From 165e8cbf59faf7cbc1b7c83eaa9b165a05a4b90e Mon Sep 17 00:00:00 2001
From: Ilari Liusvaara <ilari.liusvaara@elisanet.fi>
Date: Fri, 3 Sep 2010 17:34:09 +0300
Subject: [PATCH] Add nearest neighbor resizer

This resizer might be useful as example and for some special encoding
modes...
---
 Changelog.utf8                  |  1 +
 streamtools/Makefile            |  2 +-
 streamtools/resizer-nearest.cpp | 46 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+), 1 deletion(-)
 create mode 100644 streamtools/resizer-nearest.cpp

diff --git a/Changelog.utf8 b/Changelog.utf8
index 836be0a..51791e3 100644
--- a/Changelog.utf8
+++ b/Changelog.utf8
@@ -71,6 +71,7 @@ Changes since JPC-RR Release 10.5:
 - Add new dumping system.
 - Allow direct output to I420.
 - oggenc and x264 output drivers.
+- Add nearest neighbor resizer.
 
 Changes since JPC-RR Release 10.16:
 ===================================
diff --git a/streamtools/Makefile b/streamtools/Makefile
index 495116f..e14382d 100644
--- a/streamtools/Makefile
+++ b/streamtools/Makefile
@@ -2,7 +2,7 @@ all:  screenshot.exe dumppackets.exe picturestodump.exe audiotodump.exe demuxdum
 
 CXXFLAGS2=-g -O2 -Wall -fopenmp
 CXXFLAGS=$(CXXFLAGS2)
-RESIZE_DRIVERS=resize.o resizer-lanczos.o
+RESIZE_DRIVERS=resize.o resizer-lanczos.o resizer-nearest.o
 I420_DRIVER_FILES=output-drv-rawi420.o rgbtorgb.o
 X264_DRIVER_FILES=output-drv-x264.o rgbtorgb.o
 OUTPUT_DRIVERS=$(RESIZE_DRIVERS) dedup.o output-drv.o output-drv-rawrgbx.o output-drv-timecodev2.o output-drv-rawaudio.o output-drv-wav.o $(I420_DRIVER_FILES) $(X264_DRIVER_FILES) output-drv-oggenc.o
diff --git a/streamtools/resizer-nearest.cpp b/streamtools/resizer-nearest.cpp
new file mode 100644
index 0000000..64c5804
--- /dev/null
+++ b/streamtools/resizer-nearest.cpp
@@ -0,0 +1,46 @@
+#include "resize.hpp"
+#include <stdint.h>
+#include <cmath>
+#include <stdexcept>
+
+namespace
+{
+	inline uint32_t nnscale(uint32_t value, uint32_t trange, uint32_t srange)
+	{
+		//x / trange is as good approximation for value / srange as possible.
+		//=> x is as good approximation for value * trange / srange as possible.
+		return (uint32_t)(((uint64_t)value * trange + srange / 2) / srange);
+	}
+
+	class resizer_local : public resizer
+	{
+	public:
+		void operator()(uint8_t* target, uint32_t twidth, uint32_t theight,
+			const uint8_t* source, uint32_t swidth, uint32_t sheight)
+		{
+			uint32_t* __restrict__ src = (uint32_t*)source;
+			uint32_t* __restrict__ dest = (uint32_t*)target;
+
+			for(uint32_t y = 0; y < theight; y++)
+				for(uint32_t x = 0; x < twidth; x++) {
+					uint32_t _x = nnscale(x, swidth, twidth);
+					uint32_t _y = nnscale(y, sheight, theight);
+					dest[y * twidth + x] = src[_y * swidth + _x];
+				}
+		}
+	};
+
+	class resizer_local_factory : public resizer_factory
+	{
+	public:
+		resizer_local_factory()
+			: resizer_factory("nearest")
+		{
+		}
+
+		resizer& make(const std::string& type)
+		{
+			return *new resizer_local();
+		}
+	} factory;
+}
-- 
2.11.4.GIT