[codec/schroedinger] If pts is unavaliable, do not fall back to dts

It is more reliable to interpolate pts at the output of the decoder
than to use dts.

This requires demuxers that only provide dts (such as avi) to provide
an initial value of pts so that the decoder may interpolate correctly.

modules/codec/schroedinger.c

@@ -206,16 +206,14 @@ static void StorePicturePTS( decoder_t *p_dec, block_t *p_block, int i_pupos )
 {
     decoder_sys_t *p_sys = p_dec->p_sys;
     uint32_t u_pnum;
-    mtime_t i_pts;
 
     u_pnum = GetDWBE( p_block->p_buffer + i_pupos + 13 );
-    i_pts = p_block->i_pts > 0 ? p_block->i_pts : p_block->i_dts;
 
     for( int i=0; i<PTS_TLB_SIZE; i++ ) {
         if( p_sys->pts_tlb[i].i_empty ) {
 
             p_sys->pts_tlb[i].u_pnum = u_pnum;
-            p_sys->pts_tlb[i].i_pts = i_pts;
+            p_sys->pts_tlb[i].i_pts = p_block->i_pts;
             p_sys->pts_tlb[i].i_empty = 0;
 
             return;
@@ -223,7 +221,7 @@ static void StorePicturePTS( decoder_t *p_dec, block_t *p_block, int i_pupos )
     }
 
     msg_Err( p_dec, "Could not store PTS %"PRId64" for picture %u",
-             i_pts, u_pnum );
+             p_block->i_pts, u_pnum );
 }
 
 /*****************************************************************************