diff --git a/include/freerdp/codec/bitmap.h b/include/freerdp/codec/bitmap.h
index 507829253..2166cdfe6 100644
--- a/include/freerdp/codec/bitmap.h
+++ b/include/freerdp/codec/bitmap.h
@@ -32,7 +32,7 @@
 extern "C" {
 #endif
 
-FREERDP_API int freerdp_bitmap_compress(char* in_data, int width, int height,
+FREERDP_API int freerdp_bitmap_compress(const char* in_data, int width, int height,
 		wStream* s, int bpp, int byte_limit, int start_line, wStream* temp_s, int e);
 
 #ifdef __cplusplus
diff --git a/include/freerdp/codec/clear.h b/include/freerdp/codec/clear.h
index 05be6ed21..55b841b07 100644
--- a/include/freerdp/codec/clear.h
+++ b/include/freerdp/codec/clear.h
@@ -32,7 +32,7 @@ typedef struct _CLEAR_CONTEXT CLEAR_CONTEXT;
 extern "C" {
 #endif
 
-FREERDP_API int clear_compress(CLEAR_CONTEXT* clear, BYTE* pSrcData,
+FREERDP_API int clear_compress(CLEAR_CONTEXT* clear, const BYTE* pSrcData,
                                UINT32 SrcSize, BYTE** ppDstData, UINT32* pDstSize);
 
 FREERDP_API INT32 clear_decompress(CLEAR_CONTEXT* clear, const BYTE* pSrcData,
diff --git a/include/freerdp/codec/h264.h b/include/freerdp/codec/h264.h
index 83e3ca51d..69e02890a 100644
--- a/include/freerdp/codec/h264.h
+++ b/include/freerdp/codec/h264.h
@@ -29,7 +29,7 @@ typedef struct _H264_CONTEXT H264_CONTEXT;
 typedef BOOL (*pfnH264SubsystemInit)(H264_CONTEXT* h264);
 typedef void (*pfnH264SubsystemUninit)(H264_CONTEXT* h264);
 
-typedef int (*pfnH264SubsystemDecompress)(H264_CONTEXT* h264, BYTE* pSrcData,
+typedef int (*pfnH264SubsystemDecompress)(H264_CONTEXT* h264, const BYTE* pSrcData,
 					  UINT32 SrcSize, UINT32 plane);
 typedef int (*pfnH264SubsystemCompress)(H264_CONTEXT* h264, BYTE** ppDstData,
 					UINT32* pDstSize, UINT32 plane);
@@ -80,18 +80,18 @@ struct _H264_CONTEXT
 extern "C" {
 #endif
 
-FREERDP_API INT32 avc420_compress(H264_CONTEXT* h264, BYTE* pSrcData,
+FREERDP_API INT32 avc420_compress(H264_CONTEXT* h264, const BYTE* pSrcData,
 				  DWORD SrcFormat, UINT32 nSrcStep,
 				  UINT32 nSrcWidth, UINT32 nSrcHeight,
 				  BYTE** ppDstData, UINT32* pDstSize);
 
-FREERDP_API INT32 avc420_decompress(H264_CONTEXT* h264, BYTE* pSrcData,
+FREERDP_API INT32 avc420_decompress(H264_CONTEXT* h264, const BYTE* pSrcData,
 				    UINT32 SrcSize, BYTE* pDstData,
 				    DWORD DstFormat, UINT32 nDstStep,
 				    UINT32 nDstWidth, UINT32 nDstHeight,
 				    RECTANGLE_16* regionRects, UINT32 numRegionRect);
 
-FREERDP_API INT32 avc444_compress(H264_CONTEXT* h264, BYTE* pSrcData, DWORD SrcFormat,
+FREERDP_API INT32 avc444_compress(H264_CONTEXT* h264, const BYTE* pSrcData, DWORD SrcFormat,
 				UINT32 nSrcStep, UINT32 nSrcWidth, UINT32 nSrcHeight,
 				BYTE* op,
 				BYTE** pDstData, UINT32* pDstSize,
@@ -99,9 +99,9 @@ FREERDP_API INT32 avc444_compress(H264_CONTEXT* h264, BYTE* pSrcData, DWORD SrcF
 
 FREERDP_API INT32 avc444_decompress(H264_CONTEXT* h264, BYTE op,
 				  RECTANGLE_16* regionRects, UINT32 numRegionRect,
-				  BYTE* pSrcData, UINT32 SrcSize,
+				  const BYTE* pSrcData, UINT32 SrcSize,
 				  RECTANGLE_16* auxRegionRects, UINT32 numAuxRegionRect,
-				  BYTE* pAuxSrcData, UINT32 AuxSrcSize,
+				  const BYTE* pAuxSrcData, UINT32 AuxSrcSize,
 				  BYTE* pDstData, DWORD DstFormat,
 				  UINT32 nDstStep, UINT32 nDstWidth, UINT32 nDstHeight);
 
diff --git a/include/freerdp/codec/progressive.h b/include/freerdp/codec/progressive.h
index f373e6172..00e449ecf 100644
--- a/include/freerdp/codec/progressive.h
+++ b/include/freerdp/codec/progressive.h
@@ -36,7 +36,7 @@ extern "C" {
 #endif
 
 FREERDP_API int progressive_compress(PROGRESSIVE_CONTEXT* progressive,
-                                     BYTE* pSrcData, UINT32 SrcSize, BYTE** ppDstData, UINT32* pDstSize);
+                                    const BYTE* pSrcData, UINT32 SrcSize, BYTE** ppDstData, UINT32* pDstSize);
 
