j_decompress_ptr dinfo)
+  {
+    if (dinfo->src->bytes_in_buffer == 0)
+    {
+      printf("woah! jpeg memory buffer was incomplete! ahhhh\n");
+      return FALSE;
+    }
+    return TRUE;
+  }
+  static void buffer_source_skip(j_decompress_ptr dinfo, long num_bytes)
+  {
+    dinfo->src->next_input_byte += (size_t)num_bytes;
+    dinfo->src->bytes_in_buffer -= (size_t)num_bytes;
+  }
+  static void buffer_source_term(j_decompress_ptr dinfo) { }
+  static boolean buffer_dest_empty(j_compress_ptr cinfo)
+  {
+    // TODO: enlarge the compression buffer by a factor of 2 and
+    // copy over everything, then reset the write pointer
+    // and the number of available bytes
+  }
+  static void buffer_dest_term(j_compress_ptr cinfo) { }
+  static void jpeg_buffer_src(j_decompress_ptr dinfo, char *buf, int size)
+  {
+    if (dinfo->src == NULL)
+      dinfo->src = (struct jpeg_source_mgr *)(*dinfo->mem->alloc_small)
+        ((j_common_ptr)dinfo, JPOOL_PERMANENT, sizeof(struct jpeg_source_mgr));
+    dinfo->src->init_source = buffer_source_init;
+    dinfo->src->fill_input_buffer = buffer_source_fill;
+    dinfo->src->skip_input_data = buffer_source_skip;
+    dinfo->src->resync_to_restart = jpeg_resync_to_restart;
+    dinfo->src->next_input_byte = (JOCTET *)buf;
+    dinfo->src->bytes_in_buffer = size;
+    dinfo->src->term_source = buffer_source_term;
+  }
+  static void jpeg_buffer_dest(j_compress_ptr cinfo, char *buf, int size)
+  {
+    // TODO
+  }
+
+  void realloc_raster_if_needed()
+  {
+    if (raster_alloc_size < raster_size())
+    {
+      if (raster)
+        delete[] raster;
+      raster_alloc_size = raster_size();
+      if (raster_alloc_size)
+        raster = new uint8_t[raster_alloc_size];
+      else
+        raster = NULL;
+    }
+  }
+};
+
+
+#endif
+


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