va: allocator: use _update_image_info() to set allocator parameters.

Use this standalone function to update the allocator info and make
all ensure_image() and mem_alloc() API clean.
We also change the default way of using image. We now set the non
derive manner as the default manner, and if it fails, then fallback
to the derived image manner.
On a lot of platforms, the derived image does not have caches, so the
read and write operations have very low performance.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1698>

sys/va/gstvaallocator.c

@@ -959,11 +959,10 @@ _reset_mem (GstVaMemory * mem, GstAllocator * allocator, gsize size)
 }
 
 static inline gboolean
-_ensure_image (GstVaDisplay * display, VASurfaceID surface, GstVideoInfo * info,
+_ensure_image (GstVaDisplay * display, VASurfaceID surface,
-    VAImage * image, gboolean * derived, gboolean update_info)
+    GstVideoInfo * info, VAImage * image, gboolean derived)
 {
-  gint i;
+  gboolean ret = TRUE;
-  gboolean try_derived;
 
   if (image->image_id != VA_INVALID_ID)
     return TRUE;
@@ -971,28 +970,14 @@ _ensure_image (GstVaDisplay * display, VASurfaceID surface, GstVideoInfo * info,
   if (!_sync_surface (display, surface))
     return FALSE;
 
-  try_derived = (derived) ? *derived : FALSE;
+  if (derived) {
-
+    ret = _get_derive_image (display, surface, image);
-  if (try_derived && _get_derive_image (display, surface, image))
+  } else {
-    goto bail;
+    ret = _create_image (display, GST_VIDEO_INFO_FORMAT (info),
-  if (!_create_image (display, GST_VIDEO_INFO_FORMAT (info),
+        GST_VIDEO_INFO_WIDTH (info), GST_VIDEO_INFO_HEIGHT (info), image);
-          GST_VIDEO_INFO_WIDTH (info), GST_VIDEO_INFO_HEIGHT (info), image))
-    return FALSE;
-
-  if (derived)
-    *derived = FALSE;
-
-bail:
-  if (G_UNLIKELY (update_info)) {
-    for (i = 0; i < image->num_planes; i++) {
-      GST_VIDEO_INFO_PLANE_OFFSET (info, i) = image->offsets[i];
-      GST_VIDEO_INFO_PLANE_STRIDE (info, i) = image->pitches[i];
-    }
-
-    GST_VIDEO_INFO_SIZE (info) = image->data_size;
   }
 
-  return TRUE;
+  return ret;
 }
 
 static inline gboolean
@@ -1070,11 +1055,8 @@ _va_map_unlocked (GstVaMemory * mem, GstMapFlags flags)
 
   if (flags & GST_MAP_WRITE) {
     mem->is_dirty = TRUE;
-    mem->is_derived = FALSE;
   } else {                      /* GST_MAP_READ only */
     mem->is_dirty = FALSE;
-    mem->is_derived = va_allocator->use_derived &&
-        (GST_VIDEO_INFO_FORMAT (&va_allocator->info) == mem->surface_format);
   }
 
   if (flags & GST_MAP_VA) {
@@ -1083,10 +1065,10 @@ _va_map_unlocked (GstVaMemory * mem, GstMapFlags flags)
   }
 
   if (!_ensure_image (display, mem->surface, &va_allocator->info, &mem->image,
-          &mem->is_derived, FALSE))
+          va_allocator->use_derived))
     return NULL;
 
-  va_allocator->use_derived = mem->is_derived;
+  mem->is_derived = va_allocator->use_derived;
 
   if (!mem->is_derived) {
     if (!_get_image (display, mem->surface, &mem->image))
@@ -1238,12 +1220,8 @@ gst_va_memory_release (GstMiniObject * mini_object)
   return FALSE;
 }
 
-/* If @info is not NULL, a dummy (non-pooled) memory and its VAImage
+GstMemory *
- * are created, to update offsets and strides. The memory has to be
+gst_va_allocator_alloc (GstAllocator * allocator)
- * unrefed immediately.
- */
-static GstMemory *
-gst_va_allocator_alloc_full (GstAllocator * allocator, GstVideoInfo * info)
 {
   GstVaAllocator *self;
   GstVaMemory *mem;
@@ -1253,20 +1231,14 @@ gst_va_allocator_alloc_full (GstAllocator * allocator, GstVideoInfo * info)
 
   self = GST_VA_ALLOCATOR (allocator);
 
+  g_return_val_if_fail (self->rt_format != 0, NULL);
+
   if (!_create_surfaces (self->display, self->rt_format, self->fourcc,
           GST_VIDEO_INFO_WIDTH (&self->info),
           GST_VIDEO_INFO_HEIGHT (&self->info), self->usage_hint, NULL,
           &surface, 1))
     return NULL;
 
-  if (G_UNLIKELY (info)) {
-    VAImage image = {.image_id = VA_INVALID_ID, };
-
-    if (!_ensure_image (self->display, surface, info, &image, NULL, TRUE))
-      return NULL;
-    _destroy_image (self->display, image.image_id);
-  }
-
   mem = g_slice_new (GstVaMemory);
 
   mem->surface = surface;
@@ -1274,10 +1246,8 @@ gst_va_allocator_alloc_full (GstAllocator * allocator, GstVideoInfo * info)
 
   _reset_mem (mem, allocator, GST_VIDEO_INFO_SIZE (&self->info));
 
-  if (G_LIKELY (!info)) {
+  GST_MINI_OBJECT (mem)->dispose = gst_va_memory_release;
-    GST_MINI_OBJECT (mem)->dispose = gst_va_memory_release;
+  g_atomic_int_inc (&self->surface_count);
-    g_atomic_int_inc (&self->surface_count);
-  }
 
   GST_LOG_OBJECT (self, "Created surface %#x [%dx%d]", mem->surface,
       GST_VIDEO_INFO_WIDTH (&self->info), GST_VIDEO_INFO_HEIGHT (&self->info));
@@ -1285,12 +1255,6 @@ gst_va_allocator_alloc_full (GstAllocator * allocator, GstVideoInfo * info)
   return GST_MEMORY_CAST (mem);
 }
 
-GstMemory *
-gst_va_allocator_alloc (GstAllocator * allocator)
-{
-  return gst_va_allocator_alloc_full (allocator, NULL);
-}
-
 GstAllocator *
 gst_va_allocator_new (GstVaDisplay * display, GArray * surface_formats)
 {
@@ -1344,9 +1308,7 @@ gst_va_allocator_flush (GstAllocator * allocator)
 static gboolean
 gst_va_allocator_try (GstAllocator * allocator)
 {
-  GstMemory *mem;
   GstVaAllocator *self = GST_VA_ALLOCATOR (allocator);
-  GstVideoInfo info = self->info;
 
   self->fourcc = 0;
   self->rt_format = 0;
@@ -1371,12 +1333,10 @@ gst_va_allocator_try (GstAllocator * allocator)
     return FALSE;
   }
 
-  mem = gst_va_allocator_alloc_full (allocator, &info);
+  if (!_update_image_info (self)) {
-  if (!mem)
+    GST_ERROR_OBJECT (allocator, "Failed to update allocator info");
     return FALSE;
-  gst_memory_unref (mem);
+  }
-
-  self->info = info;
 
   GST_INFO_OBJECT (self,
       "va allocator info, surface format: %s, image format: %s, "