Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 656 insertions, 0 deletions

diff --git a/dom/media/mediacapabilities/MediaCapabilities.cpp b/dom/media/mediacapabilities/MediaCapabilities.cpp
new file mode 100644
index 0000000000..abc83dae4d
--- /dev/null
+++ b/dom/media/mediacapabilities/MediaCapabilities.cpp
@@ -0,0 +1,656 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "MediaCapabilities.h"
+
+#include <inttypes.h>
+
+#include <utility>
+
+#include "AllocationPolicy.h"
+#include "Benchmark.h"
+#include "DecoderBenchmark.h"
+#include "DecoderTraits.h"
+#include "MediaInfo.h"
+#include "MediaRecorder.h"
+#include "PDMFactory.h"
+#include "VPXDecoder.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/SchedulerGroup.h"
+#include "mozilla/StaticPrefs_media.h"
+#include "mozilla/TaskQueue.h"
+#include "mozilla/dom/Document.h"
+#include "mozilla/dom/DOMMozPromiseRequestHolder.h"
+#include "mozilla/dom/MediaCapabilitiesBinding.h"
+#include "mozilla/dom/MediaSource.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/dom/WorkerPrivate.h"
+#include "mozilla/dom/WorkerRef.h"
+#include "mozilla/layers/KnowsCompositor.h"
+#include "nsContentUtils.h"
+#include "WindowRenderer.h"
+
+static mozilla::LazyLogModule sMediaCapabilitiesLog("MediaCapabilities");
+
+#define LOG(msg, ...) \
+  DDMOZ_LOG(sMediaCapabilitiesLog, LogLevel::Debug, msg, ##__VA_ARGS__)
+
+namespace mozilla::dom {
+
+static nsCString VideoConfigurationToStr(const VideoConfiguration* aConfig) {
+  if (!aConfig) {
+    return nsCString();
+  }
+
+  nsCString hdrMetaType(
+      aConfig->mHdrMetadataType.WasPassed()
+          ? HdrMetadataTypeValues::GetString(aConfig->mHdrMetadataType.Value())
+          : "?");
+
+  nsCString colorGamut(
+      aConfig->mColorGamut.WasPassed()
+          ? ColorGamutValues::GetString(aConfig->mColorGamut.Value())
+          : "?");
+
+  nsCString transferFunction(aConfig->mTransferFunction.WasPassed()
+                                 ? TransferFunctionValues::GetString(
+                                       aConfig->mTransferFunction.Value())
+                                 : "?");
+
+  auto str = nsPrintfCString(
+      "[contentType:%s width:%d height:%d bitrate:%" PRIu64
+      " framerate:%lf hasAlphaChannel:%s hdrMetadataType:%s colorGamut:%s "
+      "transferFunction:%s scalabilityMode:%s]",
+      NS_ConvertUTF16toUTF8(aConfig->mContentType).get(), aConfig->mWidth,
+      aConfig->mHeight, aConfig->mBitrate, aConfig->mFramerate,
+      aConfig->mHasAlphaChannel.WasPassed()
+          ? aConfig->mHasAlphaChannel.Value() ? "true" : "false"
+          : "?",
+      hdrMetaType.get(), colorGamut.get(), transferFunction.get(),
+      aConfig->mScalabilityMode.WasPassed()
+          ? NS_ConvertUTF16toUTF8(aConfig->mScalabilityMode.Value()).get()
+          : "?");
+  return std::move(str);
+}
+
+static nsCString AudioConfigurationToStr(const AudioConfiguration* aConfig) {
+  if (!aConfig) {
+    return nsCString();
+  }
+  auto str = nsPrintfCString(
+      "[contentType:%s channels:%s bitrate:%" PRIu64 " samplerate:%d]",
+      NS_ConvertUTF16toUTF8(aConfig->mContentType).get(),
+      aConfig->mChannels.WasPassed()
+          ? NS_ConvertUTF16toUTF8(aConfig->mChannels.Value()).get()
+          : "?",
+      aConfig->mBitrate.WasPassed() ? aConfig->mBitrate.Value() : 0,
+      aConfig->mSamplerate.WasPassed() ? aConfig->mSamplerate.Value() : 0);
+  return std::move(str);
+}
+
+static nsCString MediaCapabilitiesInfoToStr(
+    const MediaCapabilitiesInfo* aInfo) {
+  if (!aInfo) {
+    return nsCString();
+  }
+  auto str = nsPrintfCString("[supported:%s smooth:%s powerEfficient:%s]",
+                             aInfo->Supported() ? "true" : "false",
+                             aInfo->Smooth() ? "true" : "false",
+                             aInfo->PowerEfficient() ? "true" : "false");
+  return std::move(str);
+}
+
+static nsCString MediaDecodingConfigurationToStr(
+    const MediaDecodingConfiguration& aConfig) {
+  nsCString str;
+  str += "["_ns;
+  if (aConfig.mVideo.WasPassed()) {
+    str += "video:"_ns + VideoConfigurationToStr(&aConfig.mVideo.Value());
+    if (aConfig.mAudio.WasPassed()) {
+      str += " "_ns;
+    }
+  }
+  if (aConfig.mAudio.WasPassed()) {
+    str += "audio:"_ns + AudioConfigurationToStr(&aConfig.mAudio.Value());
+  }
+  str += "]"_ns;
+  return str;
+}
+
+MediaCapabilities::MediaCapabilities(nsIGlobalObject* aParent)
+    : mParent(aParent) {}
+
+already_AddRefed<Promise> MediaCapabilities::DecodingInfo(
+    const MediaDecodingConfiguration& aConfiguration, ErrorResult& aRv) {
+  RefPtr<Promise> promise = Promise::Create(mParent, aRv);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  // If configuration is not a valid MediaConfiguration, return a Promise
+  // rejected with a TypeError.
