cog: (re-)implement 1/2/4-tap scaling

ext/cog/Makefile.am

@@ -18,6 +18,7 @@ libgstcog_la_SOURCES = \
 	cog.h \
 	cogframe.c \
 	cogframe.h \
+	cogtables.c \
 	cogutils.h \
 	cogvirtframe.c \
 	cogvirtframe.h \
@@ -32,6 +33,10 @@ libgstcog_la_SOURCES = \
 	gstcolorconvert.c \
 	gstlogoinsert.c
 
+noinst_PROGRAMS = generate_tables
+generate_tables_CFLAGS = $(GST_CFLAGS)
+generate_tables_LDADD = $(GST_LIBS)
+
 nodist_libgstcog_la_SOURCES = cogorc.c cogorc.h
 CLEANFILES = cogorc.c cogorc.h
 

ext/cog/cog.orc

@@ -318,6 +318,24 @@ mergebw t2, s2, s3
 mergewl d1, t1, t2
 
 
+.function cogorc_combine2_u8
+.dest 1 d1
+.source 1 s1
+.source 1 s2
+.param 2 p1
+.param 2 p2
+.temp 2 t1
+.temp 2 t2
+
+convubw t1, s1
+mullw t1, t1, p1
+convubw t2, s2
+mullw t2, t2, p2
+addw t1, t1, t2
+shruw t1, t1, 8
+convuuswb d1, t1
+
+
 .function cogorc_combine4_u8
 .dest 1 d1
 .source 1 s1

ext/cog/cogvirtframe.c

@@ -14,6 +14,7 @@
 
 #include "cogorc.h"
 
+extern gint8 cog_resample_table_4tap[256][4];
 
 CogFrame *
 cog_frame_new_virtual (CogMemoryDomain * domain, CogFrameFormat format,
@@ -499,17 +500,54 @@ cog_virt_frame_new_vert_downsample (CogFrame * vf, int n_taps)
 }
 
 void
-get_taps (double *taps, double x)
+cog_virt_frame_render_resample_vert_1tap (CogFrame * frame, void *_dest,
+    int component, int i)
 {
-  taps[3] = x * x * (x - 1);
+  uint8_t *dest = _dest;
-  taps[2] = x * (-x * x + x + 1);
+  uint8_t *src1;
-  x = 1 - x;
+  int n_src;
-  taps[1] = x * (-x * x + x + 1);
+  double *scale = (double *) frame->virt_priv;
-  taps[0] = x * x * (x - 1);
+  double x;
+  int src_i;
+
+  x = (*scale) * i;
+  src_i = floor (x);
+
+  n_src = frame->virt_frame1->components[component].height;
+  src1 = cog_virt_frame_get_line (frame->virt_frame1, component,
+      CLAMP (src_i + 0, 0, n_src - 1));
+
+  orc_memcpy (dest, src1, frame->components[component].width);
 }
 
 void
-cog_virt_frame_render_resample_vert (CogFrame * frame, void *_dest,
+cog_virt_frame_render_resample_vert_2tap (CogFrame * frame, void *_dest,
+    int component, int i)
+{
+  uint8_t *dest = _dest;
+  uint8_t *src1;
+  uint8_t *src2;
+  int n_src;
+  double *scale = (double *) frame->virt_priv;
+  double x;
+  int src_i;
+
+  x = (*scale) * i;
+  src_i = floor (x);
+  x -= floor (x);
+
+  n_src = frame->virt_frame1->components[component].height;
+  src1 = cog_virt_frame_get_line (frame->virt_frame1, component,
+      CLAMP (src_i + 0, 0, n_src - 1));
+  src2 = cog_virt_frame_get_line (frame->virt_frame1, component,
+      CLAMP (src_i + 1, 0, n_src - 1));
+
+  cogorc_combine2_u8 (dest, src1, src2,
+      rint (256 * (1 - x)), rint (256 * x), frame->components[component].width);
+}
+
+void
+cog_virt_frame_render_resample_vert_4tap (CogFrame * frame, void *_dest,
     int component, int i)
 {
   uint8_t *dest = _dest;
@@ -518,14 +556,14 @@ cog_virt_frame_render_resample_vert (CogFrame * frame, void *_dest,
   uint8_t *src3;
   uint8_t *src4;
   int n_src;
-  double taps[4];
   double *scale = (double *) frame->virt_priv;
   double x;
   int src_i;
+  int y;
 
   x = (*scale) * i;
   src_i = floor (x);
-  get_taps (taps, x - floor (x));
+  y = 256 * (x - floor (x));
 
   n_src = frame->virt_frame1->components[component].height;
   src1 = cog_virt_frame_get_line (frame->virt_frame1, component,
@@ -538,9 +576,10 @@ cog_virt_frame_render_resample_vert (CogFrame * frame, void *_dest,
       CLAMP (src_i + 2, 0, n_src - 1));
 
   cogorc_combine4_u8 (dest, src1, src2, src3, src4,
-      rint (taps[0] * 64.0), rint (taps[1] * 64.0),
+      cog_resample_table_4tap[y][0],
-      rint (taps[2] * 64.0), rint (taps[3] * 64.0),
+      cog_resample_table_4tap[y][1],
-      frame->components[component].width);
+      cog_resample_table_4tap[y][2],
+      cog_resample_table_4tap[y][3], frame->components[component].width);
 }
 
