commit 4f857bacd22ea4e95c0bd8a0de3da3dcd017eff3
author Yaowu Xu <yaowu@google.com> Thu Mar 27 12:54:06 2014 -0700
committer Yaowu Xu <yaowu@google.com> Fri Mar 28 16:40:29 2014 -0700
tree 71789f1e8585b2eb6c1d9c655f05211f8a900b87
parent 6fc20a8434352793f4ecb09e6369112c92952456

[BITSTREAM]Fix the scaling calculation

For very large size video image, the scaling calculation may need use
value beyond the range of int. This commit upgrade the value to 64bit
to make sure the calculation do not wrap around INT_MAX.

The change corrected the decoder behavior.

The bug affects only very large resolution video because the scaling
calculation was sufficient for image size smaller than 2^13.

This resolves issue:
https://code.google.com/p/webm/issues/detail?id=750

Change-Id: I2d2ed303ca6482f31f819f3c07d6d3e98ef3adc5

test/test-data.sha1

diff --git a/test/test-data.sha1 b/test/test-data.sha1
index 981aa4f..dbdf797 100644
--- a/test/test-data.sha1
+++ b/test/test-data.sha1
@@ -589,3 +589,5 @@
 92a756469fa438220524e7fa6ac1d38c89514d17  vp90-2-12-droppable_2.ivf.md5
 c21e97e4ba486520118d78b01a5cb6e6dc33e190  vp90-2-12-droppable_3.ivf
 601abc9e4176c70f82ac0381365e9b151fdd24cd  vp90-2-12-droppable_3.ivf.md5
+61c640dad23cd4f7ad811b867e7b7e3521f4e3ba  vp90-2-13-largescaling.webm
+bca1b02eebdb088fa3f389fe0e7571e75a71f523  vp90-2-13-largescaling.webm.md5

test/test.mk

diff --git a/test/test.mk b/test/test.mk
index 31baf05..4d96bc6 100644
--- a/test/test.mk
+++ b/test/test.mk
@@ -694,6 +694,8 @@
 LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += vp90-2-12-droppable_2.ivf.md5
 LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += vp90-2-12-droppable_3.ivf
 LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += vp90-2-12-droppable_3.ivf.md5
+LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += vp90-2-13-largescaling.webm
+LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += vp90-2-13-largescaling.webm.md5
 LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += vp91-2-04-yv444.webm
 LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += vp91-2-04-yv444.webm.md5
 

test/test_vectors.cc

diff --git a/test/test_vectors.cc b/test/test_vectors.cc
index 175151e..8c789ff 100644
--- a/test/test_vectors.cc
+++ b/test/test_vectors.cc
@@ -164,7 +164,7 @@
   "vp90-2-11-size-351x287.webm", "vp90-2-11-size-351x288.webm",
   "vp90-2-11-size-352x287.webm", "vp90-2-12-droppable_1.ivf",
   "vp90-2-12-droppable_2.ivf", "vp90-2-12-droppable_3.ivf",
-  "vp91-2-04-yv444.webm"
+  "vp90-2-13-largescaling.webm", "vp91-2-04-yv444.webm"
 };
 const int kNumVP9TestVectors = NELEMENTS(kVP9TestVectors);
 #endif  // CONFIG_VP9_DECODER

vp9/common/vp9_scale.c

diff --git a/vp9/common/vp9_scale.c b/vp9/common/vp9_scale.c
index e0f1e34..d3405fc 100644
--- a/vp9/common/vp9_scale.c
+++ b/vp9/common/vp9_scale.c
@@ -13,11 +13,11 @@
 #include "vp9/common/vp9_scale.h"
 
 static INLINE int scaled_x(int val, const struct scale_factors *sf) {
-  return val * sf->x_scale_fp >> REF_SCALE_SHIFT;
+  return (int)((int64_t)val * sf->x_scale_fp >> REF_SCALE_SHIFT);
 }
 
 static INLINE int scaled_y(int val, const struct scale_factors *sf) {
-  return val * sf->y_scale_fp >> REF_SCALE_SHIFT;
+  return (int)((int64_t)val * sf->y_scale_fp >> REF_SCALE_SHIFT);
 }
 
 static int unscaled_value(int val, const struct scale_factors *sf) {