libvpx: Add VP9 decoder.

source/libvpx/vp9/common/vp9_mbpitch.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 "vp9/common/vp9_blockd.h"
+
+typedef enum {
+  PRED = 0,
+  DEST = 1
+} BLOCKSET;
+
+static void setup_block
+(
+  BLOCKD *b,
+  int mv_stride,
+  unsigned char **base,
+  unsigned char **base2,
+  int Stride,
+  int offset,
+  BLOCKSET bs
+) {
+
+  if (bs == DEST) {
+    b->dst_stride = Stride;
+    b->dst = offset;
+    b->base_dst = base;
+  } else {
+    b->pre_stride = Stride;
+    b->pre = offset;
+    b->base_pre = base;
+    b->base_second_pre = base2;
+  }
+
+}
+
+
+static void setup_macroblock(MACROBLOCKD *xd, BLOCKSET bs) {
+  int block;
+
+  unsigned char **y, **u, **v;
+  unsigned char **y2, **u2, **v2;
+  BLOCKD *blockd = xd->block;
+  int stride;
+
+  if (bs == DEST) {
+    y = &xd->dst.y_buffer;
+    u = &xd->dst.u_buffer;
+    v = &xd->dst.v_buffer;
+  } else {
+    y = &xd->pre.y_buffer;
+    u = &xd->pre.u_buffer;
+    v = &xd->pre.v_buffer;
+
+    y2 = &xd->second_pre.y_buffer;
+    u2 = &xd->second_pre.u_buffer;
+    v2 = &xd->second_pre.v_buffer;
+  }
+
+  stride = xd->dst.y_stride;
+  for (block = 0; block < 16; block++) { /* y blocks */
+    setup_block(&blockd[block], stride, y, y2, stride,
+                (block >> 2) * 4 * stride + (block & 3) * 4, bs);
+  }
+
+  stride = xd->dst.uv_stride;
+  for (block = 16; block < 20; block++) { /* U and V blocks */
+    setup_block(&blockd[block], stride, u, u2, stride,
+      ((block - 16) >> 1) * 4 * stride + (block & 1) * 4, bs);
+
+    setup_block(&blockd[block + 4], stride, v, v2, stride,
+      ((block - 16) >> 1) * 4 * stride + (block & 1) * 4, bs);
+  }
+}
+
+void vp9_setup_block_dptrs(MACROBLOCKD *xd) {
+  int r, c;
+  BLOCKD *blockd = xd->block;
+
+  for (r = 0; r < 4; r++) {
+    for (c = 0; c < 4; c++) {
+      blockd[r * 4 + c].diff = &xd->diff[r * 4 * 16 + c * 4];
+      blockd[r * 4 + c].predictor = xd->predictor + r * 4 * 16 + c * 4;
+    }
+  }
+
+  for (r = 0; r < 2; r++) {
+    for (c = 0; c < 2; c++) {
+      blockd[16 + r * 2 + c].diff = &xd->diff[256 + r * 4 * 8 + c * 4];
+      blockd[16 + r * 2 + c].predictor =
+        xd->predictor + 256 + r * 4 * 8 + c * 4;
+
+    }
+  }
+
+  for (r = 0; r < 2; r++) {
+    for (c = 0; c < 2; c++) {
+      blockd[20 + r * 2 + c].diff = &xd->diff[320 + r * 4 * 8 + c * 4];
+      blockd[20 + r * 2 + c].predictor =
+        xd->predictor + 320 + r * 4 * 8 + c * 4;
+
+    }
+  }
+
+  blockd[24].diff = &xd->diff[384];
+
+  for (r = 0; r < 25; r++) {
+    blockd[r].qcoeff  = xd->qcoeff  + r * 16;
+    blockd[r].dqcoeff = xd->dqcoeff + r * 16;
+  }
+}
+
+void vp9_build_block_doffsets(MACROBLOCKD *xd) {
+
+  /* handle the destination pitch features */
+  setup_macroblock(xd, DEST);
+  setup_macroblock(xd, PRED);
+}