text: /*
   *  Copyright 2012 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/convert_from.h"
  
  #include "libyuv/basic_types.h"
  #include "libyuv/convert.h"  // For I420Copy
  #include "libyuv/cpu_id.h"
  #include "libyuv/planar_functions.h"
  #include "libyuv/rotate.h"
  #include "libyuv/row.h"
  #include "libyuv/scale.h"  // For ScalePlane()
  #include "libyuv/video_common.h"
  
  #ifdef __cplusplus
  namespace libyuv {
  extern "C" {
  #endif
  
  #define SUBSAMPLE(v, a, s) (v < 0) ? (-((-v + a) >> s)) : ((v + a) >> s)
  static __inline int Abs(int v) {
    return v >= 0 ? v : -v;
  }
  
  // I420 To any I4xx YUV format with mirroring.
  static int I420ToI4xx(const uint8_t* src_y,
                        int src_stride_y,
                        const uint8_t* src_u,
                        int src_stride_u,
                        const uint8_t* src_v,
                        int src_stride_v,
                        uint8_t* dst_y,
                        int dst_stride_y,
                        uint8_t* dst_u,
                        int dst_stride_u,
                        uint8_t* dst_v,
                        int dst_stride_v,
                        int src_y_width,
                        int src_y_height,
                        int dst_uv_width,
                        int dst_uv_height) {
    const int dst_y_width = Abs(src_y_width);
    const int dst_y_height = Abs(src_y_height);
    const int src_uv_width = SUBSAMPLE(src_y_width, 1, 1);
    const int src_uv_height = SUBSAMPLE(src_y_height, 1, 1);
    if (src_y_width == 0 || src_y_height == 0 || dst_uv_width <= 0 ||
        dst_uv_height <= 0) {
      return -1;
    }
    if (dst_y) {
      ScalePlane(src_y, src_stride_y, src_y_width, src_y_height, dst_y,
                 dst_stride_y, dst_y_width, dst_y_height, kFilterBilinear);
    }
    ScalePlane(src_u, src_stride_u, src_uv_width, src_uv_height, dst_u,
               dst_stride_u, dst_uv_width, dst_uv_height, kFilterBilinear);
    ScalePlane(src_v, src_stride_v, src_uv_width, src_uv_height, dst_v,
               dst_stride_v, dst_uv_width, dst_uv_height, kFilterBilinear);
    return 0;
  }
  
  // Convert 8 bit YUV to 10 bit.
  LIBYUV_API
  int I420ToI010(const uint8_t* src_y,
                 int src_stride_y,
                 const uint8_t* src_u,
                 int src_stride_u,
                 const uint8_t* src_v,
                 int src_stride_v,
                 uint16_t* dst_y,
                 int dst_stride_y,
                 uint16_t* dst_u,
                 int dst_stride_u,
                 uint16_t* dst_v,
                 int dst_stride_v,
                 int width,
                 int height) {
    int halfwidth = (width + 1) >> 1;
    int halfheight = (height + 1) >> 1;
    if (!src_u || !src_v || !dst_u || !dst_v || width <= 0 || height == 0) {
      return -1;
    }
    // Negative height means invert the image.
    if (height < 0) {
      height = -height;
      halfheight = (height + 1) >> 1;
      src_y = src_y + (height - 1) * src_stride_y;
      src_u = src_u + (halfheight - 1) * src_stride_u;
      src_v = src_v + (halfheight - 1) * src_stride_v;
      src_stride_y = -src_stride_y;
      src_stride_u = -src_stride_u;
      src_stride_v = -src_stride_v;
    }
  
    // Convert Y plane.
    Convert8To16Plane(src_y, src_stride_y, dst_y, dst_stride_y, 1024, width,
                      height);
    // Convert UV planes.
    Convert8To16Plane(src_u, src_stride_u, dst_u, dst_stride_u, 1024, halfwidth,
                      halfheight);
    Convert8To16Plane(src_v, src_stride_v, dst_v, dst_stride_v, 1024, halfwidth,
                      halfheight);
    return 0;
  }
  
