git.sesse.net Git - vlc/blob - modules/codec/ffmpeg/video_filter.c

   1 /*****************************************************************************
   2  * video filter: video filter doing chroma conversion and resizing
   3  *               using the ffmpeg library
   4  *****************************************************************************
   5  * Copyright (C) 1999-2001 the VideoLAN team
   6  * $Id$
   7  *
   8  * Authors: Gildas Bazin <gbazin@videolan.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc/vlc.h>
  33 #include <vlc_codec.h>
  34 #include <vlc_vout.h>
  35 #include <vlc_filter.h>
  36
  37 /* ffmpeg header */
  38 #ifdef HAVE_FFMPEG_AVCODEC_H
  39 #   include <ffmpeg/avcodec.h>
  40 #else
  41 #   include <avcodec.h>
  42 #endif
  43
  44 #include "ffmpeg.h"
  45
  46 #if !defined(HAVE_FFMPEG_SWSCALE_H) && !defined(HAVE_LIBSWSCALE_TREE)
  47 void E_(InitLibavcodec) ( vlc_object_t *p_object );
  48 static int CheckInit( filter_t *p_filter );
  49 static picture_t *Process( filter_t *p_filter, picture_t *p_pic );
  50
  51 /*****************************************************************************
  52  * filter_sys_t : filter descriptor
  53  *****************************************************************************/
  54 struct filter_sys_t
  55 {
  56     vlc_bool_t b_resize;
  57     vlc_bool_t b_convert;
  58     vlc_bool_t b_resize_first;
  59     vlc_bool_t b_enable_croppadd;
  60
  61     es_format_t fmt_in;
  62     int i_src_ffmpeg_chroma;
  63     es_format_t fmt_out;
  64     int i_dst_ffmpeg_chroma;
  65
  66     AVPicture tmp_pic;
  67
  68     ImgReSampleContext *p_rsc;
  69 };
  70
  71 /*****************************************************************************
  72  * OpenFilterEx: common code to OpenFilter and OpenCropPadd
  73  *****************************************************************************/
  74 static int OpenFilterEx( vlc_object_t *p_this, vlc_bool_t b_enable_croppadd )
  75 {
  76     filter_t *p_filter = (filter_t*)p_this;
  77     filter_sys_t *p_sys;
  78     vlc_bool_t b_convert, b_resize;
  79
  80     /* Check if we can handle that formats */
  81     if( E_(GetFfmpegChroma)( p_filter->fmt_in.video.i_chroma ) < 0 ||
  82         E_(GetFfmpegChroma)( p_filter->fmt_out.video.i_chroma ) < 0 )
  83     {
  84         return VLC_EGENERIC;
  85     }
  86
  87     b_resize =
  88         ( p_filter->fmt_in.video.i_width != p_filter->fmt_out.video.i_width ) ||
  89         ( p_filter->fmt_in.video.i_height != p_filter->fmt_out.video.i_height );
  90
  91     if ( b_enable_croppadd )
  92     {
  93         b_resize = b_resize ||
  94            ( p_filter->fmt_in.video.i_visible_width != p_filter->fmt_in.video.i_width ) ||
  95            ( p_filter->fmt_in.video.i_visible_height != p_filter->fmt_in.video.i_height ) ||
  96            ( p_filter->fmt_in.video.i_x_offset != 0 ) ||
  97            ( p_filter->fmt_in.video.i_y_offset != 0 ) ||
  98            ( p_filter->fmt_out.video.i_visible_width != p_filter->fmt_out.video.i_width ) ||
  99            ( p_filter->fmt_out.video.i_visible_height != p_filter->fmt_out.video.i_height ) ||
 100            ( p_filter->fmt_out.video.i_x_offset != 0 ) ||
 101            ( p_filter->fmt_out.video.i_y_offset != 0 );
 102     }
 103
 104     b_convert =
 105         ( p_filter->fmt_in.video.i_chroma != p_filter->fmt_out.video.i_chroma );
 106
 107     if( !b_resize && !b_convert )
 108     {
 109         /* Nothing to do */
 110         return VLC_EGENERIC;
 111     }
 112
 113     /* Allocate the memory needed to store the decoder's structure */
 114     if( ( p_filter->p_sys = p_sys =
 115           (filter_sys_t *)malloc(sizeof(filter_sys_t)) ) == NULL )
 116     {
 117         msg_Err( p_filter, "out of memory" );
 118         return VLC_EGENERIC;
 119     }
 120
 121     /* Misc init */
 122     p_sys->p_rsc = NULL;
