From 87c302a878a6d925f1dffb8ec93ae38ccc6019e7 Mon Sep 17 00:00:00 2001
From: Philip Heron <phil@sanslogic.co.uk>
Date: Sun, 26 Feb 2012 23:51:15 +0000
Subject: [PATCH] Round to nearest integer when quantising coefficients. Fixes
 poor image quality.

---
 Makefile | 2 +-
 ssdv.c   | 7 ++++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index 7ea30b5..5da152d 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 
 CC=gcc
 CFLAGS=-g -Wall
-LDFLAGS=-g
+LDFLAGS=-g -lm
 
 ssdv: main.o ssdv.o rs8.o
 	$(CC) $(LDFLAGS) main.o ssdv.o rs8.o -o ssdv
diff --git a/ssdv.c b/ssdv.c
index e8e89ff..9741491 100644
--- a/ssdv.c
+++ b/ssdv.c
@@ -20,6 +20,7 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
+#include <math.h>
 #include "ssdv.h"
 #include "rs8.h"
 
@@ -123,9 +124,9 @@ static uint8_t *dht_ac[3] = { std_dht10, std_dht11, std_dht11 };
 #define DDQT (dqt[s->component][1 + s->acpart])
 
 /* Helpers for converting between DQT tables */
-#define AADJ(i) (SDQT == DDQT ? (i) : (i / DDQT))
-#define UADJ(i) (SDQT == DDQT ? (i) : (i * SDQT))
-#define BADJ(i) (SDQT == DDQT ? (i) : (i * SDQT / DDQT))
+#define AADJ(i) (SDQT == DDQT ? (i) : round((double) i / DDQT))
+#define UADJ(i) (SDQT == DDQT ? (i) : round((double) i * SDQT))
+#define BADJ(i) (SDQT == DDQT ? (i) : round((double) i * SDQT / DDQT))
 
 /*
 static char *strbits(uint32_t value, uint8_t bits)