Add support for two-byte RTP header extensions to UsedRtpHeaderExtensionIds
Bug: webrtc:9985
Change-Id: I4c736cb920d1ac03e43c98a81218f037feebcd97
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/139601
Reviewed-by: Steve Anton <steveanton@webrtc.org>
Commit-Queue: Johannes Kron <kron@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28346}
diff --git a/pc/BUILD.gn b/pc/BUILD.gn
index c46d758..2458cc5 100644
--- a/pc/BUILD.gn
+++ b/pc/BUILD.gn
@@ -71,6 +71,7 @@
"srtp_transport.h",
"transport_stats.cc",
"transport_stats.h",
+ "used_ids.h",
]
deps = [
@@ -276,6 +277,7 @@
"srtp_transport_unittest.cc",
"test/rtp_transport_test_util.h",
"test/srtp_test_util.h",
+ "used_ids_unittest.cc",
]
include_dirs = [ "//third_party/libsrtp/srtp" ]
diff --git a/pc/media_session.cc b/pc/media_session.cc
index 745a1ac..fff2a40 100644
--- a/pc/media_session.cc
+++ b/pc/media_session.cc
@@ -31,6 +31,7 @@
#include "pc/media_protocol_names.h"
#include "pc/rtp_media_utils.h"
#include "pc/srtp_filter.h"
+#include "pc/used_ids.h"
#include "rtc_base/checks.h"
#include "rtc_base/helpers.h"
#include "rtc_base/logging.h"
@@ -281,94 +282,6 @@
codecs->end());
}
-template <typename IdStruct>
-class UsedIds {
- public:
- UsedIds(int min_allowed_id, int max_allowed_id)
- : min_allowed_id_(min_allowed_id),
- max_allowed_id_(max_allowed_id),
- next_id_(max_allowed_id) {}
-
- // Loops through all Id in |ids| and changes its id if it is
- // already in use by another IdStruct. Call this methods with all Id
- // in a session description to make sure no duplicate ids exists.
- // Note that typename Id must be a type of IdStruct.
- template <typename Id>
- void FindAndSetIdUsed(std::vector<Id>* ids) {
- for (const Id& id : *ids) {
- FindAndSetIdUsed(&id);
- }
- }
-
- // Finds and sets an unused id if the |idstruct| id is already in use.
- void FindAndSetIdUsed(IdStruct* idstruct) {
- const int original_id = idstruct->id;
- int new_id = idstruct->id;
-
- if (original_id > max_allowed_id_ || original_id < min_allowed_id_) {
- // If the original id is not in range - this is an id that can't be
- // dynamically changed.
- return;
- }
-
- if (IsIdUsed(original_id)) {
- new_id = FindUnusedId();
- RTC_LOG(LS_WARNING) << "Duplicate id found. Reassigning from "
- << original_id << " to " << new_id;
- idstruct->id = new_id;
- }
- SetIdUsed(new_id);
- }
-
- private:
- // Returns the first unused id in reverse order.
- // This hopefully reduce the risk of more collisions. We want to change the
- // default ids as little as possible.
- int FindUnusedId() {
- while (IsIdUsed(next_id_) && next_id_ >= min_allowed_id_) {
- --next_id_;
- }
- RTC_DCHECK(next_id_ >= min_allowed_id_);
- return next_id_;
- }
-
- bool IsIdUsed(int new_id) { return id_set_.find(new_id) != id_set_.end(); }
-
- void SetIdUsed(int new_id) { id_set_.insert(new_id); }
-
- const int min_allowed_id_;
- const int max_allowed_id_;
- int next_id_;
- std::set<int> id_set_;
-};
-
-// Helper class used for finding duplicate RTP payload types among audio, video
-// and data codecs. When bundle is used the payload types may not collide.
-class UsedPayloadTypes : public UsedIds<Codec> {
- public:
- UsedPayloadTypes()
- : UsedIds<Codec>(kDynamicPayloadTypeMin, kDynamicPayloadTypeMax) {}
-
- private:
- static const int kDynamicPayloadTypeMin = 96;
- static const int kDynamicPayloadTypeMax = 127;
-};
-
-// Helper class used for finding duplicate RTP Header extension ids among
-// audio and video extensions. Only applies to one-byte header extensions at the
-// moment. ids > 14 will always be reported as available.