  // 420 chroma is 1/2 width, 1/2 height
  // 422 chroma is 1/2 width, 1x height
  LIBYUV_API
  int I420ToI422(const uint8_t* src_y,
                 int src_stride_y,
                 const uint8_t* src_u,
                 int src_stride_u,
                 const uint8_t* src_v,
                 int src_stride_v,
                 uint8_t* dst_y,
                 int dst_stride_y,
                 uint8_t* dst_u,
                 int dst_stride_u,
                 uint8_t* dst_v,
                 int dst_stride_v,
                 int width,
                 int height) {
    const int dst_uv_width = (Abs(width) + 1) >> 1;
    const int dst_uv_height = Abs(height);
    return I420ToI4xx(src_y, src_stride_y, src_u, src_stride_u, src_v,
                      src_stride_v, dst_y, dst_stride_y, dst_u, dst_stride_u,
                      dst_v, dst_stride_v, width, height, dst_uv_width,
                      dst_uv_height);
  }
  
  // 420 chroma is 1/2 width, 1/2 height
  // 444 chroma is 1x width, 1x height
  LIBYUV_API
  int I420ToI444(const uint8_t* src_y,
                 int src_stride_y,
                 const uint8_t* src_u,
                 int src_stride_u,
                 const uint8_t* src_v,
                 int src_stride_v,
                 uint8_t* dst_y,
                 int dst_stride_y,
                 uint8_t* dst_u,
                 int dst_stride_u,
                 uint8_t* dst_v,
                 int dst_stride_v,
                 int width,
                 int height) {
    const int dst_uv_width = Abs(width);
    const int dst_uv_height = Abs(height);
    return I420ToI4xx(src_y, src_stride_y, src_u, src_stride_u, src_v,
                      src_stride_v, dst_y, dst_stride_y, dst_u, dst_stride_u,
                      dst_v, dst_stride_v, width, height, dst_uv_width,
                      dst_uv_height);
  }
  
  // Copy to I400. Source can be I420,422,444,400,NV12,NV21
  LIBYUV_API
  int I400Copy(const uint8_t* src_y,
               int src_stride_y,
               uint8_t* dst_y,
               int dst_stride_y,
               int width,
               int height) {
    if (!src_y || !dst_y || width <= 0 || height == 0) {
      return -1;
    }
    // Negative height means invert the image.
    if (height < 0) {
      height = -height;
      src_y = src_y + (height - 1) * src_stride_y;
      src_stride_y = -src_stride_y;
    }
    CopyPlane(src_y, src_stride_y, dst_y, dst_stride_y, width, height);
    return 0;
  }
  
