/*****************************************************************************
* canvas.c : automatically resize and padd a video to fit in canvas
*****************************************************************************
- * Copyright (C) 2008 the VideoLAN team
+ * Copyright (C) 2008 VLC authors and VideoLAN
* $Id$
*
* Authors: Antoine Cellerier <dionoea at videolan dot org>
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
*
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
/*****************************************************************************
static int Activate( vlc_object_t * );
static void Destroy( vlc_object_t * );
static picture_t *Filter( filter_t *, picture_t * );
-static int alloc_init( filter_t *, void * );
-#define WIDTH_TEXT N_( "Image width" )
+/* This module effectively implements a form of picture-in-picture.
+ * - The outer picture is called the canvas.
+ * - The innter picture is callsed the subpicture.
+ *
+ * NB, all of the following operatons take into account aspect ratio
+ *
+ * A canvas is of canvas_{width,height}.
+ * In Pad mode:
+ * - The subpicture is upconverted with a inverse scalefactor of:
+ * (The size of subpicture's largest dimension)
+ * --------------------------------------------
+ * (The size of canvas's equivalent dimension)
+ *
+ * Ie, The subpicture's largest dimension is made equal to the
+ * equivalent canvas dimension.
+ *
+ * - The upconverted subpicture's smallest dimension is then padded
+ * to make the upconverted subpicture have the same dimensions of
+ * the canvas.
+ *
+ * In Crop mode:
+ * - The subpicture is upconverted with an inverse scalefactor of:
+ * (The size of subpicture's smallest dimension)
+ * --------------------------------------------
+ * (The size of canvas's equivalent dimension)
+ *
+ * Ie, The subpicture's smallest dimension is made equal to the
+ * equivalent canvas dimension. (The subpicture will then be
+ * larger than the canvas)
+ *
+ * - The upconverted subpicture's largest dimension is then cropped
+ * to make the upconverted subpicture have the same dimensions of
+ * the canvas.
+ */
+
+/* NB, use of `padd' in this module is a 16-17th Century spelling of `pad' */
+
+#define WIDTH_TEXT N_( "Output width" )
#define WIDTH_LONGTEXT N_( \
- "Image width" )
-#define HEIGHT_TEXT N_( "Image height" )
+ "Output (canvas) image width" )
+#define HEIGHT_TEXT N_( "Output height" )
#define HEIGHT_LONGTEXT N_( \
- "Image height" )
-#define ASPECT_TEXT N_( "Aspect ratio" )
+ "Output (canvas) image height" )
+#define ASPECT_TEXT N_( "Output picture aspect ratio" )
#define ASPECT_LONGTEXT N_( \
- "Set aspect (like 4:3) of the video canvas" )
-#define PADD_TEXT N_( "Padd video" )
+ "Set the canvas' picture aspect ratio. " \
+ "If omitted, the canvas is assumed to have the same SAR as the input." )
+#define PADD_TEXT N_( "Pad video" )
#define PADD_LONGTEXT N_( \
"If enabled, video will be padded to fit in canvas after scaling. " \
"Otherwise, video will be cropped to fix in canvas after scaling." )
+#define CANVAS_HELP N_( "Automatically resize and pad a video" )
#define CFG_PREFIX "canvas-"
* Module descriptor
*****************************************************************************/
vlc_module_begin ()
- set_description( N_("Automatically resize and padd a video") )
+ set_shortname( N_("Canvas") )
+ set_description( N_("Canvas video filter") )
set_capability( "video filter2", 0 )
+ set_help( CANVAS_HELP )
set_callbacks( Activate, Destroy )
- add_integer_with_range( CFG_PREFIX "width", 0, 0, INT_MAX, NULL,
+ set_category( CAT_VIDEO )
+ set_subcategory( SUBCAT_VIDEO_VFILTER )
