/**
* Create a thumbnail in memory
* @param jpegData A pointer to a jpeg image in memory
* @param outData A pointer to a pointer that will point to the created jpeg thumbnail
* @return the size of the created thumbnail in bytes
* */
int create_thumbnail (unsigned char* jpegData, int jpegDataSize, unsigned char** outData, int thumb_width, int thumb_height, int max_dimension, int thumb_quality) {
Epeg_Image *im;
if (thumb_quality <= 0) thumb_quality = 85;
im = epeg_memory_open(jpegData, jpegDataSize);
if (!im) return NULL;
int w,h;
epeg_size_get(im, &w, &h);
if (max_dimension > 0) {
if (w > h) {
thumb_width = max_dimension;
thumb_height = max_dimension * h / w;
} else {
thumb_height = max_dimension;
thumb_width = max_dimension * w / h;
}
} else {
if (thumb_width < 0) {
// This means we want %thumb_width of w
thumb_width = w * (-thumb_width) / 100;
}
if (thumb_height < 0) {
// This means we want %thumb_height of h
thumb_height = h * (-thumb_height) / 100;
}
}
int decoded_size;
epeg_decode_size_set(im, thumb_width, thumb_height);
epeg_quality_set (im, thumb_quality);
epeg_memory_output_set (im, outData, &decoded_size);
epeg_encode (im);
epeg_close (im);
return decoded_size;
}
int jpeg_thumbnail (byte *data, int insize, byte **destp, int *dest_sizep, cpoint *sizep)
{
Epeg_Image *im;
int stride, valid;
im = epeg_memory_open(data, insize);
if (!im)
return 0;
sizep->x = im->in.w / CONFIG_preview_scale;
sizep->y = im->in.h / CONFIG_preview_scale;
epeg_decode_size_set (im, sizep->x, sizep->y);
epeg_quality_set (im, 75, FALSE);
// epeg_thumbnail_comments_enable (im, 1);
epeg_memory_output_set (im, destp, dest_sizep);
// epeg_encode (im);
stride = (sizep->x * im->in.jinfo.num_components + 3) & ~3;
epeg_raw (im, stride);
#if 1 // don't do this for now */
valid = im->last_valid_row;
if (valid != -1 && valid < im->in.h)
{
printf ("data short - shrink preview from %d to %d\n", sizep->y, valid / CONFIG_preview_scale);
sizep->y = valid / CONFIG_preview_scale; // shrink preview
*dest_sizep = stride * sizep->y;
}
#endif
epeg_copy (im, sizep->x, sizep->y, stride);
epeg_close (im);
return valid;
}
/*
* call-seq:
* to_blob()
*
* Returns the image data as blob and closes the image stream.
* Please note that you can't do any further operations on the image
* after using this method.
*/
static VALUE rb_epeg_image_to_blob(VALUE self)
{
if(rb_iv_get(self, "epeg_file_closed") != Qfalse) {
rb_raise(rb_eRuntimeError, "Error: closed file");
}
Epeg_Image *image;
Data_Get_Struct(self, Epeg_Image, image);
char *data;
int size;
epeg_memory_output_set(image, &data, &size);
rb_epeg_image_encode_or_trim(self, image);
VALUE blob = rb_str_new(data, size);
free(data);
rb_epeg_image_close(self);
return blob;
}
