Fixed subtitle blend module loading.

The blend module will be loaded only if needed and reloaded on chroma change.
(As a side effect it should allow displaying TEXT even when no blending module
exist)

src/video_output/vout_subpictures.c

@@ -547,10 +547,10 @@ void spu_RenderSubpictures( spu_t *p_spu, video_format_t *p_fmt,
                 p_spu->p_blend->fmt_out.video.i_y_offset = 0;
             p_spu->p_blend->fmt_out.video.i_aspect = p_fmt->i_aspect;
             p_spu->p_blend->fmt_out.video.i_chroma = p_fmt->i_chroma;
-            p_spu->p_blend->fmt_in.video.i_chroma = p_region->fmt.i_chroma;
 
-            p_spu->p_blend->p_module =
-                module_Need( p_spu->p_blend, "video blending", 0, 0 );
+            /* The blend module will be loaded when needed with the real input format */
+            memset( &p_spu->p_blend->fmt_in, 0, sizeof(p_spu->p_blend->fmt_in) );
+            p_spu->p_blend->p_module = NULL;
         }
 
         /* Load the text rendering module; it is possible there is a
@@ -721,7 +721,7 @@ void spu_RenderSubpictures( spu_t *p_spu, video_format_t *p_fmt,
                 module_Need( p_spu->p_scale, "video filter2", 0, 0 );
         }
 
-        while( p_region && p_spu->p_blend && p_spu->p_blend->pf_video_blend )
+        while( p_region )
         {
             video_format_t orig_fmt = p_region->fmt;
             vlc_bool_t b_rerender_text = VLC_FALSE;
@@ -934,7 +934,34 @@ void spu_RenderSubpictures( spu_t *p_spu, video_format_t *p_fmt,
                 i_y_offset -= ( p_spu->i_margin * i_inv_scale_y / 1000 + i_diff );
             }
 
+            if( p_subpic->b_fade )
+            {
+                mtime_t i_fade_start = ( p_subpic->i_stop +
+                                         p_subpic->i_start ) / 2;
+                mtime_t i_now = mdate();
+                if( i_now >= i_fade_start && p_subpic->i_stop > i_fade_start )
+                {
+                    i_fade_alpha = 255 * ( p_subpic->i_stop - i_now ) /
+                                   ( p_subpic->i_stop - i_fade_start );
+                }
+            }
+
+            if( p_region->fmt.i_chroma != VLC_FOURCC('T','E','X','T') )
+            {
+                if( p_spu->p_blend->fmt_in.video.i_chroma != p_region->fmt.i_chroma )
+                {
+                    /* The chroma is not the same, we need to reload the blend module
+                     * XXX to match the old behaviour just test !p_spu->p_blend->fmt_in.video.i_chroma */
+                    if( p_spu->p_blend->p_module )
+                        module_Unneed( p_spu->p_blend, p_spu->p_blend->p_module );
+
+                    p_spu->p_blend->fmt_in.video = p_region->fmt;
+                    p_spu->p_blend->p_module = module_Need( p_spu->p_blend, "video blending", 0, 0 );
+                }
+                else
+                {
                     p_spu->p_blend->fmt_in.video = p_region->fmt;
+                }
 
                 /* Force cropping if requested */
                 if( p_spu->b_force_crop )
@@ -978,23 +1005,10 @@ void spu_RenderSubpictures( spu_t *p_spu, video_format_t *p_fmt,
                     }
                 }
 
-            if( p_subpic->b_fade )
-            {
-                mtime_t i_fade_start = ( p_subpic->i_stop +
-                                         p_subpic->i_start ) / 2;
-                mtime_t i_now = mdate();
-                if( i_now >= i_fade_start && p_subpic->i_stop > i_fade_start )
-                {
-                    i_fade_alpha = 255 * ( p_subpic->i_stop - i_now ) /
-                                   ( p_subpic->i_stop - i_fade_start );
-                }
-            }
 
                 i_x_offset = __MAX( i_x_offset, 0 );
                 i_y_offset = __MAX( i_y_offset, 0 );
 
-            if( p_region->fmt.i_chroma != VLC_FOURCC('T','E','X','T') )
-            {
                 /* Update the output picture size */
                 p_spu->p_blend->fmt_out.video.i_width =
                     p_spu->p_blend->fmt_out.video.i_visible_width =
@@ -1003,10 +1017,19 @@ void spu_RenderSubpictures( spu_t *p_spu, video_format_t *p_fmt,
                     p_spu->p_blend->fmt_out.video.i_visible_height =
                         p_fmt->i_height;
 
+                if( p_spu->p_blend->p_module )
+                {
                     p_spu->p_blend->pf_video_blend( p_spu->p_blend, p_pic_dst,
                         p_pic_src, &p_region->picture, i_x_offset, i_y_offset,
                         i_fade_alpha * p_subpic->i_alpha / 255 );
                 }
+                else
+                {
+                    msg_Err( p_spu, "blending %4.4s to %4.4s failed",
+                             (char *)&p_spu->p_blend->fmt_out.video.i_chroma,
+                             (char *)&p_spu->p_blend->fmt_out.video.i_chroma );
+                }
+            }
 
             if( b_rerender_text )
             {