From 806cf03fbcbce0046331e2e349003e22238ee1a3 Mon Sep 17 00:00:00 2001
From: Wim Taymans <wim.taymans@collabora.co.uk>
Date: Wed, 6 Jul 2011 16:08:56 +0200
Subject: [PATCH] buffer: add memset function

---
 gst/gstbuffer.c | 41 +++++++++++++++++++++++++++++++++++++++++
 gst/gstbuffer.h |  2 ++
 2 files changed, 43 insertions(+)

diff --git a/gst/gstbuffer.c b/gst/gstbuffer.c
index dbfc27e660..4380f7a384 100644
--- a/gst/gstbuffer.c
+++ b/gst/gstbuffer.c
@@ -1054,6 +1054,47 @@ gst_buffer_memcmp (GstBuffer * buffer, gsize offset, gconstpointer mem,
   return res;
 }
 
+/**
+ * gst_buffer_memset:
+ * @buffer: a #GstBuffer.
+ * @offset: the offset in @buffer
+ * @val: the value to set
+ * @size: the size to set
+ *
+ * Fill @buf with @size bytes with @val starting from @offset.
+ */
+void
+gst_buffer_memset (GstBuffer * buffer, gsize offset, guint8 val, gsize size)
+{
+  gsize i, len;
+
+  g_return_if_fail (GST_IS_BUFFER (buffer));
+  g_return_if_fail (gst_buffer_is_writable (buffer));
+
+  len = GST_BUFFER_MEM_LEN (buffer);
+
+  for (i = 0; i < len && size > 0; i++) {
+    guint8 *data;
+    gsize ssize, toset;
+    GstMemory *mem;
+
+    mem = GST_BUFFER_MEM_PTR (buffer, i);
+
+    data = gst_memory_map (mem, &ssize, NULL, GST_MAP_WRITE);
+    if (ssize > offset) {
+      /* we have enough */
+      toset = MIN (ssize - offset, size);
+      memset (data + offset, val, toset);
+      size -= toset;
+      offset = 0;
+    } else {
+      /* offset past buffer, skip */
+      offset -= ssize;
+    }
+    gst_memory_unmap (mem, data, ssize);
+  }
+}
+
 /**
  * gst_buffer_copy_region:
  * @parent: a #GstBuffer.
diff --git a/gst/gstbuffer.h b/gst/gstbuffer.h
index 18726035fc..cead4c7741 100644
--- a/gst/gstbuffer.h
+++ b/gst/gstbuffer.h
@@ -249,6 +249,8 @@ void        gst_buffer_extract             (GstBuffer *buffer, gsize offset,
                                             gpointer dest, gsize size);
 gint        gst_buffer_memcmp              (GstBuffer *buffer, gsize offset,
                                             gconstpointer mem, gsize size);
+void        gst_buffer_memset              (GstBuffer *buffer, gsize offset,
+                                            guint8 val, gsize size);
 
 gsize       gst_buffer_get_size            (GstBuffer *buffer);
 void        gst_buffer_resize              (GstBuffer *buffer, gsize offset, gsize size);