video-format: add gst_video_format_info_component()

New API to find out which components are packed in a given plane.
Will prevent us from assuming a 1-1 mapping between planes and
components.

diff --git a/gst-libs/gst/video/video-format.c b/gst-libs/gst/video/video-format.c
index 7da1a51..8cefee1 100644 (file)
--- a/gst-libs/gst/video/video-format.c
+++ b/gst-libs/gst/video/video-format.c
@@ -6101,3 +6101,33 @@ gst_video_format_get_palette (GstVideoFormat format, gsize * size)
       return NULL;
   }
 }
+
+/**
+ * gst_video_format_info_component:
+ * @info: #GstVideoFormatInfo
+ * @plane: a plane number
+ * @components: (out): array used to store component numbers
+ *
+ * Fill @components with the number of all the components packed in plane @p
+ * for the format @info. A value of -1 in @components indicates that no more
+ * components are packed in the plane.
+ *
+ * Since: 1.18
+ */
+void
+gst_video_format_info_component (const GstVideoFormatInfo * info, guint plane,
+    gint components[GST_VIDEO_MAX_COMPONENTS])
+{
+  guint c, i = 0;
+
+  /* Reverse mapping of info->plane */
+  for (c = 0; c < GST_VIDEO_FORMAT_INFO_N_COMPONENTS (info); c++) {
+    if (GST_VIDEO_FORMAT_INFO_PLANE (info, c) == plane) {
+      components[i] = c;
+      i++;
+    }
+  }
+
+  for (c = i; c < GST_VIDEO_MAX_COMPONENTS; c++)
+    components[c] = -1;
+}

diff --git a/gst-libs/gst/video/video-format.h b/gst-libs/gst/video/video-format.h
index 4ab1604..48f0b5f 100644 (file)
--- a/gst-libs/gst/video/video-format.h
+++ b/gst-libs/gst/video/video-format.h
@@ -518,6 +518,9 @@ struct _GstVideoFormatInfo {
 #define GST_VIDEO_FORMAT_INFO_TILE_WS(info) ((info)->tile_ws)
 #define GST_VIDEO_FORMAT_INFO_TILE_HS(info) ((info)->tile_hs)
 
+GST_VIDEO_API
+void gst_video_format_info_component                  (const GstVideoFormatInfo *info, guint plane, gint components[GST_VIDEO_MAX_COMPONENTS]);
+
 /* format properties */
 
 GST_VIDEO_API

diff --git a/tests/check/libs/video.c b/tests/check/libs/video.c
index 391f845..7b901a6 100644 (file)
--- a/tests/check/libs/video.c
+++ b/tests/check/libs/video.c
@@ -3214,6 +3214,95 @@ GST_START_TEST (test_video_color_from_to_iso)
 
 GST_END_TEST;
 
+GST_START_TEST (test_video_format_info_plane_to_components)
+{
+  const GstVideoFormatInfo *info;
+  gint comps[GST_VIDEO_MAX_COMPONENTS];
+
+  /* RGB: 1 plane, 3 components */
+  info = gst_video_format_get_info (GST_VIDEO_FORMAT_RGB);
+
+  gst_video_format_info_component (info, 0, comps);
+  g_assert_cmpint (comps[0], ==, 0);
+  g_assert_cmpint (comps[1], ==, 1);
+  g_assert_cmpint (comps[2], ==, 2);
+  g_assert_cmpint (comps[3], ==, -1);
+
+  gst_video_format_info_component (info, 1, comps);
+  g_assert_cmpint (comps[0], ==, -1);
+  g_assert_cmpint (comps[1], ==, -1);
+  g_assert_cmpint (comps[2], ==, -1);
+  g_assert_cmpint (comps[3], ==, -1);
+
+  gst_video_format_info_component (info, 2, comps);
+  g_assert_cmpint (comps[0], ==, -1);
+  g_assert_cmpint (comps[1], ==, -1);
+  g_assert_cmpint (comps[2], ==, -1);
+  g_assert_cmpint (comps[3], ==, -1);
+
+  gst_video_format_info_component (info, 3, comps);
+  g_assert_cmpint (comps[0], ==, -1);
+  g_assert_cmpint (comps[1], ==, -1);
+  g_assert_cmpint (comps[2], ==, -1);
+  g_assert_cmpint (comps[3], ==, -1);
+
+  /* I420: 3 planes, 3 components */
+  info = gst_video_format_get_info (GST_VIDEO_FORMAT_I420);
+
+  gst_video_format_info_component (info, 0, comps);
+  g_assert_cmpint (comps[0], ==, 0);
+  g_assert_cmpint (comps[1], ==, -1);
+  g_assert_cmpint (comps[2], ==, -1);
+  g_assert_cmpint (comps[3], ==, -1);
+
+  gst_video_format_info_component (info, 1, comps);
+  g_assert_cmpint (comps[0], ==, 1);
+  g_assert_cmpint (comps[1], ==, -1);
+  g_assert_cmpint (comps[2], ==, -1);
+  g_assert_cmpint (comps[3], ==, -1);
+
+  gst_video_format_info_component (info, 2, comps);
+  g_assert_cmpint (comps[0], ==, 2);
+  g_assert_cmpint (comps[1], ==, -1);
+  g_assert_cmpint (comps[2], ==, -1);
+  g_assert_cmpint (comps[3], ==, -1);
+
+  gst_video_format_info_component (info, 3, comps);
+  g_assert_cmpint (comps[0], ==, -1);
+  g_assert_cmpint (comps[1], ==, -1);
+  g_assert_cmpint (comps[2], ==, -1);
+  g_assert_cmpint (comps[3], ==, -1);
+
+  /* NV12: 2 planes, 3 components */
+  info = gst_video_format_get_info (GST_VIDEO_FORMAT_NV12);
+
+  gst_video_format_info_component (info, 0, comps);
+  g_assert_cmpint (comps[0], ==, 0);
+  g_assert_cmpint (comps[1], ==, -1);
+  g_assert_cmpint (comps[2], ==, -1);
+  g_assert_cmpint (comps[3], ==, -1);
+
+  gst_video_format_info_component (info, 1, comps);
+  g_assert_cmpint (comps[0], ==, 1);
+  g_assert_cmpint (comps[1], ==, 2);
+  g_assert_cmpint (comps[2], ==, -1);
+  g_assert_cmpint (comps[3], ==, -1);
+
+  gst_video_format_info_component (info, 2, comps);
+  g_assert_cmpint (comps[0], ==, -1);
+  g_assert_cmpint (comps[1], ==, -1);
+  g_assert_cmpint (comps[2], ==, -1);
+  g_assert_cmpint (comps[3], ==, -1);
+
+  gst_video_format_info_component (info, 3, comps);
+  g_assert_cmpint (comps[0], ==, -1);
+  g_assert_cmpint (comps[1], ==, -1);
+  g_assert_cmpint (comps[2], ==, -1);
+  g_assert_cmpint (comps[3], ==, -1);
+}
+
+GST_END_TEST;
+
 static Suite *
 video_suite (void)
 {
@@ -3261,6 +3350,7 @@ video_suite (void)
   tcase_add_test (tc_chain, test_video_formats_pstrides);
   tcase_add_test (tc_chain, test_hdr);
   tcase_add_test (tc_chain, test_video_color_from_to_iso);
+  tcase_add_test (tc_chain, test_video_format_info_plane_to_components);
 
   return s;
 }