-// TODO(kron): This class needs to be refactored when we start to send two-byte
-// header extensions.
-class UsedRtpHeaderExtensionIds : public UsedIds<webrtc::RtpExtension> {
- public:
- UsedRtpHeaderExtensionIds()
- : UsedIds<webrtc::RtpExtension>(
- webrtc::RtpExtension::kMinId,
- webrtc::RtpExtension::kOneByteHeaderExtensionMaxId) {}
-
- private:
-};
-
static StreamParams CreateStreamParamsForNewSenderWithSsrcs(
const SenderOptions& sender,
const std::string& rtcp_cname,
@@ -1512,8 +1425,9 @@
RtpHeaderExtensions audio_rtp_extensions;
RtpHeaderExtensions video_rtp_extensions;
- GetRtpHdrExtsToOffer(current_active_contents, &audio_rtp_extensions,
- &video_rtp_extensions);
+ GetRtpHdrExtsToOffer(current_active_contents,
+ session_options.offer_extmap_allow_mixed,
+ &audio_rtp_extensions, &video_rtp_extensions);
auto offer = absl::make_unique<SessionDescription>();
@@ -1958,11 +1872,19 @@
void MediaSessionDescriptionFactory::GetRtpHdrExtsToOffer(
const std::vector<const ContentInfo*>& current_active_contents,
+ bool extmap_allow_mixed,
RtpHeaderExtensions* offer_audio_extensions,
RtpHeaderExtensions* offer_video_extensions) const {
// All header extensions allocated from the same range to avoid potential
// issues when using BUNDLE.
- UsedRtpHeaderExtensionIds used_ids;
+
+ // Strictly speaking the SDP attribute extmap_allow_mixed signals that the
+ // receiver supports an RTP stream where one- and two-byte RTP header
+ // extensions are mixed. For backwards compatibility reasons it's used in
+ // WebRTC to signal that two-byte RTP header extensions are supported.
+ UsedRtpHeaderExtensionIds used_ids(
+ extmap_allow_mixed ? UsedRtpHeaderExtensionIds::IdDomain::kTwoByteAllowed
+ : UsedRtpHeaderExtensionIds::IdDomain::kOneByteOnly);
RtpHeaderExtensions all_regular_extensions;
RtpHeaderExtensions all_encrypted_extensions;
diff --git a/pc/media_session.h b/pc/media_session.h
index 7e074cb..1de8ed4 100644
--- a/pc/media_session.h
+++ b/pc/media_session.h
@@ -203,6 +203,7 @@
RtpDataCodecs* rtp_data_codecs) const;
void GetRtpHdrExtsToOffer(
const std::vector<const ContentInfo*>& current_active_contents,
+ bool extmap_allow_mixed,
RtpHeaderExtensions* audio_extensions,
RtpHeaderExtensions* video_extensions) const;
bool AddTransportOffer(const std::string& content_name,
diff --git a/pc/used_ids.h b/pc/used_ids.h
new file mode 100644
index 0000000..78e64ca
--- /dev/null
+++ b/pc/used_ids.h
@@ -0,0 +1,168 @@
+/*
+ * Copyright 2019 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 PC_USED_IDS_H_
+#define PC_USED_IDS_H_
+
+#include <set>
+#include <vector>
+
+#include "api/rtp_parameters.h"
+#include "media/base/codec.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+
+namespace cricket {
+template <typename IdStruct>
+class UsedIds {
+ public:
+ UsedIds(int min_allowed_id, int max_allowed_id)
+ : min_allowed_id_(min_allowed_id),
+ max_allowed_id_(max_allowed_id),
+ next_id_(max_allowed_id) {}
+ virtual ~UsedIds() {}
+
+ // Loops through all Id in |ids| and changes its id if it is
+ // already in use by another IdStruct. Call this methods with all Id
+ // in a session description to make sure no duplicate ids exists.
+ // Note that typename Id must be a type of IdStruct.
+ template <typename Id>
+ void FindAndSetIdUsed(std::vector<Id>* ids) {
+ for (const Id& id : *ids) {
+ FindAndSetIdUsed(&id);
+ }
+ }
+
+ // Finds and sets an unused id if the |idstruct| id is already in use.
