diff --git a/src/doomtype.h b/src/doomtype.h
index c73a03908..3d8f4f81a 100644
--- a/src/doomtype.h
+++ b/src/doomtype.h
@@ -202,14 +202,6 @@ enum class ELightMode : int8_t
 	DoomSoftware = 16
 };
 
-// Screenshot buffer image data types
-enum ESSType
-{
-	SS_PAL,
-	SS_RGB,
-	SS_BGRA
-};
-
 // always use our own definition for consistency.
 #ifdef M_PI
 #undef M_PI
diff --git a/src/g_game.cpp b/src/g_game.cpp
index 300e4bb35..863c01bd5 100644
--- a/src/g_game.cpp
+++ b/src/g_game.cpp
@@ -75,6 +75,7 @@
 #include "i_system.h"
 #include "p_conversation.h"
 
+#include "v_video.h"
 #include "g_hub.h"
 #include "g_levellocals.h"
 #include "events.h"
diff --git a/src/gamedata/textures/formats/pngtexture.cpp b/src/gamedata/textures/formats/pngtexture.cpp
index ccf13d0da..a6557592a 100644
--- a/src/gamedata/textures/formats/pngtexture.cpp
+++ b/src/gamedata/textures/formats/pngtexture.cpp
@@ -41,6 +41,7 @@
 #include "bitmap.h"
 #include "imagehelpers.h"
 #include "image.h"
+#include "textures.h"
 
 //==========================================================================
 //
diff --git a/src/gamedata/textures/image.h b/src/gamedata/textures/image.h
index 75efc56e4..64d9d22c6 100644
--- a/src/gamedata/textures/image.h
+++ b/src/gamedata/textures/image.h
@@ -2,6 +2,7 @@
 
 #include <stdint.h>
 #include "tarray.h"
+#include "textures.h"
 #include "textures/bitmap.h"
 #include "memarena.h"
 
diff --git a/src/gamedata/textures/imagehelpers.h b/src/gamedata/textures/imagehelpers.h
index 39cd83e67..12f730db6 100644
--- a/src/gamedata/textures/imagehelpers.h
+++ b/src/gamedata/textures/imagehelpers.h
@@ -41,6 +41,7 @@
 #include "tarray.h"
 #include "colormatcher.h"
 #include "v_palette.h"
+#include "v_colortables.h"
 #include "textures/bitmap.h"
 #include "r_data/renderstyle.h"
 #include "r_data/r_translate.h"
diff --git a/src/menu/loadsavemenu.cpp b/src/menu/loadsavemenu.cpp
index 9c79906e9..8b43c9602 100644
--- a/src/menu/loadsavemenu.cpp
+++ b/src/menu/loadsavemenu.cpp
@@ -43,6 +43,7 @@
 #include "serializer.h"
 #include "vm.h"
 #include "i_system.h"
+#include "v_video.h"
 
 // Save name length limit for old binary formats.
 #define OLDSAVESTRINGSIZE		24
diff --git a/src/playsim/p_acs.cpp b/src/playsim/p_acs.cpp
index dca86a7c8..5ba454856 100644
--- a/src/playsim/p_acs.cpp
+++ b/src/playsim/p_acs.cpp
@@ -75,6 +75,7 @@
 #include "types.h"
 #include "scriptutil.h"
 #include "s_music.h"
+#include "v_video.h"
 
 	// P-codes for ACS scripts
 	enum
diff --git a/src/rendering/gl/system/gl_framebuffer.h b/src/rendering/gl/system/gl_framebuffer.h
index 512ea037b..7578103fb 100644
--- a/src/rendering/gl/system/gl_framebuffer.h
+++ b/src/rendering/gl/system/gl_framebuffer.h
@@ -2,6 +2,7 @@
 #define __GL_FRAMEBUFFER
 
 #include "gl_sysfb.h"
+#include "m_png.h"
 
 #include <memory>
 
diff --git a/src/rendering/hwrenderer/textures/hw_material.cpp b/src/rendering/hwrenderer/textures/hw_material.cpp
index a70d749fd..4c4e37ca0 100644
--- a/src/rendering/hwrenderer/textures/hw_material.cpp
+++ b/src/rendering/hwrenderer/textures/hw_material.cpp
@@ -26,6 +26,7 @@
 #include "stats.h"
 #include "r_utility.h"
 #include "c_dispatch.h"
+#include "v_video.h"
 #include "hw_ihwtexture.h"
 #include "hw_material.h"
 
diff --git a/src/rendering/v_video.h b/src/rendering/v_video.h
index 285d8d4c6..580f711e3 100644
--- a/src/rendering/v_video.h
+++ b/src/rendering/v_video.h
@@ -39,6 +39,7 @@
 #include "vectors.h"
 