+  if (!aConfiguration.mVideo.WasPassed() &&
+      !aConfiguration.mAudio.WasPassed()) {
+    aRv.ThrowTypeError<MSG_MISSING_REQUIRED_DICTIONARY_MEMBER>(
+        "'audio' or 'video' member of argument of "
+        "MediaCapabilities.decodingInfo");
+    return nullptr;
+  }
+
+  LOG("Processing %s", MediaDecodingConfigurationToStr(aConfiguration).get());
+
+  bool supported = true;
+  Maybe<MediaContainerType> videoContainer;
+  Maybe<MediaContainerType> audioContainer;
+
+  // If configuration.video is present and is not a valid video configuration,
+  // return a Promise rejected with a TypeError.
+  if (aConfiguration.mVideo.WasPassed()) {
+    videoContainer = CheckVideoConfiguration(aConfiguration.mVideo.Value());
+    if (!videoContainer) {
+      aRv.ThrowTypeError<MSG_INVALID_MEDIA_VIDEO_CONFIGURATION>();
+      return nullptr;
+    }
+
+    // We have a video configuration and it is valid. Check if it is supported.
+    supported &=
+        aConfiguration.mType == MediaDecodingType::File
+            ? CheckTypeForFile(aConfiguration.mVideo.Value().mContentType)
+            : CheckTypeForMediaSource(
+                  aConfiguration.mVideo.Value().mContentType);
+  }
+  if (aConfiguration.mAudio.WasPassed()) {
+    audioContainer = CheckAudioConfiguration(aConfiguration.mAudio.Value());
+    if (!audioContainer) {
+      aRv.ThrowTypeError<MSG_INVALID_MEDIA_AUDIO_CONFIGURATION>();
+      return nullptr;
+    }
+    // We have an audio configuration and it is valid. Check if it is supported.
+    supported &=
+        aConfiguration.mType == MediaDecodingType::File
+            ? CheckTypeForFile(aConfiguration.mAudio.Value().mContentType)
+            : CheckTypeForMediaSource(
+                  aConfiguration.mAudio.Value().mContentType);
+  }
+
+  if (!supported) {
+    auto info = MakeUnique<MediaCapabilitiesInfo>(
+        false /* supported */, false /* smooth */, false /* power efficient */);
+    LOG("%s -> %s", MediaDecodingConfigurationToStr(aConfiguration).get(),
+        MediaCapabilitiesInfoToStr(info.get()).get());
+    promise->MaybeResolve(std::move(info));
+    return promise.forget();
+  }
+
+  nsTArray<UniquePtr<TrackInfo>> tracks;
+  if (aConfiguration.mVideo.WasPassed()) {
+    MOZ_ASSERT(videoContainer.isSome(), "configuration is valid and supported");
+    auto videoTracks = DecoderTraits::GetTracksInfo(*videoContainer);
+    // If the MIME type does not imply a codec, the string MUST
+    // also have one and only one parameter that is named codecs with a value
+    // describing a single media codec. Otherwise, it MUST contain no
+    // parameters.
+    if (videoTracks.Length() != 1) {
+      promise->MaybeRejectWithTypeError<MSG_NO_CODECS_PARAMETER>(
+          videoContainer->OriginalString());
+      return promise.forget();
+    }
+    MOZ_DIAGNOSTIC_ASSERT(videoTracks.ElementAt(0),
+                          "must contain a valid trackinfo");
+    // If the type refers to an audio codec, reject now.
