Adding some AV1 constants and helper functions

I've added a basic AV1 impl to Chrome Remote Desktop and am looking into
what is needed to test with I444 (Profile-1) in our platform. This CL
adds a few helper functions, constants, and enums that can be used to
configure the SDP with different AV1 profiles. More work is still needed
but I wanted to get this in place first so I can build on it in the CRD
host code.

Change-Id: I1af9ebf31f833138e8c36e0c0a30e32289e7b58e
Bug: chromium:1329660
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/264000
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Commit-Queue: Joe Downing <joedow@google.com>
Cr-Commit-Position: refs/heads/main@{#37182}

api/video_codecs/BUILD.gn

@@ -19,6 +19,8 @@ rtc_source_set("scalability_mode") {
 rtc_library("video_codecs_api") {
   visibility = [ "*" ]
   sources = [
+    "av1_profile.cc",
+    "av1_profile.h",
     "h264_profile_level_id.cc",
     "h264_profile_level_id.h",
     "sdp_video_format.cc",

api/video_codecs/av1_profile.cc

@@ -0,0 +1,69 @@
+/*
+ *  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 "api/video_codecs/av1_profile.h"
+
+#include <map>
+#include <utility>
+
+#include "rtc_base/string_to_number.h"
+
+namespace webrtc {
+
+// Parameter name in the format parameter map for AV1 video.
+const char kAV1FmtpProfile[] = "profile";
+
+absl::string_view AV1ProfileToString(AV1Profile profile) {
+  switch (profile) {
+    case AV1Profile::kProfile0:
+      return "0";
+    case AV1Profile::kProfile1:
+      return "1";
+    case AV1Profile::kProfile2:
+      return "2";
+  }
+  return "0";
+}
+
+absl::optional<AV1Profile> StringToAV1Profile(absl::string_view str) {
+  const absl::optional<int> i = rtc::StringToNumber<int>(str);
+  if (!i.has_value())
+    return absl::nullopt;
+
+  switch (i.value()) {
+    case 0:
+      return AV1Profile::kProfile0;
+    case 1:
+      return AV1Profile::kProfile1;
+    case 2:
+      return AV1Profile::kProfile2;
+    default:
+      return absl::nullopt;
+  }
+}
+
+absl::optional<AV1Profile> ParseSdpForAV1Profile(
+    const SdpVideoFormat::Parameters& params) {
+  const auto profile_it = params.find(kAV1FmtpProfile);
+  if (profile_it == params.end())
+    return AV1Profile::kProfile0;
+  const std::string& profile_str = profile_it->second;
+  return StringToAV1Profile(profile_str);
+}
+
+bool AV1IsSameProfile(const SdpVideoFormat::Parameters& params1,
+                      const SdpVideoFormat::Parameters& params2) {
+  const absl::optional<AV1Profile> profile = ParseSdpForAV1Profile(params1);
+  const absl::optional<AV1Profile> other_profile =
+      ParseSdpForAV1Profile(params2);
+  return profile && other_profile && profile == other_profile;
+}
+
+}  // namespace webrtc

api/video_codecs/av1_profile.h

@@ -0,0 +1,57 @@
+/*
+ *  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.
+ */
+
+#ifndef API_VIDEO_CODECS_AV1_PROFILE_H_
+#define API_VIDEO_CODECS_AV1_PROFILE_H_
+
+#include <string>
+
+#include "absl/strings/string_view.h"
+#include "absl/types/optional.h"
+#include "api/video_codecs/sdp_video_format.h"
+#include "rtc_base/system/rtc_export.h"
+
+namespace webrtc {
+
+// Profile information for AV1 video.
+extern RTC_EXPORT const char kAV1FmtpProfile[];
+
+// Profiles can be found at:
+// https://aomedia.org/av1/specification/annex-a/#profiles
+// The enum values match the number specified in the SDP.
+enum class AV1Profile {
+  kProfile0 = 0,
+  kProfile1 = 1,
+  kProfile2 = 2,
+};
+
+// Helper function which converts an AV1Profile to std::string. Returns "0" if
+// an unknown value is passed in.
+RTC_EXPORT absl::string_view AV1ProfileToString(AV1Profile profile);
+
+// Helper function which converts a std::string to AV1Profile. Returns null if
+// |profile| is not a valid profile string.
+absl::optional<AV1Profile> StringToAV1Profile(absl::string_view profile);
+
+// Parses an SDP key-value map of format parameters to retrive an AV1 profile.
+// Returns an AV1Profile if one has been specified, `kProfile0` if no profile is
+// specified and an empty value if the profile key is present but contains an
+// invalid value.
+RTC_EXPORT absl::optional<AV1Profile> ParseSdpForAV1Profile(
+    const SdpVideoFormat::Parameters& params);
+
+// Returns true if the parameters have the same AV1 profile or neither contains
+// an AV1 profile, otherwise false.
+bool AV1IsSameProfile(const SdpVideoFormat::Parameters& params1,
+                      const SdpVideoFormat::Parameters& params2);
+
+}  // namespace webrtc
+
+#endif  // API_VIDEO_CODECS_AV1_PROFILE_H_

api/video_codecs/sdp_video_format.cc

@@ -11,6 +11,7 @@
 #include "api/video_codecs/sdp_video_format.h"
 