 FREERDP_API INT32 progressive_decompress(PROGRESSIVE_CONTEXT* progressive,
         const BYTE* pSrcData, UINT32 SrcSize,
diff --git a/libfreerdp/codec/bitmap.c b/libfreerdp/codec/bitmap.c
index ccb104ed2..b324cea56 100644
--- a/libfreerdp/codec/bitmap.c
+++ b/libfreerdp/codec/bitmap.c
@@ -456,7 +456,7 @@
 	bicolor_spin = 0; \
 		}
 
-int freerdp_bitmap_compress(char* srcData, int width, int height,
+int freerdp_bitmap_compress(const char* srcData, int width, int height,
 		wStream* s, int bpp, int byte_limit, int start_line, wStream* temp_s, int e)
 {
 	char *line;
diff --git a/libfreerdp/codec/clear.c b/libfreerdp/codec/clear.c
index fe2351e4b..11a78418b 100644
--- a/libfreerdp/codec/clear.c
+++ b/libfreerdp/codec/clear.c
@@ -1185,7 +1185,7 @@ fail:
 	return rc;
 }
 
-int clear_compress(CLEAR_CONTEXT* clear, BYTE* pSrcData, UINT32 SrcSize,
+int clear_compress(CLEAR_CONTEXT* clear, const BYTE* pSrcData, UINT32 SrcSize,
                    BYTE** ppDstData, UINT32* pDstSize)
 {
 	WLog_ERR(TAG, "TODO: %s not implemented!", __FUNCTION__);
diff --git a/libfreerdp/codec/h264.c b/libfreerdp/codec/h264.c
index 2222575c9..5b0e2b3f7 100644
--- a/libfreerdp/codec/h264.c
+++ b/libfreerdp/codec/h264.c
@@ -36,7 +36,7 @@
  * Dummy subsystem
  */
 
-static int dummy_decompress(H264_CONTEXT* h264, BYTE* pSrcData, UINT32 SrcSize,
+static int dummy_decompress(H264_CONTEXT* h264, const BYTE* pSrcData, UINT32 SrcSize,
                             UINT32 plane)
 {
 	return -1;
@@ -1521,7 +1521,7 @@ static BOOL avc_yuv_to_rgb(H264_CONTEXT* h264, const RECTANGLE_16* regionRects,
 	return TRUE;
 }
 
-INT32 avc420_decompress(H264_CONTEXT* h264, BYTE* pSrcData, UINT32 SrcSize,
+INT32 avc420_decompress(H264_CONTEXT* h264, const BYTE* pSrcData, UINT32 SrcSize,
                         BYTE* pDstData, DWORD DstFormat, UINT32 nDstStep,
                         UINT32 nDstWidth, UINT32 nDstHeight,
                         RECTANGLE_16* regionRects, UINT32 numRegionRects)
@@ -1546,7 +1546,7 @@ INT32 avc420_decompress(H264_CONTEXT* h264, BYTE* pSrcData, UINT32 SrcSize,
 	return 1;
 }
 
-INT32 avc420_compress(H264_CONTEXT* h264, BYTE* pSrcData, DWORD SrcFormat,
+INT32 avc420_compress(H264_CONTEXT* h264, const BYTE* pSrcData, DWORD SrcFormat,
                       UINT32 nSrcStep, UINT32 nSrcWidth, UINT32 nSrcHeight,
                       BYTE** ppDstData, UINT32* pDstSize)
 {
@@ -1598,7 +1598,7 @@ error_1:
 	return status;
 }
 
-INT32 avc444_compress(H264_CONTEXT* h264, BYTE* pSrcData, DWORD SrcFormat,
+INT32 avc444_compress(H264_CONTEXT* h264, const BYTE* pSrcData, DWORD SrcFormat,
                       UINT32 nSrcStep, UINT32 nSrcWidth, UINT32 nSrcHeight,
                       BYTE* op, BYTE** ppDstData, UINT32* pDstSize,
                       BYTE** ppAuxDstData, UINT32* pAuxDstSize)
@@ -1764,9 +1764,9 @@ static double avg(UINT64* count, double old, double size)
 
 INT32 avc444_decompress(H264_CONTEXT* h264, BYTE op,
                         RECTANGLE_16* regionRects, UINT32 numRegionRects,
-                        BYTE* pSrcData, UINT32 SrcSize,
+                        const BYTE* pSrcData, UINT32 SrcSize,
                         RECTANGLE_16* auxRegionRects, UINT32 numAuxRegionRect,
-                        BYTE* pAuxSrcData, UINT32 AuxSrcSize,
+                        const BYTE* pAuxSrcData, UINT32 AuxSrcSize,
                         BYTE* pDstData, DWORD DstFormat,
                         UINT32 nDstStep, UINT32 nDstWidth, UINT32 nDstHeight)
 {
diff --git a/libfreerdp/codec/progressive.c b/libfreerdp/codec/progressive.c
index 309d212aa..09078d292 100644
--- a/libfreerdp/codec/progressive.c
+++ b/libfreerdp/codec/progressive.c
@@ -1928,7 +1928,7 @@ INT32 progressive_decompress(PROGRESSIVE_CONTEXT* progressive,
 	return rc;
 }
 
-int progressive_compress(PROGRESSIVE_CONTEXT* progressive, BYTE* pSrcData,
+int progressive_compress(PROGRESSIVE_CONTEXT* progressive, const BYTE* pSrcData,
                          UINT32 SrcSize, BYTE** ppDstData, UINT32* pDstSize)
 {
 	return 1;