From 7a06e08ad005ded61a9a2b73b2ea027f841dcc58 Mon Sep 17 00:00:00 2001
From: Thomas Goyne <plorkyeran@aegisub.org>
Date: Tue, 27 Aug 2013 07:37:19 -0700
Subject: [PATCH] Use ycbcr_converter in YUV4MPEGVideoProvider

---
 src/video_frame.cpp             |  9 +++++++++
 src/video_frame.h               |  1 +
 src/video_provider_yuv4mpeg.cpp | 30 ++++++++++++------------------
 3 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/src/video_frame.cpp b/src/video_frame.cpp
index 91639318a..09c4e9e6d 100644
--- a/src/video_frame.cpp
+++ b/src/video_frame.cpp
@@ -28,6 +28,15 @@ VideoFrame::VideoFrame(const unsigned char *data, size_t width, size_t height, s
 {
 }
 
+VideoFrame::VideoFrame(std::vector<unsigned char>&& data, size_t width, size_t height, size_t pitch, bool flipped)
+: data(std::move(data))
+, width(width)
+, height(height)
+, pitch(pitch)
+, flipped(flipped)
+{
+}
+
 namespace {
 	// We actually have bgr_, not bgra, so we need a custom converter which ignores the alpha channel
 	struct color_converter {
diff --git a/src/video_frame.h b/src/video_frame.h
index 88055dc33..fc8a67efa 100644
--- a/src/video_frame.h
+++ b/src/video_frame.h
@@ -26,6 +26,7 @@ struct VideoFrame {
 	bool flipped;
 
 	VideoFrame(const unsigned char *data, size_t width, size_t height, size_t pitch, bool fipped);
+	VideoFrame(std::vector<unsigned char>&& data, size_t width, size_t height, size_t pitch, bool fipped);
 };
 
 wxImage GetImage(VideoFrame const& frame);
diff --git a/src/video_provider_yuv4mpeg.cpp b/src/video_provider_yuv4mpeg.cpp
index 86bcf7c5d..6f0d16845 100644
--- a/src/video_provider_yuv4mpeg.cpp
+++ b/src/video_provider_yuv4mpeg.cpp
@@ -43,6 +43,7 @@
 #include <libaegisub/log.h>
 #include <libaegisub/make_unique.h>
 #include <libaegisub/util.h>
+#include <libaegisub/ycbcr_conv.h>
 
 #include <boost/algorithm/string/case_conv.hpp>
 #include <boost/filesystem/path.hpp>
@@ -130,6 +131,8 @@ class YUV4MPEGVideoProvider final : public VideoProvider {
 
 	agi::vfr::Framerate fps;
 
+	agi::ycbcr_converter conv{agi::ycbcr_matrix::bt601, agi::ycbcr_range::tv};
+
 	/// a list of byte positions detailing where in the file
 	/// each frame header can be found
 	std::vector<uint64_t> seek_table;
@@ -390,15 +393,6 @@ int YUV4MPEGVideoProvider::IndexFile(uint64_t pos) {
 	return framecount;
 }
 
-// http://bob.allegronetwork.com/prog/tricks.html#clamp
-static FORCEINLINE int clamp(int x) {
-	x &= (~x) >> 31;
-	x -= 255;
-	x &= x >> 31;
-	x += 255;
-	return x;
-}
-
 std::shared_ptr<VideoFrame> YUV4MPEGVideoProvider::GetFrame(int n) {
 	n = mid(0, n, num_frames - 1);
 
@@ -422,15 +416,15 @@ std::shared_ptr<VideoFrame> YUV4MPEGVideoProvider::GetFrame(int n) {
 
 	for (int py = 0; py < h; ++py) {
 		for (int px = 0; px < w / 2; ++px) {
-			const int u = *src_u++ - 128;
-			const int v = *src_v++ - 128;
+			const uint8_t u = *src_u++;
+			const uint8_t v = *src_v++;
 			for (unsigned int i = 0; i < 2; ++i) {
-				const int y = (*src_y++ - 16) * 298;
-
-				*dst++ = clamp((y + 516 * u + 128) >> 8);			// Blue
-				*dst++ = clamp((y - 100 * u - 208 * v + 128) >> 8);	// Green
-				*dst++ = clamp((y + 409 * v + 128) >> 8);			// Red
-				*dst++ = 0;											// Alpha
+				const uint8_t y = *src_y++;
+				auto rgb = conv.ycbcr_to_rgb({{y, u, v}});
+				*dst++ = rgb[2];
+				*dst++ = rgb[1];
+				*dst++ = rgb[0];
+				*dst++ = 0;
 			}
 		}
 
@@ -441,7 +435,7 @@ std::shared_ptr<VideoFrame> YUV4MPEGVideoProvider::GetFrame(int n) {
 		}
 	}
 
-	return std::make_shared<VideoFrame>(data.data(), w, h, w * 4, false);
+	return std::make_shared<VideoFrame>(std::move(data), w, h, w * 4, false);
 }
 }