  LIBYUV_API
  int I422ToYUY2(const uint8_t* src_y,
                 int src_stride_y,
                 const uint8_t* src_u,
                 int src_stride_u,
                 const uint8_t* src_v,
                 int src_stride_v,
                 uint8_t* dst_yuy2,
                 int dst_stride_yuy2,
                 int width,
                 int height) {
    int y;
    void (*I422ToYUY2Row)(const uint8_t* src_y, const uint8_t* src_u,
                          const uint8_t* src_v, uint8_t* dst_yuy2, int width) =
        I422ToYUY2Row_C;
    if (!src_y || !src_u || !src_v || !dst_yuy2 || width <= 0 || height == 0) {
      return -1;
    }
    // Negative height means invert the image.
    if (height < 0) {
      height = -height;
      dst_yuy2 = dst_yuy2 + (height - 1) * dst_stride_yuy2;
      dst_stride_yuy2 = -dst_stride_yuy2;
    }
    // Coalesce rows.
    if (src_stride_y == width && src_stride_u * 2 == width &&
        src_stride_v * 2 == width && dst_stride_yuy2 == width * 2) {
      width *= height;
      height = 1;
      src_stride_y = src_stride_u = src_stride_v = dst_stride_yuy2 = 0;
    }
  #if defined(HAS_I422TOYUY2ROW_SSE2)
    if (TestCpuFlag(kCpuHasSSE2)) {
      I422ToYUY2Row = I422ToYUY2Row_Any_SSE2;
      if (IS_ALIGNED(width, 16)) {
        I422ToYUY2Row = I422ToYUY2Row_SSE2;
      }
    }
  #endif
  #if defined(HAS_I422TOYUY2ROW_AVX2)
    if (TestCpuFlag(kCpuHasAVX2)) {
      I422ToYUY2Row = I422ToYUY2Row_Any_AVX2;
      if (IS_ALIGNED(width, 32)) {
        I422ToYUY2Row = I422ToYUY2Row_AVX2;
      }
    }
  #endif
  #if defined(HAS_I422TOYUY2ROW_NEON)
    if (TestCpuFlag(kCpuHasNEON)) {
      I422ToYUY2Row = I422ToYUY2Row_Any_NEON;
      if (IS_ALIGNED(width, 16)) {
        I422ToYUY2Row = I422ToYUY2Row_NEON;
      }
    }
  #endif
  
    for (y = 0; y < height; ++y) {
      I422ToYUY2Row(src_y, src_u, src_v, dst_yuy2, width);
      src_y += src_stride_y;
      src_u += src_stride_u;
      src_v += src_stride_v;
      dst_yuy2 += dst_stride_yuy2;
    }
    return 0;
  }
  
  LIBYUV_API
  int I420ToYUY2(const uint8_t* src_y,
                 int src_stride_y,
                 const uint8_t* src_u,
                 int src_stride_u,
                 const uint8_t* src_v,
                 int src_stride_v,
                 uint8_t* dst_yuy2,
                 int dst_stride_yuy2,
                 int width,
                 int height) {
    int y;
    void (*I422ToYUY2Row)(const uint8_t* src_y, const uint8_t* src_u,
                          const uint8_t* src_v, uint8_t* dst_yuy2, int width) =
        I422ToYUY2Row_C;
    if (!src_y || !src_u || !src_v || !dst_yuy2 || width <= 0 || height == 0) {
      return -1;
    }
    // Negative height means invert the image.
    if (height < 0) {
      height = -height;
      dst_yuy2 = dst_yuy2 + (height - 1) * dst_stride_yuy2;
      dst_stride_yuy2 = -dst_stride_yuy2;
    }
  #if defined(HAS_I422TOYUY2ROW_SSE2)
    if (TestCpuFlag(kCpuHasSSE2)) {
      I422ToYUY2Row = I422ToYUY2Row_Any_SSE2;
      if (IS_ALIGNED(width, 16)) {
        I422ToYUY2Row = I422ToYUY2Row_SSE2;
      }
    }
  #endif
  #if defined(HAS_I422TOYUY2ROW_AVX2)
    if (TestCpuFlag(kCpuHasAVX2)) {
      I422ToYUY2Row = I422ToYUY2Row_Any_AVX2;
      if (IS_ALIGNED(width, 32)) {
        I422ToYUY2Row = I422ToYUY2Row_AVX2;
      }
    }
  #endif
  #if defined(HAS_I422TOYUY2ROW_NEON)
    if (TestCpuFlag(kCpuHasNEON)) {
      I422ToYUY2Row = I422ToYUY2Row_Any_NEON;
      if (IS_ALIGNED(width, 16)) {
        I422ToYUY2Row = I422ToYUY2Row_NEON;
      }
    }
  #endif
  #if defined(HAS_I422TOYUY2ROW_MMI)
    if (TestCpuFlag(kCpuHasMMI)) {
      I422ToYUY2Row = I422ToYUY2Row_Any_MMI;
      if (IS_ALIGNED(width, 8)) {
        I422ToYUY2Row = I422ToYUY2Row_MMI;
      }
    }
  #endif
  #if defined(HAS_I422TOYUY2ROW_MSA)
    if (TestCpuFlag(kCpuHasMSA)) {
      I422ToYUY2Row = I422ToYUY2Row_Any_MSA;
      if (IS_ALIGNED(width, 32)) {
        I422ToYUY2Row = I422ToYUY2Row_MSA;
      }
    }
  #endif
  