 #include "doomdef.h"
+#include "m_png.h"
 #include "dobject.h"
 #include "r_data/renderstyle.h"
 #include "c_cvars.h"
diff --git a/src/utility/m_crc32.h b/src/utility/m_crc32.h
index a39e189ea..079bffec4 100644
--- a/src/utility/m_crc32.h
+++ b/src/utility/m_crc32.h
@@ -33,7 +33,7 @@
 */
 
 #include <zlib.h>
-#include "basics.h"
+#include <stdint.h>
 
 // zlib includes some CRC32 stuff, so just use that
 
@@ -50,3 +50,8 @@ inline uint32_t CRC1 (uint32_t crc, const uint8_t c, const uint32_t *crcTable)
 {
 	return crcTable[(crc & 0xff) ^ c] ^ (crc >> 8);
 }
+
+inline uint32_t Bcrc32(const void* data, int length, uint32_t crc)
+{
+	return crc32(crc, (const Bytef*)data, length);
+}
diff --git a/src/utility/m_png.cpp b/src/utility/m_png.cpp
index 52d46f3e4..e58742da4 100644
--- a/src/utility/m_png.cpp
+++ b/src/utility/m_png.cpp
@@ -34,18 +34,21 @@
 
 // HEADER FILES ------------------------------------------------------------
 
+#include <algorithm>
 #include <stdlib.h>
 #include <zlib.h>
+#include <stdint.h>
 #ifdef _MSC_VER
 #include <malloc.h>		// for alloca()
 #endif
 
+#include "basics.h"
 #include "m_crc32.h"
 #include "m_swap.h"
 #include "c_cvars.h"
-#include "r_defs.h"
 #include "m_png.h"
 
+
 // MACROS ------------------------------------------------------------------
 
 // The maximum size of an IDAT chunk ZDoom will write. This is also the
@@ -243,7 +246,7 @@ bool M_AppendPNGText (FileWriter *file, const char *keyword, const char *text)
 {
 	struct { uint32_t len, id; char key[80]; } head;
 	int len = (int)strlen (text);
-	int keylen = MIN ((int)strlen (keyword), 79);
+	int keylen = std::min ((int)strlen (keyword), 79);
 	uint32_t crc;
 
 	head.len = BigLong(len + keylen + 1);
@@ -326,7 +329,7 @@ char *M_GetPNGText (PNGHandle *png, const char *keyword)
 		if (strncmp (keyword, png->TextChunks[i], 80) == 0)
 		{
 			// Woo! A match was found!
-			keylen = MIN<size_t> (80, strlen (keyword) + 1);
+			keylen = std::min<size_t> (80, strlen (keyword) + 1);
 			textlen = strlen (png->TextChunks[i] + keylen) + 1;
 			char *str = new char[textlen];
 			strcpy (str, png->TextChunks[i] + keylen);
@@ -348,7 +351,7 @@ bool M_GetPNGText (PNGHandle *png, const char *keyword, char *buffer, size_t buf
 		if (strncmp (keyword, png->TextChunks[i], 80) == 0)
 		{
 			// Woo! A match was found!
-			keylen = MIN<size_t> (80, strlen (keyword) + 1);
+			keylen = std::min<size_t> (80, strlen (keyword) + 1);
 			strncpy (buffer, png->TextChunks[i] + keylen, buffsize);
 			return true;
 		}
@@ -563,7 +566,7 @@ bool M_ReadIDAT (FileReader &file, uint8_t *buffer, int width, int height, int p
 		if (stream.avail_in == 0 && chunklen > 0)
 		{
 			stream.next_in = chunkbuffer;
-			stream.avail_in = (uInt)file.Read (chunkbuffer, MIN<uint32_t>(chunklen,sizeof(chunkbuffer)));
+			stream.avail_in = (uInt)file.Read (chunkbuffer, std::min<uint32_t>(chunklen,sizeof(chunkbuffer)));
 			chunklen -= stream.avail_in;
 		}
 
diff --git a/src/utility/m_png.h b/src/utility/m_png.h
index 10fd4c8e6..12e6d5adf 100644
--- a/src/utility/m_png.h
+++ b/src/utility/m_png.h
@@ -34,9 +34,18 @@
 */
 
 #include <stdio.h>
-#include "doomtype.h"
-#include "v_video.h"
+#include "zstring.h"
 #include "files.h"
+#include "palentry.h"
+#include "basics.h"
+
+// Screenshot buffer image data types
+enum ESSType
+{
+	SS_PAL,
+	SS_RGB,
+	SS_BGRA
+};
 
 class FileWriter;
 // PNG Writing --------------------------------------------------------------