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_LIBAVCODEC_AVCODEC_H
  39 #   include <libavcodec/avcodec.h>
  40 #elif defined(HAVE_FFMPEG_AVCODEC_H)
  41 #   include <ffmpeg/avcodec.h>
  42 #else
  43 #   include <avcodec.h>
  44 #endif
  45
  46 #include "ffmpeg.h"
  47
  48 #if !defined(HAVE_LIBSWSCALE_SWSCALE_H)  && !defined(HAVE_FFMPEG_SWSCALE_H) && !defined(HAVE_LIBSWSCALE_TREE)
  49 void E_(InitLibavcodec) ( vlc_object_t *p_object );
  50 static int CheckInit( filter_t *p_filter );
  51 static picture_t *Process( filter_t *p_filter, picture_t *p_pic );
  52
  53 /*****************************************************************************
  54  * filter_sys_t : filter descriptor
  55  *****************************************************************************/
  56 struct filter_sys_t
  57 {
  58     bool b_resize;
  59     bool b_convert;
  60     bool b_resize_first;
  61     bool b_enable_croppadd;
  62
  63     es_format_t fmt_in;
  64     int i_src_ffmpeg_chroma;
  65     es_format_t fmt_out;
  66     int i_dst_ffmpeg_chroma;
  67
  68     AVPicture tmp_pic;
  69
  70     ImgReSampleContext *p_rsc;
  71 };
  72
  73 /*****************************************************************************
  74  * OpenFilterEx: common code to OpenFilter and OpenCropPadd
  75  *****************************************************************************/
  76 static int OpenFilterEx( vlc_object_t *p_this, bool b_enable_croppadd )
  77 {
  78     filter_t *p_filter = (filter_t*)p_this;
  79     filter_sys_t *p_sys;
  80     bool b_convert, b_resize;
  81
  82     /* Check if we can handle that formats */
  83     if( E_(GetFfmpegChroma)( p_filter->fmt_in.video.i_chroma ) < 0 ||
  84         E_(GetFfmpegChroma)( p_filter->fmt_out.video.i_chroma ) < 0 )
  85     {
  86         return VLC_EGENERIC;
  87     }
  88
  89     b_resize =
  90         ( p_filter->fmt_in.video.i_width != p_filter->fmt_out.video.i_width ) ||
  91         ( p_filter->fmt_in.video.i_height != p_filter->fmt_out.video.i_height );
  92
  93     if ( b_enable_croppadd )
  94     {
  95         b_resize = b_resize ||
  96            ( p_filter->fmt_in.video.i_visible_width != p_filter->fmt_in.video.i_width ) ||
  97            ( p_filter->fmt_in.video.i_visible_height != p_filter->fmt_in.video.i_height ) ||
  98            ( p_filter->fmt_in.video.i_x_offset != 0 ) ||
  99            ( p_filter->fmt_in.video.i_y_offset != 0 ) ||
 100            ( p_filter->fmt_out.video.i_visible_width != p_filter->fmt_out.video.i_width ) ||
 101            ( p_filter->fmt_out.video.i_visible_height != p_filter->fmt_out.video.i_height ) ||
 102            ( p_filter->fmt_out.video.i_x_offset != 0 ) ||
 103            ( p_filter->fmt_out.video.i_y_offset != 0 );
 104     }
 105
 106     b_convert =
 107         ( p_filter->fmt_in.video.i_chroma != p_filter->fmt_out.video.i_chroma );
 108
 109     if( !b_resize && !b_convert )
 110     {
 111         /* Nothing to do */
 112         return VLC_EGENERIC;
 113     }
 114
 115     /* Allocate the memory needed to store the decoder's structure */
 116     if( ( p_filter->p_sys = p_sys =
 117           (filter_sys_t *)malloc(sizeof(filter_sys_t)) ) == NULL )
 118     {
 119         msg_Err( p_filter, "out of memory" );
 120         return VLC_EGENERIC;
 121     }
 122
 123     /* Misc init */
 124     p_sys->p_rsc = NULL;
 125     p_sys->b_enable_croppadd = b_enable_croppadd;
 126     p_sys->i_src_ffmpeg_chroma =
 127         E_(GetFfmpegChroma)( p_filter->fmt_in.video.i_chroma );
 128     p_sys->i_dst_ffmpeg_chroma =
 129         E_(GetFfmpegChroma)( p_filter->fmt_out.video.i_chroma );
 130     p_filter->pf_video_filter = Process;
 131     es_format_Init( &p_sys->fmt_in, 0, 0 );
 132     es_format_Init( &p_sys->fmt_out, 0, 0 );
 133
 134     /* Dummy alloc, will be reallocated in CheckInit */
