libvpx: Add VP9 decoder.

source/libvpx/vp9/common/vp9_reconintra4x4.c

+/*
+ *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+
+#include "vpx_ports/config.h"
+#include "vpx_mem/vpx_mem.h"
+#include "vp9/common/vp9_reconintra.h"
+#include "vp9_rtcd.h"
+
+#if CONFIG_NEWBINTRAMODES
+static int find_grad_measure(unsigned char *x, int stride, int n, int t,
+                             int dx, int dy) {
+  int i, j;
+  int count = 0, gsum = 0, gdiv;
+  /* TODO: Make this code more efficient by breaking up into two loops */
+  for (i = -t; i < n; ++i)
+    for (j = -t; j < n; ++j) {
+      int g;
+      if (i >= 0 && j >= 0) continue;
+      if (i + dy >= 0 && j + dx >= 0) continue;
+      if (i + dy < -t || i + dy >= n || j + dx < -t || j + dx >= n) continue;
+      g = abs(x[(i + dy) * stride + j + dx] - x[i * stride + j]);
+      gsum += g * g;
+      count++;
+    }
+  gdiv = (dx * dx + dy * dy) * count;
+  return ((gsum << 8) + (gdiv >> 1)) / gdiv;
+}
+
+#if CONTEXT_PRED_REPLACEMENTS == 6
+B_PREDICTION_MODE vp9_find_dominant_direction(
+    unsigned char *ptr, int stride, int n) {
+  int g[8], i, imin, imax;
+  g[1] = find_grad_measure(ptr, stride, n, 4,  2, 1);
+  g[2] = find_grad_measure(ptr, stride, n, 4,  1, 1);
+  g[3] = find_grad_measure(ptr, stride, n, 4,  1, 2);
+  g[5] = find_grad_measure(ptr, stride, n, 4, -1, 2);
+  g[6] = find_grad_measure(ptr, stride, n, 4, -1, 1);
+  g[7] = find_grad_measure(ptr, stride, n, 4, -2, 1);
+  imin = 1;
+  for (i = 2; i < 8; i += 1 + (i == 3))
+    imin = (g[i] < g[imin] ? i : imin);
+  imax = 1;
+  for (i = 2; i < 8; i += 1 + (i == 3))
+    imax = (g[i] > g[imax] ? i : imax);
+  /*
+  printf("%d %d %d %d %d %d = %d %d\n",
+         g[1], g[2], g[3], g[5], g[6], g[7], imin, imax);
+         */
+  switch (imin) {
+    case 1:
+      return B_HD_PRED;
+    case 2:
+      return B_RD_PRED;
+    case 3:
+      return B_VR_PRED;
+    case 5:
+      return B_VL_PRED;
+    case 6:
+      return B_LD_PRED;
+    case 7:
+      return B_HU_PRED;
+    default:
+      assert(0);
+  }
+}
+#elif CONTEXT_PRED_REPLACEMENTS == 4
+B_PREDICTION_MODE vp9_find_dominant_direction(
+    unsigned char *ptr, int stride, int n) {
+  int g[8], i, imin, imax;
+  g[1] = find_grad_measure(ptr, stride, n, 4,  2, 1);
+  g[3] = find_grad_measure(ptr, stride, n, 4,  1, 2);
+  g[5] = find_grad_measure(ptr, stride, n, 4, -1, 2);
+  g[7] = find_grad_measure(ptr, stride, n, 4, -2, 1);
+  imin = 1;
+  for (i = 3; i < 8; i+=2)
+    imin = (g[i] < g[imin] ? i : imin);
+  imax = 1;
+  for (i = 3; i < 8; i+=2)
+    imax = (g[i] > g[imax] ? i : imax);
+  /*
+  printf("%d %d %d %d = %d %d\n",
+         g[1], g[3], g[5], g[7], imin, imax);
+         */
+  switch (imin) {
+    case 1:
+      return B_HD_PRED;
+    case 3:
+      return B_VR_PRED;
+    case 5:
+      return B_VL_PRED;