    for (y = 0; y < height - 1; y += 2) {
      I422ToYUY2Row(src_y, src_u, src_v, dst_yuy2, width);
      I422ToYUY2Row(src_y + src_stride_y, src_u, src_v,
                    dst_yuy2 + dst_stride_yuy2, width);
      src_y += src_stride_y * 2;
      src_u += src_stride_u;
      src_v += src_stride_v;
      dst_yuy2 += dst_stride_yuy2 * 2;
    }
    if (height & 1) {
      I422ToYUY2Row(src_y, src_u, src_v, dst_yuy2, width);
    }
    return 0;
  }
  
  LIBYUV_API
  int I422ToUYVY(const uint8_t* src_y,
                 int src_stride_y,
                 const uint8_t* src_u,
                 int src_stride_u,
                 const uint8_t* src_v,
                 int src_stride_v,
                 uint8_t* dst_uyvy,
                 int dst_stride_uyvy,
                 int width,
                 int height) {
    int y;
    void (*I422ToUYVYRow)(const uint8_t* src_y, const uint8_t* src_u,
                          const uint8_t* src_v, uint8_t* dst_uyvy, int width) =
        I422ToUYVYRow_C;
    if (!src_y || !src_u || !src_v || !dst_uyvy || width <= 0 || height == 0) {
      return -1;
    }
    // Negative height means invert the image.
    if (height < 0) {
      height = -height;
      dst_uyvy = dst_uyvy + (height - 1) * dst_stride_uyvy;
      dst_stride_uyvy = -dst_stride_uyvy;
    }
    // Coalesce rows.
    if (src_stride_y == width && src_stride_u * 2 == width &&
        src_stride_v * 2 == width && dst_stride_uyvy == width * 2) {
      width *= height;
      height = 1;
      src_stride_y = src_stride_u = src_stride_v = dst_stride_uyvy = 0;
    }
  #if defined(HAS_I422TOUYVYROW_SSE2)
    if (TestCpuFlag(kCpuHasSSE2)) {
      I422ToUYVYRow = I422ToUYVYRow_Any_SSE2;
      if (IS_ALIGNED(width, 16)) {
        I422ToUYVYRow = I422ToUYVYRow_SSE2;
      }
    }
  #endif
  #if defined(HAS_I422TOUYVYROW_AVX2)
    if (TestCpuFlag(kCpuHasAVX2)) {
      I422ToUYVYRow = I422ToUYVYRow_Any_AVX2;
      if (IS_ALIGNED(width, 32)) {
        I422ToUYVYRow = I422ToUYVYRow_AVX2;
      }
    }
  #endif
  #if defined(HAS_I422TOUYVYROW_NEON)
    if (TestCpuFlag(kCpuHasNEON)) {
      I422ToUYVYRow = I422ToUYVYRow_Any_NEON;
      if (IS_ALIGNED(width, 16)) {
        I422ToUYVYRow = I422ToUYVYRow_NEON;
      }
    }
  #endif
  #if defined(HAS_I422TOUYVYROW_MMI)
    if (TestCpuFlag(kCpuHasMMI)) {
      I422ToUYVYRow = I422ToUYVYRow_Any_MMI;
      if (IS_ALIGNED(width, 8)) {
        I422ToUYVYRow = I422ToUYVYRow_MMI;
      }
    }
  #endif
  #if defined(HAS_I422TOUYVYROW_MSA)
    if (TestCpuFlag(kCpuHasMSA)) {
      I422ToUYVYRow = I422ToUYVYRow_Any_MSA;
      if (IS_ALIGNED(width, 32)) {
        I422ToUYVYRow = I422ToUYVYRow_MSA;
      }
    }
  #endif
  
    for (y = 0; y < height; ++y) {
      I422ToUYVYRow(src_y, src_u, src_v, dst_uyvy, width);
      src_y += src_stride_y;
      src_u += src_stride_u;
      src_v += src_stride_v;
      dst_uyvy += dst_stride_uyvy;
    }
    return 0;
  }
  
