h264parse: expose compatible profiles to downstream

Some video bitstreams report a too restrictive set of profiles. If a video
decoder was to strictly follow the indicated profile, it wouldn't support that
stream, whereas it could in theory and in practice. So we should relax the
profile restriction for allowing the decoder to get connected with parser.

https://bugzilla.gnome.org/show_bug.cgi?id=739992

diff --git a/gst/videoparsers/gsth264parse.c b/gst/videoparsers/gsth264parse.c
index db8e909..5517866 100644 (file)
--- a/gst/videoparsers/gsth264parse.c
+++ b/gst/videoparsers/gsth264parse.c
@@ -1197,6 +1197,176 @@ gst_h264_parse_get_par (GstH264Parse * h264parse, gint * num, gint * den)
   }
 }
 
+static GstCaps *
+get_compatible_profile_caps (GstH264SPS * sps)
+{
+  GstCaps *caps = NULL;
+  const gchar **profiles = NULL;
+  gint i;
+  GValue compat_profiles = G_VALUE_INIT;
+  g_value_init (&compat_profiles, GST_TYPE_LIST);
+
+  switch (sps->profile_idc) {
+    case GST_H264_PROFILE_EXTENDED:
+      if (sps->constraint_set0_flag) {  /* A.2.1 */
+        if (sps->constraint_set1_flag) {
+          static const gchar *profile_array[] =
+              { "constrained-baseline", "baseline", "main", "high",
+            "high-10", "high-4:2:2", "high-4:4:4", NULL
+          };
+          profiles = profile_array;
+        } else {
+          static const gchar *profile_array[] = { "baseline", NULL };
+          profiles = profile_array;
+        }
+      } else if (sps->constraint_set1_flag) {   /* A.2.2 */
+        static const gchar *profile_array[] =
+            { "main", "high", "high-10", "high-4:2:2", "high-4:4:4", NULL };
+        profiles = profile_array;
+      }
+      break;
+    case GST_H264_PROFILE_BASELINE:
+      if (sps->constraint_set1_flag) {  /* A.2.1 */
+        static const gchar *profile_array[] =
+            { "constrained-baseline", "main", "high", "high-10", "high-4:2:2",
+          "high-4:4:4", NULL
+        };
+        profiles = profile_array;
+      } else {
+        static const gchar *profile_array[] = { "extended", NULL };
+        profiles = profile_array;
+      }
+      break;
+    case GST_H264_PROFILE_MAIN:
+    {
+      static const gchar *profile_array[] =
+          { "high", "high-10", "high-4:2:2", "high-4:4:4", NULL };
+      profiles = profile_array;
+    }
+      break;
+    case GST_H264_PROFILE_HIGH:
+      if (sps->constraint_set1_flag) {
+        static const gchar *profile_array[] =
+            { "main", "high-10", "high-4:2:2", "high-4:4:4", NULL };
+        profiles = profile_array;
+      } else {
+        static const gchar *profile_array[] =
+            { "high-10", "high-4:2:2", "high-4:4:4", NULL };
+        profiles = profile_array;
+      }
+      break;
+    case GST_H264_PROFILE_HIGH10:
+      if (sps->constraint_set1_flag) {
+        static const gchar *profile_array[] =
+            { "main", "high", "high-4:2:2", "high-4:4:4", NULL };
+        profiles = profile_array;
+      } else {
+        if (sps->constraint_set3_flag) {        /* A.2.8 */
+          static const gchar *profile_array[] =
+              { "high-10", "high-4:2:2", "high-4:4:4", "high-4:2:2-intra",
+            "high-4:4:4-intra", NULL
+          };
+          profiles = profile_array;
+        } else {
+          static const gchar *profile_array[] =
+              { "high-4:2:2", "high-4:4:4", NULL };
+          profiles = profile_array;
+        }
+      }
+      break;
+    case GST_H264_PROFILE_HIGH_422:
+      if (sps->constraint_set1_flag) {
