From 6196026c76f84e01eb6e81fbb60e052c865e13c9 Mon Sep 17 00:00:00 2001
From: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Date: Sun, 16 Mar 2014 16:55:43 +0100
Subject: [PATCH] v4l2bufferpool: Enforce activation outside of process

Enforce pool being activate from before calling pool process. This should
help catching basic errors in the usage of buffer pool.
---
 sys/v4l2/gstv4l2bufferpool.c | 21 ++-------------------
 sys/v4l2/gstv4l2sink.c       | 23 +++++++++++++++++++++++
 2 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/sys/v4l2/gstv4l2bufferpool.c b/sys/v4l2/gstv4l2bufferpool.c
index f1170301fe..eb359044bc 100644
--- a/sys/v4l2/gstv4l2bufferpool.c
+++ b/sys/v4l2/gstv4l2bufferpool.c
@@ -1438,6 +1438,8 @@ gst_v4l2_buffer_pool_process (GstV4l2BufferPool * pool, GstBuffer * buf)
 
   GST_DEBUG_OBJECT (pool, "process buffer %p", buf);
 
+  g_return_val_if_fail (gst_buffer_pool_is_active (bpool), GST_FLOW_ERROR);
+
   switch (obj->type) {
     case V4L2_BUF_TYPE_VIDEO_CAPTURE:
     case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
@@ -1495,20 +1497,6 @@ gst_v4l2_buffer_pool_process (GstV4l2BufferPool * pool, GstBuffer * buf)
             GST_LOG_OBJECT (pool, "processing buffer from our pool");
           } else {
             GST_LOG_OBJECT (pool, "alloc buffer from our pool");
-            if (!gst_buffer_pool_is_active (bpool)) {
-              GstStructure *config;
-
-              /* this pool was not activated, configure and activate */
-              GST_DEBUG_OBJECT (pool, "activating pool");
-
-              config = gst_buffer_pool_get_config (bpool);
-              gst_buffer_pool_config_add_option (config,
-                  GST_BUFFER_POOL_OPTION_VIDEO_META);
-              gst_buffer_pool_set_config (bpool, config);
-
-              if (!gst_buffer_pool_set_active (bpool, TRUE))
-                goto activate_failed;
-            }
 
             /* this can block if all buffers are outstanding which would be
              * strange because we would expect the upstream element to have
@@ -1565,11 +1553,6 @@ done:
   return ret;
 
   /* ERRORS */
-activate_failed:
-  {
-    GST_ERROR_OBJECT (obj->element, "failed to activate pool");
-    return GST_FLOW_ERROR;
-  }
 acquire_failed:
   {
     GST_WARNING_OBJECT (obj->element, "failed to acquire a buffer: %s",
diff --git a/sys/v4l2/gstv4l2sink.c b/sys/v4l2/gstv4l2sink.c
index 24f6d3f9d6..41989d5348 100644
--- a/sys/v4l2/gstv4l2sink.c
+++ b/sys/v4l2/gstv4l2sink.c
@@ -600,12 +600,28 @@ gst_v4l2sink_show_frame (GstBaseSink * bsink, GstBuffer * buf)
   GstFlowReturn ret;
   GstV4l2Sink *v4l2sink = GST_V4L2SINK (bsink);
   GstV4l2Object *obj = v4l2sink->v4l2object;
+  GstBufferPool *bpool = GST_BUFFER_POOL (obj->pool);
 
   GST_DEBUG_OBJECT (v4l2sink, "render buffer: %p", buf);
 
   if (G_UNLIKELY (obj->pool == NULL))
     goto not_negotiated;
 
+  if (G_UNLIKELY (!gst_buffer_pool_is_active (bpool))) {
+    GstStructure *config;
+
+    /* this pool was not activated, configure and activate */
+    GST_DEBUG_OBJECT (bsink, "activating pool");
+
+    config = gst_buffer_pool_get_config (bpool);
+    gst_buffer_pool_config_add_option (config,
+        GST_BUFFER_POOL_OPTION_VIDEO_META);
+    gst_buffer_pool_set_config (bpool, config);
+
+    if (!gst_buffer_pool_set_active (bpool, TRUE))
+      goto activate_failed;
+  }
+
   ret =
       gst_v4l2_buffer_pool_process (GST_V4L2_BUFFER_POOL_CAST (obj->pool), buf);
 
@@ -617,4 +633,11 @@ not_negotiated:
     GST_ERROR_OBJECT (bsink, "not negotiated");
     return GST_FLOW_NOT_NEGOTIATED;
   }
+activate_failed:
+  {
+    GST_ELEMENT_ERROR (bsink, RESOURCE, SETTINGS,
+        (_("Failed to allocated required memory.")),
+        ("Buffer pool activation failed"));
+    return GST_FLOW_ERROR;
+  }
 }