Add hi_prec_buf_t for higher precision intermediate values for interpolation filter.

src/image.c

@@ -172,6 +172,28 @@ void yuv_t_free(yuv_t * yuv)
   free(yuv);
 }
 
+hi_prec_buf_t * hi_prec_buf_t_alloc(int luma_size)
+{
+  // Get buffers with separate mallocs in order to take advantage of
+  // automatic buffer overrun checks.
+  hi_prec_buf_t *yuv = (hi_prec_buf_t *)malloc(sizeof(*yuv));
+  yuv->y = (int16_t *)malloc(luma_size * sizeof(*yuv->y));
+  yuv->u = (int16_t *)malloc(luma_size / 2 * sizeof(*yuv->u));
+  yuv->v = (int16_t *)malloc(luma_size / 2 * sizeof(*yuv->v));
+  yuv->size = luma_size;
+
+  return yuv;
+}
+
+void hi_prec_buf_t_free(hi_prec_buf_t * yuv)
+{
+  free(yuv->y);
+  free(yuv->u);
+  free(yuv->v);
+  free(yuv);
+}
+
+
 /**
  * \brief Diagonally interpolate SAD outside the frame.
  *

src/image.h

@@ -34,6 +34,13 @@ typedef struct {
   kvz_pixel v[LCU_CHROMA_SIZE];
 } lcu_yuv_t;
 
+typedef struct {
+  int size;
+  int16_t *y;
+  int16_t *u;
+  int16_t *v;
+} hi_prec_buf_t;
+
 typedef struct {
   int size;
   kvz_pixel *y;
@@ -57,6 +64,10 @@ kvz_picture *image_make_subimage(kvz_picture *const orig_image,
 yuv_t * yuv_t_alloc(int luma_size);
 void yuv_t_free(yuv_t * yuv);
 
+hi_prec_buf_t * hi_prec_buf_t_alloc(int luma_size);
+void hi_prec_buf_t_free(hi_prec_buf_t * yuv);
+
+
 //Algorithms
 unsigned image_calc_sad(const kvz_picture *pic, const kvz_picture *ref, int pic_x, int pic_y, int ref_x, int ref_y,
                         int block_width, int block_height, int max_lcu_below);