X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=driver.c;h=04e236912ca45d56bc4f1a34f16b3c04185112d9;hb=9d977ffbb1bc9cfe41d5e074de51bb9d7bed96d7;hp=fd861f25d7b56250aadf7f1666174e9fb2fe9b41;hpb=a733460846675aab7117c5cf1213d1b62785793d;p=fjl

diff --git a/driver.c b/driver.c
index fd861f2..04e2369 100644
--- a/driver.c
+++ b/driver.c
@@ -194,13 +194,11 @@ void read_scan(struct byte_source* source, struct jpeg_image* image, huffman_tab
 					uint8_t pixdata[DCTSIZE2];	
 					idct_choice(coeff, image->idct_data[image->qtable[cn]], pixdata);
 
-					for (unsigned y = 0; y < DCTSIZE; ++y) {
-						unsigned real_x = (mcu_x * image->hsample[cn] + local_xb) * DCTSIZE;
-						unsigned real_y = (mcu_y * image->vsample[cn] + local_yb) * DCTSIZE + y;
-					
-						memcpy(image->pixel_data[cn] + real_y * stride + real_x,
-						       pixdata + y * DCTSIZE,
-						       DCTSIZE);
+					unsigned real_x = (mcu_x * image->hsample[cn] + local_xb) * DCTSIZE;
+					unsigned real_y = (mcu_y * image->vsample[cn] + local_yb) * DCTSIZE;
+					uint8_t* dest_pixdata = image->pixel_data[cn] + real_y * stride + real_x;
+					for (unsigned y = 0; y < DCTSIZE; ++y, dest_pixdata += stride) {
+						memcpy(dest_pixdata, pixdata + y * DCTSIZE, DCTSIZE);
 					}
 				}
 			}
@@ -214,8 +212,9 @@ void read_scan(struct byte_source* source, struct jpeg_image* image, huffman_tab
 			const int c = 1;
 			if (mcu_y == image->num_blocks_vertical) {
 				unsigned stride = image->num_blocks_horizontal * image->hsample[c] * DCTSIZE;
-				printf("P5\n%u %u\n255\n", stride, image->height);
-				fwrite(image->pixel_data[c], stride * image->height, 1, stdout);
+				unsigned height = image->num_blocks_vertical * image->vsample[c] * DCTSIZE;
+				printf("P5\n%u %u\n255\n", stride, height);
+				fwrite(image->pixel_data[c], stride * height, 1, stdout);
 			}
 		}
 	}