+    case 7:
+      return B_HU_PRED;
+    default:
+      assert(0);
+  }
+}
+#elif CONTEXT_PRED_REPLACEMENTS == 0
+B_PREDICTION_MODE vp9_find_dominant_direction(
+    unsigned char *ptr, int stride, int n) {
+  int g[8], i, imin, imax;
+  g[0] = find_grad_measure(ptr, stride, n, 4,  1, 0);
+  g[1] = find_grad_measure(ptr, stride, n, 4,  2, 1);
+  g[2] = find_grad_measure(ptr, stride, n, 4,  1, 1);
+  g[3] = find_grad_measure(ptr, stride, n, 4,  1, 2);
+  g[4] = find_grad_measure(ptr, stride, n, 4,  0, 1);
+  g[5] = find_grad_measure(ptr, stride, n, 4, -1, 2);
+  g[6] = find_grad_measure(ptr, stride, n, 4, -1, 1);
+  g[7] = find_grad_measure(ptr, stride, n, 4, -2, 1);
+  imax = 0;
+  for (i = 1; i < 8; i++)
+    imax = (g[i] > g[imax] ? i : imax);
+  imin = 0;
+  for (i = 1; i < 8; i++)
+    imin = (g[i] < g[imin] ? i : imin);
+
+  switch (imin) {
+    case 0:
+      return B_HE_PRED;
+    case 1:
+      return B_HD_PRED;
+    case 2:
+      return B_RD_PRED;
+    case 3:
+      return B_VR_PRED;
+    case 4:
+      return B_VE_PRED;
+    case 5:
+      return B_VL_PRED;
+    case 6:
+      return B_LD_PRED;
+    case 7:
+      return B_HU_PRED;
+    default:
+      assert(0);
+  }
+}
+#endif
+
+B_PREDICTION_MODE vp9_find_bpred_context(BLOCKD *x) {
+  unsigned char *ptr = *(x->base_dst) + x->dst;
+  int stride = x->dst_stride;
+  return vp9_find_dominant_direction(ptr, stride, 4);
+}
+#endif
+
+void vp9_intra4x4_predict(BLOCKD *x,
+                          int b_mode,
+                          unsigned char *predictor) {
+  int i, r, c;
+
+  unsigned char *Above = *(x->base_dst) + x->dst - x->dst_stride;
+  unsigned char Left[4];
+  unsigned char top_left = Above[-1];
+
+  Left[0] = (*(x->base_dst))[x->dst - 1];
+  Left[1] = (*(x->base_dst))[x->dst - 1 + x->dst_stride];
+  Left[2] = (*(x->base_dst))[x->dst - 1 + 2 * x->dst_stride];
+  Left[3] = (*(x->base_dst))[x->dst - 1 + 3 * x->dst_stride];
+
+#if CONFIG_NEWBINTRAMODES
+  if (b_mode == B_CONTEXT_PRED)
+    b_mode = x->bmi.as_mode.context;
+#endif
+
+  switch (b_mode) {
+    case B_DC_PRED: {
+      int expected_dc = 0;
+
+      for (i = 0; i < 4; i++) {
+        expected_dc += Above[i];
+        expected_dc += Left[i];
+      }
+
+      expected_dc = (expected_dc + 4) >> 3;
+
+      for (r = 0; r < 4; r++) {
+        for (c = 0; c < 4; c++) {
+          predictor[c] = expected_dc;
+        }
+
+        predictor += 16;
+      }
+    }
+    break;
+    case B_TM_PRED: {
+      /* prediction similar to true_motion prediction */
+      for (r = 0; r < 4; r++) {
+        for (c = 0; c < 4; c++) {
+          int pred = Above[c] - top_left + Left[r];
+
+          if (pred < 0)
+            pred = 0;
+
+          if (pred > 255)
+            pred = 255;
+
+          predictor[c] = pred;
+        }
+
+        predictor += 16;
