Remove obsolete FF_API_REFERENCE_DTS cruft.

libavformat/avformat.h

@@ -826,11 +826,6 @@ typedef struct AVStream {
 
     int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
 
-#if FF_API_REFERENCE_DTS
-    /* a hack to keep ABI compatibility for avconv, which accesses parser even
-     * though it should not */
-    int64_t do_not_use;
-#endif
     // Timestamp generation support:
     int64_t first_dts;
     int64_t cur_dts;

libavformat/version.h

@@ -48,9 +48,6 @@
  * dropped at a future version bump. The defines themselves are not part of
  * the public API and may change, break or disappear at any time.
  */
-#ifndef FF_API_REFERENCE_DTS
-#define FF_API_REFERENCE_DTS            (LIBAVFORMAT_VERSION_MAJOR < 56)
-#endif
 #ifndef FF_API_LAVF_BITEXACT
 #define FF_API_LAVF_BITEXACT            (LIBAVFORMAT_VERSION_MAJOR < 57)
 #endif