demux: mp4: set interlacing flags

modules/demux/mp4/essetup.c

@@ -221,6 +221,12 @@ int SetupVideoES( demux_t *p_demux, mp4_track_t *p_track, MP4_Box_t *p_sample )
         p_track->fmt.video.i_sar_den = BOXDATA(p_pasp)->i_vertical_spacing;
     }
 
+    const MP4_Box_t *p_fiel = MP4_BoxGet( p_sample, "fiel" );
+    if( p_fiel && BOXDATA(p_fiel) )
+    {
+        p_track->i_block_flags = BOXDATA(p_fiel)->i_flags;
+    }
+
     /* now see if esds is present and if so create a data packet
         with decoder_specific_info  */
     MP4_Box_t *p_esds = MP4_BoxGet( p_sample, "esds" );

modules/demux/mp4/mp4.c

@@ -515,6 +515,8 @@ static void MP4_Block_Send( demux_t *p_demux, mp4_track_t *p_track, block_t *p_b
                              p_track->fmt.i_codec );
     }
 
+    p_block->i_flags |= p_track->i_block_flags;
+
     /* ASF packets in mov */
     if( p_track->p_asf )
     {

modules/demux/mp4/mp4.h

@@ -75,6 +75,7 @@ typedef struct
     bool b_mac_encoding;
 
     es_format_t fmt;
+    uint32_t    i_block_flags;
     uint8_t     rgi_chans_reordering[AOUT_CHAN_MAX];
     bool        b_chans_reorder;
     es_out_id_t *p_es;