diff --git a/cpymo-tool/Makefile b/cpymo-tool/Makefile
index fb994374..7d4f609a 100644
--- a/cpymo-tool/Makefile
+++ b/cpymo-tool/Makefile
@@ -7,7 +7,7 @@ INC := $(wildcard *.h) $(wildcard ../cpymo/*.h)
 SRC_TOOL  := $(wildcard *.c)
 
 OBJS := $(patsubst %.c, $(BUILD_DIR)/%.o, $(SRC_TOOL))
-CFLAGS := -g -DDEBUG -DLEAKCHECK
+CFLAGS := -O3 -DNDEBUG -DLEAKCHECK
 
 CC = cc -c
 LD = cc
diff --git a/cpymo-tool/cpymo_tool_ffmpeg.c b/cpymo-tool/cpymo_tool_ffmpeg.c
index d95c7679..5a5d38d7 100644
--- a/cpymo-tool/cpymo_tool_ffmpeg.c
+++ b/cpymo-tool/cpymo_tool_ffmpeg.c
@@ -3,27 +3,22 @@
 #include <stdio.h>
 #include <string.h>
 
-#ifdef _WIN32
-#define NUL_DEVICE "nul"
-#else
-#define NUL_DEVICE "/dev/null"
-#endif
-
 error_t cpymo_tool_ffmpeg_search(const char **out_ffmpeg_command)
 {
     #define TRY(CMD) \
-        if (system(CMD " -version > " NUL_DEVICE) == 0) { \
+        if (system(CMD " -version") == 0) { \
             *out_ffmpeg_command = CMD; \
             return CPYMO_ERR_SUCC; \
         } \
 
     #ifdef _WIN32
+    TRY("ffmpeg");
     TRY("cmd /c ffmpeg");
+    TRY("powershell ./ffmpeg");
     #else
     TRY("./ffmpeg");
-    #endif
-
     TRY("ffmpeg");
+    #endif
 
     #undef TRY
 
@@ -45,12 +40,11 @@ error_t cpymo_tool_ffmpeg_call(
         + strlen(src)
         + strlen(dst)
         + strlen(fmt)
-        + strlen(NUL_DEVICE)
         + flags_len
-        + 32 + strlen(NUL_DEVICE));
+        + 32);
     if (command == NULL) return CPYMO_ERR_OUT_OF_MEM;
 
-    sprintf(command, "%s -i \"%s\" -y -v quiet -f %s %s%s\"%s\" > " NUL_DEVICE,
+    sprintf(command, "%s -i \"%s\" -y -v quiet -f %s %s%s\"%s\"",
         ffmpeg_command,
         src,
         fmt,
diff --git a/cpymo-tool/cpymo_tool_image.c b/cpymo-tool/cpymo_tool_image.c
index 2db4cf7d..2ab0347c 100644
--- a/cpymo-tool/cpymo_tool_image.c
+++ b/cpymo-tool/cpymo_tool_image.c
@@ -86,7 +86,7 @@ error_t cpymo_tool_image_load_attach_mask_from_memory(cpymo_tool_image *img, voi
 
 error_t cpymo_tool_image_detach_mask(const cpymo_tool_image *img, cpymo_tool_image *out_mask)
 {
-    out_mask->pixels = (stbi_uc *)malloc(out_mask->width * out_mask->height);
+    out_mask->pixels = (stbi_uc *)malloc(img->width * img->height);
     if (out_mask->pixels == NULL) return CPYMO_ERR_OUT_OF_MEM;
 
     out_mask->channels = 1;