modules/video_filter/fps.c

   1 /*****************************************************************************
   2  * fps.c : fps conversion plugin for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2014 VLC authors and VideoLAN
   5  *
   6  * Author: Ilkka Ollakka <ileoo at videolan dot org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License as published by
  10  * the Free Software Foundation; either version 2.1 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 /*****************************************************************************
  24  * Preamble
  25  *****************************************************************************/
  26
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <vlc_common.h>
  32 #include <vlc_plugin.h>
  33 #include <vlc_filter.h>
  34 #include <vlc_picture.h>
  35
  36 static int Open( vlc_object_t *p_this);
  37 static void Close( vlc_object_t *p_this);
  38 static picture_t *Filter( filter_t *p_filter, picture_t *p_picture);
  39
  40 #define CFG_PREFIX "fps-"
  41
  42 #define FPS_TEXT N_( "Frame rate" )
  43
  44 vlc_module_begin ()
  45     set_description( N_("FPS conversion video filter") )
  46     set_shortname( N_("FPS Converter" ))
  47     set_capability( "video filter", 0 )
  48     set_category( CAT_VIDEO )
  49     set_subcategory( SUBCAT_VIDEO_VFILTER )
  50
  51     add_shortcut( "fps" )
  52     add_string( CFG_PREFIX "fps", NULL, FPS_TEXT, FPS_TEXT, false )
  53     set_callbacks( Open, Close )
  54 vlc_module_end ()
  55
  56 static const char *const ppsz_filter_options[] = {
  57     "fps",
  58     NULL
  59 };
  60
  61 /* We'll store pointer for previous picture we have received
  62    and copy that if needed on framerate increase (not preferred)*/
  63 struct filter_sys_t
  64 {
  65     date_t          next_output_pts; /**< output calculated PTS */
  66     picture_t       *p_previous_pic;
  67     int             i_output_frame_interval;
  68 };
  69
  70 static picture_t *Filter( filter_t *p_filter, picture_t *p_picture)
  71 {
  72     filter_sys_t *p_sys = p_filter->p_sys;
  73     /* If input picture doesn't have actual valid timestamp,
  74         we don't really have currently a way to know what else
  75         to do with it other than drop it for now*/
  76     if( unlikely( p_picture->date < VLC_TS_0) )
  77     {
  78         msg_Dbg( p_filter, "skipping non-dated picture");
  79         picture_Release( p_picture );
  80         return NULL;
  81     }
  82
  83     p_picture->format.i_frame_rate = p_filter->fmt_out.video.i_frame_rate;
  84     p_picture->format.i_frame_rate_base = p_filter->fmt_out.video.i_frame_rate_base;
  85
  86     /* First time we get some valid timestamp, we'll take it as base for output
  87         later on we retake new timestamp if it has jumped too much */
  88     if( unlikely( ( date_Get( &p_sys->next_output_pts ) == VLC_TS_INVALID ) ||
  89                    ( p_picture->date > ( date_Get( &p_sys->next_output_pts ) + (mtime_t)p_sys->i_output_frame_interval ) )
  90                 ) )
  91     {
  92         msg_Dbg( p_filter, "Resetting timestamps" );
  93         date_Set( &p_sys->next_output_pts, p_picture->date );
  94         if( p_sys->p_previous_pic )
  95             picture_Release( p_sys->p_previous_pic );
  96         p_sys->p_previous_pic = picture_Hold( p_picture );
  97         date_Increment( &p_sys->next_output_pts, 1 );
  98         return p_picture;
  99     }
 100
 101     /* Check if we can skip input as better should follow */
 102     if( p_picture->date <
 103         ( date_Get( &p_sys->next_output_pts ) - (mtime_t)p_sys->i_output_frame_interval ) )
 104     {
 105         if( p_sys->p_previous_pic )
 106             picture_Release( p_sys->p_previous_pic );
 107         p_sys->p_previous_pic = p_picture;
 108         return NULL;
 109     }
 110
 111     p_sys->p_previous_pic->date = date_Get( &p_sys->next_output_pts );
 112     date_Increment( &p_sys->next_output_pts, 1 );
 113
 114     picture_t *last_pic = p_sys->p_previous_pic;
 115     /* Duplicating pictures are not that effective and framerate increase
 116         should be avoided, it's only here as filter should work in that direction too*/
 117     while( unlikely( (date_Get( &p_sys->next_output_pts ) + p_sys->i_output_frame_interval ) < p_picture->date ) )
 118     {
 119         picture_t *p_tmp = NULL;
 120         p_tmp = picture_NewFromFormat( &p_filter->fmt_out.video );
 121
 122         picture_Copy( p_tmp, p_sys->p_previous_pic);
 123         p_tmp->date = date_Get( &p_sys->next_output_pts );
 124         p_tmp->p_next = NULL;
 125
 126         last_pic->p_next = p_tmp;
 127         last_pic = p_tmp;
 128         date_Increment( &p_sys->next_output_pts, 1 );
 129     }
 130
 131     last_pic = p_sys->p_previous_pic;
 132     p_sys->p_previous_pic = p_picture;
 133     return last_pic;
 134 }
 135
 136 static int Open( vlc_object_t *p_this)
 137 {
 138     filter_t *p_filter = (filter_t*)p_this;
 139     filter_sys_t *p_sys;
 140
 141     p_sys = p_filter->p_sys = malloc( sizeof( *p_sys ) );
 142
 143     if( unlikely( !p_sys ) )
 144         return VLC_ENOMEM;
 145
 146     config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
 147                        p_filter->p_cfg );
 148
 149     video_format_Clean( &p_filter->fmt_out.video );
 150     video_format_Copy( &p_filter->fmt_out.video, &p_filter->fmt_in.video );
 151
 152     /* If we don't have fps option, use filter output values */
 153     if( var_InheritURational( p_filter, &p_filter->fmt_out.video.i_frame_rate,
 154                                         &p_filter->fmt_out.video.i_frame_rate_base, CFG_PREFIX "fps" ) )
 155     {
 156         p_filter->fmt_out.video.i_frame_rate = p_filter->fmt_in.video.i_frame_rate;
 157         p_filter->fmt_out.video.i_frame_rate_base = p_filter->fmt_in.video.i_frame_rate_base;
 158     }
 159
 160     msg_Dbg( p_filter, "Converting fps from %d/%d -> %d/%d",
 161             p_filter->fmt_in.video.i_frame_rate, p_filter->fmt_in.video.i_frame_rate_base,
 162             p_filter->fmt_out.video.i_frame_rate, p_filter->fmt_out.video.i_frame_rate_base );
 163
 164     p_sys->i_output_frame_interval = p_filter->fmt_out.video.i_frame_rate_base * CLOCK_FREQ / p_filter->fmt_out.video.i_frame_rate;
 165
 166     date_Init( &p_sys->next_output_pts,
 167                p_filter->fmt_out.video.i_frame_rate, p_filter->fmt_out.video.i_frame_rate_base );
 168
 169     date_Set( &p_sys->next_output_pts, VLC_TS_INVALID );
 170     p_sys->p_previous_pic = NULL;
 171
 172     p_filter->pf_video_filter = Filter;
 173     return VLC_SUCCESS;
 174 }
 175
 176 static void Close( vlc_object_t *p_this )
 177 {
 178     filter_t *p_filter = (filter_t*)p_this;
 179     if( p_filter->p_sys->p_previous_pic )
 180         picture_Release( p_filter->p_sys->p_previous_pic );
 181     free( p_filter->p_sys );
 182 }