1 /*****************************************************************************
2 * canvas.c : automatically resize and padd a video to fit in canvas
3 *****************************************************************************
4 * Copyright (C) 2008 the VideoLAN team
7 * Authors: Antoine Cellerier <dionoea at videolan dot org>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 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 General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, 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." )
98 #define CFG_PREFIX "canvas-"
100 /*****************************************************************************
102 *****************************************************************************/
104 set_shortname( N_("Canvas") )
105 set_description( N_("Automatically resize and pad a video") )
106 set_capability( "video filter2", 0 )
107 set_callbacks( Activate, Destroy )
109 set_category( CAT_VIDEO )
110 set_subcategory( SUBCAT_VIDEO_VFILTER )
112 add_integer_with_range( CFG_PREFIX "width", 0, 0, INT_MAX, NULL,
113 WIDTH_TEXT, WIDTH_LONGTEXT, false )
114 add_integer_with_range( CFG_PREFIX "height", 0, 0, INT_MAX, NULL,
115 HEIGHT_TEXT, HEIGHT_LONGTEXT, false )
117 add_string( CFG_PREFIX "aspect", NULL, NULL,
118 ASPECT_TEXT, ASPECT_LONGTEXT, false )
120 add_bool( CFG_PREFIX "padd", true, NULL,
121 PADD_TEXT, PADD_LONGTEXT, false )
124 static const char *const ppsz_filter_options[] = {
125 "width", "height", "aspect", "padd", NULL
130 filter_chain_t *p_chain;
133 /*****************************************************************************
135 *****************************************************************************/
136 static int Activate( vlc_object_t *p_this )
138 filter_t *p_filter = (filter_t *)p_this;
139 unsigned i_canvas_width; /* width of output canvas */
140 unsigned i_canvas_height; /* height of output canvas */
141 unsigned i_canvas_aspect; /* canvas PictureAspectRatio */
142 es_format_t fmt; /* target format after up/down conversion */
143 char psz_croppadd[100];
145 char *psz_aspect, *psz_parser;
148 if( !p_filter->b_allow_fmt_out_change )
150 msg_Err( p_filter, "Picture format change isn't allowed" );
154 if( p_filter->fmt_in.video.i_chroma != p_filter->fmt_out.video.i_chroma )
156 msg_Err( p_filter, "Input and output chromas don't match" );
160 config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
163 i_canvas_width = var_CreateGetInteger( p_filter, CFG_PREFIX "width" );
164 i_canvas_height = var_CreateGetInteger( p_filter, CFG_PREFIX "height" );
166 if( i_canvas_width == 0 || i_canvas_height == 0 )
168 msg_Err( p_filter, "Width and height options must be set" );
172 if( i_canvas_width & 1 || i_canvas_height & 1 )
174 /* If this restriction were ever relaxed, it is very important to
175 * get the field polatiry correct */
176 msg_Err( p_filter, "Width and height options must be even integers" );
180 psz_aspect = var_CreateGetNonEmptyString( p_filter, CFG_PREFIX "aspect" );
183 psz_parser = strchr( psz_aspect, ':' );
184 int numerator = atoi( psz_aspect );
185 int denominator = psz_parser ? atoi( psz_parser+1 ) : 0;
186 denominator = denominator == 0 ? 1 : denominator;
187 i_canvas_aspect = numerator * VOUT_ASPECT_FACTOR / denominator;
190 if( numerator <= 0 || denominator < 0 )
192 msg_Err( p_filter, "Aspect ratio must be strictly positive" );
198 /* if there is no user supplied aspect ratio, assume the canvas
199 * has the same sample aspect ratio as the subpicture */
200 /* aspect = subpic_sar * canvas_width / canvas_height
201 * where subpic_sar = subpic_ph * subpic_par / subpic_pw */
202 i_canvas_aspect = (uint64_t) p_filter->fmt_in.video.i_height
203 * p_filter->fmt_in.video.i_aspect
205 / (i_canvas_height * p_filter->fmt_in.video.i_width);
208 b_padd = var_CreateGetBool( p_filter, CFG_PREFIX "padd" );
210 filter_sys_t *p_sys = (filter_sys_t *)malloc( sizeof( filter_sys_t ) );
213 p_filter->p_sys = p_sys;
215 p_sys->p_chain = filter_chain_New( p_filter, "video filter2", true,
216 alloc_init, NULL, p_filter );
217 if( !p_sys->p_chain )
219 msg_Err( p_filter, "Could not allocate filter chain" );
224 es_format_Copy( &fmt, &p_filter->fmt_in );
226 /* one dimension will end up with one of the following: */
227 fmt.video.i_width = i_canvas_width;
228 fmt.video.i_height = i_canvas_height;
233 if( i_canvas_aspect > p_filter->fmt_in.video.i_aspect )
