ConvertFromI420: use halfstride instead of halfwidth

source/convert_from.cc

 /*
  *  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.
  */
 
@@ skipping 1076 matching lines @@
     case FOURCC_NV21: {
       uint8* 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;
     }
     // TODO(fbarchard): Add M420.
     // Triplanar formats
-    // TODO(fbarchard): halfstride instead of halfwidth
     case FOURCC_I420:
     case FOURCC_YV12: {
-      int halfwidth = (width + 1) / 2;
+      dst_sample_stride = dst_sample_stride ? dst_sample_stride : width;
+      int halfstride = (dst_sample_stride + 1) / 2;
       int halfheight = (height + 1) / 2;
       uint8* dst_u;
       uint8* dst_v;
       if (format == FOURCC_YV12) {
-        dst_v = dst_sample + width * height;
-        dst_u = dst_v + halfwidth * halfheight;
+        dst_v = dst_sample + dst_sample_stride * height;
+        dst_u = dst_v + halfstride * halfheight;
       } else {
-        dst_u = dst_sample + width * height;
-        dst_v = dst_u + halfwidth * halfheight;
+        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, width,
-                   dst_u, halfwidth, dst_v, halfwidth, width, height);
+      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: {
-      int halfwidth = (width + 1) / 2;
+      dst_sample_stride = dst_sample_stride ? dst_sample_stride : width;
+      int halfstride = (dst_sample_stride + 1) / 2;
       uint8* dst_u;
       uint8* dst_v;
       if (format == FOURCC_YV16) {
-        dst_v = dst_sample + width * height;
-        dst_u = dst_v + halfwidth * height;
+        dst_v = dst_sample + dst_sample_stride * height;
+        dst_u = dst_v + halfstride * height;
       } else {
-        dst_u = dst_sample + width * height;
-        dst_v = dst_u + halfwidth * height;
+        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, width,
-                     dst_u, halfwidth, dst_v, halfwidth, width, 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* dst_u;
       uint8* dst_v;
       if (format == FOURCC_YV24) {
-        dst_v = dst_sample + width * height;
-        dst_u = dst_v + width * height;
+        dst_v = dst_sample + dst_sample_stride * height;
+        dst_u = dst_v + dst_sample_stride * height;
       } else {
-        dst_u = dst_sample + width * height;
-        dst_v = dst_u + width * height;
+        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, width,
-                     dst_u, width, dst_v, width, width, 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