@@ -754,6 +754,7 @@ HAVE_LIST="

     dev_video_bktr_ioctl_bt848_h

     dlfcn_h

     dlopen

+    dos_paths

     ebp_available

     ebx_available

     fast_64bit

@@ -1295,6 +1296,7 @@ case $target_os in

         SLIB_UNINSTALL_EXTRA_CMD='rm -f "$(SHLIBDIR)/$(SLIBNAME:$(SLIBSUF)=.lib)"'

         SHFLAGS='-shared -Wl,--output-def,$$(@:$(SLIBSUF)=.def) -Wl,--enable-runtime-pseudo-reloc -Wl,--enable-auto-image-base'

         objformat="win32"

+        enable dos_paths

         ;;

     cygwin*)

         target_os=cygwin

@@ -1312,6 +1314,7 @@ case $target_os in

         SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)'

         SHFLAGS='-shared -Wl,--enable-auto-image-base'

         objformat="win32"

+        enable dos_paths

         ;;

     *-dos|freedos|opendos)

         disable ffplay ffserver vhook

@@ -1319,6 +1322,7 @@ case $target_os in

         network_extralibs="-lsocket"

         EXESUF=".exe"

         objformat="win32"

+        enable dos_paths

         ;;

     linux)

         enable dv1394

@@ -1350,6 +1354,7 @@ case $target_os in

         SLIB_INSTALL_EXTRA_CMD='install -m 644 $(SUBDIR)$(LIBPREF)$(NAME)_dll.a $(SUBDIR)$(LIBPREF)$(NAME)_dll.lib "$(LIBDIR)"'

         SLIB_UNINSTALL_EXTRA_CMD='rm -f "$(LIBDIR)"/$(LIBPREF)$(NAME)_dll.a "$(LIBDIR)"/$(LIBPREF)$(NAME)_dll.lib'

         disable vhook

+        enable dos_paths

         ;;

     interix)

         disable vhook

@@ -21,6 +21,7 @@

 #include "libavutil/avstring.h"

 #include "libavcodec/opt.h"

+#include "os_support.h"

 #include "avformat.h"

 #if LIBAVFORMAT_VERSION_MAJOR >= 53

@@ -115,7 +116,7 @@ int url_open(URLContext **puc, const char *filename, int flags)

         p++;

     }

     /* if the protocol has length 1, we consider it is a dos drive */

-    if (*p == '\0' || (q - proto_str) <= 1) {

+    if (*p == '\0' || is_dos_path(filename)) {

     file_proto:

         strcpy(proto_str, "file");

     } else {

@@ -32,6 +32,15 @@

 #  define lseek(f,p,w) _lseeki64((f), (p), (w))

 #endif

+static inline int is_dos_path(const char *path)

+{

+#ifdef HAVE_DOS_PATHS

+    if (path[0] && path[1] == ':')

+        return 1;

+#endif

+    return 0;

+}

+

 #ifdef __BEOS__

 #  include <sys/socket.h>

 #  include <netinet/in.h>