diff --git a/gst/gstbuffer.c b/gst/gstbuffer.c
index 52add64e5d..7f92694776 100644
--- a/gst/gstbuffer.c
+++ b/gst/gstbuffer.c
@@ -205,7 +205,9 @@ gst_buffer_copy_into (GstBuffer * dest, GstBuffer * src,
   g_warn_if_fail (gst_buffer_is_writable (dest));
 #endif
 
-  GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p", src, dest);
+  GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p, offset %" G_GSIZE_FORMAT
+      "-%" G_GSIZE_FORMAT "/%" G_GSIZE_FORMAT, src, dest, offset, size,
+      bufsize);
 
   if (flags & GST_BUFFER_COPY_FLAGS) {
     guint mask;
@@ -222,7 +224,7 @@ gst_buffer_copy_into (GstBuffer * dest, GstBuffer * src,
     if (offset == 0) {
       GST_BUFFER_TIMESTAMP (dest) = GST_BUFFER_TIMESTAMP (src);
       GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
-      if (size == gst_buffer_get_size (src)) {
+      if (size == bufsize) {
         GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
         GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
       }
@@ -594,6 +596,9 @@ gst_buffer_trim (GstBuffer * buffer, gsize offset, gsize size)
   gsize bsize;
   GstMemory *mem;
 
+  GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSIZE_FORMAT "-%" G_GSIZE_FORMAT,
+      buffer, offset, size);
+
   g_return_if_fail (gst_buffer_is_writable (buffer));
 
   arr = (GPtrArray *) buffer->memory;
@@ -926,7 +931,8 @@ gst_buffer_create_sub (GstBuffer * buffer, gsize offset, gsize size)
   /* create the new buffer */
   subbuffer = gst_buffer_new ();
 
-  GST_CAT_LOG (GST_CAT_BUFFER, "new subbuffer %p of %p", subbuffer, buffer);
+  GST_CAT_LOG (GST_CAT_BUFFER, "new subbuffer %p of %p %" G_GSIZE_FORMAT
+      "-%" G_GSIZE_FORMAT, subbuffer, buffer, offset, size);
 
   gst_buffer_copy_into (subbuffer, buffer, GST_BUFFER_COPY_ALL, offset, size);
 
diff --git a/gst/gstmemory.c b/gst/gstmemory.c
index 54a4fdab2c..5412f224f4 100644
--- a/gst/gstmemory.c
+++ b/gst/gstmemory.c
@@ -116,7 +116,7 @@ _default_mem_get_sizes (GstMemoryDefault * mem, gsize * maxsize)
 static void
 _default_mem_trim (GstMemoryDefault * mem, gsize offset, gsize size)
 {
-  g_return_if_fail (size + mem->offset + offset > mem->maxsize);
+  g_return_if_fail (size + mem->offset + offset <= mem->maxsize);
 
   mem->offset += offset;
   mem->size = size;
@@ -198,7 +198,7 @@ static void
 _default_mem_extract (GstMemoryDefault * mem, gsize offset, gpointer dest,
     gsize size)
 {
-  g_return_if_fail (size + mem->offset + offset > mem->maxsize);
+  g_return_if_fail (size + mem->offset + offset <= mem->maxsize);
 
   memcpy (dest, mem->data + mem->offset + offset, size);
 }
diff --git a/libs/gst/base/gstbasetransform.c b/libs/gst/base/gstbasetransform.c
index 930ab56e43..19087c2dcc 100644
--- a/libs/gst/base/gstbasetransform.c
+++ b/libs/gst/base/gstbasetransform.c
@@ -1539,7 +1539,7 @@ gst_base_transform_prepare_output_buffer (GstBaseTransform * trans,
       /* no valid buffer yet, make one, metadata is writable */
       *out_buf = gst_buffer_new_and_alloc (outsize);
       gst_buffer_copy_into (*out_buf, in_buf,
-          GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, 0);
+          GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, -1);
     } else {
       GST_DEBUG_OBJECT (trans, "reuse input buffer");
       *out_buf = in_buf;
@@ -1608,7 +1608,7 @@ gst_base_transform_prepare_output_buffer (GstBaseTransform * trans,
       gst_buffer_set_caps (*out_buf, outcaps);
     if (copymeta)
       gst_buffer_copy_into (*out_buf, in_buf,
-          GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, 0);
+          GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, -1);
     /* clear the GAP flag when the subclass does not understand it */
     if (!trans->priv->gap_aware)
       GST_BUFFER_FLAG_UNSET (*out_buf, GST_BUFFER_FLAG_GAP);