+
+ add_integer_with_range( CFG_PREFIX "width", 0, 0, INT_MAX,
WIDTH_TEXT, WIDTH_LONGTEXT, false )
- add_integer_with_range( CFG_PREFIX "height", 0, 0, INT_MAX, NULL,
+ add_integer_with_range( CFG_PREFIX "height", 0, 0, INT_MAX,
HEIGHT_TEXT, HEIGHT_LONGTEXT, false )
- add_string( CFG_PREFIX "aspect", "4:3", NULL,
+ add_string( CFG_PREFIX "aspect", NULL,
ASPECT_TEXT, ASPECT_LONGTEXT, false )
- add_bool( CFG_PREFIX "padd", true, NULL,
+ add_bool( CFG_PREFIX "padd", true,
PADD_TEXT, PADD_LONGTEXT, false )
vlc_module_end ()
filter_chain_t *p_chain;
};
+static picture_t *video_new( filter_t *p_filter )
+{
+ return filter_NewPicture( p_filter->owner.sys );
+}
+
/*****************************************************************************
*
*****************************************************************************/
static int Activate( vlc_object_t *p_this )
{
filter_t *p_filter = (filter_t *)p_this;
- unsigned int i_width, i_height;
- es_format_t fmt;
+ unsigned i_canvas_width; /* visible width of output canvas */
+ unsigned i_canvas_height; /* visible height of output canvas */
+ unsigned i_canvas_aspect; /* canvas PictureAspectRatio */
+ es_format_t fmt; /* target format after up/down conversion */
char psz_croppadd[100];
int i_padd,i_offset;
char *psz_aspect, *psz_parser;
- int i_aspect;
bool b_padd;
+ unsigned i_fmt_in_aspect;
if( !p_filter->b_allow_fmt_out_change )
{
config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
p_filter->p_cfg );
- i_width = var_CreateGetInteger( p_filter, CFG_PREFIX "width" );
- i_height = var_CreateGetInteger( p_filter, CFG_PREFIX "height" );
+ i_canvas_width = var_CreateGetInteger( p_filter, CFG_PREFIX "width" );
+ i_canvas_height = var_CreateGetInteger( p_filter, CFG_PREFIX "height" );
- if( i_width == 0 || i_height == 0 )
+ if( i_canvas_width == 0 || i_canvas_height == 0 )
{
msg_Err( p_filter, "Width and height options must be set" );
return VLC_EGENERIC;
}
- if( i_width & 1 || i_height & 1 )
+ if( i_canvas_width & 1 || i_canvas_height & 1 )
{
+ /* If this restriction were ever relaxed, it is very important to
+ * get the field polatiry correct */
msg_Err( p_filter, "Width and height options must be even integers" );
return VLC_EGENERIC;
}
+ if( p_filter->fmt_in.video.i_sar_num )
+ i_fmt_in_aspect = (int64_t)p_filter->fmt_in.video.i_sar_num *
+ p_filter->fmt_in.video.i_visible_width *
+ VOUT_ASPECT_FACTOR /
+ p_filter->fmt_in.video.i_sar_den /
+ p_filter->fmt_in.video.i_visible_height;
+ else
+ i_fmt_in_aspect = (int64_t)p_filter->fmt_in.video.i_visible_width *
+ VOUT_ASPECT_FACTOR /
+ p_filter->fmt_in.video.i_visible_height;
+
psz_aspect = var_CreateGetNonEmptyString( p_filter, CFG_PREFIX "aspect" );
- if( !psz_aspect )
+ if( psz_aspect )
{
- msg_Err( p_filter, "Aspect ratio must be set" );
- return VLC_EGENERIC;
+ psz_parser = strchr( psz_aspect, ':' );
+ int numerator = atoi( psz_aspect );
+ int denominator = psz_parser ? atoi( psz_parser+1 ) : 0;
+ denominator = denominator == 0 ? 1 : denominator;
+ i_canvas_aspect = numerator * VOUT_ASPECT_FACTOR / denominator;
+ free( psz_aspect );
+
+ if( numerator <= 0 || denominator < 0 )
+ {
+ msg_Err( p_filter, "Aspect ratio must be strictly positive" );
+ return VLC_EGENERIC;
+ }
}
- psz_parser = strchr( psz_aspect, ':' );
- if( psz_parser ) psz_parser++;
- if( psz_parser && atoi( psz_parser ) > 0 )
- i_aspect = atoi( psz_aspect ) * VOUT_ASPECT_FACTOR / atoi( psz_parser );
else
- i_aspect = atof( psz_aspect ) * VOUT_ASPECT_FACTOR;
- free( psz_aspect );
-
- if( i_aspect <= 0 )
{
- msg_Err( p_filter, "Aspect ratio must be strictly positive" );
