From dd08b83c876275ae4741225a4820997c935b956d Mon Sep 17 00:00:00 2001
From: Stefano Sabatini <stefano.sabatini-lala@poste.it>
Date: Sat, 16 Jan 2010 10:43:53 +0000
Subject: Implement null video source.

Originally committed as revision 21240 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 doc/libavfilter.texi       | 16 +++++++++
 libavfilter/Makefile       |  2 ++
 libavfilter/allfilters.c   |  2 ++
 libavfilter/avfilter.h     |  2 +-
 libavfilter/vsrc_nullsrc.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 104 insertions(+), 1 deletion(-)
 create mode 100644 libavfilter/vsrc_nullsrc.c

diff --git a/doc/libavfilter.texi b/doc/libavfilter.texi
index 0e473fdfee..28f24bce9f 100644
--- a/doc/libavfilter.texi
+++ b/doc/libavfilter.texi
@@ -197,4 +197,20 @@ Flip the input video vertically.
 ./ffmpeg -i in.avi -vfilters "vflip" out.avi
 @end example
 
+@chapter Available video sources
+
+Below is a description of the currently available video sources.
+
+@section nullsrc
+
+Null video source, never return images. It is mainly useful as a
+template and to be employed in analysis / debugging tools.
+
+It accepts as optional parameter a string of the form
+``width:height'', where ``width'' and ``height'' specify the size of
+the configured source.
+
+The default values of ``width'' and ``height'' are respectively 352
+and 288 (corresponding to the CIF size format).
+
 @bye
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index b8a8772bae..08d60800f4 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -20,4 +20,6 @@ OBJS-$(CONFIG_SCALE_FILTER)                  += vf_scale.o
 OBJS-$(CONFIG_SLICIFY_FILTER)                += vf_slicify.o
 OBJS-$(CONFIG_VFLIP_FILTER)                  += vf_vflip.o
 
+OBJS-$(CONFIG_NULLSRC_FILTER)                += vsrc_nullsrc.o
+
 include $(SUBDIR)../subdir.mak
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index a4cbdade86..81eec21598 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -41,4 +41,6 @@ void avfilter_register_all(void)
     REGISTER_FILTER (SCALE, scale, vf);
     REGISTER_FILTER (SLICIFY, slicify, vf);
     REGISTER_FILTER (VFLIP, vflip, vf);
+
+    REGISTER_FILTER (NULLSRC, nullsrc, vsrc);
 }
diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h
index 8f12d7d1d5..5b85427ac1 100644
--- a/libavfilter/avfilter.h
+++ b/libavfilter/avfilter.h
@@ -25,7 +25,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  1
-#define LIBAVFILTER_VERSION_MINOR 15
+#define LIBAVFILTER_VERSION_MINOR 16
 #define LIBAVFILTER_VERSION_MICRO  0
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
diff --git a/libavfilter/vsrc_nullsrc.c b/libavfilter/vsrc_nullsrc.c
new file mode 100644
index 0000000000..ff14ea68b2
--- /dev/null
+++ b/libavfilter/vsrc_nullsrc.c
@@ -0,0 +1,83 @@
+/*
+ * 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/vsrc_nullsrc.c
+ * null video source
+ */
+
+#include "avfilter.h"
+
+typedef struct {
+    int w, h;
+} NullContext;
+
+static int init(AVFilterContext *ctx, const char *args, void *opaque)
+{
+    NullContext *priv = ctx->priv;
+
+    priv->w = 352;
+    priv->h = 288;
+
+    if (args)
+        sscanf(args, "%d:%d", &priv->w, &priv->h);
+
+    if (priv->w <= 0 || priv->h <= 0) {
+        av_log(ctx, AV_LOG_ERROR, "Non-positive size values are not acceptable.\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int config_props(AVFilterLink *outlink)
+{
+    NullContext *priv = outlink->src->priv;
+
+    outlink->w = priv->w;
+    outlink->h = priv->h;
+
+    av_log(outlink->src, AV_LOG_INFO, "w:%d h:%d\n", priv->w, priv->h);
+
+    return 0;
+}
+
+static int request_frame(AVFilterLink *link)
+{
+    return -1;
+}
+
+AVFilter avfilter_vsrc_nullsrc = {
+    .name        = "nullsrc",
+    .description = "Null video source, never return images.",
+
+    .init       = init,
+    .priv_size = sizeof(NullContext),
+
+    .inputs    = (AVFilterPad[]) {{ .name = NULL}},
+
+    .outputs   = (AVFilterPad[]) {
+        {
+            .name            = "default",
+            .type            = CODEC_TYPE_VIDEO,
+            .config_props    = config_props,
+            .request_frame   = request_frame,
+        },
+        { .name = NULL}
+    },
+};
-- 
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