 135     avpicture_alloc( &p_sys->tmp_pic, p_sys->i_src_ffmpeg_chroma,
 136                      p_filter->fmt_out.video.i_width,
 137                      p_filter->fmt_out.video.i_height );
 138
 139     if( CheckInit( p_filter ) != VLC_SUCCESS )
 140     {
 141         if( p_sys->p_rsc ) img_resample_close( p_sys->p_rsc );
 142         avpicture_free( &p_sys->tmp_pic );
 143         free( p_sys );
 144         return VLC_EGENERIC;
 145     }
 146
 147     msg_Dbg( p_filter, "input: %ix%i %4.4s -> %ix%i %4.4s",
 148              p_filter->fmt_in.video.i_width, p_filter->fmt_in.video.i_height,
 149              (char *)&p_filter->fmt_in.video.i_chroma,
 150              p_filter->fmt_out.video.i_width, p_filter->fmt_out.video.i_height,
 151              (char *)&p_filter->fmt_out.video.i_chroma );
 152
 153     /* libavcodec needs to be initialized for some chroma conversions */
 154     E_(InitLibavcodec)(p_this);
 155
 156     return VLC_SUCCESS;
 157 }
 158
 159 /*****************************************************************************
 160  * OpenFilter: probe the filter and return score
 161  *****************************************************************************/
 162 int E_(OpenFilter)( vlc_object_t *p_this )
 163 {
 164     return OpenFilterEx( p_this, false );
 165 }
 166
 167 /*****************************************************************************
 168  * OpenCropPadd: probe the filter and return score
 169  *****************************************************************************/
 170 int E_(OpenCropPadd)( vlc_object_t *p_this )
 171 {
 172     return OpenFilterEx( p_this, true );
 173 }
 174
 175
 176 /*****************************************************************************
 177  * CloseFilter: clean up the filter
 178  *****************************************************************************/
 179 void E_(CloseFilter)( vlc_object_t *p_this )
 180 {
 181     filter_t *p_filter = (filter_t*)p_this;
 182     filter_sys_t *p_sys = p_filter->p_sys;
 183
 184     if( p_sys->p_rsc ) img_resample_close( p_sys->p_rsc );
 185     avpicture_free( &p_sys->tmp_pic );
 186
 187     free( p_sys );
 188 }
 189
 190 /*****************************************************************************
 191  * CheckInit: Initialise filter when necessary
 192  *****************************************************************************/
 193 static int CheckInit( filter_t *p_filter )
 194 {
 195     filter_sys_t *p_sys = p_filter->p_sys;
 196     bool b_change;
 197     int i_croptop=0;
 198     int i_cropbottom=0;
 199     int i_cropleft=0;
 200     int i_cropright=0;
 201     int i_paddtop=0;
 202     int i_paddbottom=0;
 203     int i_paddleft=0;
 204     int i_paddright=0;
 205
 206     b_change = ( p_filter->fmt_in.video.i_width != p_sys->fmt_in.video.i_width ) ||
 207         ( p_filter->fmt_in.video.i_height != p_sys->fmt_in.video.i_height ) ||
 208         ( p_filter->fmt_out.video.i_width != p_sys->fmt_out.video.i_width ) ||
 209         ( p_filter->fmt_out.video.i_height != p_sys->fmt_out.video.i_height );
 210
 211     if ( p_sys->b_enable_croppadd )
 212     {
 213         b_change = b_change ||
 214             ( p_filter->fmt_in.video.i_y_offset != p_sys->fmt_in.video.i_y_offset ) ||
 215             ( p_filter->fmt_in.video.i_x_offset != p_sys->fmt_in.video.i_x_offset ) ||
 216             ( p_filter->fmt_in.video.i_visible_width != p_sys->fmt_in.video.i_visible_width ) ||
 217             ( p_filter->fmt_in.video.i_visible_height != p_sys->fmt_in.video.i_visible_height ) ||
 218             ( p_filter->fmt_out.video.i_y_offset != p_sys->fmt_out.video.i_y_offset ) ||
 219             ( p_filter->fmt_out.video.i_x_offset != p_sys->fmt_out.video.i_x_offset ) ||
 220             ( p_filter->fmt_out.video.i_visible_width != p_sys->fmt_out.video.i_visible_width ) ||