+      }
+    }
+    break;
+
+    case B_VE_PRED: {
+
+      unsigned int ap[4];
+      ap[0] = Above[0];
+      ap[1] = Above[1];
+      ap[2] = Above[2];
+      ap[3] = Above[3];
+
+      for (r = 0; r < 4; r++) {
+        for (c = 0; c < 4; c++) {
+
+          predictor[c] = ap[c];
+        }
+
+        predictor += 16;
+      }
+
+    }
+    break;
+
+
+    case B_HE_PRED: {
+
+      unsigned int lp[4];
+      lp[0] = Left[0];
+      lp[1] = Left[1];
+      lp[2] = Left[2];
+      lp[3] = Left[3];
+
+      for (r = 0; r < 4; r++) {
+        for (c = 0; c < 4; c++) {
+          predictor[c] = lp[r];
+        }
+
+        predictor += 16;
+      }
+    }
+    break;
+    case B_LD_PRED: {
+      unsigned char *ptr = Above;
+      predictor[0 * 16 + 0] = (ptr[0] + ptr[1] * 2 + ptr[2] + 2) >> 2;
+      predictor[0 * 16 + 1] =
+        predictor[1 * 16 + 0] = (ptr[1] + ptr[2] * 2 + ptr[3] + 2) >> 2;
+      predictor[0 * 16 + 2] =
+        predictor[1 * 16 + 1] =
+          predictor[2 * 16 + 0] = (ptr[2] + ptr[3] * 2 + ptr[4] + 2) >> 2;
+      predictor[0 * 16 + 3] =
+        predictor[1 * 16 + 2] =
+          predictor[2 * 16 + 1] =
+            predictor[3 * 16 + 0] = (ptr[3] + ptr[4] * 2 + ptr[5] + 2) >> 2;
+      predictor[1 * 16 + 3] =
+        predictor[2 * 16 + 2] =
+          predictor[3 * 16 + 1] = (ptr[4] + ptr[5] * 2 + ptr[6] + 2) >> 2;
+      predictor[2 * 16 + 3] =
+        predictor[3 * 16 + 2] = (ptr[5] + ptr[6] * 2 + ptr[7] + 2) >> 2;
+      predictor[3 * 16 + 3] = (ptr[6] + ptr[7] * 2 + ptr[7] + 2) >> 2;
+
+    }
+    break;
+    case B_RD_PRED: {
+
+      unsigned char pp[9];
+
+      pp[0] = Left[3];
+      pp[1] = Left[2];
+      pp[2] = Left[1];
+      pp[3] = Left[0];
+      pp[4] = top_left;
+      pp[5] = Above[0];
+      pp[6] = Above[1];
+      pp[7] = Above[2];
+      pp[8] = Above[3];
+
+      predictor[3 * 16 + 0] = (pp[0] + pp[1] * 2 + pp[2] + 2) >> 2;
+      predictor[3 * 16 + 1] =
+        predictor[2 * 16 + 0] = (pp[1] + pp[2] * 2 + pp[3] + 2) >> 2;
+      predictor[3 * 16 + 2] =
+        predictor[2 * 16 + 1] =
+          predictor[1 * 16 + 0] = (pp[2] + pp[3] * 2 + pp[4] + 2) >> 2;
+      predictor[3 * 16 + 3] =
+        predictor[2 * 16 + 2] =
+          predictor[1 * 16 + 1] =
+            predictor[0 * 16 + 0] = (pp[3] + pp[4] * 2 + pp[5] + 2) >> 2;
+      predictor[2 * 16 + 3] =
+        predictor[1 * 16 + 2] =
+          predictor[0 * 16 + 1] = (pp[4] + pp[5] * 2 + pp[6] + 2) >> 2;
+      predictor[1 * 16 + 3] =
+        predictor[0 * 16 + 2] = (pp[5] + pp[6] * 2 + pp[7] + 2) >> 2;
+      predictor[0 * 16 + 3] = (pp[6] + pp[7] * 2 + pp[8] + 2) >> 2;
+
+    }
+    break;
+    case B_VR_PRED: {
+
+      unsigned char pp[9];
+
+      pp[0] = Left[3];
+      pp[1] = Left[2];
+      pp[2] = Left[1];
+      pp[3] = Left[0];
