third_party/libyuv/source/planar_functions.c

/*
 *  Copyright 2011 The LibYuv 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 "libyuv/planar_functions.h"

#include <assert.h>
#include <string.h>  // for memset()

#include "libyuv/row.h"
#include "libyuv/scale_row.h"  // for ScaleRowDown2

// Copy a plane of data
void CopyPlane(const uint8_t* src_y,
               int src_stride_y,
               uint8_t* dst_y,
               int dst_stride_y,
               int width,
               int height) {
  int y;
  void (*CopyRow)(const uint8_t* src, uint8_t* dst, int width) = CopyRow_C;
  if (width <= 0 || height == 0) {
    return;
  }
  // Negative height means invert the image.
  if (height < 0) {
    height = -height;
    dst_y = dst_y + (height - 1) * dst_stride_y;
    dst_stride_y = -dst_stride_y;
  }
  // Coalesce rows.
  if (src_stride_y == width && dst_stride_y == width) {
    width *= height;
    height = 1;
    src_stride_y = dst_stride_y = 0;
  }
  // Nothing to do.
  if (src_y == dst_y && src_stride_y == dst_stride_y) {
    return;
  }

  // Copy plane
  for (y = 0; y < height; ++y) {
    CopyRow(src_y, dst_y, width);
    src_y += src_stride_y;
    dst_y += dst_stride_y;
  }
}

void CopyPlane_16(const uint16_t* src_y,
                  int src_stride_y,
                  uint16_t* dst_y,
                  int dst_stride_y,
                  int width,
                  int height) {
  CopyPlane((const uint8_t*)src_y, src_stride_y * 2, (uint8_t*)dst_y,
            dst_stride_y * 2, width * 2, height);
}