 221             ( p_filter->fmt_out.video.i_visible_height != p_sys->fmt_out.video.i_visible_height );
 222     }
 223
 224     if ( b_change )
 225     {
 226         if( p_sys->p_rsc ) img_resample_close( p_sys->p_rsc );
 227
 228         p_sys->p_rsc = NULL;
 229         p_sys->b_convert =
 230           ( p_filter->fmt_in.video.i_chroma != p_filter->fmt_out.video.i_chroma );
 231
 232         p_sys->b_resize =
 233           ( p_filter->fmt_in.video.i_width != p_filter->fmt_out.video.i_width ) ||
 234           ( p_filter->fmt_in.video.i_height != p_filter->fmt_out.video.i_height );
 235
 236         p_sys->b_resize_first =
 237           ( p_filter->fmt_in.video.i_width * p_filter->fmt_in.video.i_height ) >
 238           ( p_filter->fmt_out.video.i_width * p_filter->fmt_out.video.i_height );
 239
 240         if( p_sys->b_resize &&
 241             ( p_sys->i_src_ffmpeg_chroma != PIX_FMT_YUV420P ) &&
 242             ( p_sys->i_src_ffmpeg_chroma != PIX_FMT_YUVJ420P ) &&
 243             ( p_sys->i_dst_ffmpeg_chroma != PIX_FMT_YUV420P ) &&
 244             ( p_sys->i_dst_ffmpeg_chroma != PIX_FMT_YUVJ420P ) )
 245         {
 246             msg_Err( p_filter, "img_resample_init only deals with I420" );
 247             return VLC_EGENERIC;
 248         }
 249         else if( ( p_sys->i_src_ffmpeg_chroma != PIX_FMT_YUV420P ) &&
 250                  ( p_sys->i_src_ffmpeg_chroma != PIX_FMT_YUVJ420P ) )
 251         {
 252             p_sys->b_resize_first = false;
 253         }
 254         else if( ( p_sys->i_dst_ffmpeg_chroma != PIX_FMT_YUV420P ) &&
 255                  ( p_sys->i_dst_ffmpeg_chroma != PIX_FMT_YUVJ420P ) )
 256         {
 257             p_sys->b_resize_first = true;
 258         }
 259
 260         if ( p_sys->b_enable_croppadd )
 261         {
 262             p_sys->b_resize = p_sys->b_resize ||
 263                 ( p_filter->fmt_in.video.i_visible_width != p_filter->fmt_in.video.i_width ) ||
 264                 ( p_filter->fmt_in.video.i_visible_height != p_filter->fmt_in.video.i_height ) ||
 265                 ( p_filter->fmt_in.video.i_x_offset != 0 ) ||
 266                 ( p_filter->fmt_in.video.i_y_offset != 0 ) ||
 267                 ( p_filter->fmt_out.video.i_visible_width != p_filter->fmt_out.video.i_width ) ||
 268                 ( p_filter->fmt_out.video.i_visible_height != p_filter->fmt_out.video.i_height ) ||
 269                 ( p_filter->fmt_out.video.i_x_offset != 0 ) ||
 270                 ( p_filter->fmt_out.video.i_y_offset != 0 );
 271         }
 272
 273         if( p_sys->b_resize )
 274         {
 275             if ( p_sys->b_enable_croppadd )
 276             {
 277                 i_croptop = p_filter->fmt_in.video.i_y_offset;
 278                 i_cropbottom = p_filter->fmt_in.video.i_height
 279                                        - p_filter->fmt_in.video.i_visible_height
 280                                        - p_filter->fmt_in.video.i_y_offset;
 281                 i_cropleft = p_filter->fmt_in.video.i_x_offset;
 282                 i_cropright = p_filter->fmt_in.video.i_width
 283                                       - p_filter->fmt_in.video.i_visible_width
 284                                       - p_filter->fmt_in.video.i_x_offset;
 285
 286
 287                 i_paddtop = p_filter->fmt_out.video.i_y_offset;
 288                 i_paddbottom = p_filter->fmt_out.video.i_height
 289                                        - p_filter->fmt_out.video.i_visible_height
 290                                        - p_filter->fmt_out.video.i_y_offset;
 291                 i_paddleft = p_filter->fmt_out.video.i_x_offset;
 292                 i_paddright = p_filter->fmt_out.video.i_width
 293                                       - p_filter->fmt_out.video.i_visible_width