+ void FindAndSetIdUsed(IdStruct* idstruct) {
+ const int original_id = idstruct->id;
+ int new_id = idstruct->id;
+
+ if (original_id > max_allowed_id_ || original_id < min_allowed_id_) {
+ // If the original id is not in range - this is an id that can't be
+ // dynamically changed.
+ return;
+ }
+
+ if (IsIdUsed(original_id)) {
+ new_id = FindUnusedId();
+ RTC_LOG(LS_WARNING) << "Duplicate id found. Reassigning from "
+ << original_id << " to " << new_id;
+ idstruct->id = new_id;
+ }
+ SetIdUsed(new_id);
+ }
+
+ protected:
+ bool IsIdUsed(int new_id) { return id_set_.find(new_id) != id_set_.end(); }
+ const int min_allowed_id_;
+ const int max_allowed_id_;
+
+ private:
+ // Returns the first unused id in reverse order.
+ // This hopefully reduces the risk of more collisions. We want to change the
+ // default ids as little as possible. This function is virtual and can be
+ // overriden if the search for unused IDs should follow a specific pattern.
+ virtual int FindUnusedId() {
+ while (IsIdUsed(next_id_) && next_id_ >= min_allowed_id_) {
+ --next_id_;
+ }
+ RTC_DCHECK(next_id_ >= min_allowed_id_);
+ return next_id_;
+ }
+
+ void SetIdUsed(int new_id) {
+ RTC_DCHECK(new_id >= min_allowed_id_);
+ RTC_DCHECK(new_id <= max_allowed_id_);
+ RTC_DCHECK(!IsIdUsed(new_id));
+ id_set_.insert(new_id);
+ }
+ int next_id_;
+ std::set<int> id_set_;
+};
+
+// Helper class used for finding duplicate RTP payload types among audio, video
+// and data codecs. When bundle is used the payload types may not collide.
+class UsedPayloadTypes : public UsedIds<Codec> {
+ public:
+ UsedPayloadTypes()
+ : UsedIds<Codec>(kDynamicPayloadTypeMin, kDynamicPayloadTypeMax) {}
+
+ private:
+ static const int kDynamicPayloadTypeMin = 96;
+ static const int kDynamicPayloadTypeMax = 127;
+};
+
+// Helper class used for finding duplicate RTP Header extension ids among
+// audio and video extensions.
+class UsedRtpHeaderExtensionIds : public UsedIds<webrtc::RtpExtension> {
+ public:
+ enum class IdDomain {
+ // Only allocate IDs that fit in one-byte header extensions.
+ kOneByteOnly,
+ // Prefer to allocate one-byte header extension IDs, but overflow to
+ // two-byte if none are left.
+ kTwoByteAllowed,
+ };
+
+ explicit UsedRtpHeaderExtensionIds(IdDomain id_domain)
+ : UsedIds<webrtc::RtpExtension>(
+ webrtc::RtpExtension::kMinId,
+ id_domain == IdDomain::kTwoByteAllowed
+ ? webrtc::RtpExtension::kMaxId
+ : webrtc::RtpExtension::kOneByteHeaderExtensionMaxId),
+ id_domain_(id_domain),
+ next_extension_id_(webrtc::RtpExtension::kOneByteHeaderExtensionMaxId) {
+ }
+
+ private:
+ // Returns the first unused id in reverse order from the max id of one byte
+ // header extensions. This hopefully reduce the risk of more collisions. We
+ // want to change the default ids as little as possible. If no unused id is
+ // found and two byte header extensions are enabled (i.e.,
+ // |extmap_allow_mixed_| is true), search for unused ids from 15 to 255.
+ int FindUnusedId() override {
+ if (next_extension_id_ <=
+ webrtc::RtpExtension::kOneByteHeaderExtensionMaxId) {
+ // First search in reverse order from the max id of one byte header
+ // extensions.
+ while (IsIdUsed(next_extension_id_) &&
+ next_extension_id_ >= min_allowed_id_) {
+ --next_extension_id_;
+ }
+ }
+
+ if (id_domain_ == IdDomain::kTwoByteAllowed) {
+ if (next_extension_id_ < min_allowed_id_) {
+ // We have searched among all one-byte IDs without finding an unused ID,
+ // continue at the first two-byte ID.
