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." )
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
, NULL
,
115 WIDTH_TEXT
, WIDTH_LONGTEXT
, false )
116 add_integer_with_range( CFG_PREFIX
"height", 0, 0, INT_MAX
, NULL
,
117 HEIGHT_TEXT
, HEIGHT_LONGTEXT
, false )
119 add_string( CFG_PREFIX
"aspect", NULL
, NULL
,
120 ASPECT_TEXT
, ASPECT_LONGTEXT
, false )
122 add_bool( CFG_PREFIX
"padd", true, NULL
,
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
; /* width of output canvas */
142 unsigned i_canvas_height
; /* 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 i_fmt_in_aspect
= (int64_t)p_filter
->fmt_in
.video
.i_sar_num
*
184 p_filter
->fmt_in
.video
.i_width
*
186 p_filter
->fmt_in
.video
.i_sar_den
/
187 p_filter
->fmt_in
.video
.i_height
;
188 psz_aspect
= var_CreateGetNonEmptyString( p_filter
, CFG_PREFIX
"aspect" );
191 psz_parser
= strchr( psz_aspect
, ':' );
192 int numerator
= atoi( psz_aspect
);
193 int denominator
= psz_parser
? atoi( psz_parser
+1 ) : 0;
194 denominator
= denominator
== 0 ? 1 : denominator
;
195 i_canvas_aspect
= numerator
* VOUT_ASPECT_FACTOR
/ denominator
;
198 if( numerator
<= 0 || denominator
< 0 )
200 msg_Err( p_filter
, "Aspect ratio must be strictly positive" );
206 /* if there is no user supplied aspect ratio, assume the canvas
207 * has the same sample aspect ratio as the subpicture */
208 /* aspect = subpic_sar * canvas_width / canvas_height
209 * where subpic_sar = subpic_ph * subpic_par / subpic_pw */
210 i_canvas_aspect
= (uint64_t) p_filter
->fmt_in
.video
.i_height
213 / (i_canvas_height
* p_filter
->fmt_in
.video
.i_width
);
216 b_padd
= var_CreateGetBool( p_filter
, CFG_PREFIX
"padd" );
218 filter_sys_t
*p_sys
= (filter_sys_t
*)malloc( sizeof( filter_sys_t
) );
221 p_filter
->p_sys
= p_sys
;
223 p_sys
->p_chain
= filter_chain_New( p_filter
, "video filter2", true,
224 alloc_init
, NULL
, p_filter
);
225 if( !p_sys
->p_chain
)
227 msg_Err( p_filter
, "Could not allocate filter chain" );
232 es_format_Copy( &fmt
, &p_filter
->fmt_in
);
234 /* one dimension will end up with one of the following: */
235 fmt
.video
.i_width
= i_canvas_width
;
236 fmt
.video
.i_height
= i_canvas_height
;
241 if( i_canvas_aspect
> i_fmt_in_aspect
)
243 /* The canvas has a wider aspect than the subpicture:
244 * ie, pillarbox the [scaled] subpicture */
245 /* The following is derived form:
246 * width = upconverted_subpic_height * subpic_par / canvas_sar
247 * where canvas_sar = canvas_width / (canvas_height * canvas_par)
249 fmt
.video
.i_width
= i_canvas_width
252 if( fmt
.video
.i_width
& 1 ) fmt
.video
.i_width
-= 1;
254 i_padd
= (i_canvas_width
- fmt
.video
.i_width
) / 2;
255 i_offset
= (i_padd
& 1);
256 snprintf( psz_croppadd
, 100, "croppadd{paddleft=%d,paddright=%d}",
257 i_padd
- i_offset
, i_padd
+ i_offset
);
261 /* The canvas has a taller aspect than the subpicture:
262 * ie, letterbox the [scaled] subpicture */
263 fmt
.video
.i_height
= i_canvas_height
266 if( fmt
.video
.i_height
& 1 ) fmt
.video
.i_height
-= 1;
268 i_padd
= (i_canvas_height
- fmt
.video
.i_height
) / 2;
269 i_offset
= (i_padd
& 1);
270 snprintf( psz_croppadd
, 100, "croppadd{paddtop=%d,paddbottom=%d}",
271 i_padd
- i_offset
, i_padd
+ i_offset
);
277 if( i_canvas_aspect
< i_fmt_in_aspect
)
279 /* The canvas has a narrower aspect than the subpicture:
280 * ie, crop the [scaled] subpicture horizontally */
281 fmt
.video
.i_width
= i_canvas_width
284 if( fmt
.video
.i_width
& 1 ) fmt
.video
.i_width
-= 1;
286 i_padd
= (fmt
.video
.i_width
- i_canvas_width
) / 2;
287 i_offset
= (i_padd
& 1);
288 snprintf( psz_croppadd
, 100, "croppadd{cropleft=%d,cropright=%d}",
289 i_padd
- i_offset
, i_padd
+ i_offset
);
293 /* The canvas has a shorter aspect than the subpicture:
294 * ie, crop the [scaled] subpicture vertically */
295 fmt
.video
.i_height
= i_canvas_height
298 if( fmt
.video
.i_height
& 1 ) fmt
.video
.i_height
-= 1;
300 i_padd
= (fmt
.video
.i_height
- i_canvas_height
) / 2;
301 i_offset
= (i_padd
& 1);
302 snprintf( psz_croppadd
, 100, "croppadd{croptop=%d,cropbottom=%d}",
303 i_padd
- i_offset
, i_padd
+ i_offset
);
307 /* xxx, should the clean area include the letter-boxing?
308 * probably not, as some codecs can make use of that information
309 * and it should be a scaled version of the input clean area
311 fmt
.video
.i_visible_width
= fmt
.video
.i_width
;
312 fmt
.video
.i_visible_height
= fmt
.video
.i_height
;
314 filter_chain_Reset( p_sys
->p_chain
, &p_filter
->fmt_in
, &fmt
);
315 /* Append scaling module */
316 filter_chain_AppendFilter( p_sys
->p_chain
, NULL
, NULL
, NULL
, NULL
);
317 /* Append padding module */
318 filter_chain_AppendFromString( p_sys
->p_chain
, psz_croppadd
);
320 fmt
= *filter_chain_GetFmtOut( p_sys
->p_chain
);
321 es_format_Copy( &p_filter
->fmt_out
, &fmt
);
323 p_filter
->fmt_out
.video
.i_sar_num
=
324 i_canvas_aspect
* p_filter
->fmt_out
.video
.i_height
;
325 p_filter
->fmt_out
.video
.i_sar_den
=
326 VOUT_ASPECT_FACTOR
* p_filter
->fmt_out
.video
.i_width
;
328 if( p_filter
->fmt_out
.video
.i_width
!= i_canvas_width
329 || p_filter
->fmt_out
.video
.i_height
!= i_canvas_height
)
331 msg_Warn( p_filter
, "Looks like something went wrong. "
332 "Output size is %dx%d while we asked for %dx%d",
333 p_filter
->fmt_out
.video
.i_width
,
334 p_filter
->fmt_out
.video
.i_height
,
335 i_canvas_width
, i_canvas_height
);
338 p_filter
->pf_video_filter
= Filter
;
343 /*****************************************************************************
345 *****************************************************************************/
346 static void Destroy( vlc_object_t
*p_this
)
348 filter_t
*p_filter
= (filter_t
*)p_this
;
349 filter_chain_Delete( p_filter
->p_sys
->p_chain
);
350 free( p_filter
->p_sys
);
353 /*****************************************************************************
355 *****************************************************************************/
356 static picture_t
*Filter( filter_t
*p_filter
, picture_t
*p_pic
)
358 return filter_chain_VideoFilter( p_filter
->p_sys
->p_chain
, p_pic
);
361 /*****************************************************************************
363 *****************************************************************************/
364 static picture_t
*video_new( filter_t
*p_filter
)
366 return filter_NewPicture( (filter_t
*)p_filter
->p_owner
);
369 static void video_del( filter_t
*p_filter
, picture_t
*p_pic
)
371 return filter_DeletePicture( (filter_t
*)p_filter
->p_owner
, p_pic
);
374 static int alloc_init( filter_t
*p_filter
, void *p_data
)
376 p_filter
->p_owner
= p_data
;
377 p_filter
->pf_video_buffer_new
= video_new
;
378 p_filter
->pf_video_buffer_del
= video_del
;