 123     p_sys->b_enable_croppadd = b_enable_croppadd;
 124     p_sys->i_src_ffmpeg_chroma =
 125         E_(GetFfmpegChroma)( p_filter->fmt_in.video.i_chroma );
 126     p_sys->i_dst_ffmpeg_chroma =
 127         E_(GetFfmpegChroma)( p_filter->fmt_out.video.i_chroma );
 128     p_filter->pf_video_filter = Process;
 129     es_format_Init( &p_sys->fmt_in, 0, 0 );
 130     es_format_Init( &p_sys->fmt_out, 0, 0 );
 131
 132     /* Dummy alloc, will be reallocated in CheckInit */
 133     avpicture_alloc( &p_sys->tmp_pic, p_sys->i_src_ffmpeg_chroma,
 134                      p_filter->fmt_out.video.i_width,
 135                      p_filter->fmt_out.video.i_height );
 136
 137     if( CheckInit( p_filter ) != VLC_SUCCESS )
 138     {
 139         free( p_sys );
 140         return VLC_EGENERIC;
 141     }
 142
 143     msg_Dbg( p_filter, "input: %ix%i %4.4s -> %ix%i %4.4s",
 144              p_filter->fmt_in.video.i_width, p_filter->fmt_in.video.i_height,
 145              (char *)&p_filter->fmt_in.video.i_chroma,
 146              p_filter->fmt_out.video.i_width, p_filter->fmt_out.video.i_height,
 147              (char *)&p_filter->fmt_out.video.i_chroma );
 148
 149     /* libavcodec needs to be initialized for some chroma conversions */
 150     E_(InitLibavcodec)(p_this);
 151
 152     return VLC_SUCCESS;
 153 }
 154
 155 /*****************************************************************************
 156  * OpenFilter: probe the filter and return score
 157  *****************************************************************************/
 158 int E_(OpenFilter)( vlc_object_t *p_this )
 159 {
 160     return OpenFilterEx( p_this, VLC_FALSE );
 161 }
 162
 163 /*****************************************************************************
 164  * OpenCropPadd: probe the filter and return score
 165  *****************************************************************************/
 166 int E_(OpenCropPadd)( vlc_object_t *p_this )
 167 {
 168     return OpenFilterEx( p_this, VLC_TRUE );
 169 }
 170
 171
 172 /*****************************************************************************
 173  * CloseFilter: clean up the filter
 174  *****************************************************************************/
 175 void E_(CloseFilter)( vlc_object_t *p_this )
 176 {
 177     filter_t *p_filter = (filter_t*)p_this;
 178     filter_sys_t *p_sys = p_filter->p_sys;
 179
 180     if( p_sys->p_rsc ) img_resample_close( p_sys->p_rsc );
 181     avpicture_free( &p_sys->tmp_pic );
 182
 183     free( p_sys );
 184 }
 185
 186 /*****************************************************************************
 187  * CheckInit: Initialise filter when necessary
 188  *****************************************************************************/
 189 static int CheckInit( filter_t *p_filter )
 190 {
 191     filter_sys_t *p_sys = p_filter->p_sys;
 192     vlc_bool_t b_change;
 193     int i_croptop=0;
 194     int i_cropbottom=0;
 195     int i_cropleft=0;
 196     int i_cropright=0;
 197     int i_paddtop=0;
 198     int i_paddbottom=0;
 199     int i_paddleft=0;
 200     int i_paddright=0;
 201
 202     b_change = ( p_filter->fmt_in.video.i_width != p_sys->fmt_in.video.i_width ) ||
 203         ( p_filter->fmt_in.video.i_height != p_sys->fmt_in.video.i_height ) ||
 204         ( p_filter->fmt_out.video.i_width != p_sys->fmt_out.video.i_width ) ||
 205         ( p_filter->fmt_out.video.i_height != p_sys->fmt_out.video.i_height );
 206
 207     if ( p_sys->b_enable_croppadd )
 208     {
 209         b_change = b_change ||
 210             ( p_filter->fmt_in.video.i_y_offset != p_sys->fmt_in.video.i_y_offset ) ||
 211             ( p_filter->fmt_in.video.i_x_offset != p_sys->fmt_in.video.i_x_offset ) ||
 212             ( p_filter->fmt_in.video.i_visible_width != p_sys->fmt_in.video.i_visible_width ) ||
 213             ( p_filter->fmt_in.video.i_visible_height != p_sys->fmt_in.video.i_visible_height ) ||
