libavcodec: use 64bit counter in deprecated audio encoder API to prevent...

libavcodec: use 64bit counter in deprecated audio encoder API to prevent problems regarding negative dts
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/internal.h

@@ -82,7 +82,7 @@ typedef struct AVCodecInternal {
      * Internal sample count used by avcodec_encode_audio() to fabricate pts.
      * Can be removed along with avcodec_encode_audio().
      */
-    int sample_count;
+    int64_t sample_count;
 #endif
 
     /**