@@ -78,4 +78,8 @@ build.

 Below is a description of the currently available video filters.

+@section null

+

+Pass the source unchanged to the output.

+

 @bye

@@ -11,6 +11,6 @@ OBJS = allfilters.o                                                     \

        defaults.o                                                       \

        formats.o                                                        \

-#OBJS-$(CONFIG_XXX_FILTER)    += vf_xxx.o

+OBJS-$(CONFIG_NULL_FILTER)    += vf_null.o

 include $(SUBDIR)../subdir.mak

@@ -34,6 +34,5 @@ void avfilter_register_all(void)

         return;

     initialized = 1;

-//    REGISTER_FILTER (CROP,crop,vf);

-

+    REGISTER_FILTER (NULL,null,vf);

 }

new file mode 100644

@@ -0,0 +1,56 @@

+/*

+ * This file is part of FFmpeg.

+ *

+ * FFmpeg 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.

+ *

+ * FFmpeg 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 FFmpeg; if not, write to the Free Software

+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

+ */

+

+/**

+ * @file libavfilter/vf_null.c

+ * null filter

+ */

+

+#include "avfilter.h"

+

+static AVFilterPicRef *get_video_buffer(AVFilterLink *link, int perms, int w, int h)

+{

+    return avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h);

+}

+

+static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)

+{

+    avfilter_start_frame(link->dst->outputs[0], picref);

+}

+

+static void end_frame(AVFilterLink *link)

+{

+    avfilter_end_frame(link->dst->outputs[0]);

+}

+

+AVFilter avfilter_vf_null = {

+    .name      = "null",

+

+    .priv_size = 0,

+

+    .inputs    = (AVFilterPad[]) {{ .name             = "default",

+                                    .type             = CODEC_TYPE_VIDEO,

+                                    .get_video_buffer = get_video_buffer,

+                                    .start_frame      = start_frame,

+                                    .end_frame        = end_frame },

+                                  { .name = NULL}},

+

+    .outputs   = (AVFilterPad[]) {{ .name             = "default",

+                                    .type             = CODEC_TYPE_VIDEO, },

+                                  { .name = NULL}},

+};