+      pp[4] = top_left;
+      pp[5] = Above[0];
+      pp[6] = Above[1];
+      pp[7] = Above[2];
+      pp[8] = Above[3];
+
+
+      predictor[3 * 16 + 0] = (pp[1] + pp[2] * 2 + pp[3] + 2) >> 2;
+      predictor[2 * 16 + 0] = (pp[2] + pp[3] * 2 + pp[4] + 2) >> 2;
+      predictor[3 * 16 + 1] =
+        predictor[1 * 16 + 0] = (pp[3] + pp[4] * 2 + pp[5] + 2) >> 2;
+      predictor[2 * 16 + 1] =
+        predictor[0 * 16 + 0] = (pp[4] + pp[5] + 1) >> 1;
+      predictor[3 * 16 + 2] =
+        predictor[1 * 16 + 1] = (pp[4] + pp[5] * 2 + pp[6] + 2) >> 2;
+      predictor[2 * 16 + 2] =
+        predictor[0 * 16 + 1] = (pp[5] + pp[6] + 1) >> 1;
+      predictor[3 * 16 + 3] =
+        predictor[1 * 16 + 2] = (pp[5] + pp[6] * 2 + pp[7] + 2) >> 2;
+      predictor[2 * 16 + 3] =
+        predictor[0 * 16 + 2] = (pp[6] + pp[7] + 1) >> 1;
+      predictor[1 * 16 + 3] = (pp[6] + pp[7] * 2 + pp[8] + 2) >> 2;
+      predictor[0 * 16 + 3] = (pp[7] + pp[8] + 1) >> 1;
+
+    }
+    break;
+    case B_VL_PRED: {
+
+      unsigned char *pp = Above;
+
+      predictor[0 * 16 + 0] = (pp[0] + pp[1] + 1) >> 1;
+      predictor[1 * 16 + 0] = (pp[0] + pp[1] * 2 + pp[2] + 2) >> 2;
+      predictor[2 * 16 + 0] =
+        predictor[0 * 16 + 1] = (pp[1] + pp[2] + 1) >> 1;
+      predictor[1 * 16 + 1] =
+        predictor[3 * 16 + 0] = (pp[1] + pp[2] * 2 + pp[3] + 2) >> 2;
+      predictor[2 * 16 + 1] =
+        predictor[0 * 16 + 2] = (pp[2] + pp[3] + 1) >> 1;
+      predictor[3 * 16 + 1] =
+        predictor[1 * 16 + 2] = (pp[2] + pp[3] * 2 + pp[4] + 2) >> 2;
+      predictor[0 * 16 + 3] =
+        predictor[2 * 16 + 2] = (pp[3] + pp[4] + 1) >> 1;
+      predictor[1 * 16 + 3] =
+        predictor[3 * 16 + 2] = (pp[3] + pp[4] * 2 + pp[5] + 2) >> 2;
+      predictor[2 * 16 + 3] = (pp[4] + pp[5] * 2 + pp[6] + 2) >> 2;
+      predictor[3 * 16 + 3] = (pp[5] + pp[6] * 2 + pp[7] + 2) >> 2;
+    }
+    break;
+
+    case B_HD_PRED: {
+      unsigned char pp[9];
+      pp[0] = Left[3];
+      pp[1] = Left[2];
+      pp[2] = Left[1];
+      pp[3] = Left[0];
+      pp[4] = top_left;
+      pp[5] = Above[0];
+      pp[6] = Above[1];
+      pp[7] = Above[2];
+      pp[8] = Above[3];
+
+
+      predictor[3 * 16 + 0] = (pp[0] + pp[1] + 1) >> 1;
+      predictor[3 * 16 + 1] = (pp[0] + pp[1] * 2 + pp[2] + 2) >> 2;
+      predictor[2 * 16 + 0] =
+        predictor[3 * 16 + 2] = (pp[1] + pp[2] + 1) >> 1;
+      predictor[2 * 16 + 1] =
+        predictor[3 * 16 + 3] = (pp[1] + pp[2] * 2 + pp[3] + 2) >> 2;
+      predictor[2 * 16 + 2] =
+        predictor[1 * 16 + 0] = (pp[2] + pp[3] + 1) >> 1;
+      predictor[2 * 16 + 3] =
+        predictor[1 * 16 + 1] = (pp[2] + pp[3] * 2 + pp[4] + 2) >> 2;
+      predictor[1 * 16 + 2] =
+        predictor[0 * 16 + 0] = (pp[3] + pp[4] + 1) >> 1;
+      predictor[1 * 16 + 3] =
