Support RGBA in scale video-filter. This is a backport from trunk [19552:21020].

modules/video_filter/scale.c

@@ -3,7 +3,7 @@
  *  Uses the low quality "nearest neighbour" algorithm.
  *****************************************************************************
  * Copyright (C) 2003 the VideoLAN team
- * $Id$
+ * $Id: fde9f41689fe615649e0431f705af1fc53ecffbd $
  *
  * Author: Gildas Bazin <gbazin@videolan.org>
  *
@@ -66,7 +66,8 @@ static int OpenFilter( vlc_object_t *p_this )
     filter_sys_t *p_sys;
 
     if( ( p_filter->fmt_in.video.i_chroma != VLC_FOURCC('Y','U','V','P') &&
-          p_filter->fmt_in.video.i_chroma != VLC_FOURCC('Y','U','V','A') ) ||
+          p_filter->fmt_in.video.i_chroma != VLC_FOURCC('Y','U','V','A') &&
+          p_filter->fmt_in.video.i_chroma != VLC_FOURCC('R','G','B','A') ) ||
         p_filter->fmt_in.video.i_chroma != p_filter->fmt_out.video.i_chroma )
     {
         return VLC_EGENERIC;
@@ -106,10 +107,18 @@ static void CloseFilter( vlc_object_t *p_this )
 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 {
     picture_t *p_pic_dst;
-    int i_plane, i, j, k, l;
+    int i_plane;
 
     if( !p_pic ) return NULL;
-    
+
+    if( (p_filter->fmt_in.video.i_height == 0) ||
+        (p_filter->fmt_in.video.i_width == 0) )
+        return NULL;
+
+    if( (p_filter->fmt_out.video.i_height == 0) ||
+        (p_filter->fmt_out.video.i_width == 0) )
+        return NULL;
+
     /* Request output picture */
     p_pic_dst = p_filter->pf_vout_buffer_new( p_filter );
     if( !p_pic_dst )
@@ -120,30 +129,87 @@ static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
         return NULL;
     }
 