 294                                       - p_filter->fmt_out.video.i_x_offset;
 295             }
 296
 297             p_sys->p_rsc = img_resample_full_init(
 298                                p_filter->fmt_out.video.i_width,
 299                                p_filter->fmt_out.video.i_height,
 300                                p_filter->fmt_in.video.i_width,
 301                                p_filter->fmt_in.video.i_height,
 302                                i_croptop,i_cropbottom,
 303                                i_cropleft,i_cropright,
 304                                i_paddtop,i_paddbottom,
 305                                i_paddleft,i_paddright );
 306
 307             if( !p_sys->p_rsc )
 308             {
 309                 msg_Err( p_filter, "img_resample_init failed" );
 310                 return VLC_EGENERIC;
 311             }
 312
 313             msg_Dbg( p_filter, "input: %ix%i -> %ix%i",
 314                 p_filter->fmt_out.video.i_width,
 315                 p_filter->fmt_out.video.i_height,
 316                 p_filter->fmt_in.video.i_width,
 317                 p_filter->fmt_in.video.i_height);
 318
 319         }
 320
 321         avpicture_free( &p_sys->tmp_pic );
 322
 323         if( p_sys->b_resize_first )
 324         {
 325             /* Resizing then conversion */
 326             avpicture_alloc( &p_sys->tmp_pic, p_sys->i_src_ffmpeg_chroma,
 327                              p_filter->fmt_out.video.i_width,
 328                              p_filter->fmt_out.video.i_height );
 329         }
 330         else
 331         {
 332             /* Conversion then resizing */
 333             avpicture_alloc( &p_sys->tmp_pic, p_sys->i_dst_ffmpeg_chroma,
 334                              p_filter->fmt_in.video.i_width,
 335                              p_filter->fmt_in.video.i_height );
 336         }
 337
 338         p_sys->fmt_in = p_filter->fmt_in;
 339         p_sys->fmt_out = p_filter->fmt_out;
 340     }
 341
 342     return VLC_SUCCESS;
 343 }
 344
 345 /* fill padd code from ffmpeg */
 346 static int padcolor[3] = { 16, 128, 128 };
 347
 348 /* Expects img to be yuv420 */
 349 static void fill_pad_region( AVPicture* img, int height, int width,
 350         int padtop, int padbottom, int padleft, int padright, int *color )
 351 {
 352     int i, y, shift;
 353     uint8_t *optr;
 354
 355     for ( i = 0; i < 3; i++ )
 356     {
 357         shift = ( i == 0 ) ? 0 : 1;
 358
 359         if ( padtop || padleft )
 360         {
 361             memset( img->data[i], color[i], ( ( ( img->linesize[i] * padtop ) +
 362                             padleft ) >> shift) );
 363         }
 364
 365         if ( padleft || padright )
 366         {
 367             optr = img->data[i] + ( img->linesize[i] * ( padtop >> shift ) ) +
 368                 ( img->linesize[i] - ( padright >> shift ) );
 369
 370             for ( y = 0; y < ( ( height - ( padtop + padbottom ) ) >> shift ); y++ )
 371             {
 372                 memset( optr, color[i], ( padleft + padright ) >> shift );
 373                 optr += img->linesize[i];
 374             }
 375         }
 376
 377         if (padbottom)
 378         {
 379             optr = img->data[i] + ( img->linesize[i] * ( ( height - padbottom ) >> shift ) );
 380             memset( optr, color[i], ( ( img->linesize[i] * padbottom ) >> shift ) );
 381         }
 382     }
 383 }
 384
 385 /* Workaround, because old libavcodec doesnt know how to padd */
 386 static void img_resample_padd( ImgReSampleContext *s, AVPicture *output,
 387         const AVPicture *input, int padtop, int padleft )
 388 {
 389     AVPicture nopadd_pic = *output;
 390
 391     /* shift out top and left padding for old ffmpeg */
 392     nopadd_pic.data[0] += ( nopadd_pic.linesize[0] * padtop + padleft );