 #include "absl/strings/match.h"
+#include "api/video_codecs/av1_profile.h"
 #include "api/video_codecs/h264_profile_level_id.h"
 #include "api/video_codecs/video_codec.h"
 #include "api/video_codecs/vp9_profile.h"
@@ -55,6 +56,8 @@ bool IsSameCodecSpecific(const SdpVideoFormat& format1,
                                          format2.parameters);
     case kVideoCodecVP9:
       return VP9IsSameProfile(format1.parameters, format2.parameters);
+    case kVideoCodecAV1:
+      return AV1IsSameProfile(format1.parameters, format2.parameters);
     default:
       return true;
   }

api/video_codecs/test/sdp_video_format_unittest.cc

@@ -23,14 +23,14 @@ typedef SdpVideoFormat::Parameters Params;
 TEST(SdpVideoFormatTest, SameCodecNameNoParameters) {
   EXPECT_TRUE(Sdp("H264").IsSameCodec(Sdp("h264")));
   EXPECT_TRUE(Sdp("VP8").IsSameCodec(Sdp("vp8")));
-  EXPECT_TRUE(Sdp("Vp9").IsSameCodec(Sdp("vp9")));
+  EXPECT_TRUE(Sdp("VP9").IsSameCodec(Sdp("vp9")));
   EXPECT_TRUE(Sdp("AV1").IsSameCodec(Sdp("Av1")));
 }
 
 TEST(SdpVideoFormatTest, DifferentCodecNameNoParameters) {
   EXPECT_FALSE(Sdp("H264").IsSameCodec(Sdp("VP8")));
   EXPECT_FALSE(Sdp("VP8").IsSameCodec(Sdp("VP9")));
-  EXPECT_FALSE(Sdp("AV1").IsSameCodec(Sdp("")));
+  EXPECT_FALSE(Sdp("AV1").IsSameCodec(Sdp("VP8")));
 }
 
 TEST(SdpVideoFormatTest, SameCodecNameSameParameters) {
@@ -45,6 +45,11 @@ TEST(SdpVideoFormatTest, SameCodecNameSameParameters) {
   EXPECT_TRUE(
       Sdp("H264", Params{{"profile-level-id", "640c34"}})
           .IsSameCodec(Sdp("H264", Params{{"profile-level-id", "640c34"}})));
+  EXPECT_TRUE(Sdp("AV1").IsSameCodec(Sdp("AV1", Params{{"profile", "0"}})));
+  EXPECT_TRUE(Sdp("AV1", Params{{"profile", "0"}})
+                  .IsSameCodec(Sdp("AV1", Params{{"profile", "0"}})));
+  EXPECT_TRUE(Sdp("AV1", Params{{"profile", "2"}})
+                  .IsSameCodec(Sdp("AV1", Params{{"profile", "2"}})));
 }
 
 TEST(SdpVideoFormatTest, SameCodecNameDifferentParameters) {
@@ -59,6 +64,11 @@ TEST(SdpVideoFormatTest, SameCodecNameDifferentParameters) {
   EXPECT_FALSE(
       Sdp("H264", Params{{"profile-level-id", "640c34"}})
           .IsSameCodec(Sdp("H264", Params{{"profile-level-id", "42f00b"}})));
+  EXPECT_FALSE(Sdp("AV1").IsSameCodec(Sdp("AV1", Params{{"profile", "1"}})));
+  EXPECT_FALSE(Sdp("AV1", Params{{"profile", "0"}})
+                   .IsSameCodec(Sdp("AV1", Params{{"profile", "1"}})));
+  EXPECT_FALSE(Sdp("AV1", Params{{"profile", "1"}})
+                   .IsSameCodec(Sdp("AV1", Params{{"profile", "2"}})));
 }
 
 TEST(SdpVideoFormatTest, DifferentCodecNameSameParameters) {
@@ -72,6 +82,10 @@ TEST(SdpVideoFormatTest, DifferentCodecNameSameParameters) {
   EXPECT_FALSE(
       Sdp("H264", Params{{"profile-level-id", "640c34"}})
           .IsSameCodec(Sdp("VP8", Params{{"profile-level-id", "640c34"}})));
+  EXPECT_FALSE(Sdp("AV1", Params{{"profile", "0"}})
+                   .IsSameCodec(Sdp("H264", Params{{"profile", "0"}})));
+  EXPECT_FALSE(Sdp("AV1", Params{{"profile", "2"}})
+                   .IsSameCodec(Sdp("VP9", Params{{"profile", "2"}})));
 }
 
 TEST(SdpVideoFormatTest, H264PacketizationMode) {