235 /* The canvas has a wider aspect than the subpicture:
236 * ie, pillarbox the [scaled] subpicture */
237 /* The following is derived form:
238 * width = upconverted_subpic_height * subpic_par / canvas_sar
239 * where canvas_sar = canvas_width / (canvas_height * canvas_par)
241 fmt.video.i_width = i_canvas_width
242 * p_filter->fmt_in.video.i_aspect
244 if( fmt.video.i_width & 1 ) fmt.video.i_width -= 1;
246 i_padd = (i_canvas_width - fmt.video.i_width) / 2;
247 i_offset = (i_padd & 1);
248 snprintf( psz_croppadd, 100, "croppadd{paddleft=%d,paddright=%d}",
249 i_padd - i_offset, i_padd + i_offset );
253 /* The canvas has a taller aspect than the subpicture:
254 * ie, letterbox the [scaled] subpicture */
255 fmt.video.i_height = i_canvas_height
257 / p_filter->fmt_in.video.i_aspect;
258 if( fmt.video.i_height & 1 ) fmt.video.i_height -= 1;
260 i_padd = (i_canvas_height - fmt.video.i_height ) / 2;
261 i_offset = (i_padd & 1);
262 snprintf( psz_croppadd, 100, "croppadd{paddtop=%d,paddbottom=%d}",
263 i_padd - i_offset, i_padd + i_offset );
269 if( i_canvas_aspect < p_filter->fmt_in.video.i_aspect )
271 /* The canvas has a narrower aspect than the subpicture:
272 * ie, crop the [scaled] subpicture horizontally */
273 fmt.video.i_width = i_canvas_width
274 * p_filter->fmt_in.video.i_aspect
276 if( fmt.video.i_width & 1 ) fmt.video.i_width -= 1;
278 i_padd = (fmt.video.i_width - i_canvas_width) / 2;
279 i_offset = (i_padd & 1);
280 snprintf( psz_croppadd, 100, "croppadd{cropleft=%d,cropright=%d}",
281 i_padd - i_offset, i_padd + i_offset );
285 /* The canvas has a shorter aspect than the subpicture:
286 * ie, crop the [scaled] subpicture vertically */
287 fmt.video.i_height = i_canvas_height
289 / p_filter->fmt_in.video.i_aspect;
290 if( fmt.video.i_height & 1 ) fmt.video.i_height -= 1;
292 i_padd = (fmt.video.i_height - i_canvas_height) / 2;
293 i_offset = (i_padd & 1);
294 snprintf( psz_croppadd, 100, "croppadd{croptop=%d,cropbottom=%d}",
295 i_padd - i_offset, i_padd + i_offset );
299 /* xxx, should the clean area include the letter-boxing?
300 * probably not, as some codecs can make use of that information
301 * and it should be a scaled version of the input clean area
303 fmt.video.i_visible_width = fmt.video.i_width;
304 fmt.video.i_visible_height = fmt.video.i_height;
306 filter_chain_Reset( p_sys->p_chain, &p_filter->fmt_in, &fmt );
307 /* Append scaling module */
308 filter_chain_AppendFilter( p_sys->p_chain, NULL, NULL, NULL, NULL );
309 /* Append padding module */
310 filter_chain_AppendFromString( p_sys->p_chain, psz_croppadd );
312 fmt = *filter_chain_GetFmtOut( p_sys->p_chain );
313 es_format_Copy( &p_filter->fmt_out, &fmt );
315 p_filter->fmt_out.video.i_aspect = i_canvas_aspect;
317 if( p_filter->fmt_out.video.i_width != i_canvas_width
318 || p_filter->fmt_out.video.i_height != i_canvas_height )
320 msg_Warn( p_filter, "Looks like something went wrong. "
321 "Output size is %dx%d while we asked for %dx%d",
322 p_filter->fmt_out.video.i_width,
323 p_filter->fmt_out.video.i_height,
324 i_canvas_width, i_canvas_height );
327 p_filter->pf_video_filter = Filter;
332 /*****************************************************************************
334 *****************************************************************************/
335 static void Destroy( vlc_object_t *p_this )
337 filter_t *p_filter = (filter_t *)p_this;
338 filter_chain_Delete( p_filter->p_sys->p_chain );
339 free( p_filter->p_sys );
342 /*****************************************************************************
344 *****************************************************************************/
345 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
347 return filter_chain_VideoFilter( p_filter->p_sys->p_chain, p_pic );
350 /*****************************************************************************
352 *****************************************************************************/
353 static picture_t *video_new( filter_t *p_filter )
355 return filter_NewPicture( (filter_t*)p_filter->p_owner );
358 static void video_del( filter_t *p_filter, picture_t *p_pic )
360 return filter_DeletePicture( (filter_t*)p_filter->p_owner, p_pic );
363 static int alloc_init( filter_t *p_filter, void *p_data )
365 p_filter->p_owner = p_data;
366 p_filter->pf_vout_buffer_new = video_new;
367 p_filter->pf_vout_buffer_del = video_del;