  LIBYUV_API
  int I420ToUYVY(const uint8_t* src_y,
                 int src_stride_y,
                 const uint8_t* src_u,
                 int src_stride_u,
                 const uint8_t* src_v,
                 int src_stride_v,
                 uint8_t* dst_uyvy,
                 int dst_stride_uyvy,
                 int width,
                 int height) {
    int y;
    void (*I422ToUYVYRow)(const uint8_t* src_y, const uint8_t* src_u,
                          const uint8_t* src_v, uint8_t* dst_uyvy, int width) =
        I422ToUYVYRow_C;
    if (!src_y || !src_u || !src_v || !dst_uyvy || width <= 0 || height == 0) {
      return -1;
    }
    // Negative height means invert the image.
    if (height < 0) {
      height = -height;
      dst_uyvy = dst_uyvy + (height - 1) * dst_stride_uyvy;
      dst_stride_uyvy = -dst_stride_uyvy;
    }
  #if defined(HAS_I422TOUYVYROW_SSE2)
    if (TestCpuFlag(kCpuHasSSE2)) {
      I422ToUYVYRow = I422ToUYVYRow_Any_SSE2;
      if (IS_ALIGNED(width, 16)) {
        I422ToUYVYRow = I422ToUYVYRow_SSE2;
      }
    }
  #endif
  #if defined(HAS_I422TOUYVYROW_AVX2)
    if (TestCpuFlag(kCpuHasAVX2)) {
      I422ToUYVYRow = I422ToUYVYRow_Any_AVX2;
      if (IS_ALIGNED(width, 32)) {
        I422ToUYVYRow = I422ToUYVYRow_AVX2;
      }
    }
  #endif
  #if defined(HAS_I422TOUYVYROW_NEON)
    if (TestCpuFlag(kCpuHasNEON)) {
      I422ToUYVYRow = I422ToUYVYRow_Any_NEON;
      if (IS_ALIGNED(width, 16)) {
        I422ToUYVYRow = I422ToUYVYRow_NEON;
      }
    }
  #endif
  #if defined(HAS_I422TOUYVYROW_MMI)
    if (TestCpuFlag(kCpuHasMMI)) {
      I422ToUYVYRow = I422ToUYVYRow_Any_MMI;
      if (IS_ALIGNED(width, 8)) {
        I422ToUYVYRow = I422ToUYVYRow_MMI;
      }
    }
  #endif
  #if defined(HAS_I422TOUYVYROW_MSA)
    if (TestCpuFlag(kCpuHasMSA)) {
      I422ToUYVYRow = I422ToUYVYRow_Any_MSA;
      if (IS_ALIGNED(width, 32)) {
        I422ToUYVYRow = I422ToUYVYRow_MSA;
      }
    }
  #endif
  
    for (y = 0; y < height - 1; y += 2) {
      I422ToUYVYRow(src_y, src_u, src_v, dst_uyvy, width);
      I422ToUYVYRow(src_y + src_stride_y, src_u, src_v,
                    dst_uyvy + dst_stride_uyvy, width);
      src_y += src_stride_y * 2;
      src_u += src_stride_u;
      src_v += src_stride_v;
      dst_uyvy += dst_stride_uyvy * 2;
    }
    if (height & 1) {
      I422ToUYVYRow(src_y, src_u, src_v, dst_uyvy, width);
    }
    return 0;
  }
  
