Check in a stable copy for reference against future changes. Should

not affect or be seen in upcoming release.

modules/codec/ogt/render.c

+/*****************************************************************************
+ * render.c : Philips OGT (SVCD Subtitle) renderer
+ *****************************************************************************
+ * Copyright (C) 2003 VideoLAN
+ * $Id: render.c,v 1.1 2003/12/26 01:39:35 rocky Exp $
+ *
+ * Author: Rocky Bernstein 
+ *   based on code from: 
+ *          Sam Hocevar <sam@zoy.org>
+ *          Rudolf Cornelissen <rag.cornelissen@inter.nl.net>
+ *          Roine Gustafsson <roine@popstar.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Preamble
+ *****************************************************************************/
+#include <vlc/vlc.h>
+#include <vlc/vout.h>
+#include <vlc/decoder.h>
+
+#include "ogt.h"
+
+/*****************************************************************************
+ * Local prototypes
+ *****************************************************************************/
+static void RenderI420( vout_thread_t *, picture_t *, const subpicture_t *,
+                        vlc_bool_t );
+
+/*****************************************************************************
+ * RenderSPU: draw an SPU on a picture
+ *****************************************************************************
+ 
+  This is a fast implementation of the subpicture drawing code. The
+  data has been preprocessed. Each byte has a run-length 1 in the upper
+  nibble and a color in the lower nibble. The interleaving of rows has
+  been done. Most sanity checks are already done so that this
+  routine can be as fast as possible.
+
+ *****************************************************************************/
+void E_(RenderSPU)( vout_thread_t *p_vout, picture_t *p_pic,
+                    const subpicture_t *p_spu )
+{
+
+#ifndef FINISHED
+    printf("+++%x\n", p_vout->output.i_chroma);
+#endif
+  
+    switch( p_vout->output.i_chroma )
+    {
+        /* I420 target, no scaling */
+        case VLC_FOURCC('I','4','2','0'):
+        case VLC_FOURCC('I','Y','U','V'):
+        case VLC_FOURCC('Y','V','1','2'):
+            RenderI420( p_vout, p_pic, p_spu, p_spu->p_sys->b_crop );
+            break;
+
+        /* RV16 target, scaling */
+        case VLC_FOURCC('R','V','1','6'):
+            msg_Err( p_vout, "RV16 not implimented yet" );
+	    break;
+
+        /* RV32 target, scaling */
+        case VLC_FOURCC('R','V','2','4'):
+        case VLC_FOURCC('R','V','3','2'):
+            msg_Err( p_vout, "RV24/VF32 not implimented yet" );
+	    break;
+
+        /* NVidia overlay, no scaling */
+        case VLC_FOURCC('Y','U','Y','2'):
+            msg_Err( p_vout, "YUV2 not implimented yet" );
+	    break;
+
+        default:
+            msg_Err( p_vout, "unknown chroma, can't render SPU" );
+            break;
+    }
+}
+
+/* Following functions are local */
+
+static void RenderI420( vout_thread_t *p_vout, picture_t *p_pic,
+                        const subpicture_t *p_spu, vlc_bool_t b_crop )
+{
+  /* Common variables */
+  uint8_t *p_dest;
+  uint8_t *p_destptr;
+  ogt_yuvt_t *p_source;
+  
+  int i_x, i_y;
+  uint16_t i_colprecomp, i_destalpha;
+  
+  /* Crop-specific */
+  int i_x_start, i_y_start, i_x_end, i_y_end;
+  /* int i=0; */
+  
+  p_dest = p_pic->Y_PIXELS + p_spu->i_x + p_spu->i_width
+    + p_pic->Y_PITCH * ( p_spu->i_y + p_spu->i_height );
+  
+  i_x_start = p_spu->i_width - p_spu->p_sys->i_x_end;
+  i_y_start = p_pic->Y_PITCH * (p_spu->i_height - p_spu->p_sys->i_y_end );
+  i_x_end   = p_spu->i_width - p_spu->p_sys->i_x_start;
+  i_y_end   = p_pic->Y_PITCH * (p_spu->i_height - p_spu->p_sys->i_y_start );
+  
+  p_source = (ogt_yuvt_t *)p_spu->p_sys->p_data;
+
+  /* printf("+++spu width: %d, height %d\n", p_spu->i_width, 
+     p_spu->i_height); */
+  
+  /* Draw until we reach the bottom of the subtitle */
+  for( i_y = p_spu->i_height * p_pic->Y_PITCH ;
+       i_y ;
+       i_y -= p_pic->Y_PITCH )
+    {
+      /* printf("+++begin line: %d,\n", i++); */
+      /* Draw until we reach the end of the line */
+      for( i_x = p_spu->i_width ; i_x ; i_x--, p_source++ )
+        {
+	  
+	  if( b_crop
+	      && ( i_x < i_x_start || i_x > i_x_end
+		   || i_y < i_y_start || i_y > i_y_end ) )
+            {
+	      continue;
+            }
+
+	  /* printf( "t: %x, y: %x, u: %x, v: %x\n", 
+	     p_source->t, p_source->y, p_source->u, p_source->v ); */
+	  
+	  switch( p_source->t )
+            {
+	    case 0x00: 
+	      /* Completely transparent. Don't change underlying pixel */
+	      break;
+	      
+	    case 0x0f:
+	      /* Completely opaque. Completely overwrite underlying
+		 pixel with subtitle pixel. */
+
+	      p_destptr = p_dest - i_x - i_y;
+
+	      i_colprecomp = (uint16_t) ( p_source->y * 15 );
+	      *p_destptr = i_colprecomp >> 4;
+
+	      break;
+	      
+	    default:
+	      /* Blend in underlying pixel subtitle pixel. */
+
+	      /* To be able to divide by 16 (>>4) we add 1 to the alpha.
+	       * This means Alpha 0 won't be completely transparent, but
+	       * that's handled in a special case above anyway. */
+
+	      p_destptr = p_dest - i_x - i_y;
+
+	      i_colprecomp = (uint16_t) ( (p_source->y 
+					   * (uint16_t)(p_source->t + 1) ) );
+	      i_destalpha = 15 - p_source->t;
+
+	      *p_destptr = ( i_colprecomp +
+			       (uint16_t)*p_destptr * i_destalpha ) >> 4;
+	      break;
+            }
+        }
+    }
+}
+