+ next_extension_id_ =
+ webrtc::RtpExtension::kOneByteHeaderExtensionMaxId + 1;
+ }
+
+ if (next_extension_id_ >
+ webrtc::RtpExtension::kOneByteHeaderExtensionMaxId) {
+ while (IsIdUsed(next_extension_id_) &&
+ next_extension_id_ <= max_allowed_id_) {
+ ++next_extension_id_;
+ }
+ }
+ }
+ RTC_DCHECK(next_extension_id_ >= min_allowed_id_);
+ RTC_DCHECK(next_extension_id_ <= max_allowed_id_);
+ return next_extension_id_;
+ }
+
+ const IdDomain id_domain_;
+ int next_extension_id_;
+};
+
+} // namespace cricket
+
+#endif // PC_USED_IDS_H_
diff --git a/pc/used_ids_unittest.cc b/pc/used_ids_unittest.cc
new file mode 100644
index 0000000..43e6208
--- /dev/null
+++ b/pc/used_ids_unittest.cc
@@ -0,0 +1,176 @@
+/*
+ * Copyright 2019 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 "pc/used_ids.h"
+#include "test/gtest.h"
+
+using cricket::UsedIds;
+using cricket::UsedRtpHeaderExtensionIds;
+
+struct Foo {
+ int id;
+};
+
+TEST(UsedIdsTest, UniqueIdsAreUnchanged) {
+ UsedIds<Foo> used_ids(1, 5);
+ for (int i = 1; i <= 5; ++i) {
+ Foo id = {i};
+ used_ids.FindAndSetIdUsed(&id);
+ EXPECT_EQ(id.id, i);
+ }
+}
+
+TEST(UsedIdsTest, IdsOutsideRangeAreUnchanged) {
+ UsedIds<Foo> used_ids(1, 5);
+
+ Foo id_11 = {11};
+ Foo id_12 = {12};
+ Foo id_12_collision = {12};
+ Foo id_13 = {13};
+ Foo id_13_collision = {13};
+
+ used_ids.FindAndSetIdUsed(&id_11);
+ EXPECT_EQ(id_11.id, 11);
+ used_ids.FindAndSetIdUsed(&id_12);
+ EXPECT_EQ(id_12.id, 12);
+ used_ids.FindAndSetIdUsed(&id_12_collision);
+ EXPECT_EQ(id_12_collision.id, 12);
+ used_ids.FindAndSetIdUsed(&id_13);
+ EXPECT_EQ(id_13.id, 13);
+ used_ids.FindAndSetIdUsed(&id_13_collision);
+ EXPECT_EQ(id_13_collision.id, 13);
+}
+
+TEST(UsedIdsTest, CollisionsAreReassignedIdsInReverseOrder) {
+ UsedIds<Foo> used_ids(1, 10);
+ Foo id_1 = {1};
+ Foo id_2 = {2};
+ Foo id_2_collision = {2};
+ Foo id_3 = {3};
+ Foo id_3_collision = {3};
+
+ used_ids.FindAndSetIdUsed(&id_1);
+ used_ids.FindAndSetIdUsed(&id_2);
+ used_ids.FindAndSetIdUsed(&id_2_collision);
+ EXPECT_EQ(id_2_collision.id, 10);
+ used_ids.FindAndSetIdUsed(&id_3);
+ used_ids.FindAndSetIdUsed(&id_3_collision);
+ EXPECT_EQ(id_3_collision.id, 9);
+}
+
+struct TestParams {
+ UsedRtpHeaderExtensionIds::IdDomain id_domain;
+ int max_id;
+};
+
+class UsedRtpHeaderExtensionIdsTest
+ : public ::testing::TestWithParam<TestParams> {};
+
+constexpr TestParams kOneByteTestParams = {
+ UsedRtpHeaderExtensionIds::IdDomain::kOneByteOnly, 14};
+constexpr TestParams kTwoByteTestParams = {
+ UsedRtpHeaderExtensionIds::IdDomain::kTwoByteAllowed, 255};
+
+INSTANTIATE_TEST_SUITE_P(,
+ UsedRtpHeaderExtensionIdsTest,
+ ::testing::Values(kOneByteTestParams,
+ kTwoByteTestParams));
+
+TEST_P(UsedRtpHeaderExtensionIdsTest, UniqueIdsAreUnchanged) {
+ UsedRtpHeaderExtensionIds used_ids(GetParam().id_domain);
+
+ // Fill all IDs.