+        predictor[0 * 16 + 1] = (pp[3] + pp[4] * 2 + pp[5] + 2) >> 2;
+      predictor[0 * 16 + 2] = (pp[4] + pp[5] * 2 + pp[6] + 2) >> 2;
+      predictor[0 * 16 + 3] = (pp[5] + pp[6] * 2 + pp[7] + 2) >> 2;
+    }
+    break;
+
+
+    case B_HU_PRED: {
+      unsigned char *pp = Left;
+      predictor[0 * 16 + 0] = (pp[0] + pp[1] + 1) >> 1;
+      predictor[0 * 16 + 1] = (pp[0] + pp[1] * 2 + pp[2] + 2) >> 2;
+      predictor[0 * 16 + 2] =
+        predictor[1 * 16 + 0] = (pp[1] + pp[2] + 1) >> 1;
+      predictor[0 * 16 + 3] =
+        predictor[1 * 16 + 1] = (pp[1] + pp[2] * 2 + pp[3] + 2) >> 2;
+      predictor[1 * 16 + 2] =
+        predictor[2 * 16 + 0] = (pp[2] + pp[3] + 1) >> 1;
+      predictor[1 * 16 + 3] =
+        predictor[2 * 16 + 1] = (pp[2] + pp[3] * 2 + pp[3] + 2) >> 2;
+      predictor[2 * 16 + 2] =
+        predictor[2 * 16 + 3] =
+          predictor[3 * 16 + 0] =
+            predictor[3 * 16 + 1] =
+              predictor[3 * 16 + 2] =
+                predictor[3 * 16 + 3] = pp[3];
+    }
+    break;
+
+#if CONFIG_NEWBINTRAMODES
+    case B_CONTEXT_PRED:
+    break;
+    /*
+    case B_CORNER_PRED:
+    corner_predictor(predictor, 16, 4, Above, Left);
+    break;
+    */
+#endif
+  }
+}
+
+#if CONFIG_COMP_INTRA_PRED
+void vp9_comp_intra4x4_predict_c(BLOCKD *x,
+                               int b_mode, int b_mode2,
+                               unsigned char *out_predictor) {
+  unsigned char predictor[2][4 * 16];
+  int i, j;
+
+  vp9_intra4x4_predict(x, b_mode, predictor[0]);
+  vp9_intra4x4_predict(x, b_mode2, predictor[1]);
+
+  for (i = 0; i < 16 * 4; i += 16) {
+    for (j = i; j < i + 4; j++) {
+      out_predictor[j] = (predictor[0][j] + predictor[1][j] + 1) >> 1;
+    }
+  }
+}
+#endif
+
+/* copy 4 bytes from the above right down so that the 4x4 prediction modes using pixels above and
+ * to the right prediction have filled in pixels to use.
+ */
+void vp9_intra_prediction_down_copy(MACROBLOCKD *xd) {
+  int extend_edge = (xd->mb_to_right_edge == 0 && xd->mb_index < 2);
+  unsigned char *above_right = *(xd->block[0].base_dst) + xd->block[0].dst -
+                               xd->block[0].dst_stride + 16;
+  unsigned int *src_ptr = (unsigned int *)
+      (above_right - (xd->mb_index == 3 ? 16 * xd->block[0].dst_stride : 0));
+
+  unsigned int *dst_ptr0 = (unsigned int *)above_right;
+  unsigned int *dst_ptr1 =
+    (unsigned int *)(above_right + 4 * xd->block[0].dst_stride);
+  unsigned int *dst_ptr2 =
+    (unsigned int *)(above_right + 8 * xd->block[0].dst_stride);
+  unsigned int *dst_ptr3 =
+    (unsigned int *)(above_right + 12 * xd->block[0].dst_stride);
+
+  if (extend_edge) {
+    *src_ptr = ((uint8_t *) src_ptr)[-1] * 0x01010101U;
+  }
+
+  *dst_ptr0 = *src_ptr;
+  *dst_ptr1 = *src_ptr;
+  *dst_ptr2 = *src_ptr;
+  *dst_ptr3 = *src_ptr;
+}