  LIBYUV_API
  int I420ToNV12(const uint8_t* src_y,
                 int src_stride_y,
                 const uint8_t* src_u,
                 int src_stride_u,
                 const uint8_t* src_v,
                 int src_stride_v,
                 uint8_t* dst_y,
                 int dst_stride_y,
                 uint8_t* dst_uv,
                 int dst_stride_uv,
                 int width,
                 int height) {
    int halfwidth = (width + 1) / 2;
    int halfheight = (height + 1) / 2;
    if (!src_y || !src_u || !src_v || !dst_y || !dst_uv || width <= 0 ||
        height == 0) {
      return -1;
    }
    // Negative height means invert the image.
    if (height < 0) {
      height = -height;
      halfheight = (height + 1) >> 1;
      src_y = src_y + (height - 1) * src_stride_y;
      src_u = src_u + (halfheight - 1) * src_stride_u;
      src_v = src_v + (halfheight - 1) * src_stride_v;
      src_stride_y = -src_stride_y;
      src_stride_u = -src_stride_u;
      src_stride_v = -src_stride_v;
    }
    if (dst_y) {
      CopyPlane(src_y, src_stride_y, dst_y, dst_stride_y, width, height);
    }
    MergeUVPlane(src_u, src_stride_u, src_v, src_stride_v, dst_uv, dst_stride_uv,
                 halfwidth, halfheight);
    return 0;
  }
  
  LIBYUV_API
  int I420ToNV21(const uint8_t* src_y,
                 int src_stride_y,
                 const uint8_t* src_u,
                 int src_stride_u,
                 const uint8_t* src_v,
                 int src_stride_v,
                 uint8_t* dst_y,
                 int dst_stride_y,
                 uint8_t* dst_vu,
                 int dst_stride_vu,
                 int width,
                 int height) {
    return I420ToNV12(src_y, src_stride_y, src_v, src_stride_v, src_u,
                      src_stride_u, dst_y, dst_stride_y, dst_vu, dst_stride_vu,
                      width, height);
  }
  