- return VLC_EGENERIC;
+ /* if there is no user supplied aspect ratio, assume the canvas
+ * has the same sample aspect ratio as the subpicture */
+ /* aspect = subpic_sar * canvas_width / canvas_height
+ * where subpic_sar = subpic_ph * subpic_par / subpic_pw */
+ i_canvas_aspect = (uint64_t) p_filter->fmt_in.video.i_visible_height
+ * i_fmt_in_aspect
+ * i_canvas_width
+ / (i_canvas_height * p_filter->fmt_in.video.i_visible_width);
}
b_padd = var_CreateGetBool( p_filter, CFG_PREFIX "padd" );
return VLC_ENOMEM;
p_filter->p_sys = p_sys;
- p_sys->p_chain = filter_chain_New( p_filter, "video filter2", true,
- alloc_init, NULL, p_filter );
+ filter_owner_t owner = {
+ .sys = p_filter,
+ .video = {
+ .buffer_new = video_new,
+ },
+ };
+
+ p_sys->p_chain = filter_chain_NewVideo( p_filter, true, &owner );
if( !p_sys->p_chain )
{
msg_Err( p_filter, "Could not allocate filter chain" );
es_format_Copy( &fmt, &p_filter->fmt_in );
- fmt.video.i_width = i_width;
- fmt.video.i_height = ( p_filter->fmt_in.video.i_height * i_width )
- / p_filter->fmt_in.video.i_width;
- fmt.video.i_height = ( fmt.video.i_height * i_aspect )
- / p_filter->fmt_in.video.i_aspect;
+ /* one dimension will end up with one of the following: */
+ fmt.video.i_visible_width = i_canvas_width;
+ fmt.video.i_visible_height = i_canvas_height;
if( b_padd )
{
/* Padd */
- if( fmt.video.i_height > i_height )
+ if( i_canvas_aspect > i_fmt_in_aspect )
{
- fmt.video.i_height = i_height;
- fmt.video.i_width = ( p_filter->fmt_in.video.i_width * i_height )
- / p_filter->fmt_in.video.i_height;
- fmt.video.i_width = ( fmt.video.i_width * p_filter->fmt_in.video.i_aspect )
- / i_aspect;
- if( fmt.video.i_width & 1 ) fmt.video.i_width -= 1;
-
- i_padd = (i_width - fmt.video.i_width) / 2;
+ /* The canvas has a wider aspect than the subpicture:
+ * ie, pillarbox the [scaled] subpicture */
+ /* The following is derived form:
+ * width = upconverted_subpic_height * subpic_par / canvas_sar
+ * where canvas_sar = canvas_width / (canvas_height * canvas_par)
+ * then simplify */
+ fmt.video.i_visible_width = i_canvas_width
+ * i_fmt_in_aspect
+ / i_canvas_aspect;
+ if( fmt.video.i_visible_width & 1 ) fmt.video.i_visible_width -= 1;
+
+ i_padd = (i_canvas_width - fmt.video.i_visible_width) / 2;
i_offset = (i_padd & 1);
- /* Gruik */
snprintf( psz_croppadd, 100, "croppadd{paddleft=%d,paddright=%d}",
i_padd - i_offset, i_padd + i_offset );
}
else
{
- if( fmt.video.i_height & 1 ) fmt.video.i_height -= 1;
- i_padd = (i_height - fmt.video.i_height ) / 2;
+ /* The canvas has a taller aspect than the subpicture:
+ * ie, letterbox the [scaled] subpicture */
+ fmt.video.i_visible_height = i_canvas_height
+ * i_canvas_aspect
+ / i_fmt_in_aspect;
+ if( fmt.video.i_visible_height & 1 ) fmt.video.i_visible_height -= 1;
+
+ i_padd = (i_canvas_height - fmt.video.i_visible_height ) / 2;
i_offset = (i_padd & 1);
- /* Gruik */
snprintf( psz_croppadd, 100, "croppadd{paddtop=%d,paddbottom=%d}",
i_padd - i_offset, i_padd + i_offset );
}
else
{
/* Crop */
- if( fmt.video.i_height < i_height )
+ if( i_canvas_aspect < i_fmt_in_aspect )
{
- fmt.video.i_height = i_height;
- fmt.video.i_width = ( p_filter->fmt_in.video.i_width * i_height )
- / p_filter->fmt_in.video.i_height;
- fmt.video.i_width = ( fmt.video.i_width * p_filter->fmt_in.video.i_aspect )
- / i_aspect;
- if( fmt.video.i_width & 1 ) fmt.video.i_width -= 1;
-
- i_padd = (fmt.video.i_width - i_width) / 2;
- i_offset = (i_padd & 1);
- /* Gruik */
+ /* The canvas has a narrower aspect than the subpicture:
+ * ie, crop the [scaled] subpicture horizontally */
