From c6b237da9e77c969833514567a54f4cc44ca874a Mon Sep 17 00:00:00 2001
From: Panagiotis Issaris <takis.issaris@uhasselt.be>
Date: Mon, 11 Dec 2006 15:53:55 +0000
Subject: [PATCH] Adding H.264 DCT.

Originally committed as revision 7282 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavcodec/Makefile  |  2 +-
 libavcodec/dsputil.c |  8 +++++
 libavcodec/h264dsp.c | 81 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 90 insertions(+), 1 deletion(-)
 create mode 100644 libavcodec/h264dsp.c

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 10278089d5..3b7a3a528a 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -86,7 +86,7 @@ OBJS-$(CONFIG_GIF_ENCODER)             += gif.o
 OBJS-$(CONFIG_H261_DECODER)            += h261.o
 OBJS-$(CONFIG_H261_ENCODER)            += h261.o
 OBJS-$(CONFIG_H264_DECODER)            += h264.o
-OBJS-$(CONFIG_H264_ENCODER)            += h264enc.o
+OBJS-$(CONFIG_H264_ENCODER)            += h264enc.o h264dsp.o
 OBJS-$(CONFIG_HUFFYUV_DECODER)         += huffyuv.o
 OBJS-$(CONFIG_HUFFYUV_ENCODER)         += huffyuv.o
 OBJS-$(CONFIG_IDCIN_DECODER)           += idcinvideo.o
diff --git a/libavcodec/dsputil.c b/libavcodec/dsputil.c
index c5e82d434f..916d8658cd 100644
--- a/libavcodec/dsputil.c
+++ b/libavcodec/dsputil.c
@@ -2549,6 +2549,11 @@ void ff_put_vc1_mspel_mc00_c(uint8_t *dst, uint8_t *src, int stride, int rnd) {
 }
 #endif /* CONFIG_VC1_DECODER||CONFIG_WMV3_DECODER */
 
+#if defined(CONFIG_H264_ENCODER)
+/* H264 specific */
+void ff_h264dsp_init(DSPContext* c, AVCodecContext *avctx);
+#endif /* CONFIG_H264_ENCODER */
+
 static void wmv2_mspel8_v_lowpass(uint8_t *dst, uint8_t *src, int dstStride, int srcStride, int w){
     uint8_t *cm = ff_cropTbl + MAX_NEG_CROP;
     int i;
@@ -4026,6 +4031,9 @@ void dsputil_init(DSPContext* c, AVCodecContext *avctx)
 #if defined(CONFIG_VC1_DECODER) || defined(CONFIG_WMV3_DECODER)
     ff_vc1dsp_init(c,avctx);
 #endif
+#if defined(CONFIG_H264_ENCODER)
+    ff_h264dsp_init(c,avctx);
+#endif
 
     c->put_mspel_pixels_tab[0]= put_mspel8_mc00_c;
     c->put_mspel_pixels_tab[1]= put_mspel8_mc10_c;
diff --git a/libavcodec/h264dsp.c b/libavcodec/h264dsp.c
new file mode 100644
index 0000000000..4f18afac4a
--- /dev/null
+++ b/libavcodec/h264dsp.c
@@ -0,0 +1,81 @@
+/*
+ * H.264/MPEG-4 Part 10 (Base profile) encoder.
+ *
+ * DSP functions
+ *
+ * Copyright (c) 2006 Expertisecentrum Digitale Media, UHasselt
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file h264dsp.c
+ * H.264 encoder related DSP utils
+ *
+ */
+
+#include "dsputil.h"
+
+extern const uint8_t ff_div6[52];
+extern const uint8_t ff_rem6[52];
+
+#define  H264_DCT_PART1(X) \
+         a = block[0][X]+block[3][X]; \
+         c = block[0][X]-block[3][X]; \
+         b = block[1][X]+block[2][X]; \
+         d = block[1][X]-block[2][X]; \
+         pieces[0][X] = a+b; \
+         pieces[2][X] = a-b; \
+         pieces[1][X] = (c<<1)+d; \
+         pieces[3][X] = c-(d<<1);
+
+#define  H264_DCT_PART2(X) \
+         a = pieces[X][0]+pieces[X][3]; \
+         c = pieces[X][0]-pieces[X][3]; \
+         b = pieces[X][1]+pieces[X][2]; \
+         d = pieces[X][1]-pieces[X][2]; \
+         block[0][X] = a+b; \
+         block[2][X] = a-b; \
+         block[1][X] = (c<<1)+d; \
+         block[3][X] = c-(d<<1);
+
+/**
+ * Transform the provided matrix using the H.264 modified DCT.
+ * @note
+ * we'll always work with transposed input blocks, to avoid having to make a
+ * distinction between C and mmx implementations.
+ *
+ * @param block transposed input block
+ */
+static void h264_dct_c(DCTELEM block[4][4])
+{
+    DCTELEM pieces[4][4];
+    DCTELEM a, b, c, d;
+
+    H264_DCT_PART1(0);
+    H264_DCT_PART1(1);
+    H264_DCT_PART1(2);
+    H264_DCT_PART1(3);
+    H264_DCT_PART2(0);
+    H264_DCT_PART2(1);
+    H264_DCT_PART2(2);
+    H264_DCT_PART2(3);
+}
+
+void ff_h264dsp_init(DSPContext* c, AVCodecContext *avctx)
+{
+    c->h264_dct = h264_dct_c;
+}
+