ksvideosrc: Fix buffer handling

The pseudo buffer pool code was using gst_buffer_is_writable()
alone to try and figure-out if cached buffer could be reused.
It needs to check for memory writability too. Also check map
result and fix map flags.

https://bugzilla.gnome.org/show_bug.cgi?id=734264

3 files changed, 30 insertions, 14 deletions

diff --git a/sys/winks/gstksvideodevice.c b/sys/winks/gstksvideodevice.c
index 994f2f49b..71fa4e8ad 100644
--- a/sys/winks/gstksvideodevice.c
+++ b/sys/winks/gstksvideodevice.c
@@ -912,10 +912,12 @@ gst_ks_read_request_pick_buffer (GstKsVideoDevice * self, ReadRequest * req)
   gboolean buffer_found = FALSE;
   guint i;
 
-  buffer_found = gst_buffer_is_writable (req->buf);
+  buffer_found = gst_buffer_is_writable (req->buf)
+      && gst_buffer_is_all_memory_writable (req->buf);
 
   for (i = 0; !buffer_found && i < G_N_ELEMENTS (priv->spare_buffers); i++) {
-    if (gst_buffer_is_writable (priv->spare_buffers[i])) {
+    if (gst_buffer_is_writable (priv->spare_buffers[i])
+        && gst_buffer_is_all_memory_writable (priv->spare_buffers[i])) {
       GstBuffer *hold;
 
       hold = req->buf;
@@ -963,7 +965,9 @@ gst_ks_video_device_request_frame (GstKsVideoDevice * self, ReadRequest * req,
   params = &req->params;
   memset (params, 0, sizeof (KSSTREAM_READ_PARAMS));
 
-  gst_buffer_map (req->buf, &info, GST_MAP_READ);
+  if (!gst_buffer_map (req->buf, &info, GST_MAP_WRITE))
+    goto map_failed;
+
   params->header.Size = sizeof (KSSTREAM_HEADER) + sizeof (KS_FRAME_INFO);
   params->header.PresentationTime.Numerator = 1;
   params->header.PresentationTime.Denominator = 1;
@@ -994,6 +998,10 @@ error_ioctl:
         error_code, error_str);
     return FALSE;
   }
+map_failed:
+  {
+    return FALSE;
+  }
 }
 
 GstFlowReturn
@@ -1161,20 +1169,23 @@ error_get_result:
   }
 }
 
-void
-gst_ks_video_device_postprocess_frame (GstKsVideoDevice * self,
-    guint8 * buf, guint buf_size)
+gboolean
+gst_ks_video_device_postprocess_frame (GstKsVideoDevice * self, GstBuffer * buf)
 {
   GstKsVideoDevicePrivate *priv = GST_KS_VIDEO_DEVICE_GET_PRIVATE (self);
 
   /* If it's RGB we need to flip the image */
   if (priv->rgb_swap_buf != NULL) {
+    GstMapInfo info;
     gint stride, line;
     guint8 *dst, *src;
 
-    stride = buf_size / priv->height;
-    dst = buf;
-    src = buf + buf_size - stride;
+    if (!gst_buffer_map (buf, &info, GST_MAP_READWRITE))
+      return FALSE;
+
+    stride = info.size / priv->height;
+    dst = info.data;
+    src = info.data + info.size - stride;
 
     for (line = 0; line < priv->height / 2; line++) {
       memcpy (priv->rgb_swap_buf, dst, stride);
@@ -1185,7 +1196,11 @@ gst_ks_video_device_postprocess_frame (GstKsVideoDevice * self,
       dst += stride;
       src -= stride;
     }
+
+    gst_buffer_unmap (buf, &info);
   }
+
+  return TRUE;
 }
 
 void
diff --git a/sys/winks/gstksvideodevice.h b/sys/winks/gstksvideodevice.h
index d148f922d..105b79da3 100644
--- a/sys/winks/gstksvideodevice.h
+++ b/sys/winks/gstksvideodevice.h
@@ -77,7 +77,7 @@ GstClockTime gst_ks_video_device_get_duration (GstKsVideoDevice * self);
 gboolean gst_ks_video_device_get_latency (GstKsVideoDevice * self, GstClockTime * min_latency, GstClockTime * max_latency);
 
 GstFlowReturn gst_ks_video_device_read_frame (GstKsVideoDevice * self, GstBuffer ** buf, GstClockTime * presentation_time, gulong * error_code, gchar ** error_str);
-void gst_ks_video_device_postprocess_frame (GstKsVideoDevice * self, guint8 * buf, guint buf_size);
+gboolean gst_ks_video_device_postprocess_frame (GstKsVideoDevice * self, GstBuffer *buf);
 void gst_ks_video_device_cancel (GstKsVideoDevice * self);
 void gst_ks_video_device_cancel_stop (GstKsVideoDevice * self);
 
diff --git a/sys/winks/gstksvideosrc.c b/sys/winks/gstksvideosrc.c
index 2694ac701..cd61a995f 100644
--- a/sys/winks/gstksvideosrc.c
+++ b/sys/winks/gstksvideosrc.c
@@ -950,7 +950,6 @@ gst_ks_video_src_create (GstPushSrc * pushsrc, GstBuffer ** buf)
   GstClockTime presentation_time;
   gulong error_code;
   gchar *error_str;
-  GstMapInfo info;
 
   g_assert (priv->device != NULL);
 
@@ -987,9 +986,11 @@ gst_ks_video_src_create (GstPushSrc * pushsrc, GstBuffer ** buf)
   if (G_UNLIKELY (priv->do_stats))
     gst_ks_video_src_update_statistics (self);
 
-  gst_buffer_map (*buf, &info, GST_MAP_WRITE);
-  gst_ks_video_device_postprocess_frame (priv->device, info.data, info.size);
-  gst_buffer_unmap (*buf, &info);
+  if (!gst_ks_video_device_postprocess_frame (priv->device, *buf)) {
+    GST_ELEMENT_ERROR (self, RESOURCE, FAILED, ("Postprocessing failed"),
+        ("Postprocessing failed"));
+    return GST_FLOW_ERROR;
+  }
 
   return GST_FLOW_OK;