+        static const gchar *profile_array[] =
+            { "main", "high", "high-10", "high-4:4:4", NULL };
+        profiles = profile_array;
+      } else {
+        if (sps->constraint_set3_flag) {        /* A.2.9 */
+          static const gchar *profile_array[] =
+              { "high-4:2:2", "high-4:4:4", "high-4:4:4-intra", NULL };
+          profiles = profile_array;
+        } else {
+          static const gchar *profile_array[] = { "high-4:4:4", NULL };
+          profiles = profile_array;
+        }
+      }
+      break;
+    case GST_H264_PROFILE_HIGH_444:
+      if (sps->constraint_set1_flag) {
+        static const gchar *profile_array[] =
+            { "main", "high", "high-10", "high-4:2:2", NULL };
+        profiles = profile_array;
+      } else if (sps->constraint_set3_flag) {   /* A.2.10 */
+        static const gchar *profile_array[] = { "high-4:4:4", NULL };
+        profiles = profile_array;
+      }
+      break;
+    case GST_H264_PROFILE_MULTIVIEW_HIGH:
+      /* Fix: should add GST_H264_PROFILE_STEREO_HIGH as compatible
+       * profile if number of views == 2. */
+      break;
+    default:
+      break;
+  }
+
+  if (profiles) {
+    GValue value = G_VALUE_INIT;
+    caps = gst_caps_new_empty_simple ("video/x-h264");
+    for (i = 0; profiles[i]; i++) {
+      g_value_init (&value, G_TYPE_STRING);
+      g_value_set_string (&value, profiles[i]);
+      gst_value_list_append_value (&compat_profiles, &value);
+      g_value_unset (&value);
+    }
+    gst_caps_set_value (caps, "profile", &compat_profiles);
+    g_value_unset (&compat_profiles);
+  }
+
+  return caps;
+}
+
+/* if downstream didn't support the exact profile indicated in sps header,
+ * check for the compatible profiles also */
+static void
+ensure_caps_profile (GstH264Parse * h264parse, GstCaps * caps, GstH264SPS * sps)
+{
+  GstCaps *filter_caps, *peer_caps, *compat_caps;
+
+  filter_caps = gst_caps_new_empty_simple ("video/x-h264");
+  peer_caps =
+      gst_pad_peer_query_caps (GST_BASE_PARSE_SRC_PAD (h264parse), filter_caps);
+
+  if (peer_caps && !gst_caps_can_intersect (caps, peer_caps)) {
+    GstStructure *structure;
+
+    compat_caps = get_compatible_profile_caps (sps);
+    if (compat_caps != NULL) {
+      GstCaps *res_caps = NULL;
+
+      res_caps = gst_caps_intersect (peer_caps, compat_caps);
+
+      if (res_caps && !gst_caps_is_empty (res_caps)) {
+        const gchar *profile_str = NULL;
+
+        res_caps = gst_caps_fixate (res_caps);
+        structure = gst_caps_get_structure (res_caps, 0);
+        profile_str = gst_structure_get_string (structure, "profile");
+        if (profile_str) {
+          gst_caps_set_simple (caps, "profile", G_TYPE_STRING, profile_str,
+              NULL);
+          GST_DEBUG_OBJECT (h264parse,
+              "Setting compatible profile %s to the caps", profile_str);
+        }
+      }
+      if (res_caps)
+        gst_caps_unref (res_caps);
+      gst_caps_unref (compat_caps);
+    }
+  }
+  if (peer_caps)
+    gst_caps_unref (peer_caps);
+  gst_caps_unref (filter_caps);
+}
+
 static void
 gst_h264_parse_update_src_caps (GstH264Parse * h264parse, GstCaps * caps)
 {
@@ -1364,6 +1534,8 @@ gst_h264_parse_update_src_caps (GstH264Parse * h264parse, GstCaps * caps)
         gst_codec_utils_h264_caps_set_level_and_profile (caps,
             map.data + 1, map.size - 1);
         gst_buffer_unmap (sps_buf, &map);
+        /* relax the profile constraint to find a suitable decoder */
+        ensure_caps_profile (h264parse, caps, sps);
       }
     }