fps: new video filter to convert between fps rates

modules/MODULES_LIST

@@ -134,6 +134,7 @@ $Id$
  * float_mixer: Precise float audio mixer
  * fluidsynth: Software MIDI synthetizer using libfluidsynth
  * folder: folder meta data and art finder
+ * fps: convert picture rate
  * freetype: Utility to put text on video using freetype2
  * freeze: picture freezing video filter
  * ftp: FTP Network access module

modules/video_filter/Modules.am

@@ -10,6 +10,7 @@ SOURCES_blend = blend.cpp
 SOURCES_scale = scale.c
 SOURCES_marq = marq.c
 SOURCES_rss = rss.c
+SOURCES_fps = fps.c
 SOURCES_motiondetect = motiondetect.c
 
 libdeinterlace_plugin_la_SOURCES = \
@@ -163,5 +164,6 @@ video_filter_LTLIBRARIES += \
 	libanaglyph_plugin.la \
 	liboldmovie_plugin.la \
 	libvhs_plugin.la \
+	libfps_plugin.la \
 	libfreeze_plugin.la
 

modules/video_filter/fps.c

+/*****************************************************************************
+ * fps.c : fps conversion plugin for vlc
+ *****************************************************************************
+ * Copyright (C) 2014 VLC authors and VideoLAN
+ *
+ * Author: Ilkka Ollakka <ileoo at videolan dot org>
+ *
+ * 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 Lesser General Public License for more details.
+ *
+ * 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.
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Preamble
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <vlc_common.h>
+#include <vlc_plugin.h>
+#include <vlc_filter.h>
+
+int Open( vlc_object_t *p_this);
+void Close( vlc_object_t *p_this);
+picture_t *Filter( filter_t *p_filter, picture_t *p_picture);
+
+#define CFG_PREFIX "fps-"
+
+vlc_module_begin ()
+    set_description( N_("FPS conversion video filter") )
+    set_shortname( N_("FPS Converter" ))
+    set_capability( "video filter2", 0 )
+    set_category( CAT_VIDEO )
+    set_subcategory( SUBCAT_VIDEO_VFILTER )
+
+    add_shortcut( "fps" )
+    add_string( CFG_PREFIX "fps", NULL, NULL,
+               NULL, false )
+    set_callbacks( Open, Close )
+vlc_module_end ()
+
+static const char *const ppsz_filter_options[] = {
+    "fps",
+    NULL
+};
+
+/* We'll store pointer for previous picture we have received
+   and copy that if needed on framerate increase (not preferred)*/
+struct filter_sys_t
+{
+    date_t          next_output_pts; /**< output calculated PTS */
+    picture_t       *p_previous_pic;
+    int             i_output_frame_interval;
+};
+
+picture_t *Filter( filter_t *p_filter, picture_t *p_picture)
+{
+    filter_sys_t *p_sys = p_filter->p_sys;
+    /* If input picture doesn't have actual valid timestamp,
+        we don't really have currently a way to know what else
+        to do with it other than drop it for now*/
+    if( unlikely( p_picture->date < VLC_TS_0) )
+    {
+        msg_Dbg( p_filter, "skipping non-dated picture");
+        picture_Release( p_picture );
+        return NULL;
+    }
+    /* First time we get some valid timestamp, we'll take it as base for output*/
+    if( unlikely( date_Get( &p_sys->next_output_pts ) == VLC_TS_INVALID ) )
+    {
+        msg_Dbg( p_filter, "Resetting timestamps" );
+        date_Set( &p_sys->next_output_pts, p_picture->date );
+        p_sys->p_previous_pic = picture_Hold( p_picture );
+        date_Increment( &p_sys->next_output_pts, p_filter->fmt_out.video.i_frame_rate_base );
+        return p_picture;
+    }
+
+    /* Check if we can skip input as better should follow */
+    if( p_picture->date <
+        ( date_Get( &p_sys->next_output_pts ) - (mtime_t)p_sys->i_output_frame_interval ) )
+    {
+        if( p_sys->p_previous_pic )
+            picture_Release( p_sys->p_previous_pic );
+        p_sys->p_previous_pic = p_picture;
+        return NULL;
+    }
+
+    p_sys->p_previous_pic->date = date_Get( &p_sys->next_output_pts );
+    date_Increment( &p_sys->next_output_pts, p_filter->fmt_out.video.i_frame_rate_base );
+
+    picture_t *last_pic = p_sys->p_previous_pic;
+    /* Duplicating pictures are not that effective and framerate increase
+        should be avoided, it's only here as filter should work in that direction too*/
+    while( unlikely( (date_Get( &p_sys->next_output_pts ) + p_sys->i_output_frame_interval ) < p_picture->date ) )
+    {
+        picture_t *p_tmp = NULL;
+        p_tmp = picture_NewFromFormat( &p_filter->fmt_in.video );
+
+        picture_Copy( p_tmp, p_sys->p_previous_pic);
+        p_tmp->date = date_Get( &p_sys->next_output_pts );
+        p_tmp->p_next = NULL;
+
+        last_pic->p_next = p_tmp;
+        last_pic = p_tmp;
+        date_Increment( &p_sys->next_output_pts, p_filter->fmt_out.video.i_frame_rate_base );
+    }
+
+    last_pic = p_sys->p_previous_pic;
+    p_sys->p_previous_pic = p_picture;
+    return last_pic;
+}
+
+int Open( vlc_object_t *p_this)
+{
+    filter_t *p_filter = (filter_t*)p_this;
+    filter_sys_t *p_sys;
+
+    p_sys = p_filter->p_sys = malloc( sizeof( *p_sys ) );
+
+    if( unlikely( !p_sys ) )
+        return VLC_ENOMEM;
+
+    unsigned frame_rate = p_filter->fmt_out.video.i_frame_rate, frame_rate_base = p_filter->fmt_out.video.i_frame_rate_base;
+
+    config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
+                       p_filter->p_cfg );
+
+    /* If we don't have fps option, use filter output values */
+    if( var_InheritURational( p_filter, &frame_rate, &frame_rate_base, CFG_PREFIX "fps" ) )
+    {
+        frame_rate = p_filter->fmt_out.video.i_frame_rate;
+        frame_rate_base = p_filter->fmt_out.video.i_frame_rate_base;
+    }
+
+
+    memcpy( &p_filter->fmt_out.video, &p_filter->fmt_in.video, sizeof(video_format_t));
+    p_filter->fmt_out.video.i_frame_rate = frame_rate;
+    p_filter->fmt_out.video.i_frame_rate_base = frame_rate_base;
+
+    msg_Dbg( p_filter, "Converting fps from %d/%d -> %d/%d",
+            p_filter->fmt_in.video.i_frame_rate, p_filter->fmt_in.video.i_frame_rate_base,
+            p_filter->fmt_out.video.i_frame_rate, p_filter->fmt_out.video.i_frame_rate_base );
+
+    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;
+
+    date_Init( &p_sys->next_output_pts,
+               p_filter->fmt_out.video.i_frame_rate, 1);
+
+    date_Set( &p_sys->next_output_pts, VLC_TS_INVALID );
+
+    p_filter->pf_video_filter = Filter;
+    return VLC_SUCCESS;
+}
+
+void Close( vlc_object_t *p_this )
+{
+    filter_t *p_filter = (filter_t*)p_this;
+    if( p_filter->p_sys->p_previous_pic )
+        picture_Release( p_filter->p_sys->p_previous_pic );
+    free( p_filter->p_sys );
+}