 214             ( p_filter->fmt_out.video.i_y_offset != p_sys->fmt_out.video.i_y_offset ) ||
 215             ( p_filter->fmt_out.video.i_x_offset != p_sys->fmt_out.video.i_x_offset ) ||
 216             ( p_filter->fmt_out.video.i_visible_width != p_sys->fmt_out.video.i_visible_width ) ||
 217             ( p_filter->fmt_out.video.i_visible_height != p_sys->fmt_out.video.i_visible_height );
 218     }
 219
 220     if ( b_change )
 221     {
 222         if( p_sys->p_rsc ) img_resample_close( p_sys->p_rsc );
 223
 224         p_sys->p_rsc = NULL;
 225         p_sys->b_convert =
 226           ( p_filter->fmt_in.video.i_chroma != p_filter->fmt_out.video.i_chroma );
 227
 228         p_sys->b_resize =
 229           ( p_filter->fmt_in.video.i_width != p_filter->fmt_out.video.i_width ) ||
 230           ( p_filter->fmt_in.video.i_height != p_filter->fmt_out.video.i_height );
 231
 232         p_sys->b_resize_first =
 233           ( p_filter->fmt_in.video.i_width * p_filter->fmt_in.video.i_height ) >
 234           ( p_filter->fmt_out.video.i_width * p_filter->fmt_out.video.i_height );
 235
 236         if( p_sys->b_resize &&
 237             ( p_sys->i_src_ffmpeg_chroma != PIX_FMT_YUV420P ) &&
 238             ( p_sys->i_src_ffmpeg_chroma != PIX_FMT_YUVJ420P ) &&
 239             ( p_sys->i_dst_ffmpeg_chroma != PIX_FMT_YUV420P ) &&
 240             ( p_sys->i_dst_ffmpeg_chroma != PIX_FMT_YUVJ420P ) )
 241         {
 242             msg_Err( p_filter, "img_resample_init only deals with I420" );
 243             return VLC_EGENERIC;
 244         }
 245         else if( ( p_sys->i_src_ffmpeg_chroma != PIX_FMT_YUV420P ) &&
 246                  ( p_sys->i_src_ffmpeg_chroma != PIX_FMT_YUVJ420P ) )
 247         {
 248             p_sys->b_resize_first = VLC_FALSE;
 249         }
 250         else if( ( p_sys->i_dst_ffmpeg_chroma != PIX_FMT_YUV420P ) &&
 251                  ( p_sys->i_dst_ffmpeg_chroma != PIX_FMT_YUVJ420P ) )
 252         {
 253             p_sys->b_resize_first = VLC_TRUE;
 254         }
 255
 256         if ( p_sys->b_enable_croppadd )
 257         {
 258             p_sys->b_resize = p_sys->b_resize ||
 259                 ( p_filter->fmt_in.video.i_visible_width != p_filter->fmt_in.video.i_width ) ||
 260                 ( p_filter->fmt_in.video.i_visible_height != p_filter->fmt_in.video.i_height ) ||
 261                 ( p_filter->fmt_in.video.i_x_offset != 0 ) ||
 262                 ( p_filter->fmt_in.video.i_y_offset != 0 ) ||
 263                 ( p_filter->fmt_out.video.i_visible_width != p_filter->fmt_out.video.i_width ) ||
 264                 ( p_filter->fmt_out.video.i_visible_height != p_filter->fmt_out.video.i_height ) ||
 265                 ( p_filter->fmt_out.video.i_x_offset != 0 ) ||
 266                 ( p_filter->fmt_out.video.i_y_offset != 0 );
 267         }
 268
 269         if( p_sys->b_resize )
 270         {
 271             if ( p_sys->b_enable_croppadd )
 272             {
 273                 i_croptop = p_filter->fmt_in.video.i_y_offset;
 274                 i_cropbottom = p_filter->fmt_in.video.i_height
 275                                        - p_filter->fmt_in.video.i_visible_height
 276                                        - p_filter->fmt_in.video.i_y_offset;
 277                 i_cropleft = p_filter->fmt_in.video.i_x_offset;
 278                 i_cropright = p_filter->fmt_in.video.i_width
 279                                       - p_filter->fmt_in.video.i_visible_width
 280                                       - p_filter->fmt_in.video.i_x_offset;
 281
 282
 283                 i_paddtop = p_filter->fmt_out.video.i_y_offset;
 284                 i_paddbottom = p_filter->fmt_out.video.i_height
 285                                        - p_filter->fmt_out.video.i_visible_height
 286                                        - p_filter->fmt_out.video.i_y_offset;
