1 /*****************************************************************************
2 * canvas.c : automatically resize and padd a video to fit in canvas
3 *****************************************************************************
4 * Copyright (C) 2008 VLC authors and VideoLAN
7 * Authors: Antoine Cellerier <dionoea at videolan dot org>
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU Lesser General Public License as published by
11 * the Free Software Foundation; either version 2.1 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public License
20 * along with this program; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22 *****************************************************************************/
24 /*****************************************************************************
26 *****************************************************************************/
34 #include <vlc_common.h>
35 #include <vlc_plugin.h>
36 #include <vlc_filter.h>
38 /*****************************************************************************
39 * Local and extern prototypes.
40 *****************************************************************************/
41 static int Activate( vlc_object_t * );
42 static void Destroy( vlc_object_t * );
43 static picture_t *Filter( filter_t *, picture_t * );
44 static int alloc_init( filter_t *, void * );
46 /* This module effectively implements a form of picture-in-picture.
47 * - The outer picture is called the canvas.
48 * - The innter picture is callsed the subpicture.
50 * NB, all of the following operatons take into account aspect ratio
52 * A canvas is of canvas_{width,height}.
54 * - The subpicture is upconverted with a inverse scalefactor of:
55 * (The size of subpicture's largest dimension)
56 * --------------------------------------------
57 * (The size of canvas's equivalent dimension)
59 * Ie, The subpicture's largest dimension is made equal to the
60 * equivalent canvas dimension.
62 * - The upconverted subpicture's smallest dimension is then padded
63 * to make the upconverted subpicture have the same dimensions of
67 * - The subpicture is upconverted with an inverse scalefactor of:
68 * (The size of subpicture's smallest dimension)
69 * --------------------------------------------
70 * (The size of canvas's equivalent dimension)
72 * Ie, The subpicture's smallest dimension is made equal to the
73 * equivalent canvas dimension. (The subpicture will then be
74 * larger than the canvas)
76 * - The upconverted subpicture's largest dimension is then cropped
77 * to make the upconverted subpicture have the same dimensions of
81 /* NB, use of `padd' in this module is a 16-17th Century spelling of `pad' */
83 #define WIDTH_TEXT N_( "Output width" )
84 #define WIDTH_LONGTEXT N_( \
85 "Output (canvas) image width" )
86 #define HEIGHT_TEXT N_( "Output height" )
87 #define HEIGHT_LONGTEXT N_( \
88 "Output (canvas) image height" )
89 #define ASPECT_TEXT N_( "Output picture aspect ratio" )
90 #define ASPECT_LONGTEXT N_( \
91 "Set the canvas' picture aspect ratio. " \
92 "If omitted, the canvas is assumed to have the same SAR as the input." )
93 #define PADD_TEXT N_( "Pad video" )
94 #define PADD_LONGTEXT N_( \
95 "If enabled, video will be padded to fit in canvas after scaling. " \
96 "Otherwise, video will be cropped to fix in canvas after scaling." )
97 #define CANVAS_HELP N_( "Automatically resize and pad a video" )
99 #define CFG_PREFIX "canvas-"
101 /*****************************************************************************
103 *****************************************************************************/
105 set_shortname( N_("Canvas") )
106 set_description( N_("Canvas video filter") )
107 set_capability( "video filter2", 0 )
108 set_help( CANVAS_HELP )
109 set_callbacks( Activate, Destroy )
111 set_category( CAT_VIDEO )
112 set_subcategory( SUBCAT_VIDEO_VFILTER )
114 add_integer_with_range( CFG_PREFIX "width", 0, 0, INT_MAX,
115 WIDTH_TEXT, WIDTH_LONGTEXT, false )
116 add_integer_with_range( CFG_PREFIX "height", 0, 0, INT_MAX,
117 HEIGHT_TEXT, HEIGHT_LONGTEXT, false )
