let freerdp_image_scale() determine step size

(cherry picked from commit cba618115471a7072902aa137af5962f0e0c4c1e)

diff --git a/libfreerdp/codec/color.c b/libfreerdp/codec/color.c
index 6c29552..a0fce37 100644 (file)
--- a/libfreerdp/codec/color.c
+++ b/libfreerdp/codec/color.c
@@ -777,6 +777,13 @@ BOOL freerdp_image_scale(BYTE* pDstData, DWORD DstFormat, UINT32 nDstStep, UINT3
                          UINT32 nSrcWidth, UINT32 nSrcHeight)
 {
        BOOL rc = FALSE;
+
+       if (nDstStep == 0)
+               nDstStep = nDstWidth * GetBytesPerPixel(DstFormat);
+
+       if (nSrcStep == 0)
+               nSrcStep = nSrcWidth * GetBytesPerPixel(SrcFormat);
+
 #if defined(SWSCALE_FOUND) || defined(CAIRO_FOUND)
        const BYTE* src = &pSrcData[nXSrc * GetBytesPerPixel(SrcFormat) + nYSrc * nSrcStep];
        BYTE* dst = &pDstData[nXDst * GetBytesPerPixel(DstFormat) + nYDst * nDstStep];