 287                 i_paddleft = p_filter->fmt_out.video.i_x_offset;
 288                 i_paddright = p_filter->fmt_out.video.i_width
 289                                       - p_filter->fmt_out.video.i_visible_width
 290                                       - p_filter->fmt_out.video.i_x_offset;
 291             }
 292
 293             p_sys->p_rsc = img_resample_full_init(
 294                                p_filter->fmt_out.video.i_width,
 295                                p_filter->fmt_out.video.i_height,
 296                                p_filter->fmt_in.video.i_width,
 297                                p_filter->fmt_in.video.i_height,
 298                                i_croptop,i_cropbottom,
 299                                i_cropleft,i_cropright,
 300                                i_paddtop,i_paddbottom,
 301                                i_paddleft,i_paddright );
 302
 303             if( !p_sys->p_rsc )
 304             {
 305                 msg_Err( p_filter, "img_resample_init failed" );
 306                 return VLC_EGENERIC;
 307             }
 308
 309             msg_Dbg( p_filter, "input: %ix%i -> %ix%i",
 310                 p_filter->fmt_out.video.i_width,
 311                 p_filter->fmt_out.video.i_height,
 312                 p_filter->fmt_in.video.i_width,
 313                 p_filter->fmt_in.video.i_height);
 314
 315         }
 316
 317         avpicture_free( &p_sys->tmp_pic );
 318
 319         if( p_sys->b_resize_first )
 320         {
 321             /* Resizing then conversion */
 322             avpicture_alloc( &p_sys->tmp_pic, p_sys->i_src_ffmpeg_chroma,
 323                              p_filter->fmt_out.video.i_width,
 324                              p_filter->fmt_out.video.i_height );
 325         }
 326         else
 327         {
 328             /* Conversion then resizing */
 329             avpicture_alloc( &p_sys->tmp_pic, p_sys->i_dst_ffmpeg_chroma,
 330                              p_filter->fmt_in.video.i_width,
 331                              p_filter->fmt_in.video.i_height );
 332         }
 333
 334         p_sys->fmt_in = p_filter->fmt_in;
 335         p_sys->fmt_out = p_filter->fmt_out;
 336     }
 337
 338     return VLC_SUCCESS;
 339 }
 340
 341 /* fill padd code from ffmpeg */
 342 static int padcolor[3] = { 16, 128, 128 };
 343
 344 /* Expects img to be yuv420 */
 345 static void fill_pad_region( AVPicture* img, int height, int width,
 346         int padtop, int padbottom, int padleft, int padright, int *color )
 347 {
 348     int i, y, shift;
 349     uint8_t *optr;
 350
 351     for ( i = 0; i < 3; i++ )
 352     {
 353         shift = ( i == 0 ) ? 0 : 1;
 354
 355         if ( padtop || padleft )
 356         {
 357             memset( img->data[i], color[i], ( ( ( img->linesize[i] * padtop ) +
 358                             padleft ) >> shift) );
 359         }
 360
 361         if ( padleft || padright )
 362         {
 363             optr = img->data[i] + ( img->linesize[i] * ( padtop >> shift ) ) +
 364                 ( img->linesize[i] - ( padright >> shift ) );
 365
 366             for ( y = 0; y < ( ( height - ( padtop + padbottom ) ) >> shift ); y++ )
 367             {
 368                 memset( optr, color[i], ( padleft + padright ) >> shift );
 369                 optr += img->linesize[i];
 370             }
 371         }
 372
 373         if (padbottom)
 374         {
 375             optr = img->data[i] + ( img->linesize[i] * ( ( height - padbottom ) >> shift ) );
 376             memset( optr, color[i], ( ( img->linesize[i] * padbottom ) >> shift ) );
 377         }
 378     }
 379 }
 380
 381 /* Workaround, because old libavcodec doesnt know how to padd */
 382 static void img_resample_padd( ImgReSampleContext *s, AVPicture *output,
 383         const AVPicture *input, int padtop, int padleft )