 CogFrame *
@@ -548,10 +587,17 @@ cog_virt_frame_new_vert_resample (CogFrame * vf, int height)
 {
   CogFrame *virt_frame;
   double *scale;
+  int taps = 4;
 
   virt_frame = cog_frame_new_virtual (NULL, vf->format, vf->width, height);
   virt_frame->virt_frame1 = vf;
-  virt_frame->render_line = cog_virt_frame_render_resample_vert;
+  if (taps == 1) {
+    virt_frame->render_line = cog_virt_frame_render_resample_vert_1tap;
+  } else if (taps == 2) {
+    virt_frame->render_line = cog_virt_frame_render_resample_vert_2tap;
+  } else {
+    virt_frame->render_line = cog_virt_frame_render_resample_vert_4tap;
+  }
 
   scale = malloc (sizeof (double));
   virt_frame->virt_priv = scale;
@@ -562,34 +608,91 @@ cog_virt_frame_new_vert_resample (CogFrame * vf, int height)
 }
 
 void
-cog_virt_frame_render_resample_horiz (CogFrame * frame, void *_dest,
+cog_virt_frame_render_resample_horiz_1tap (CogFrame * frame, void *_dest,
     int component, int i)
 {
   uint8_t *dest = _dest;
   uint8_t *src;
   int j;
   int n_src;
-  double taps[4];
+  int scale = frame->param1;
-  double *scale = (double *) frame->virt_priv;
+  int acc;
-  int src_i;
 
   n_src = frame->virt_frame1->components[component].width;
   src = cog_virt_frame_get_line (frame->virt_frame1, component, i);
 
+  acc = 0;
   for (j = 0; j < frame->components[component].width; j++) {
-    double x;
+    dest[j] = src[(acc >> 8)];
-    double y = 0;
+    acc += scale;
+  }
+}
 
-    x = (*scale) * j;
+void
-    src_i = floor (x);
+cog_virt_frame_render_resample_horiz_4tap (CogFrame * frame, void *_dest,
-    get_taps (taps, x - floor (x));
+    int component, int i)
+{
+  uint8_t *dest = _dest;
+  uint8_t *src;
+  int j;
+  int n_src;
+  int scale = frame->param1;
+  int acc;
 
-    y = 0;
+  n_src = frame->virt_frame1->components[component].width;
-    y += taps[0] * src[CLAMP (src_i - 1, 0, n_src - 1)];
+  src = cog_virt_frame_get_line (frame->virt_frame1, component, i);
-    y += taps[1] * src[CLAMP (src_i + 0, 0, n_src - 1)];
+
-    y += taps[2] * src[CLAMP (src_i + 1, 0, n_src - 1)];
+  acc = 0;
-    y += taps[3] * src[CLAMP (src_i + 2, 0, n_src - 1)];
+  for (j = 0; j < 1; j++) {
-    dest[j] = CLAMP (rint (y), 0, 255);
+    int src_i;
+    int y;
+    int z;
+
+    src_i = acc >> 8;
+    y = acc & 255;
+
+    z = 32;
+    z += cog_resample_table_4tap[y][0] * src[CLAMP (src_i - 1, 0, n_src - 1)];
+    z += cog_resample_table_4tap[y][1] * src[CLAMP (src_i + 0, 0, n_src - 1)];
+    z += cog_resample_table_4tap[y][2] * src[CLAMP (src_i + 1, 0, n_src - 1)];
+    z += cog_resample_table_4tap[y][3] * src[CLAMP (src_i + 2, 0, n_src - 1)];
+    z >>= 6;
+    dest[j] = CLAMP (z, 0, 255);
+    acc += scale;
+  }
+  for (; j < frame->components[component].width - 2; j++) {
+    int src_i;
+    int y;
+    int z;
+
+    src_i = acc >> 8;
+    y = acc & 255;
+
+    z = 32;
+    z += cog_resample_table_4tap[y][0] * src[src_i - 1];
+    z += cog_resample_table_4tap[y][1] * src[src_i + 0];
+    z += cog_resample_table_4tap[y][2] * src[src_i + 1];
+    z += cog_resample_table_4tap[y][3] * src[src_i + 2];
+    z >>= 6;
+    dest[j] = CLAMP (z, 0, 255);
+    acc += scale;
+  }
+  for (; j < frame->components[component].width; j++) {
+    int src_i;
+    int y;
+    int z;
+
+    src_i = acc >> 8;
+    y = acc & 255;
+
+    z = 32;
+    z += cog_resample_table_4tap[y][0] * src[CLAMP (src_i - 1, 0, n_src - 1)];
+    z += cog_resample_table_4tap[y][1] * src[CLAMP (src_i + 0, 0, n_src - 1)];
+    z += cog_resample_table_4tap[y][2] * src[CLAMP (src_i + 1, 0, n_src - 1)];
+    z += cog_resample_table_4tap[y][3] * src[CLAMP (src_i + 2, 0, n_src - 1)];
+    z >>= 6;
+    dest[j] = CLAMP (z, 0, 255);
+    acc += scale;
   }
 }
 
@@ -598,15 +701,21 @@ cog_virt_frame_new_horiz_resample (CogFrame * vf, int width)
 {
   CogFrame *virt_frame;
   double *scale;
+  int taps = 4;
 
   virt_frame = cog_frame_new_virtual (NULL, vf->format, width, vf->height);
   virt_frame->virt_frame1 = vf;
-  virt_frame->render_line = cog_virt_frame_render_resample_horiz;
+  if (taps == 1) {
+    virt_frame->render_line = cog_virt_frame_render_resample_horiz_1tap;
+  } else {
+    virt_frame->render_line = cog_virt_frame_render_resample_horiz_4tap;
+  }
 
   scale = malloc (sizeof (double));
   virt_frame->virt_priv = scale;
 
   *scale = (double) vf->width / width;
+  virt_frame->param1 = 256.0 * (*scale);
 
   return virt_frame;
 }