- Add new file internal.h for common internal-use-only functions.

- Add new function av_tempfile() for creating temporary files; contains
  workaround for MinGW.
- Make XviD stuff use av_tempfile().

Originally committed as revision 5245 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/utils.c

@@ -33,6 +33,9 @@
 #include <stdarg.h>
 #include <limits.h>
 #include <float.h>
+#ifdef CONFIG_WIN32
+#include <fcntl.h>
+#endif
 
 const uint8_t ff_reverse[256]={
 0x00,0x80,0x40,0xC0,0x20,0xA0,0x60,0xE0,0x10,0x90,0x50,0xD0,0x30,0xB0,0x70,0xF0,
@@ -1349,3 +1352,39 @@ unsigned int av_xiphlacing(unsigned char *s, unsigned int v)
     n++;
     return n;
 }
+
+/* Wrapper to work around the lack of mkstemp() on mingw/cygin.
+ * Also, tries to create file in /tmp first, if possible.
+ * *prefix can be a character constant; *filename will be allocated internally.
+ * Returns file descriptor of opened file (or -1 on error)
+ * and opened file name in **filename. */
+int av_tempfile(char *prefix, char **filename) {
+    int fd=-1;
+#ifdef CONFIG_WIN32
+    *filename = tempnam(".", prefix);
+#else
+    size_t len = strlen(prefix) + 12; /* room for "/tmp/" and "XXXXXX\0" */
+    *filename = av_malloc(len * sizeof(char));
+#endif
+    /* -----common section-----*/
+    if (*filename == NULL) {
+        av_log(NULL, AV_LOG_ERROR, "ff_tempfile: Cannot allocate file name\n");
+        return -1;
+    }
+#ifdef CONFIG_WIN32
+    fd = open(*filename, _O_RDWR | _O_BINARY | _O_CREAT, 0444);
+#else
+    snprintf(*filename, len, "/tmp/%sXXXXXX", prefix);
+    fd = mkstemp(*filename);
+    if (fd < 0) {
+        snprintf(*filename, len, "./%sXXXXXX", prefix);
+        fd = mkstemp(*filename);
+    }
+#endif
+    /* -----common section-----*/
+    if (fd < 0) {
+        av_log(NULL, AV_LOG_ERROR, "ff_tempfile: Cannot open temporary file %s\n", *filename);
+        return -1;
+    }
+    return fd; /* success */
+}