* modules/stream_out/mosaic_bridge.c: Added a --sout-mosaic-bridge-sar

   parameter to specify the sample aspect ratio of the destination
   background. In this case, one of {width, height} can be omitted (set
   to 0) and it will be calculated based on the PAR of the source and
   the SAR of the background.

modules/stream_out/mosaic_bridge.c

@@ -48,6 +48,7 @@ struct sout_stream_sys_t
     decoder_t       *p_decoder;
     image_handler_t *p_image; /* filter for resizing */
     int i_height, i_width;
+    int i_sar_num, i_sar_den;
     char *psz_id;
     vlc_bool_t b_inited;
 };
@@ -106,6 +107,9 @@ static void video_unlink_picture_decoder( decoder_t *, picture_t * );
 #define HEIGHT_TEXT N_("Video height")
 #define HEIGHT_LONGTEXT N_( \
     "Allows you to specify the output video height." )
+#define RATIO_TEXT N_("Sample aspect ratio")
+#define RATIO_LONGTEXT N_( \
+    "Sample aspect ratio of the destination (1:1, 3:4, 2:3)." )
 
 #define SOUT_CFG_PREFIX "sout-mosaic-bridge-"
 
@@ -121,6 +125,8 @@ vlc_module_begin();
                  WIDTH_LONGTEXT, VLC_TRUE );
     add_integer( SOUT_CFG_PREFIX "height", 0, NULL, HEIGHT_TEXT,
                  HEIGHT_LONGTEXT, VLC_TRUE );
+    add_string( SOUT_CFG_PREFIX "sar", "1:1", NULL, RATIO_TEXT,
+                RATIO_LONGTEXT, VLC_FALSE );
 
     set_callbacks( Open, Close );
 
@@ -128,7 +134,7 @@ vlc_module_begin();
 vlc_module_end();
 
 static const char *ppsz_sout_options[] = {
-    "id", "width", "height", NULL
+    "id", "width", "height", "sar", NULL
 };
 
 /*****************************************************************************
@@ -160,6 +166,32 @@ static int Open( vlc_object_t *p_this )
     var_Get( p_stream, SOUT_CFG_PREFIX "width", &val );
     p_sys->i_width = val.i_int; 
 
+    var_Get( p_stream, SOUT_CFG_PREFIX "sar", &val );
+    if ( val.psz_string )
+    {
+        char *psz_parser = strchr( val.psz_string, ':' );
+
+        if( psz_parser )
+        {
+            *psz_parser++ = '\0';
+            p_sys->i_sar_num = atoi( val.psz_string );
+            p_sys->i_sar_den = atoi( psz_parser );
+            vlc_reduce( &p_sys->i_sar_num, &p_sys->i_sar_den,
+                        p_sys->i_sar_num, p_sys->i_sar_den, 0 );
+        }
+        else
+        {
+            msg_Warn( p_stream, "bad aspect ratio %s", val.psz_string );
+            p_sys->i_sar_num = p_sys->i_sar_den = 1;
+        }
+
+        free( val.psz_string );
+    }
+    else
+    {
+        p_sys->i_sar_num = p_sys->i_sar_den = 1;
+    }
+
     if ( p_sys->i_height || p_sys->i_width )
     {
         p_sys->p_image = image_HandlerCreate( p_stream );
@@ -386,8 +418,26 @@ static int Send( sout_stream_t *p_stream, sout_stream_id_t *id,
             fmt_in = p_sys->p_decoder->fmt_out.video;
 
             fmt_out.i_chroma = VLC_FOURCC('Y','U','V','A');
-            fmt_out.i_width = p_sys->i_width;
-            fmt_out.i_height = p_sys->i_height;
+
+            if ( !p_sys->i_height )
+            {
+                fmt_out.i_width = p_sys->i_width;
+                fmt_out.i_height = (p_sys->i_width * VOUT_ASPECT_FACTOR
+                    * p_sys->i_sar_num / p_sys->i_sar_den / fmt_in.i_aspect)
+                      & ~0x1;
+            }
+            else if ( !p_sys->i_width )
+            {
+                fmt_out.i_height = p_sys->i_height;
+                fmt_out.i_width = (p_sys->i_height * fmt_in.i_aspect
+                    * p_sys->i_sar_den / p_sys->i_sar_num / VOUT_ASPECT_FACTOR)
+                      & ~0x1;
+            }
+            else
+            {
+                fmt_out.i_width = p_sys->i_width;
+                fmt_out.i_height = p_sys->i_height;
+            }
             fmt_out.i_visible_width = fmt_out.i_width;
             fmt_out.i_visible_height = fmt_out.i_height;