fix A/52 spdif output regression

A/52 spdif output was broken by the switch over to the new filter API.

  * a52tofloat32 should only take control if there is _no_ spdif
    output requested otherwise the decoded stream ends up on the spdif
    device

  * a52tospdif has to set a pts/dts value otherwise the frames get
    (wrongfully) discarded as too late because a wrong pts/dts value
    got evaluated by aout_OutputNextBuffer()
Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

modules/audio_filter/converter/a52tofloat32.c

@@ -353,7 +353,9 @@ static int OpenFilter( vlc_object_t *p_this )
     filter_sys_t *p_sys;
     int i_ret;
 
-    if( p_filter->fmt_in.i_codec != VLC_CODEC_A52  )
+    if( p_filter->fmt_in.i_codec != VLC_CODEC_A52 ||
+        p_filter->fmt_out.audio.i_format == VLC_CODEC_SPDIFB ||
+        p_filter->fmt_out.audio.i_format == VLC_CODEC_SPDIFL )
     {
         return VLC_EGENERIC;
     }

modules/audio_filter/converter/a52tospdif.c

@@ -111,6 +111,8 @@ static block_t *DoWork( filter_t * p_filter, block_t *p_in_buf )
     vlc_memset( p_out + 8 + i_frame_size * 2, 0,
                 AOUT_SPDIF_SIZE - i_frame_size * 2 - 8 );
 
+    p_out_buf->i_dts = p_in_buf->i_dts;
+    p_out_buf->i_pts = p_in_buf->i_pts;
     p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
     p_out_buf->i_buffer = AOUT_SPDIF_SIZE;
 out: