decoder: add initial infrastructure for marking corrupted output.

Add initial infrastructure in core codec library and vaapidecode to mark
corrupted frames as such. A corrupted frame is such a frame that was
reconstructed from invalid references for instance.

https://bugzilla.gnome.org/show_bug.cgi?id=751434

Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>

gst-libs/gst/vaapi/gstvaapidecoder_objects.c

@@ -117,6 +117,12 @@ gst_vaapi_picture_create (GstVaapiPicture * picture,
             GST_VAAPI_PICTURE_FLAG_ONEFIELD |
             GST_VAAPI_PICTURE_FLAG_RFF | GST_VAAPI_PICTURE_FLAG_MVC));
 
+    // Propagate "corrupted" flag while not presuming that the second
+    // field is itself corrupted if the first one was marked as such
+    if (GST_VAAPI_PICTURE_IS_CORRUPTED (parent_picture) &&
+        !(args->flags & GST_VAAPI_CREATE_PICTURE_FLAG_FIELD))
+      GST_VAAPI_PICTURE_FLAG_SET (picture, GST_VAAPI_PICTURE_FLAG_CORRUPTED);
+
     picture->structure = parent_picture->structure;
     if ((args->flags & GST_VAAPI_CREATE_PICTURE_FLAG_FIELD) &&
         GST_VAAPI_PICTURE_IS_INTERLACED (picture)) {
@@ -348,6 +354,9 @@ do_output (GstVaapiPicture * picture)
     GST_VIDEO_CODEC_FRAME_FLAG_SET (out_frame,
         GST_VIDEO_CODEC_FRAME_FLAG_DECODE_ONLY);
 
+  if (GST_VAAPI_PICTURE_IS_CORRUPTED (picture))
+    flags |= GST_VAAPI_SURFACE_PROXY_FLAG_CORRUPTED;
+
   if (GST_VAAPI_PICTURE_IS_MVC (picture)) {
     if (picture->voc == 0)
       flags |= GST_VAAPI_SURFACE_PROXY_FLAG_FFB;

gst-libs/gst/vaapi/gstvaapidecoder_objects.h

@@ -68,6 +68,8 @@ typedef enum
  * @GST_VAAPI_PICTURE_FLAG_ONEFIELD: only one field is valid
  * @GST_VAAPI_PICTURE_FLAG_MVC: multiview component
  * @GST_VAAPI_PICTURE_FLAG_RFF: repeat-first-field
+ * @GST_VAAPI_PICTURE_FLAG_CORRUPTED: picture was reconstructed from
+ *   corrupted references
  * @GST_VAAPI_PICTURE_FLAG_LAST: first flag that can be used by subclasses
  *
  * Enum values used for #GstVaapiPicture flags.
@@ -83,7 +85,8 @@ typedef enum
   GST_VAAPI_PICTURE_FLAG_ONEFIELD   = (GST_VAAPI_CODEC_OBJECT_FLAG_LAST << 6),
   GST_VAAPI_PICTURE_FLAG_MVC        = (GST_VAAPI_CODEC_OBJECT_FLAG_LAST << 7),
   GST_VAAPI_PICTURE_FLAG_RFF        = (GST_VAAPI_CODEC_OBJECT_FLAG_LAST << 8),
-  GST_VAAPI_PICTURE_FLAG_LAST       = (GST_VAAPI_CODEC_OBJECT_FLAG_LAST << 9),
+  GST_VAAPI_PICTURE_FLAG_CORRUPTED  = (GST_VAAPI_CODEC_OBJECT_FLAG_LAST << 9),
+  GST_VAAPI_PICTURE_FLAG_LAST       = (GST_VAAPI_CODEC_OBJECT_FLAG_LAST << 10),
 } GstVaapiPictureFlags;
 
 #define GST_VAAPI_PICTURE_FLAGS         GST_VAAPI_MINI_OBJECT_FLAGS
@@ -126,6 +129,9 @@ typedef enum
 #define GST_VAAPI_PICTURE_IS_MVC(picture) \
   (GST_VAAPI_PICTURE_FLAG_IS_SET (picture, GST_VAAPI_PICTURE_FLAG_MVC))
 
+#define GST_VAAPI_PICTURE_IS_CORRUPTED(picture) \
+  (GST_VAAPI_PICTURE_FLAG_IS_SET (picture, GST_VAAPI_PICTURE_FLAG_CORRUPTED))
+
 /**
  * GstVaapiPicture:
  *

gst-libs/gst/vaapi/gstvaapisurfaceproxy.h

@@ -38,6 +38,8 @@ G_BEGIN_DECLS
  * @GST_VAAPI_SURFACE_PROXY_FLAG_ONEFIELD: only one field is available
  * @GST_VAAPI_SURFACE_PROXY_FLAG_FFB: first frame in bundle, e.g. the first
  *   view component of a MultiView Coded (MVC) frame
+ * @GST_VAAPI_SURFACE_PROXY_FLAG_CORRUPTED: the underlying surface is
+ *   corrupted somehow, e.g. reconstructed from invalid references
  * @GST_VAAPI_SURFACE_PROXY_FLAG_LAST: first flag that can be used by subclasses
  *
  * Flags for #GstVaapiDecoderFrame.
@@ -49,6 +51,7 @@ typedef enum
   GST_VAAPI_SURFACE_PROXY_FLAG_RFF = (1 << 2),
   GST_VAAPI_SURFACE_PROXY_FLAG_ONEFIELD = (1 << 3),
   GST_VAAPI_SURFACE_PROXY_FLAG_FFB = (1 << 4),
+  GST_VAAPI_SURFACE_PROXY_FLAG_CORRUPTED = (1 << 5),
   GST_VAAPI_SURFACE_PROXY_FLAG_LAST = (1 << 8)
 } GstVaapiSurfaceProxyFlags;
 

gst/vaapi/gstvaapidecode.c

@@ -264,7 +264,7 @@ gst_vaapidecode_push_decoded_frame (GstVideoDecoder * vdec,
   GstFlowReturn ret;
   const GstVaapiRectangle *crop_rect;
   GstVaapiVideoMeta *meta;
-  guint flags;
+  guint flags, out_flags = 0;
 
   if (!GST_VIDEO_CODEC_FRAME_IS_DECODE_ONLY (out_frame)) {
     proxy = gst_video_codec_frame_get_user_data (out_frame);
@@ -282,16 +282,18 @@ gst_vaapidecode_push_decoded_frame (GstVideoDecoder * vdec,
     gst_vaapi_video_meta_set_surface_proxy (meta, proxy);
 
     flags = gst_vaapi_surface_proxy_get_flags (proxy);
+    if (flags & GST_VAAPI_SURFACE_PROXY_FLAG_CORRUPTED)
+      out_flags |= GST_BUFFER_FLAG_CORRUPTED;
     if (flags & GST_VAAPI_SURFACE_PROXY_FLAG_INTERLACED) {
-      guint out_flags = GST_VIDEO_BUFFER_FLAG_INTERLACED;
+      out_flags |= GST_VIDEO_BUFFER_FLAG_INTERLACED;
       if (flags & GST_VAAPI_SURFACE_PROXY_FLAG_TFF)
         out_flags |= GST_VIDEO_BUFFER_FLAG_TFF;
       if (flags & GST_VAAPI_SURFACE_PROXY_FLAG_RFF)
         out_flags |= GST_VIDEO_BUFFER_FLAG_RFF;
       if (flags & GST_VAAPI_SURFACE_PROXY_FLAG_ONEFIELD)
         out_flags |= GST_VIDEO_BUFFER_FLAG_ONEFIELD;
-      GST_BUFFER_FLAG_SET (out_frame->output_buffer, out_flags);
     }
+    GST_BUFFER_FLAG_SET (out_frame->output_buffer, out_flags);
 
     crop_rect = gst_vaapi_surface_proxy_get_crop_rect (proxy);
     if (crop_rect) {