Makes a second (final) validation stats update (#497)

If multiple GOPs are validated and the validation started
being out of sync, but sync was established, the first GOP
should no longer be ignored. Therefore, perform a final
stats update after having looped through the GOPs.

Co-authored-by: bjornvolcker <[email protected]>

Author: bjornvolcker

lib/src/sv_auth.c

@@ -1179,6 +1179,7 @@ maybe_validate_gop(signed_video_t *self, bu_info_t *bu)
     int max_loop = 10;
     bool update_validation_status = false;
     bool public_key_has_changed = false;
+    bool start_sei_in_sync = validation_flags->sei_in_sync;
     char sei_validation_status = 'U';
     // Keep validating as long as there are pending GOPs.
     bool stop_validating = false;
@@ -1249,6 +1250,36 @@ maybe_validate_gop(signed_video_t *self, bu_info_t *bu)
       DEBUG_LOG("Validation aborted after reaching max number of loops");
     }
 
+    if (start_sei_in_sync != validation_flags->sei_in_sync) {
+      // Some partial GOPs may have been discarded due to being out of sync at that time
+      // because they were in fact correctly invalid. Get stats another time and update
+      // |latest->authenticity|.
+      SignedVideoAuthenticityResult valid = SV_AUTH_RESULT_NOT_OK;
+      int num_invalid;
+      int num_missed;
+      bu_list_get_stats(self->bu_list, NULL, &num_invalid, &num_missed);
+      DEBUG_LOG("Number of invalid Bitstream Units = %d.", num_invalid);
+      DEBUG_LOG("Number of missed Bitstream Units  = %d.", num_missed);
+
+      valid = (num_invalid > 0) ? SV_AUTH_RESULT_NOT_OK : SV_AUTH_RESULT_OK;
+
+      // Determine if this GOP is valid, but has missing information. This happens if we have
+      // detected missed BUs or if the GOP is incomplete.
+      if (valid == SV_AUTH_RESULT_OK && (num_missed > 0)) {
+        valid = SV_AUTH_RESULT_OK_WITH_MISSING_INFO;
+      }
+      // Update |latest_validation| with the validation result.
+      if (latest->authenticity <= SV_AUTH_RESULT_SIGNATURE_PRESENT) {
+        // Still either pending validation or video has no signature. Update with the current
+        // result.
+        latest->authenticity = valid;
+      } else if (valid < latest->authenticity) {
+        // Current GOP validated a worse authenticity compared to what has been validated so
+        // far. Update with this worse result, since that is what should rule the total
+        // validation.
+        latest->authenticity = valid;
+      }
+    }
     SV_THROW(bu_list_update_status(bu_list, update_validation_status));
     if (validation_flags->is_first_validation) {
       update_sei_in_validation(self, false, NULL, &sei_validation_status);

tests/check/check_signed_video_auth.c

@@ -524,14 +524,9 @@ START_TEST(modify_one_p_frame)
     //         ISPPIS                      ....P.      (  valid, 1 pending)
     //                                                           6 pending
     //             ISP                         P.P     (invalid, 3 pending)
-    expected.valid_gops = 2;  // 1;
-    expected.invalid_gops = 0;
+    expected.valid_gops = 1;
     expected.pending_bu = 6;
     expected.has_signature = 1;
-    // Temporary stats
-    expected.valid_gops_with_missing_info = 0;
-    expected.missed_bu = 0;
-    final_validation.authenticity = SV_AUTH_RESULT_OK;
   }
   validate_stream(NULL, list, expected, true);