ConvertFromI420: use halfstride instead of halfwidth

source/convert_from.cc

Index: source/convert_from.cc
diff --git a/source/convert_from.cc b/source/convert_from.cc
index f81054c20d2c696d221f0dcc8b28abe1435e5441..d285e98d6b2d25452eacabeb9c4bd5c938b087f9 100644
--- a/source/convert_from.cc
+++ b/source/convert_from.cc
@@ -1094,53 +1094,58 @@ int ConvertFromI420(const uint8* y,
     }
     // 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.