vout_subpictures.c: Do not call the scaling module if the subpicture is using...

vout_subpictures.c: Do not call the scaling module if the subpicture is using RGBA. The current way subpictures scaling and blending modules loading work is kind of flawed. It assumes that the module will be able to handle all the possible types of input chromas. This worked fine previously (since all modules allowing to scale/blend YUVP also handled YUVA), but doesn't now (the scaling module doesn't support RGBA. blending works fine).
vout_pictures.*: Add core support for RGBA pictures.

src/video_output/vout_pictures.c

@@ -592,6 +592,7 @@ void vout_InitFormat( video_frame_format_t *p_format, vlc_fourcc_t i_chroma,
             break;
 
         case FOURCC_RV32:
+        case FOURCC_RGBA:
             p_format->i_bits_per_pixel = 32;
             break;
         case FOURCC_RV24:
@@ -820,6 +821,7 @@ int __vout_InitPicture( vlc_object_t *p_this, picture_t *p_pic,
             break;
 
         case FOURCC_RV32:
+        case FOURCC_RGBA:
             p_pic->p->i_lines = i_height_aligned;
             p_pic->p->i_visible_lines = i_height;
             p_pic->p->i_pitch = i_width_aligned * 4;

src/video_output/vout_pictures.h

@@ -44,6 +44,9 @@
 /* Packed RGB 32bpp, usually 0x00ff0000, 0x0000ff00, 0x000000ff */
 #define FOURCC_RV32         VLC_FOURCC('R','V','3','2')
 
+/* Packed RGBA 32bpp, like RV32 with 0xff000000 used for alpha */
+#define FOURCC_RGBA         VLC_FOURCC('R','G','B','A')
+
 /* Planar YUV 4:2:0, Y:U:V */
 #define FOURCC_I420         VLC_FOURCC('I','4','2','0')
 #define FOURCC_IYUV         VLC_FOURCC('I','Y','U','V')

src/video_output/vout_subpictures.c

@@ -502,6 +502,7 @@ void spu_RenderSubpictures( spu_t *p_spu, video_format_t *p_fmt,
             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 = VLC_FOURCC('Y','U','V','P');
+            /* XXX: We'll also be using it for YUVA and RGBA blending ... */
 
             p_spu->p_blend->p_module =
                 module_Need( p_spu->p_blend, "video blending", 0, 0 );
@@ -612,6 +613,7 @@ void spu_RenderSubpictures( spu_t *p_spu, video_format_t *p_fmt,
             p_spu->p_scale->fmt_out.video.i_chroma =
                 p_spu->p_scale->fmt_in.video.i_chroma =
                     VLC_FOURCC('Y','U','V','P');
+            /* XXX: We'll also be using it for YUVA and RGBA blending ... */
             p_spu->p_scale->fmt_in.video.i_width =
                 p_spu->p_scale->fmt_in.video.i_height = 32;
             p_spu->p_scale->fmt_out.video.i_width =
@@ -671,7 +673,8 @@ void spu_RenderSubpictures( spu_t *p_spu, video_format_t *p_fmt,
             }
 
             if( (i_scale_width != 1000 || i_scale_height != 1000) &&
-                p_spu->p_scale && !p_region->p_cache )
+                p_spu->p_scale && !p_region->p_cache &&
+                VLC_FOURCC('R','G','B','A') != p_region->fmt.i_chroma /* FIXME */ )
             {
                 picture_t *p_pic;