 393     nopadd_pic.data[1] += ( nopadd_pic.linesize[1] * padtop + padleft ) >> 1;
 394     nopadd_pic.data[2] += ( nopadd_pic.linesize[2] * padtop + padleft ) >> 1;
 395     img_resample( s, &nopadd_pic, input );
 396 }
 397
 398
 399 /*****************************************************************************
 400  * Do the processing here
 401  *****************************************************************************/
 402 static picture_t *Process( filter_t *p_filter, picture_t *p_pic )
 403 {
 404     filter_sys_t *p_sys = p_filter->p_sys;
 405     AVPicture src_pic, dest_pic;
 406     AVPicture *p_src, *p_dst;
 407     picture_t *p_pic_dst;
 408     int i;
 409
 410     /* Check if format properties changed */
 411     if( CheckInit( p_filter ) != VLC_SUCCESS ) return 0;
 412
 413     /* Request output picture */
 414     p_pic_dst = p_filter->pf_vout_buffer_new( p_filter );
 415     if( !p_pic_dst )
 416     {
 417         msg_Warn( p_filter, "can't get output picture" );
 418         p_pic->pf_release( p_pic );
 419         return NULL;
 420     }
 421
 422     /* Prepare the AVPictures for the conversion */
 423     for( i = 0; i < p_pic->i_planes; i++ )
 424     {
 425         src_pic.data[i] = p_pic->p[i].p_pixels;
 426         src_pic.linesize[i] = p_pic->p[i].i_pitch;
 427     }
 428     for( i = 0; i < p_pic_dst->i_planes; i++ )
 429     {
 430         dest_pic.data[i] = p_pic_dst->p[i].p_pixels;
 431         dest_pic.linesize[i] = p_pic_dst->p[i].i_pitch;
 432     }
 433
 434     /* Special cases */
 435     if( p_filter->fmt_in.video.i_chroma == VLC_FOURCC('Y','V','1','2') ||
 436         p_filter->fmt_in.video.i_chroma == VLC_FOURCC('Y','V','U','9') )
 437     {
 438         /* Invert U and V */
 439         src_pic.data[1] = p_pic->p[2].p_pixels;
 440         src_pic.data[2] = p_pic->p[1].p_pixels;
 441     }
 442     if( p_filter->fmt_out.video.i_chroma == VLC_FOURCC('Y','V','1','2') ||
 443         p_filter->fmt_out.video.i_chroma == VLC_FOURCC('Y','V','U','9') )
 444     {
 445         /* Invert U and V */
 446         dest_pic.data[1] = p_pic_dst->p[2].p_pixels;
 447         dest_pic.data[2] = p_pic_dst->p[1].p_pixels;
 448     }
 449     if( p_sys->i_src_ffmpeg_chroma == PIX_FMT_RGB24 )
 450         if( p_filter->fmt_in.video.i_bmask == 0x00ff0000 )
 451             p_sys->i_src_ffmpeg_chroma = PIX_FMT_BGR24;
 452
 453     p_src = &src_pic;
 454
 455     if( p_sys->b_resize && p_sys->p_rsc )
 456     {
 457         p_dst = &dest_pic;
 458         if( p_sys->b_resize_first )
 459         {
 460             if( p_sys->b_convert ) p_dst = &p_sys->tmp_pic;
 461
 462             img_resample( p_sys->p_rsc, p_dst, p_src );
 463
 464             if (p_sys->b_enable_croppadd)
 465             {
 466                 if (p_filter->fmt_out.video.i_visible_width != p_filter->fmt_out.video.i_width ||
 467                     p_filter->fmt_out.video.i_visible_height != p_filter->fmt_out.video.i_height ||
 468                     p_filter->fmt_out.video.i_x_offset != 0 ||
 469                     p_filter->fmt_out.video.i_y_offset != 0)
 470                 {
 471                     fill_pad_region(p_dst, p_filter->fmt_out.video.i_height,
 472                                     p_filter->fmt_out.video.i_width,
 473                                     p_filter->fmt_out.video.i_y_offset,
 474                                     p_filter->fmt_out.video.i_height
 475                                       - p_filter->fmt_out.video.i_visible_height
 476                                       - p_filter->fmt_out.video.i_y_offset,
 477                                     p_filter->fmt_out.video.i_x_offset,
 478                                     p_filter->fmt_out.video.i_width
 479                                       - p_filter->fmt_out.video.i_visible_width
