v4l2: log buffer copies on queue underrun in perf category

v4l2src has a slow path where it does buffer-copies when it runs out of queued
buffers. Log this to performance category to help monitoring it.

diff --git a/sys/v4l2/gstv4l2.c b/sys/v4l2/gstv4l2.c
index 409526c..99287b3 100644 (file)
--- a/sys/v4l2/gstv4l2.c
+++ b/sys/v4l2/gstv4l2.c
@@ -38,11 +38,13 @@
 
 /* used in v4l2_calls.c and v4l2src_calls.c */
 GST_DEBUG_CATEGORY (v4l2_debug);
+GST_DEBUG_CATEGORY (GST_CAT_PERFORMANCE);
 
 static gboolean
 plugin_init (GstPlugin * plugin)
 {
   GST_DEBUG_CATEGORY_INIT (v4l2_debug, "v4l2", 0, "V4L2 API calls");
+  GST_DEBUG_CATEGORY_GET (GST_CAT_PERFORMANCE, "GST_PERFORMANCE");
 
   if (!gst_element_register (plugin, "v4l2src", GST_RANK_PRIMARY,
           GST_TYPE_V4L2SRC) ||

diff --git a/sys/v4l2/v4l2src_calls.c b/sys/v4l2/v4l2src_calls.c
index 9142ac4..73de302 100644 (file)
--- a/sys/v4l2/v4l2src_calls.c
+++ b/sys/v4l2/v4l2src_calls.c
@@ -49,6 +49,7 @@
 
 GST_DEBUG_CATEGORY_EXTERN (v4l2src_debug);
 #define GST_CAT_DEFAULT v4l2src_debug
+GST_DEBUG_CATEGORY_EXTERN (GST_CAT_PERFORMANCE);
 
 /* lalala... */
 #define GST_V4L2_SET_ACTIVE(element) (element)->buffer = GINT_TO_POINTER (-1)
@@ -157,6 +158,10 @@ gst_v4l2src_grab_frame (GstV4l2Src * v4l2src, GstBuffer ** buf)
       || !gst_v4l2_buffer_pool_available_buffers (pool);
 
   if (G_UNLIKELY (need_copy)) {
+    if (!v4l2src->always_copy) {
+      GST_CAT_LOG_OBJECT (GST_CAT_PERFORMANCE, v4l2src,
+          "running out of buffers, making a copy to reuse current one");
+    }
     *buf = gst_buffer_copy (pool_buffer);
     GST_BUFFER_FLAG_UNSET (*buf, GST_BUFFER_FLAG_READONLY);
     /* this will requeue */