+ for (int j = 1; j <= GetParam().max_id; ++j) {
+ webrtc::RtpExtension extension("", j);
+ used_ids.FindAndSetIdUsed(&extension);
+ EXPECT_EQ(extension.id, j);
+ }
+}
+
+TEST_P(UsedRtpHeaderExtensionIdsTest, PrioritizeReassignmentToOneByteIds) {
+ UsedRtpHeaderExtensionIds used_ids(GetParam().id_domain);
+ webrtc::RtpExtension id_1("", 1);
+ webrtc::RtpExtension id_2("", 2);
+ webrtc::RtpExtension id_2_collision("", 2);
+ webrtc::RtpExtension id_3("", 3);
+ webrtc::RtpExtension id_3_collision("", 3);
+
+ // Expect that colliding IDs are reassigned to one-byte IDs.
+ used_ids.FindAndSetIdUsed(&id_1);
+ used_ids.FindAndSetIdUsed(&id_2);
+ used_ids.FindAndSetIdUsed(&id_2_collision);
+ EXPECT_EQ(id_2_collision.id, 14);
+ used_ids.FindAndSetIdUsed(&id_3);
+ used_ids.FindAndSetIdUsed(&id_3_collision);
+ EXPECT_EQ(id_3_collision.id, 13);
+}
+
+TEST_F(UsedRtpHeaderExtensionIdsTest, TwoByteIdsAllowed) {
+ UsedRtpHeaderExtensionIds used_ids(
+ UsedRtpHeaderExtensionIds::IdDomain::kTwoByteAllowed);
+
+ // Fill all one byte IDs.
+ for (int i = 1; i < 15; ++i) {
+ webrtc::RtpExtension id("", i);
+ used_ids.FindAndSetIdUsed(&id);
+ }
+
+ // Add new extensions with colliding IDs.
+ webrtc::RtpExtension id1_collision("", 1);
+ webrtc::RtpExtension id2_collision("", 2);
+ webrtc::RtpExtension id3_collision("", 3);
+
+ // Expect to reassign to two-byte header extension IDs.
+ used_ids.FindAndSetIdUsed(&id1_collision);
+ EXPECT_EQ(id1_collision.id, 15);
+ used_ids.FindAndSetIdUsed(&id2_collision);
+ EXPECT_EQ(id2_collision.id, 16);
+ used_ids.FindAndSetIdUsed(&id3_collision);
+ EXPECT_EQ(id3_collision.id, 17);
+}
+
+// Death tests.
+// Disabled on Android because death tests misbehave on Android, see
+// base/test/gtest_util.h.
+#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+TEST(UsedIdsDeathTest, DieWhenAllIdsAreOccupied) {
+ UsedIds<Foo> used_ids(1, 5);
+ for (int i = 1; i <= 5; ++i) {
+ Foo id = {i};
+ used_ids.FindAndSetIdUsed(&id);
+ }
+ Foo id_collision = {3};
+ EXPECT_DEATH(used_ids.FindAndSetIdUsed(&id_collision), "");
+}
+
+using UsedRtpHeaderExtensionIdsDeathTest = UsedRtpHeaderExtensionIdsTest;
+INSTANTIATE_TEST_SUITE_P(,
+ UsedRtpHeaderExtensionIdsDeathTest,
+ ::testing::Values(kOneByteTestParams,
+ kTwoByteTestParams));
+
+TEST_P(UsedRtpHeaderExtensionIdsDeathTest, DieWhenAllIdsAreOccupied) {
+ UsedRtpHeaderExtensionIds used_ids(GetParam().id_domain);
+
+ // Fill all IDs.
+ for (int j = 1; j <= GetParam().max_id; ++j) {
+ webrtc::RtpExtension id("", j);
+ used_ids.FindAndSetIdUsed(&id);
+ }
+
+ webrtc::RtpExtension id1_collision("", 1);
+ webrtc::RtpExtension id2_collision("", 2);
+ webrtc::RtpExtension id3_collision("", GetParam().max_id);
+
+ EXPECT_DEATH(used_ids.FindAndSetIdUsed(&id1_collision), "");
+ EXPECT_DEATH(used_ids.FindAndSetIdUsed(&id2_collision), "");
+ EXPECT_DEATH(used_ids.FindAndSetIdUsed(&id3_collision), "");
+}
+#endif // RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