119 add_string( CFG_PREFIX "aspect", NULL,
120 ASPECT_TEXT, ASPECT_LONGTEXT, false )
122 add_bool( CFG_PREFIX "padd", true,
123 PADD_TEXT, PADD_LONGTEXT, false )
126 static const char *const ppsz_filter_options[] = {
127 "width", "height", "aspect", "padd", NULL
132 filter_chain_t *p_chain;
135 /*****************************************************************************
137 *****************************************************************************/
138 static int Activate( vlc_object_t *p_this )
140 filter_t *p_filter = (filter_t *)p_this;
141 unsigned i_canvas_width; /* visible width of output canvas */
142 unsigned i_canvas_height; /* visible height of output canvas */
143 unsigned i_canvas_aspect; /* canvas PictureAspectRatio */
144 es_format_t fmt; /* target format after up/down conversion */
145 char psz_croppadd[100];
147 char *psz_aspect, *psz_parser;
149 unsigned i_fmt_in_aspect;
151 if( !p_filter->b_allow_fmt_out_change )
153 msg_Err( p_filter, "Picture format change isn't allowed" );
157 if( p_filter->fmt_in.video.i_chroma != p_filter->fmt_out.video.i_chroma )
159 msg_Err( p_filter, "Input and output chromas don't match" );
163 config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
166 i_canvas_width = var_CreateGetInteger( p_filter, CFG_PREFIX "width" );
167 i_canvas_height = var_CreateGetInteger( p_filter, CFG_PREFIX "height" );
169 if( i_canvas_width == 0 || i_canvas_height == 0 )
171 msg_Err( p_filter, "Width and height options must be set" );
175 if( i_canvas_width & 1 || i_canvas_height & 1 )
177 /* If this restriction were ever relaxed, it is very important to
178 * get the field polatiry correct */
179 msg_Err( p_filter, "Width and height options must be even integers" );
183 if( p_filter->fmt_in.video.i_sar_num )
184 i_fmt_in_aspect = (int64_t)p_filter->fmt_in.video.i_sar_num *
185 p_filter->fmt_in.video.i_visible_width *
187 p_filter->fmt_in.video.i_sar_den /
188 p_filter->fmt_in.video.i_visible_height;
190 i_fmt_in_aspect = (int64_t)p_filter->fmt_in.video.i_visible_width *
192 p_filter->fmt_in.video.i_visible_height;
194 psz_aspect = var_CreateGetNonEmptyString( p_filter, CFG_PREFIX "aspect" );
197 psz_parser = strchr( psz_aspect, ':' );
198 int numerator = atoi( psz_aspect );
199 int denominator = psz_parser ? atoi( psz_parser+1 ) : 0;
200 denominator = denominator == 0 ? 1 : denominator;
201 i_canvas_aspect = numerator * VOUT_ASPECT_FACTOR / denominator;
204 if( numerator <= 0 || denominator < 0 )
206 msg_Err( p_filter, "Aspect ratio must be strictly positive" );
212 /* if there is no user supplied aspect ratio, assume the canvas
213 * has the same sample aspect ratio as the subpicture */
214 /* aspect = subpic_sar * canvas_width / canvas_height
215 * where subpic_sar = subpic_ph * subpic_par / subpic_pw */
216 i_canvas_aspect = (uint64_t) p_filter->fmt_in.video.i_visible_height
219 / (i_canvas_height * p_filter->fmt_in.video.i_visible_width);
222 b_padd = var_CreateGetBool( p_filter, CFG_PREFIX "padd" );
224 filter_sys_t *p_sys = (filter_sys_t *)malloc( sizeof( filter_sys_t ) );
227 p_filter->p_sys = p_sys;
229 p_sys->p_chain = filter_chain_New( p_filter, "video filter2", true,
230 alloc_init, NULL, p_filter );
231 if( !p_sys->p_chain )
233 msg_Err( p_filter, "Could not allocate filter chain" );
238 es_format_Copy( &fmt, &p_filter->fmt_in );
240 /* one dimension will end up with one of the following: */
241 fmt.video.i_visible_width = i_canvas_width;
242 fmt.video.i_visible_height = i_canvas_height;
247 if( i_canvas_aspect > i_fmt_in_aspect )
249 /* The canvas has a wider aspect than the subpicture:
250 * ie, pillarbox the [scaled] subpicture */
251 /* The following is derived form:
252 * width = upconverted_subpic_height * subpic_par / canvas_sar
253 * where canvas_sar = canvas_width / (canvas_height * canvas_par)
255 fmt.video.i_visible_width = i_canvas_width
258 if( fmt.video.i_visible_width & 1 ) fmt.video.i_visible_width -= 1;
260 i_padd = (i_canvas_width - fmt.video.i_visible_width) / 2;
261 i_offset = (i_padd & 1);
262 snprintf( psz_croppadd, 100, "croppadd{paddleft=%d,paddright=%d}",