-    for( i_plane = 0; i_plane < p_pic_dst->i_planes; i_plane++ )
+    if( p_filter->fmt_in.video.i_chroma != VLC_FOURCC('R','G','B','A') )
     {
-        uint8_t *p_src = p_pic->p[i_plane].p_pixels;
-        uint8_t *p_dst = p_pic_dst->p[i_plane].p_pixels;
-        int i_src_pitch = p_pic->p[i_plane].i_pitch;
-        int i_dst_pitch = p_pic_dst->p[i_plane].i_pitch;
-
-        for( i = 0; i < p_pic_dst->p[i_plane].i_visible_lines; i++ )
+        for( i_plane = 0; i_plane < p_pic_dst->i_planes; i_plane++ )
         {
-            l = ( p_filter->fmt_in.video.i_height * i +
-                  p_filter->fmt_out.video.i_height / 2 ) /
-                p_filter->fmt_out.video.i_height;
-
-            l = __MIN( (int)p_filter->fmt_in.video.i_height - 1, l );
-
-            for( j = 0; j < p_pic_dst->p[i_plane].i_visible_pitch; j++ )
+            const int i_src_pitch    = p_pic->p[i_plane].i_pitch;
+            const int i_dst_pitch    = p_pic_dst->p[i_plane].i_pitch;
+            const int i_src_height   = p_filter->fmt_in.video.i_height;
+            const int i_src_width    = p_filter->fmt_in.video.i_width;
+            const int i_dst_height   = p_filter->fmt_out.video.i_height;
+            const int i_dst_width    = p_filter->fmt_out.video.i_width;
+            const int i_dst_visible_lines =
+                                       p_pic_dst->p[i_plane].i_visible_lines;
+            const int i_dst_visible_pitch =
+                                       p_pic_dst->p[i_plane].i_visible_pitch;
+            const int i_dst_hidden_pitch  = i_dst_pitch - i_dst_visible_pitch;
+#define SHIFT_SIZE 16
+            const int i_height_coef  = ( i_src_height << SHIFT_SIZE )
+                                       / i_dst_height;
+            const int i_width_coef   = ( i_src_width << SHIFT_SIZE )
+                                       / i_dst_width;
+            const int i_src_height_1 = i_src_height - 1;
+            const int i_src_width_1  = i_src_width - 1;
+
+            uint8_t *p_src = p_pic->p[i_plane].p_pixels;
+            uint8_t *p_dst = p_pic_dst->p[i_plane].p_pixels;
+            uint8_t *p_dstendline = p_dst + i_dst_visible_pitch;
+            const uint8_t *p_dstend = p_dst + i_dst_visible_lines*i_dst_pitch;
+
+            int l = 1<<(SHIFT_SIZE-1);
+            for( ; p_dst < p_dstend;
+                 p_dst += i_dst_hidden_pitch,
+                 p_dstendline += i_dst_pitch, l += i_height_coef )
             {
-                k = ( p_filter->fmt_in.video.i_width * j +
-                      p_filter->fmt_out.video.i_width / 2 ) /
-                    p_filter->fmt_out.video.i_width;
-
-                k = __MIN( (int)p_filter->fmt_in.video.i_width - 1, k );
-
-                p_dst[i * i_dst_pitch + j] = p_src[l * i_src_pitch + k];
+                int k = 1<<(SHIFT_SIZE-1);
+                uint8_t *p_srcl = p_src
+                       + (__MIN( i_src_height_1, l >> SHIFT_SIZE )*i_src_pitch);
+
+                for( ; p_dst < p_dstendline; p_dst++, k += i_width_coef )
+                {
+                    *p_dst = p_srcl[__MIN( i_src_width_1, k >> SHIFT_SIZE )];
+                }
+            }
+        }
+    }
+    else /* RGBA */
+    {
+        const int i_src_pitch = p_pic->p->i_pitch;
+        const int i_dst_pitch = p_pic_dst->p->i_pitch;
+        const int i_src_height   = p_filter->fmt_in.video.i_height;
+        const int i_src_width    = p_filter->fmt_in.video.i_width;
+        const int i_dst_height   = p_filter->fmt_out.video.i_height;
+        const int i_dst_width    = p_filter->fmt_out.video.i_width;
+        const int i_dst_visible_lines =
+                                   p_pic_dst->p->i_visible_lines;
+        const int i_dst_visible_pitch =
+                                   p_pic_dst->p->i_visible_pitch;
+        const int i_dst_hidden_pitch  = i_dst_pitch - i_dst_visible_pitch;
+        const int i_height_coef  = ( i_src_height << SHIFT_SIZE )
+                                   / i_dst_height;
+        const int i_width_coef   = ( i_src_width << SHIFT_SIZE )
+                                   / i_dst_width;
+        const int i_src_height_1 = i_src_height - 1;
+        const int i_src_width_1  = i_src_width - 1;
+
+        uint32_t *p_src = (uint32_t*)p_pic->p->p_pixels;
+        uint32_t *p_dst = (uint32_t*)p_pic_dst->p->p_pixels;
+        uint32_t *p_dstendline = p_dst + (i_dst_visible_pitch>>2);
+        const uint32_t *p_dstend = p_dst + i_dst_visible_lines*(i_dst_pitch>>2);
+
+        int l = 1<<(SHIFT_SIZE-1);
+        for( ; p_dst < p_dstend;
+             p_dst += (i_dst_hidden_pitch>>2),
+             p_dstendline += (i_dst_pitch>>2),
+             l += i_height_coef )
+        {
+            int k = 1<<(SHIFT_SIZE-1);
+            uint32_t *p_srcl = p_src
+                    + (__MIN( i_src_height_1, l >> SHIFT_SIZE )*(i_src_pitch>>2));
+            for( ; p_dst < p_dstendline; p_dst++, k += i_width_coef )
+            {
+                *p_dst = p_srcl[__MIN( i_src_width_1, k >> SHIFT_SIZE )];
             }
         }
     }