hevc: Change the assumption of time_scale.

HM uses time_scale in frame level.
So we follow what HM does.

Author: VFR-maniac

hevc.c

@@ -900,7 +900,7 @@ static int hevc_parse_sps_minimally
         else
         {
             sps->vui.num_units_in_tick = 1;     /* arbitrary */
-            sps->vui.time_scale        = 50;    /* arbitrary */
+            sps->vui.time_scale        = 25;    /* arbitrary */
         }
         if( lsmash_bits_get( bits, 1 ) )    /* bitstream_restriction_flag */
         {
@@ -927,7 +927,7 @@ static int hevc_parse_sps_minimally
         sps->vui.frame_field_info_present_flag = sps->ptl.general.progressive_source_flag
                                               && sps->ptl.general.interlaced_source_flag;
         sps->vui.num_units_in_tick             = 1;     /* arbitrary */
-        sps->vui.time_scale                    = 50;    /* arbitrary */
+        sps->vui.time_scale                    = 25;    /* arbitrary */
         sps->vui.min_spatial_segmentation_idc  = 0;
     }
     return bits->bs->error ? -1 : 0;

importer.c

@@ -3898,6 +3898,9 @@ static int hevc_importer_probe( importer_t *importer )
                                        &importer_info->composition_reordering_present,
                                        &importer_info->last_delta,
                                        max_composition_delay, num_access_units );
+    summary->timescale *= 2;    /* We assume that picture timing is in field level.
+                                 * For HEVC, it seems time_scale is set in frame level basically.
+                                 * So multiply by 2 for reducing timebase and timescale. */
     nalu_reduce_timescale( timestamp, npt, &importer_info->last_delta, &summary->timescale, num_access_units );
     lsmash_free( npt );
     importer_info->ts_list.sample_count = num_access_units;