Change the definition of AVERROR_NUMEXPECTED at the next libavutil

major bump, using an FFmpeg specific error code rather than EDOM,
which has a quite different semantics.

Originally committed as revision 22528 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavutil/error.h

@@ -38,6 +38,7 @@
 #define AVERROR_IO          AVERROR(EIO)     /**< I/O error */
 #define AVERROR_NOENT       AVERROR(ENOENT)  /**< No such file or directory. */
 #define AVERROR_NOMEM       AVERROR(ENOMEM)  /**< not enough memory */
+#define AVERROR_NUMEXPECTED AVERROR(EDOM)    /**< Number syntax expected in filename. */
 #define AVERROR_UNKNOWN     AVERROR(EINVAL)  /**< unknown error */
 #endif
 
@@ -45,8 +46,11 @@
 #define AVERROR_INVALIDDATA AVERROR(EINVAL)  /**< invalid data found */
 #define AVERROR_NOFMT       AVERROR(EILSEQ)  /**< unknown format */
 #define AVERROR_NOTSUPP     AVERROR(ENOSYS)  /**< Operation not supported. */
-#define AVERROR_NUMEXPECTED AVERROR(EDOM)    /**< Number syntax expected in filename. */
 
 #define AVERROR_PATCHWELCOME    (-MKTAG('P','A','W','E')) /**< Not yet implemented in FFmpeg. Patches welcome. */
 
+#if LIBAVUTIL_VERSION_MAJOR > 50
+#define AVERROR_NUMEXPECTED     (-MKTAG('N','U','E','X')) /**< Number syntax expected in filename. */
+#endif
+
 #endif /* AVUTIL_ERROR_H */