Import aom library

This is the reference implementation for the Alliance for Open Media's av1 video code.

The commit used was 4d668d7feb1f8abd809d1bca0418570a7f142a36.

third_party/aom/av1/common/cfl.c

@@ -0,0 +1,240 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include "av1/common/cfl.h"
+#include "av1/common/common_data.h"
+#include "av1/common/onyxc_int.h"
+
+#include "aom/internal/aom_codec_internal.h"
+
+void cfl_init(CFL_CTX *cfl, AV1_COMMON *cm, int subsampling_x,
+              int subsampling_y) {
+  if (!((subsampling_x == 0 && subsampling_y == 0) ||
+        (subsampling_x == 1 && subsampling_y == 1))) {
+    aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
+                       "Only 4:4:4 and 4:2:0 are currently supported by CfL");
+  }
+  memset(&cfl->y_pix, 0, sizeof(uint8_t) * MAX_SB_SQUARE);
+  cfl->subsampling_x = subsampling_x;
+  cfl->subsampling_y = subsampling_y;
+}
+
+// CfL computes its own block-level DC_PRED. This is required to compute both
+// alpha_cb and alpha_cr before the prediction are computed.
+void cfl_dc_pred(MACROBLOCKD *xd, BLOCK_SIZE plane_bsize, TX_SIZE tx_size) {
+  const struct macroblockd_plane *const pd_u = &xd->plane[AOM_PLANE_U];
+  const struct macroblockd_plane *const pd_v = &xd->plane[AOM_PLANE_V];
+
+  const uint8_t *const dst_u = pd_u->dst.buf;
+  const uint8_t *const dst_v = pd_v->dst.buf;
+
+  const int dst_u_stride = pd_u->dst.stride;
+  const int dst_v_stride = pd_v->dst.stride;
+
+  const int block_width = (plane_bsize != BLOCK_INVALID)
+                              ? block_size_wide[plane_bsize]
+                              : tx_size_wide[tx_size];
+  const int block_height = (plane_bsize != BLOCK_INVALID)
+                               ? block_size_high[plane_bsize]
+                               : tx_size_high[tx_size];
+
+  // Number of pixel on the top and left borders.
+  const int num_pel = block_width + block_height;
+
+  int sum_u = 0;
+  int sum_v = 0;
+
+  // Match behavior of build_intra_predictors (reconintra.c) at superblock
+  // boundaries:
+  //
+  // 127 127 127 .. 127 127 127 127 127 127
+  // 129  A   B  ..  Y   Z
+  // 129  C   D  ..  W   X
+  // 129  E   F  ..  U   V
+  // 129  G   H  ..  S   T   T   T   T   T
+  // ..
+
+  // TODO(ltrudeau) replace this with DC_PRED assembly
+  if (xd->up_available && xd->mb_to_right_edge >= 0) {
+    for (int i = 0; i < block_width; i++) {
+      sum_u += dst_u[-dst_u_stride + i];
+      sum_v += dst_v[-dst_v_stride + i];
+    }
+  } else {
+    sum_u = block_width * 127;
+    sum_v = block_width * 127;
+  }
+
+  if (xd->left_available && xd->mb_to_bottom_edge >= 0) {
+    for (int i = 0; i < block_height; i++) {
+      sum_u += dst_u[i * dst_u_stride - 1];
+      sum_v += dst_v[i * dst_v_stride - 1];
+    }
+  } else {
+    sum_u += block_height * 129;
+    sum_v += block_height * 129;
+  }
+
+  xd->cfl->dc_pred[CFL_PRED_U] = (sum_u + (num_pel >> 1)) / num_pel;
+  xd->cfl->dc_pred[CFL_PRED_V] = (sum_v + (num_pel >> 1)) / num_pel;
+}
+
+// Predict the current transform block using CfL.
+// it is assumed that dst points at the start of the transform block
+void cfl_predict_block(const CFL_CTX *cfl, uint8_t *dst, int dst_stride,
+                       int row, int col, TX_SIZE tx_size, int dc_pred) {
+  const int tx_block_width = tx_size_wide[tx_size];
+  const int tx_block_height = tx_size_high[tx_size];
+
+  // TODO(ltrudeau) implement alpha
+  // Place holder for alpha
+  const double alpha = 0;
+  const double y_avg = cfl_load(cfl, dst, dst_stride, row, col, tx_size);
+
+  for (int j = 0; j < tx_block_height; j++) {
+    for (int i = 0; i < tx_block_width; i++) {
+      dst[i] = (uint8_t)(alpha * y_avg + dc_pred + 0.5);
+    }
+    dst += dst_stride;
+  }
+}
+
+void cfl_store(CFL_CTX *cfl, const uint8_t *input, int input_stride, int row,
+               int col, TX_SIZE tx_size) {
+  const int tx_width = tx_size_wide[tx_size];
+  const int tx_height = tx_size_high[tx_size];
+  const int tx_off_log2 = tx_size_wide_log2[0];
+
+  // Store the input into the CfL pixel buffer
+  uint8_t *y_pix = &cfl->y_pix[(row * MAX_SB_SIZE + col) << tx_off_log2];
+
+  // Check that we remain inside the pixel buffer.
+  assert(MAX_SB_SIZE * (row + tx_height - 1) + col + tx_width - 1 <