 384 {
 385     AVPicture nopadd_pic = *output;
 386
 387     /* shift out top and left padding for old ffmpeg */
 388     nopadd_pic.data[0] += ( nopadd_pic.linesize[0] * padtop + padleft );
 389     nopadd_pic.data[1] += ( nopadd_pic.linesize[1] * padtop + padleft ) >> 1;
 390     nopadd_pic.data[2] += ( nopadd_pic.linesize[2] * padtop + padleft ) >> 1;
 391     img_resample( s, &nopadd_pic, input );
 392 }
 393
 394
 395 /*****************************************************************************
 396  * Do the processing here
 397  *****************************************************************************/
 398 static picture_t *Process( filter_t *p_filter, picture_t *p_pic )
 399 {
 400     filter_sys_t *p_sys = p_filter->p_sys;
 401     AVPicture src_pic, dest_pic;
 402     AVPicture *p_src, *p_dst;
 403     picture_t *p_pic_dst;
 404     int i;
 405
 406     /* Check if format properties changed */
 407     if( CheckInit( p_filter ) != VLC_SUCCESS ) return 0;
 408
 409     /* Request output picture */
 410     p_pic_dst = p_filter->pf_vout_buffer_new( p_filter );
 411     if( !p_pic_dst )
 412     {
 413         msg_Warn( p_filter, "can't get output picture" );
 414         p_pic->pf_release( p_pic );
 415         return NULL;
 416     }
 417
 418     /* Prepare the AVPictures for the conversion */
 419     for( i = 0; i < p_pic->i_planes; i++ )
 420     {
 421         src_pic.data[i] = p_pic->p[i].p_pixels;
 422         src_pic.linesize[i] = p_pic->p[i].i_pitch;
 423     }
 424     for( i = 0; i < p_pic_dst->i_planes; i++ )
 425     {
 426         dest_pic.data[i] = p_pic_dst->p[i].p_pixels;
 427         dest_pic.linesize[i] = p_pic_dst->p[i].i_pitch;
 428     }
 429
 430     /* Special cases */
 431     if( p_filter->fmt_in.video.i_chroma == VLC_FOURCC('Y','V','1','2') ||
 432         p_filter->fmt_in.video.i_chroma == VLC_FOURCC('Y','V','U','9') )
 433     {
 434         /* Invert U and V */
 435         src_pic.data[1] = p_pic->p[2].p_pixels;
 436         src_pic.data[2] = p_pic->p[1].p_pixels;
 437     }
 438     if( p_filter->fmt_out.video.i_chroma == VLC_FOURCC('Y','V','1','2') ||
 439         p_filter->fmt_out.video.i_chroma == VLC_FOURCC('Y','V','U','9') )
 440     {
 441         /* Invert U and V */
 442         dest_pic.data[1] = p_pic_dst->p[2].p_pixels;
 443         dest_pic.data[2] = p_pic_dst->p[1].p_pixels;
 444     }
 445     if( p_sys->i_src_ffmpeg_chroma == PIX_FMT_RGB24 )
 446         if( p_filter->fmt_in.video.i_bmask == 0x00ff0000 )
 447             p_sys->i_src_ffmpeg_chroma = PIX_FMT_BGR24;
 448
 449     p_src = &src_pic;
 450
 451     if( p_sys->b_resize && p_sys->p_rsc )
 452     {
 453         p_dst = &dest_pic;
 454         if( p_sys->b_resize_first )
 455         {
 456             if( p_sys->b_convert ) p_dst = &p_sys->tmp_pic;
 457
 458             img_resample( p_sys->p_rsc, p_dst, p_src );
 459
 460             if (p_sys->b_enable_croppadd)
 461             {
 462                 if (p_filter->fmt_out.video.i_visible_width != p_filter->fmt_out.video.i_width ||
 463                     p_filter->fmt_out.video.i_visible_height != p_filter->fmt_out.video.i_height ||
 464                     p_filter->fmt_out.video.i_x_offset != 0 ||
 465                     p_filter->fmt_out.video.i_y_offset != 0)
 466                 {
 467                     fill_pad_region(p_dst, p_filter->fmt_out.video.i_height,
 468                                     p_filter->fmt_out.video.i_width,
 469                                     p_filter->fmt_out.video.i_y_offset,
 470                                     p_filter->fmt_out.video.i_height
 471                                       - p_filter->fmt_out.video.i_visible_height
 472                                       - p_filter->fmt_out.video.i_y_offset,
 473                                     p_filter->fmt_out.video.i_x_offset,
