lavc/hevcdec: only set no_rasl_output_flag for IRAP frames

Its meaning is only specified for IRAP frames.

As it's currently never used otherwise, this should not change decoder
behaviour, but will be useful in future commits.

libavcodec/hevc/hevcdec.c

@@ -2925,7 +2925,9 @@ static int hevc_frame_start(HEVCContext *s)
     s->is_decoded        = 0;
     s->first_nal_type    = s->nal_unit_type;
 
-    s->no_rasl_output_flag = IS_IDR(s) || IS_BLA(s) || (s->nal_unit_type == HEVC_NAL_CRA_NUT && s->last_eos);
+    if (IS_IRAP(s))
+        s->no_rasl_output_flag = IS_IDR(s) || IS_BLA(s) ||
+                                 (s->nal_unit_type == HEVC_NAL_CRA_NUT && s->last_eos);
 
     /* 8.3.1 */
     if (s->temporal_id == 0 &&

libavcodec/hevc/hevcdec.h

@@ -493,6 +493,7 @@ typedef struct HEVCContext {
     int overlap;
 
     int is_decoded;
+    // NoRaslOutputFlag associated with the last IRAP frame
     int no_rasl_output_flag;
 
     HEVCPredContext hpc;