+ fmt.video.i_visible_width = i_canvas_width
+ * i_fmt_in_aspect
+ / i_canvas_aspect;
+ if( fmt.video.i_visible_width & 1 ) fmt.video.i_visible_width -= 1;
+
+ i_padd = (fmt.video.i_visible_width - i_canvas_width) / 2;
+ i_offset = (i_padd & 1);
snprintf( psz_croppadd, 100, "croppadd{cropleft=%d,cropright=%d}",
i_padd - i_offset, i_padd + i_offset );
}
else
{
- if( fmt.video.i_height & 1 ) fmt.video.i_height -= 1;
- i_padd = (fmt.video.i_height - i_height) / 2;
+ /* The canvas has a shorter aspect than the subpicture:
+ * ie, crop the [scaled] subpicture vertically */
+ fmt.video.i_visible_height = i_canvas_height
+ * i_canvas_aspect
+ / i_fmt_in_aspect;
+ if( fmt.video.i_visible_height & 1 ) fmt.video.i_visible_height -= 1;
+
+ i_padd = (fmt.video.i_visible_height - i_canvas_height) / 2;
i_offset = (i_padd & 1);
- /* Gruik */
snprintf( psz_croppadd, 100, "croppadd{croptop=%d,cropbottom=%d}",
i_padd - i_offset, i_padd + i_offset );
}
}
- fmt.video.i_visible_width = fmt.video.i_width;
- fmt.video.i_visible_height = fmt.video.i_height;
+ /* xxx, should the clean area include the letter-boxing?
+ * probably not, as some codecs can make use of that information
+ * and it should be a scaled version of the input clean area
+ * -- davidf */
+ fmt.video.i_width = p_filter->fmt_in.video.i_width * fmt.video.i_visible_width / p_filter->fmt_in.video.i_visible_width;
+ fmt.video.i_height = p_filter->fmt_in.video.i_height * fmt.video.i_visible_height / p_filter->fmt_in.video.i_visible_height;
filter_chain_Reset( p_sys->p_chain, &p_filter->fmt_in, &fmt );
/* Append scaling module */
filter_chain_AppendFilter( p_sys->p_chain, NULL, NULL, NULL, NULL );
- /* Append padding module */
- filter_chain_AppendFromString( p_sys->p_chain, psz_croppadd );
+ /* Append croppadd module if we actually do cropping or padding instead of just scaling*/
+ if( i_padd > 0 )
+ filter_chain_AppendFromString( p_sys->p_chain, psz_croppadd );
fmt = *filter_chain_GetFmtOut( p_sys->p_chain );
es_format_Copy( &p_filter->fmt_out, &fmt );
- p_filter->fmt_out.video.i_aspect = i_aspect * i_width / i_height;
+ vlc_ureduce( &p_filter->fmt_out.video.i_sar_num,
+ &p_filter->fmt_out.video.i_sar_den,
+ i_canvas_aspect * p_filter->fmt_out.video.i_visible_height,
+ VOUT_ASPECT_FACTOR * p_filter->fmt_out.video.i_visible_width,
+ 0);
- if( p_filter->fmt_out.video.i_width != i_width
- || p_filter->fmt_out.video.i_height != i_height )
+ if( p_filter->fmt_out.video.i_visible_width != i_canvas_width
+ || p_filter->fmt_out.video.i_visible_height != i_canvas_height )
{
msg_Warn( p_filter, "Looks like something went wrong. "
"Output size is %dx%d while we asked for %dx%d",
- p_filter->fmt_out.video.i_width,
- p_filter->fmt_out.video.i_height,
- i_width, i_height );
+ p_filter->fmt_out.video.i_visible_width,
+ p_filter->fmt_out.video.i_visible_height,
+ i_canvas_width, i_canvas_height );
}
p_filter->pf_video_filter = Filter;
{
return filter_chain_VideoFilter( p_filter->p_sys->p_chain, p_pic );
}
-
-/*****************************************************************************
- *
- *****************************************************************************/
-static picture_t *video_new( filter_t *p_filter )
-{
- return filter_NewPicture( (filter_t*)p_filter->p_owner );
-}
-
-static void video_del( filter_t *p_filter, picture_t *p_pic )
-{
- return filter_DeletePicture( (filter_t*)p_filter->p_owner, p_pic );
-}
-
-static int alloc_init( filter_t *p_filter, void *p_data )
-{
- p_filter->p_owner = p_data;
- p_filter->pf_vout_buffer_new = video_new;
- p_filter->pf_vout_buffer_del = video_del;
- return VLC_SUCCESS;
-}