shithub: openh264

Info  •  Files  •  Log  •  Branches

Merge pull request #2499 from saamas/encoder-avoid-valgrind-downsampling-false-positives

[Encoder] Avoid valgrind downsampling false positives

--- a/codec/encoder/core/src/wels_preprocess.cpp

+++ b/codec/encoder/core/src/wels_preprocess.cpp

@@ -36,6 +36,17 @@

 #include "utils.h"

 #include "encoder.h"

+namespace {

+

+void ClearEndOfLinePadding (uint8_t* pData, int32_t iStride, int32_t iWidth, int32_t iHeight) {

+  if (iWidth < iStride) {

+    for (int32_t i = 0; i < iHeight; ++i)

+      memset (pData + i * iStride + iWidth, 0, iStride - iWidth);

+  }

+}

+

+} // anon ns.

+

 namespace WelsEnc {

@@ -501,6 +512,20 @@

                                           pParam->SUsedPicRect.iHeight, false, 0);

     if (pScaledPicture->pScaledInputPicture == NULL)

       return -1;

+

+    // Avoid valgrind false positives.

+    //

+    // X86 SIMD downsampling routines may, for convenience, read slightly beyond

+    // the input data and into the alignment padding area beyond each line. This

+    // causes valgrind to warn about uninitialized values even if these values

+    // only affect lanes of a SIMD vector that are effectively never used.

+    //

+    // Avoid these false positives by zero-initializing the padding area beyond

+    // each line of the source buffer used for downsampling.

+    SPicture* pPic = pScaledPicture->pScaledInputPicture;

+    ClearEndOfLinePadding (pPic->pData[0], pPic->iLineSize[0], pPic->iWidthInPixel, pPic->iHeightInPixel);

+    ClearEndOfLinePadding (pPic->pData[1], pPic->iLineSize[1], pPic->iWidthInPixel >> 1, pPic->iHeightInPixel >> 1);

+    ClearEndOfLinePadding (pPic->pData[2], pPic->iLineSize[2], pPic->iWidthInPixel >> 1, pPic->iHeightInPixel >> 1);

   }

   return 0;

 }