New enum ScalabilityMode.

Used instead of string representation in lower-levels of encoder configuration, to avoid string comparisons (with risk of misspelling) in lots of places.

Bug: webrtc:11607
Change-Id: I4d51c2265aac297c29976d2aa601d8ffb33b7326
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/259870
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Florent Castelli <orphis@webrtc.org>
Reviewed-by: Åsa Persson <asapersson@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#36706}

modules/video_coding/svc/scalability_mode_util.cc

@@ -0,0 +1,96 @@
+/*
+ *  Copyright (c) 2022 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "modules/video_coding/svc/scalability_mode_util.h"
+
+#include "absl/strings/string_view.h"
+#include "absl/types/optional.h"
+#include "api/video_codecs/scalability_mode.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+absl::optional<ScalabilityMode> ScalabilityModeFromString(
+    absl::string_view mode_string) {
+  if (mode_string == "L1T1")
+    return ScalabilityMode::kL1T1;
+  if (mode_string == "L1T2")
+    return ScalabilityMode::kL1T2;
+  if (mode_string == "L1T3")
+    return ScalabilityMode::kL1T3;
+
+  if (mode_string == "L2T1")
+    return ScalabilityMode::kL2T1;
+  if (mode_string == "L2T1h")
+    return ScalabilityMode::kL2T1h;
+  if (mode_string == "L2T1_KEY")
+    return ScalabilityMode::kL2T1_KEY;
+
+  if (mode_string == "L2T2")
+    return ScalabilityMode::kL2T2;
+  if (mode_string == "L2T2_KEY")
+    return ScalabilityMode::kL2T2_KEY;
+  if (mode_string == "L2T2_KEY_SHIFT")
+    return ScalabilityMode::kL2T2_KEY_SHIFT;
+  if (mode_string == "L2T3_KEY")
+    return ScalabilityMode::kL2T3_KEY;
+
+  if (mode_string == "L3T1")
+    return ScalabilityMode::kL3T1;
+  if (mode_string == "L3T3")
+    return ScalabilityMode::kL3T3;
+  if (mode_string == "L3T3_KEY")
+    return ScalabilityMode::kL3T3_KEY;
+
+  if (mode_string == "S2T1")
+    return ScalabilityMode::kS2T1;
+  if (mode_string == "S3T3")
+    return ScalabilityMode::kS3T3;
+
+  return absl::nullopt;
+}
+
+absl::string_view ScalabilityModeToString(ScalabilityMode scalability_mode) {
+  switch (scalability_mode) {
+    case ScalabilityMode::kL1T1:
+      return "L1T1";
+    case ScalabilityMode::kL1T2:
+      return "L1T2";
+    case ScalabilityMode::kL1T3:
+      return "L1T3";
+    case ScalabilityMode::kL2T1:
+      return "L2T1";
+    case ScalabilityMode::kL2T1h:
+      return "L2T1h";
+    case ScalabilityMode::kL2T1_KEY:
+      return "L2T1_KEY";
+    case ScalabilityMode::kL2T2:
+      return "L2T2";
+    case ScalabilityMode::kL2T2_KEY:
+      return "L2T2_KEY";
+    case ScalabilityMode::kL2T2_KEY_SHIFT:
+      return "L2T2_KEY_SHIFT";
+    case ScalabilityMode::kL2T3_KEY:
+      return "L2T3_KEY";
+    case ScalabilityMode::kL3T1:
+      return "L3T1";
+    case ScalabilityMode::kL3T3:
+      return "L3T3";
+    case ScalabilityMode::kL3T3_KEY:
+      return "L3T3_KEY";
+    case ScalabilityMode::kS2T1:
+      return "S2T1";
+    case ScalabilityMode::kS3T3:
+      return "S3T3";
+  }
+  RTC_CHECK_NOTREACHED();
+}
+
+}  // namespace webrtc