[FFmpeg-devel] [PATCH] hardcode motionpixels.c mp_rgb_yuv_table

Reimar Döffinger Reimar.Doeffinger
Wed Oct 28 20:30:01 CET 2009


Hello,
another rather large (ca. 90 kB) table for an obscure format.
Unfortunately I do not know the details of this format and if this table
has to be exact.
This would be interesting since using a matrix-vector-multiplication it
seem only to be possible to come within +-3 of the values in this table,
so if it has to be exact there is not really a (decently performant)
way to avoid the table completely.
-------------- next part --------------
Index: libavcodec/motionpixels.c
===================================================================
--- libavcodec/motionpixels.c	(revision 20399)
+++ libavcodec/motionpixels.c	(working copy)
@@ -25,9 +25,7 @@
 
 #define MAX_HUFF_CODES 16
 
-typedef struct YuvPixel {
-    int8_t y, v, u;
-} YuvPixel;
+#include "motionpixels_tablegen.h"
 
 typedef struct HuffCode {
     int code;
@@ -51,61 +49,11 @@
     int bswapbuf_size;
 } MotionPixelsContext;
 
-static YuvPixel mp_rgb_yuv_table[1 << 15];
-
-static int mp_yuv_to_rgb(int y, int v, int u, int clip_rgb) {
-    static const uint8_t *cm = ff_cropTbl + MAX_NEG_CROP;
-    int r, g, b;
-
-    r = (1000 * y + 701 * v) / 1000;
-    g = (1000 * y - 357 * v - 172 * u) / 1000;
-    b = (1000 * y + 886 * u) / 1000;
-    if (clip_rgb)
-        return ((cm[r * 8] & 0xF8) << 7) | ((cm[g * 8] & 0xF8) << 2) | (cm[b * 8] >> 3);
-    if ((unsigned)r < 32 && (unsigned)g < 32 && (unsigned)b < 32)
-        return (r << 10) | (g << 5) | b;
-    return 1 << 15;
-}
-
-static void mp_set_zero_yuv(YuvPixel *p)
-{
-    int i, j;
-
-    for (i = 0; i < 31; ++i) {
-        for (j = 31; j > i; --j)
-            if (!(p[j].u | p[j].v | p[j].y))
-                p[j] = p[j - 1];
-        for (j = 0; j < 31 - i; ++j)
-            if (!(p[j].u | p[j].v | p[j].y))
-                p[j] = p[j + 1];
-    }
-}
-
-static void mp_build_rgb_yuv_table(YuvPixel *p)
-{
-    int y, v, u, i;
-
-    for (y = 0; y <= 31; ++y)
-        for (v = -31; v <= 31; ++v)
-            for (u = -31; u <= 31; ++u) {
-                i = mp_yuv_to_rgb(y, v, u, 0);
-                if (i < (1 << 15) && !(p[i].u | p[i].v | p[i].y)) {
-                    p[i].y = y;
-                    p[i].v = v;
-                    p[i].u = u;
-                }
-            }
-    for (i = 0; i < 1024; ++i)
-        mp_set_zero_yuv(p + i * 32);
-}
-
 static av_cold int mp_decode_init(AVCodecContext *avctx)
 {
     MotionPixelsContext *mp = avctx->priv_data;
 
