Debug option for drawing motion vectors.

Postproc level that uses Bresenham's line algorithm
to draw motion vectors onto the postproc buffer.

Change-Id: I34c7daa324f2bdfee71e84fcb1c50b90fa06f6fb

vp8/common/postproc.c

@@ -76,7 +76,7 @@ const short vp8_rv[] =
 
 
 extern void vp8_blit_text(const char *msg, unsigned char *address, const int pitch);
-
+extern void vp8_blit_line(int x0, int x1, int y0, int y1, unsigned char *image, const int pitch);
 /***********************************************************************************************************
  */
 void vp8_post_proc_down_and_across_c
@@ -450,6 +450,45 @@ void vp8_plane_add_noise_c(unsigned char *Start, char *noise,
 #define RTCD_VTABLE(oci) NULL
 #endif
 
+static void constrain_line (int x0, int *x1, int y0, int *y1, int width, int height)
+{
+    int dx = *x1 - x0;
+    int dy = *y1 - y0;
+
+    if (*x1 > width)
+    {
+        *x1 = width;
+        if (dy)
+            *y1 = ((width-x0)*dy)/dx + y0;
+        dx = *x1 - x0;
+        dy = *y1 - y0;
+    }
+    if (*x1 < 0)
+    {
+        *x1 = 0;
+        if (dy)
+            *y1 = ((0-x0)*dy)/dx + y0;
+        dx = *x1 - x0;
+        dy = *y1 - y0;
+    }
+    if (*y1 > height)
+    {
+        *y1 = height;
+        if (dx)
+            *x1 = ((height-y0)*dx)/dy + x0;
+        dx = *x1 - x0;
+        dy = *y1 - y0;
+    }
+    if (*y1 < 0)
+    {
+        *y1 = 0;
+        if (dx)
+            *x1 = ((0-y0)*dx)/dy + x0;
+        dx = *x1 - x0;
+        dy = *y1 - y0;
+    }
+}
+
 int vp8_post_proc_frame(VP8_COMMON *oci, YV12_BUFFER_CONFIG *dest, int deblock_level, int noise_level, int flags)
 {
     char message[512];
@@ -622,8 +661,37 @@ int vp8_post_proc_frame(VP8_COMMON *oci, YV12_BUFFER_CONFIG *dest, int deblock_l
 #endif
 
     }
+    else if (flags & VP8D_DEBUG_LEVEL5)
+    {
+        YV12_BUFFER_CONFIG *post = &oci->post_proc_buffer;
+        int width  = post->y_width;
+        int height = post->y_height;
+        int mb_cols = width  >> 4;
+        unsigned char *y_buffer = oci->post_proc_buffer.y_buffer;
+        int y_stride = oci->post_proc_buffer.y_stride;
+        MODE_INFO *mi = oci->mi;
+        int x0, y0;
+
+        for (y0 = 8; y0 < (height + 8); y0 += 16)
+        {
+            for (x0 = 8; x0 < (width + 8); x0 += 16)
+            {
+               int x1, y1;
+               if (mi->mbmi.mode >= NEARESTMV)
+                {
+                    MV *mv = &mi->mbmi.mv.as_mv;
 
+                    x1 = x0 + (mv->col >> 3);
+                    y1 = y0 + (mv->row >> 3);
 
+                    constrain_line (x0, &x1, y0, &y1, width, height);
+                    vp8_blit_line (x0, x1, y0, y1, y_buffer, y_stride);
+                }
+                mi++;
+            }
+            mi++;
+        }
+    }
 
     *dest = oci->post_proc_buffer;
 

vp8/common/ppflags.h

@@ -21,6 +21,7 @@ enum
     VP8D_DEBUG_LEVEL2   = 16,
     VP8D_DEBUG_LEVEL3   = 32,
     VP8D_DEBUG_LEVEL4   = 64,
+    VP8D_DEBUG_LEVEL5   = 128,
 };
 
 #endif

vp8/common/textblit.c

@@ -8,7 +8,7 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-
+#include <stdlib.h>
 
 
 void vp8_blit_text(const char *msg, unsigned char *address, const int pitch)
@@ -51,3 +51,80 @@ void vp8_blit_text(const char *msg, unsigned char *address, const int pitch)
         colpos++;
     }
 }
+
+static void plot (const int x, const int y, unsigned char *image, const int pitch)
+{
+    image [x+y*pitch] ^= 255;
+}
+
+// Bresenham line algorithm
+void vp8_blit_line(int x0, int x1, int y0, int y1, unsigned char *image, const int pitch)
+{
+    int steep = abs(y1 - y0) > abs(x1 - x0);
+    int deltax, deltay;
+    int error, ystep, y, x;
+
+    if (steep)
+    {
+        int t;
+        t = x0;
+        x0 = y0;
+        y0 = t;
+
+        t = x1;
+        x1 = y1;
+        y1 = t;
+    }
+
+    if (x0 > x1)
+    {
+        int t;
+        t = x0;
+        x0 = x1;
+        x1 = t;
+
+        t = y0;
+        y0 = y1;
+        y1 = t;
+    }
+
+    deltax = x1 - x0;
+    deltay = abs(y1 - y0);
+    error  = deltax / 2;
+
+    y = y0;
+
+    if (y0 < y1)
+        ystep = 1;
+    else
+        ystep = -1;
+
+    if (steep)
+    {
+        for (x = x0; x <= x1; x++)
+        {
+            plot(y,x, image, pitch);
+
+            error = error - deltay;
+            if (error < 0)
+            {
+                y = y + ystep;
+                error = error + deltax;
+            }
+        }
+    }
+    else
+    {
+        for (x = x0; x <= x1; x++)
+        {
+            plot(x,y, image, pitch);
+
+            error = error - deltay;
+            if (error < 0)
+            {
+                y = y + ystep;
+                error = error + deltax;
+            }
+        }
+    }
+}