  // Convert I420 to specified format
  LIBYUV_API
  int ConvertFromI420(const uint8_t* y,
                      int y_stride,
                      const uint8_t* u,
                      int u_stride,
                      const uint8_t* v,
                      int v_stride,
                      uint8_t* dst_sample,
                      int dst_sample_stride,
                      int width,
                      int height,
                      uint32_t fourcc) {
    uint32_t format = CanonicalFourCC(fourcc);
    int r = 0;
    if (!y || !u || !v || !dst_sample || width <= 0 || height == 0) {
      return -1;
    }
    switch (format) {
      // Single plane formats
      case FOURCC_YUY2:
        r = I420ToYUY2(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                       dst_sample_stride ? dst_sample_stride : width * 2, width,
                       height);
        break;
      case FOURCC_UYVY:
        r = I420ToUYVY(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                       dst_sample_stride ? dst_sample_stride : width * 2, width,
                       height);
        break;
      case FOURCC_RGBP:
        r = I420ToRGB565(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                         dst_sample_stride ? dst_sample_stride : width * 2, width,
                         height);
        break;
      case FOURCC_RGBO:
        r = I420ToARGB1555(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                           dst_sample_stride ? dst_sample_stride : width * 2,
                           width, height);
        break;
      case FOURCC_R444:
        r = I420ToARGB4444(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                           dst_sample_stride ? dst_sample_stride : width * 2,
                           width, height);
        break;
      case FOURCC_24BG:
        r = I420ToRGB24(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                        dst_sample_stride ? dst_sample_stride : width * 3, width,
                        height);
        break;
      case FOURCC_RAW:
        r = I420ToRAW(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                      dst_sample_stride ? dst_sample_stride : width * 3, width,
                      height);
        break;
      case FOURCC_ARGB:
        r = I420ToARGB(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                       dst_sample_stride ? dst_sample_stride : width * 4, width,
                       height);
        break;
      case FOURCC_BGRA:
        r = I420ToBGRA(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                       dst_sample_stride ? dst_sample_stride : width * 4, width,
                       height);
        break;
      case FOURCC_ABGR:
        r = I420ToABGR(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                       dst_sample_stride ? dst_sample_stride : width * 4, width,
                       height);
        break;
      case FOURCC_RGBA:
        r = I420ToRGBA(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                       dst_sample_stride ? dst_sample_stride : width * 4, width,
                       height);
        break;
      case FOURCC_AR30:
        r = I420ToAR30(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                       dst_sample_stride ? dst_sample_stride : width * 4, width,
                       height);
        break;
      case FOURCC_I400:
        r = I400Copy(y, y_stride, dst_sample,
                     dst_sample_stride ? dst_sample_stride : width, width,
                     height);
        break;
      case FOURCC_NV12: {
        uint8_t* dst_uv = dst_sample + width * height;
        r = I420ToNV12(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                       dst_sample_stride ? dst_sample_stride : width, dst_uv,
                       dst_sample_stride ? dst_sample_stride : width, width,
                       height);
        break;
      }
      case FOURCC_NV21: {
        uint8_t* dst_vu = dst_sample + width * height;
        r = I420ToNV21(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                       dst_sample_stride ? dst_sample_stride : width, dst_vu,
                       dst_sample_stride ? dst_sample_stride : width, width,
                       height);
        break;
      }
      // Triplanar formats
      case FOURCC_I420:
      case FOURCC_YV12: {
        dst_sample_stride = dst_sample_stride ? dst_sample_stride : width;
        int halfstride = (dst_sample_stride + 1) / 2;
        int halfheight = (height + 1) / 2;
        uint8_t* dst_u;
        uint8_t* dst_v;
        if (format == FOURCC_YV12) {
          dst_v = dst_sample + dst_sample_stride * height;
          dst_u = dst_v + halfstride * halfheight;
        } else {
          dst_u = dst_sample + dst_sample_stride * height;
          dst_v = dst_u + halfstride * halfheight;
        }
        r = I420Copy(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                     dst_sample_stride, dst_u, halfstride, dst_v, halfstride,
                     width, height);
        break;
      }
      case FOURCC_I422:
      case FOURCC_YV16: {
        dst_sample_stride = dst_sample_stride ? dst_sample_stride : width;
        int halfstride = (dst_sample_stride + 1) / 2;
        uint8_t* dst_u;
        uint8_t* dst_v;
        if (format == FOURCC_YV16) {
          dst_v = dst_sample + dst_sample_stride * height;
          dst_u = dst_v + halfstride * height;
        } else {
          dst_u = dst_sample + dst_sample_stride * height;
          dst_v = dst_u + halfstride * height;
        }
        r = I420ToI422(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                       dst_sample_stride, dst_u, halfstride, dst_v, halfstride,
                       width, height);
        break;
      }
      case FOURCC_I444:
      case FOURCC_YV24: {
        dst_sample_stride = dst_sample_stride ? dst_sample_stride : width;
        uint8_t* dst_u;
        uint8_t* dst_v;
        if (format == FOURCC_YV24) {
          dst_v = dst_sample + dst_sample_stride * height;
          dst_u = dst_v + dst_sample_stride * height;
        } else {
          dst_u = dst_sample + dst_sample_stride * height;
          dst_v = dst_u + dst_sample_stride * height;
        }
        r = I420ToI444(y, y_stride, u, u_stride, v, v_stride, dst_sample,
                       dst_sample_stride, dst_u, dst_sample_stride, dst_v,
                       dst_sample_stride, width, height);
        break;
      }
      // Formats not supported - MJPG, biplanar, some rgb formats.
      default:
        return -1;  // unknown fourcc - return failure code.
    }
    return r;
  }
  
  #ifdef __cplusplus
  }  // extern "C"
  }  // namespace libyuv
  #endif
  