hevc: Initialize sample aspect to valid value.

Without this, it is 0/0 by default, which is not allowed.
This sets it to 0/1, which means "undefined".
Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>

libavcodec/hevc_ps.c

@@ -755,6 +755,7 @@ int ff_hevc_decode_nal_sps(HEVCContext *s)
 
     sps->sps_temporal_mvp_enabled_flag          = get_bits1(gb);
     sps->sps_strong_intra_smoothing_enable_flag = get_bits1(gb);
+    sps->vui.sar = vui_sar[0];
     vui_present = get_bits1(gb);
     if (vui_present)
         decode_vui(s, sps);