 480                                       - p_filter->fmt_out.video.i_x_offset,
 481                                     padcolor);
 482                 }
 483             }
 484
 485             p_src = p_dst;
 486         }
 487     }
 488
 489     if( p_sys->b_convert )
 490     {
 491         video_format_t *p_fmt = &p_filter->fmt_out.video;
 492         p_dst = &dest_pic;
 493         if( p_sys->b_resize && !p_sys->b_resize_first )
 494         {
 495             p_dst = &p_sys->tmp_pic;
 496             p_fmt = &p_filter->fmt_in.video;
 497         }
 498
 499         img_convert( p_dst, p_sys->i_dst_ffmpeg_chroma,
 500                      p_src, p_sys->i_src_ffmpeg_chroma,
 501                      p_fmt->i_width, p_fmt->i_height );
 502
 503         p_src = p_dst;
 504     }
 505
 506     if( p_sys->b_resize && !p_sys->b_resize_first && p_sys->p_rsc )
 507     {
 508         p_dst = &dest_pic;
 509
 510         img_resample( p_sys->p_rsc, p_dst, p_src );
 511
 512         if (p_sys->b_enable_croppadd)
 513         {
 514             if (p_filter->fmt_out.video.i_visible_width != p_filter->fmt_out.video.i_width ||
 515                 p_filter->fmt_out.video.i_visible_height != p_filter->fmt_out.video.i_height ||
 516                 p_filter->fmt_out.video.i_x_offset != 0 ||
 517                 p_filter->fmt_out.video.i_y_offset != 0)
 518             {
 519                 fill_pad_region(p_dst, p_filter->fmt_out.video.i_height,
 520                                 p_filter->fmt_out.video.i_width,
 521                                 p_filter->fmt_out.video.i_y_offset,
 522                                 p_filter->fmt_out.video.i_height
 523                                   - p_filter->fmt_out.video.i_visible_height
 524                                   - p_filter->fmt_out.video.i_y_offset,
 525                                 p_filter->fmt_out.video.i_x_offset,
 526                                 p_filter->fmt_out.video.i_width
 527                                   - p_filter->fmt_out.video.i_visible_width
 528                                   - p_filter->fmt_out.video.i_x_offset,
 529                                 padcolor);
 530             }
 531         }
 532     }
 533
 534     /* Special case for RV32 -> YUVA */
 535     if( !p_sys->b_resize &&
 536         p_filter->fmt_in.video.i_chroma == VLC_FOURCC('R','V','3','2') &&
 537         p_filter->fmt_out.video.i_chroma == VLC_FOURCC('Y','U','V','A') )
 538     {
 539         uint8_t *p_src = p_pic->p[0].p_pixels;
 540         int i_src_pitch = p_pic->p[0].i_pitch;
 541         uint8_t *p_dst = p_pic_dst->p[3].p_pixels;
 542         int i_dst_pitch = p_pic_dst->p[3].i_pitch;
 543         uint32_t l,j;
 544
 545         for( l = 0; l < p_filter->fmt_out.video.i_height; l++ )
 546         {
 547             for( j = 0; j < p_filter->fmt_out.video.i_width; j++ )
 548             {
 549               p_dst[j] = p_src[j*4+3];
 550             }
 551             p_src += i_src_pitch;
 552             p_dst += i_dst_pitch;
 553         }
 554     }
 555     else if( p_filter->fmt_out.video.i_chroma == VLC_FOURCC('Y','U','V','A') )
 556     {
 557         /* Special case for YUVA */
 558         memset( p_pic_dst->p[3].p_pixels, 0xFF,
 559                 p_pic_dst->p[3].i_pitch * p_pic_dst->p[3].i_lines );
 560     }
 561
 562     p_pic_dst->date = p_pic->date;
 563     p_pic_dst->b_force = p_pic->b_force;
 564     p_pic_dst->i_nb_fields = p_pic->i_nb_fields;
 565     p_pic_dst->b_progressive = p_pic->b_progressive;
 566     p_pic_dst->b_top_field_first = p_pic->b_top_field_first;
 567
 568     p_pic->pf_release( p_pic );
 569     return p_pic_dst;
 570 }
 571 #endif /* ( (defined(HAVE_LIBSWSCALE_SWSCALE_H)  || defined(HAVE_FFMPEG_SWSCALE_H) || defined(HAVE_LIBSWSCALE_TREE)) */