-    if (!mp_rgb_yuv_table[0].u) {
-        mp_build_rgb_yuv_table(mp_rgb_yuv_table);
-    }
+    motionpixels_tableinit();
     mp->avctx = avctx;
     dsputil_init(&mp->dsp, avctx);
     mp->changes_map = av_mallocz(avctx->width * avctx->height);
Index: libavcodec/motionpixels_tablegen.c
===================================================================
--- libavcodec/motionpixels_tablegen.c	(revision 0)
+++ libavcodec/motionpixels_tablegen.c	(revision 0)
@@ -0,0 +1,42 @@
+/*
+ * Generate a header file for hardcoded motionpixels RGB to YUV table
+ *
+ * Copyright (c) 2009 Reimar D?ffinger <Reimar.Doeffinger at gmx.de>
+ *
+ * This file is part of FFmpeg.
+ *
+ * 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
+ */
+
+#include <stdlib.h>
+#define CONFIG_HARDCODED_TABLES 0
+#include "motionpixels_tablegen.h"
+#include "tableprint.h"
+
+void tableinit(void)
+{
+    motionpixels_tableinit();
+}
+
+const struct tabledef tables[] = {
+    {
+        "static const YuvPixel mp_rgb_yuv_table[1 << 15]",
+        write_int8_2d_array,
+        mp_rgb_yuv_table,
+        1 << 15,
+        3
+    },
+    { NULL }
+};
Index: libavcodec/motionpixels_tablegen.h
===================================================================
--- libavcodec/motionpixels_tablegen.h	(revision 0)
+++ libavcodec/motionpixels_tablegen.h	(revision 0)
@@ -0,0 +1,95 @@
+/*
+ * Header file for hardcoded motionpixels RGB to YUV table
+ *
+ * Copyright (c) 2009 Reimar D?ffinger <Reimar.Doeffinger at gmx.de>
+ *
+ * This file is part of FFmpeg.
+ *
+ * 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
+ */
+
+#ifndef MOTIONPIXELS_TABLEGEN_H
+#define MOTIONPIXELS_TABLEGEN_H
+
+#include <stdint.h>
+
+typedef struct YuvPixel {
+    int8_t y, v, u;
+} YuvPixel;
+
+#ifndef MAX_NEG_CROP
+#define MAX_NEG_CROP 0
+#define ff_cropTbl ((uint8_t *)NULL)
+#endif
+static int mp_yuv_to_rgb(int y, int v, int u, int clip_rgb) {
+    static const uint8_t *cm = ff_cropTbl + MAX_NEG_CROP;
+    int r, g, b;
+
+    r = (1000 * y + 701 * v) / 1000;
+    g = (1000 * y - 357 * v - 172 * u) / 1000;
+    b = (1000 * y + 886 * u) / 1000;
+    if (clip_rgb)
+        return ((cm[r * 8] & 0xF8) << 7) | ((cm[g * 8] & 0xF8) << 2) | (cm[b * 8] >> 3);
+    if ((unsigned)r < 32 && (unsigned)g < 32 && (unsigned)b < 32)
+        return (r << 10) | (g << 5) | b;
+    return 1 << 15;
+}
+
+#if CONFIG_HARDCODED_TABLES
+#define motionpixels_tableinit()
+#include "motionpixels_tables.h"
+#else
+static YuvPixel mp_rgb_yuv_table[1 << 15];
+
+static void mp_set_zero_yuv(YuvPixel *p)
+{
+    int i, j;
+
+    for (i = 0; i < 31; ++i) {
+        for (j = 31; j > i; --j)
+            if (!(p[j].u | p[j].v | p[j].y))
+                p[j] = p[j - 1];
+        for (j = 0; j < 31 - i; ++j)
+            if (!(p[j].u | p[j].v | p[j].y))
+                p[j] = p[j + 1];
+    }
+}
+
+static void mp_build_rgb_yuv_table(YuvPixel *p)
+{
+    int y, v, u, i;
+
+    for (y = 0; y <= 31; ++y)
+        for (v = -31; v <= 31; ++v)
+            for (u = -31; u <= 31; ++u) {
+                i = mp_yuv_to_rgb(y, v, u, 0);
+                if (i < (1 << 15) && !(p[i].u | p[i].v | p[i].y)) {
+                    p[i].y = y;
+                    p[i].v = v;
+                    p[i].u = u;
+                }
+            }
+    for (i = 0; i < 1024; ++i)
+        mp_set_zero_yuv(p + i * 32);
+}
+
+static void motionpixels_tableinit(void)
+{
+    if (!mp_rgb_yuv_table[0].u)
+        mp_build_rgb_yuv_table(mp_rgb_yuv_table);
+}
+#endif /* CONFIG_HARDCODED_TABLES */
+
+#endif /* MOTIONPIXELS_TABLEGEN_H */
Index: libavcodec/Makefile
===================================================================
--- libavcodec/Makefile	(revision 20403)
+++ libavcodec/Makefile	(working copy)
@@ -711,5 +711,6 @@
 	$(HOSTCC) $(HOSTCFLAGS) $(HOSTLDFLAGS) -o $@ $^ $(HOSTLIBS)
 
 $(SUBDIR)mpegaudiodec.o: $(SUBDIR)mpegaudio_tables.h
+$(SUBDIR)motionpixels.o: $(SUBDIR)motionpixels_tables.h
 $(SUBDIR)%_tables.h: $(SUBDIR)%_tablegen$(HOSTEXESUF)
 	./$< > $@
Index: libavcodec/tableprint.c
===================================================================
--- libavcodec/tableprint.c	(revision 20402)
+++ libavcodec/tableprint.c	(working copy)
@@ -52,6 +52,7 @@
     }\
 }
 
+WRITE_2D_FUNC(int8,   int8_t)
 WRITE_2D_FUNC(uint32, uint32_t)
 
 int main(int argc, char *argv[])
Index: libavcodec/tableprint.h
===================================================================
--- libavcodec/tableprint.h	(revision 20400)
+++ libavcodec/tableprint.h	(working copy)
@@ -32,6 +32,7 @@
  */
 void write_int8_array     (const void *, int, int);
 void write_uint32_array   (const void *, int, int);
+void write_int8_2d_array  (const void *, int, int);
 void write_uint32_2d_array(const void *, int, int);
 /** \} */ // end of printfuncs group
 



More information about the ffmpeg-devel mailing list