+         MAX_SB_SQUARE);
+
+  for (int j = 0; j < tx_height; j++) {
+    for (int i = 0; i < tx_width; i++) {
+      y_pix[i] = input[i];
+    }
+    y_pix += MAX_SB_SIZE;
+    input += input_stride;
+  }
+
+  // Store the surface of the pixel buffer that was written to, this way we
+  // can manage chroma overrun (e.g. when the chroma surfaces goes beyond the
+  // frame boundary)
+  if (col == 0 && row == 0) {
+    cfl->y_width = tx_width;
+    cfl->y_height = tx_height;
+  } else {
+    cfl->y_width = OD_MAXI((col << tx_off_log2) + tx_width, cfl->y_width);
+    cfl->y_height = OD_MAXI((row << tx_off_log2) + tx_height, cfl->y_height);
+  }
+}
+
+// Load from the CfL pixel buffer into output
+double cfl_load(const CFL_CTX *cfl, uint8_t *output, int output_stride, int row,
+                int col, TX_SIZE tx_size) {
+  const int tx_width = tx_size_wide[tx_size];
+  const int tx_height = tx_size_high[tx_size];
+  const int sub_x = cfl->subsampling_x;
+  const int sub_y = cfl->subsampling_y;
+  const int tx_off_log2 = tx_size_wide_log2[0];
+
+  const uint8_t *y_pix;
+
+  int diff_width = 0;
+  int diff_height = 0;
+
+  int pred_row_offset = 0;
+  int output_row_offset = 0;
+  int top_left, bot_left;
+
+  // TODO(ltrudeau) add support for 4:2:2
+  if (sub_y == 0 && sub_x == 0) {
+    y_pix = &cfl->y_pix[(row * MAX_SB_SIZE + col) << tx_off_log2];
+    int uv_width = (col << tx_off_log2) + tx_width;
+    diff_width = uv_width - cfl->y_width;
+    int uv_height = (row << tx_off_log2) + tx_width;
+    diff_height = uv_height - cfl->y_height;
+    for (int j = 0; j < tx_height; j++) {
+      for (int i = 0; i < tx_width; i++) {
+        // In 4:4:4, pixels match 1 to 1
+        output[output_row_offset + i] = y_pix[pred_row_offset + i];
+      }
+      pred_row_offset += MAX_SB_SIZE;
+      output_row_offset += output_stride;
+    }
+  } else if (sub_y == 1 && sub_x == 1) {
+    y_pix = &cfl->y_pix[(row * MAX_SB_SIZE + col) << (tx_off_log2 + sub_y)];
+    int uv_width = ((col << tx_off_log2) + tx_width) << sub_x;
+    diff_width = (uv_width - cfl->y_width) >> sub_x;
+    int uv_height = ((row << tx_off_log2) + tx_width) << sub_y;
+    diff_height = (uv_height - cfl->y_height) >> sub_y;
+    for (int j = 0; j < tx_height; j++) {
+      for (int i = 0; i < tx_width; i++) {
+        top_left = (pred_row_offset + i) << sub_y;
+        bot_left = top_left + MAX_SB_SIZE;
+        // In 4:2:0, average pixels in 2x2 grid
+        output[output_row_offset + i] = OD_SHR_ROUND(
+            y_pix[top_left] + y_pix[top_left + 1]        // Top row
+                + y_pix[bot_left] + y_pix[bot_left + 1]  // Bottom row
+            ,
+            2);
+      }
+      pred_row_offset += MAX_SB_SIZE;
+      output_row_offset += output_stride;
+    }
+  } else {
+    assert(0);  // Unsupported chroma subsampling
+  }
+  // Due to frame boundary issues, it is possible that the total area of
+  // covered by Chroma exceeds that of Luma. When this happens, we write over
+  // the broken data by repeating the last columns and/or rows.
+  //
+  // Note that in order to manage the case where both rows and columns
+  // overrun,
+  // we apply rows first. This way, when the rows overrun the bottom of the
+  // frame, the columns will be copied over them.
+  if (diff_width > 0) {
+    int last_pixel;
+    output_row_offset = tx_width - diff_width;
+
+    for (int j = 0; j < tx_height; j++) {
+      last_pixel = output_row_offset - 1;
+      for (int i = 0; i < diff_width; i++) {
+        output[output_row_offset + i] = output[last_pixel];
+      }
+      output_row_offset += output_stride;
+    }
+  }
+
+  if (diff_height > 0) {
+    output_row_offset = diff_height * output_stride;
+    const int last_row_offset = output_row_offset - output_stride;
+    for (int j = 0; j < diff_height; j++) {
+      for (int i = 0; i < tx_width; i++) {
+        output[output_row_offset + i] = output[last_row_offset + i];
+      }
+      output_row_offset += output_stride;
+    }
+  }
+
+  int avg = 0;
+  output_row_offset = 0;
+  for (int j = 0; j < tx_height; j++) {
+    for (int i = 0; i < tx_width; i++) {
+      avg += output[output_row_offset + i];
+    }
+    output_row_offset += output_stride;
+  }
+  return avg / (double)(tx_width * tx_height);
+}