 474                                     p_filter->fmt_out.video.i_width
 475                                       - p_filter->fmt_out.video.i_visible_width
 476                                       - p_filter->fmt_out.video.i_x_offset,
 477                                     padcolor);
 478                 }
 479             }
 480
 481             p_src = p_dst;
 482         }
 483     }
 484
 485     if( p_sys->b_convert )
 486     {
 487         video_format_t *p_fmt = &p_filter->fmt_out.video;
 488         p_dst = &dest_pic;
 489         if( p_sys->b_resize && !p_sys->b_resize_first )
 490         {
 491             p_dst = &p_sys->tmp_pic;
 492             p_fmt = &p_filter->fmt_in.video;
 493         }
 494
 495         img_convert( p_dst, p_sys->i_dst_ffmpeg_chroma,
 496                      p_src, p_sys->i_src_ffmpeg_chroma,
 497                      p_fmt->i_width, p_fmt->i_height );
 498
 499         p_src = p_dst;
 500     }
 501
 502     if( p_sys->b_resize && !p_sys->b_resize_first && p_sys->p_rsc )
 503     {
 504         p_dst = &dest_pic;
 505
 506         img_resample( p_sys->p_rsc, p_dst, p_src );
 507
 508         if (p_sys->b_enable_croppadd)
 509         {
 510             if (p_filter->fmt_out.video.i_visible_width != p_filter->fmt_out.video.i_width ||
 511                 p_filter->fmt_out.video.i_visible_height != p_filter->fmt_out.video.i_height ||
 512                 p_filter->fmt_out.video.i_x_offset != 0 ||
 513                 p_filter->fmt_out.video.i_y_offset != 0)
 514             {
 515                 fill_pad_region(p_dst, p_filter->fmt_out.video.i_height,
 516                                 p_filter->fmt_out.video.i_width,
 517                                 p_filter->fmt_out.video.i_y_offset,
 518                                 p_filter->fmt_out.video.i_height
 519                                   - p_filter->fmt_out.video.i_visible_height
 520                                   - p_filter->fmt_out.video.i_y_offset,
 521                                 p_filter->fmt_out.video.i_x_offset,
 522                                 p_filter->fmt_out.video.i_width
 523                                   - p_filter->fmt_out.video.i_visible_width
 524                                   - p_filter->fmt_out.video.i_x_offset,
 525                                 padcolor);
 526             }
 527         }
 528     }
 529
 530     /* Special case for RV32 -> YUVA */
 531     if( !p_sys->b_resize &&
 532         p_filter->fmt_in.video.i_chroma == VLC_FOURCC('R','V','3','2') &&
 533         p_filter->fmt_out.video.i_chroma == VLC_FOURCC('Y','U','V','A') )
 534     {
 535         uint8_t *p_src = p_pic->p[0].p_pixels;
 536         int i_src_pitch = p_pic->p[0].i_pitch;
 537         uint8_t *p_dst = p_pic_dst->p[3].p_pixels;
 538         int i_dst_pitch = p_pic_dst->p[3].i_pitch;
 539         uint32_t l,j;
 540
 541         for( l = 0; l < p_filter->fmt_out.video.i_height; l++ )
 542         {
 543             for( j = 0; j < p_filter->fmt_out.video.i_width; j++ )
 544             {
 545               p_dst[j] = p_src[j*4+3];
 546             }
 547             p_src += i_src_pitch;
 548             p_dst += i_dst_pitch;
 549         }
 550     }
 551     else if( p_filter->fmt_out.video.i_chroma == VLC_FOURCC('Y','U','V','A') )
 552     {
 553         /* Special case for YUVA */
 554         memset( p_pic_dst->p[3].p_pixels, 0xFF,
 555                 p_pic_dst->p[3].i_pitch * p_pic_dst->p[3].i_lines );
 556     }
 557
 558     p_pic_dst->date = p_pic->date;
 559     p_pic_dst->b_force = p_pic->b_force;
 560     p_pic_dst->i_nb_fields = p_pic->i_nb_fields;
 561     p_pic_dst->b_progressive = p_pic->b_progressive;
 562     p_pic_dst->b_top_field_first = p_pic->b_top_field_first;
 563
 564     p_pic->pf_release( p_pic );
 565     return p_pic_dst;
 566 }
 567 #endif /* ( (defined(HAVE_FFMPEG_SWSCALE_H) || defined(HAVE_LIBSWSCALE_TREE)) */