263 i_padd - i_offset, i_padd + i_offset );
267 /* The canvas has a taller aspect than the subpicture:
268 * ie, letterbox the [scaled] subpicture */
269 fmt.video.i_visible_height = i_canvas_height
272 if( fmt.video.i_visible_height & 1 ) fmt.video.i_visible_height -= 1;
274 i_padd = (i_canvas_height - fmt.video.i_visible_height ) / 2;
275 i_offset = (i_padd & 1);
276 snprintf( psz_croppadd, 100, "croppadd{paddtop=%d,paddbottom=%d}",
277 i_padd - i_offset, i_padd + i_offset );
283 if( i_canvas_aspect < i_fmt_in_aspect )
285 /* The canvas has a narrower aspect than the subpicture:
286 * ie, crop the [scaled] subpicture horizontally */
287 fmt.video.i_visible_width = i_canvas_width
290 if( fmt.video.i_visible_width & 1 ) fmt.video.i_visible_width -= 1;
292 i_padd = (fmt.video.i_visible_width - i_canvas_width) / 2;
293 i_offset = (i_padd & 1);
294 snprintf( psz_croppadd, 100, "croppadd{cropleft=%d,cropright=%d}",
295 i_padd - i_offset, i_padd + i_offset );
299 /* The canvas has a shorter aspect than the subpicture:
300 * ie, crop the [scaled] subpicture vertically */
301 fmt.video.i_visible_height = i_canvas_height
304 if( fmt.video.i_visible_height & 1 ) fmt.video.i_visible_height -= 1;
306 i_padd = (fmt.video.i_visible_height - i_canvas_height) / 2;
307 i_offset = (i_padd & 1);
308 snprintf( psz_croppadd, 100, "croppadd{croptop=%d,cropbottom=%d}",
309 i_padd - i_offset, i_padd + i_offset );
313 /* xxx, should the clean area include the letter-boxing?
314 * probably not, as some codecs can make use of that information
315 * and it should be a scaled version of the input clean area
317 fmt.video.i_width = p_filter->fmt_in.video.i_width * fmt.video.i_visible_width / p_filter->fmt_in.video.i_visible_width;
318 fmt.video.i_height = p_filter->fmt_in.video.i_height * fmt.video.i_visible_height / p_filter->fmt_in.video.i_visible_height;
320 filter_chain_Reset( p_sys->p_chain, &p_filter->fmt_in, &fmt );
321 /* Append scaling module */
322 filter_chain_AppendFilter( p_sys->p_chain, NULL, NULL, NULL, NULL );
323 /* Append padding module */
324 filter_chain_AppendFromString( p_sys->p_chain, psz_croppadd );
326 fmt = *filter_chain_GetFmtOut( p_sys->p_chain );
327 es_format_Copy( &p_filter->fmt_out, &fmt );
329 vlc_ureduce( &p_filter->fmt_out.video.i_sar_num,
330 &p_filter->fmt_out.video.i_sar_den,
331 i_canvas_aspect * p_filter->fmt_out.video.i_visible_height,
332 VOUT_ASPECT_FACTOR * p_filter->fmt_out.video.i_visible_width,
335 if( p_filter->fmt_out.video.i_visible_width != i_canvas_width
336 || p_filter->fmt_out.video.i_visible_height != i_canvas_height )
338 msg_Warn( p_filter, "Looks like something went wrong. "
339 "Output size is %dx%d while we asked for %dx%d",
340 p_filter->fmt_out.video.i_visible_width,
341 p_filter->fmt_out.video.i_visible_height,
342 i_canvas_width, i_canvas_height );
345 p_filter->pf_video_filter = Filter;
350 /*****************************************************************************
352 *****************************************************************************/
353 static void Destroy( vlc_object_t *p_this )
355 filter_t *p_filter = (filter_t *)p_this;
356 filter_chain_Delete( p_filter->p_sys->p_chain );
357 free( p_filter->p_sys );
360 /*****************************************************************************
362 *****************************************************************************/
363 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
365 return filter_chain_VideoFilter( p_filter->p_sys->p_chain, p_pic );
368 /*****************************************************************************
370 *****************************************************************************/
371 static picture_t *video_new( filter_t *p_filter )
373 return filter_NewPicture( (filter_t*)p_filter->p_owner );
376 static void video_del( filter_t *p_filter, picture_t *p_pic )
378 return filter_DeletePicture( (filter_t*)p_filter->p_owner, p_pic );
381 static int alloc_init( filter_t *p_filter, void *p_data )
383 p_filter->p_owner = p_data;
384 p_filter->pf_video_buffer_new = video_new;
385 p_filter->pf_video_buffer_del = video_del;