+    if (videoTracks[0]->GetType() != TrackInfo::kVideoTrack) {
+      promise
+          ->MaybeRejectWithTypeError<MSG_INVALID_MEDIA_VIDEO_CONFIGURATION>();
+      return promise.forget();
+    }
+    tracks.AppendElements(std::move(videoTracks));
+  }
+  if (aConfiguration.mAudio.WasPassed()) {
+    MOZ_ASSERT(audioContainer.isSome(), "configuration is valid and supported");
+    auto audioTracks = DecoderTraits::GetTracksInfo(*audioContainer);
+    // If the MIME type does not imply a codec, the string MUST
+    // also have one and only one parameter that is named codecs with a value
+    // describing a single media codec. Otherwise, it MUST contain no
+    // parameters.
+    if (audioTracks.Length() != 1) {
+      promise->MaybeRejectWithTypeError<MSG_NO_CODECS_PARAMETER>(
+          audioContainer->OriginalString());
+      return promise.forget();
+    }
+    MOZ_DIAGNOSTIC_ASSERT(audioTracks.ElementAt(0),
+                          "must contain a valid trackinfo");
+    // If the type refers to a video codec, reject now.
+    if (audioTracks[0]->GetType() != TrackInfo::kAudioTrack) {
+      promise
+          ->MaybeRejectWithTypeError<MSG_INVALID_MEDIA_AUDIO_CONFIGURATION>();
+      return promise.forget();
+    }
+    tracks.AppendElements(std::move(audioTracks));
+  }
+
+  using CapabilitiesPromise = MozPromise<MediaCapabilitiesInfo, MediaResult,
+                                         /* IsExclusive = */ true>;
+  nsTArray<RefPtr<CapabilitiesPromise>> promises;
+
+  RefPtr<TaskQueue> taskQueue =
+      TaskQueue::Create(GetMediaThreadPool(MediaThreadType::PLATFORM_DECODER),
+                        "MediaCapabilities::TaskQueue");
+  for (auto&& config : tracks) {
+    TrackInfo::TrackType type =
+        config->IsVideo() ? TrackInfo::kVideoTrack : TrackInfo::kAudioTrack;
+
+    MOZ_ASSERT(type == TrackInfo::kAudioTrack ||
+                   videoContainer->ExtendedType().GetFramerate().isSome(),
+               "framerate is a required member of VideoConfiguration");
+
+    if (type == TrackInfo::kAudioTrack) {
+      // There's no need to create an audio decoder has we only want to know if
+      // such codec is supported. We do need to call the PDMFactory::Supports
+      // API outside the main thread to get accurate results.
+      promises.AppendElement(
+          InvokeAsync(taskQueue, __func__, [config = std::move(config)]() {
+            RefPtr<PDMFactory> pdm = new PDMFactory();
+            SupportDecoderParams params{*config};
+            if (pdm->Supports(params, nullptr /* decoder doctor */).isEmpty()) {
+              return CapabilitiesPromise::CreateAndReject(NS_ERROR_FAILURE,
+                                                          __func__);
+            }
+            return CapabilitiesPromise::CreateAndResolve(
+                MediaCapabilitiesInfo(true /* supported */, true /* smooth */,
+                                      true /* power efficient */),
+                __func__);
+          }));
+      continue;
+    }
+
+    // On Windows, the MediaDataDecoder expects to be created on a thread
+    // supporting MTA, which the main thread doesn't. So we use our task queue
+    // to create such decoder and perform initialization.
+
+    RefPtr<layers::KnowsCompositor> compositor = GetCompositor();
+    float frameRate =
+        static_cast<float>(videoContainer->ExtendedType().GetFramerate().ref());
+    const bool shouldResistFingerprinting =
+        mParent->ShouldResistFingerprinting(RFPTarget::MediaCapabilities);
+
+    // clang-format off
+    promises.AppendElement(InvokeAsync(
+        taskQueue, __func__,
+        [taskQueue, frameRate, shouldResistFingerprinting, compositor,
+         config = std::move(config)]() mutable -> RefPtr<CapabilitiesPromise> {
+          // MediaDataDecoder keeps a reference to the config object, so we must
+          // keep it alive until the decoder has been shutdown.
+          static Atomic<uint32_t> sTrackingIdCounter(0);
+          TrackingId trackingId(TrackingId::Source::MediaCapabilities,
+                                sTrackingIdCounter++,
+                                TrackingId::TrackAcrossProcesses::Yes);
+          CreateDecoderParams params{
+              *config, compositor,
+              CreateDecoderParams::VideoFrameRate(frameRate),
+              TrackInfo::kVideoTrack, Some(std::move(trackingId))};
+          // We want to ensure that all decoder's queries are occurring only
+          // once at a time as it can quickly exhaust the system resources
+          // otherwise.
+          static RefPtr<AllocPolicy> sVideoAllocPolicy = [&taskQueue]() {
+            SchedulerGroup::Dispatch(
+                NS_NewRunnableFunction(
+                    "MediaCapabilities::AllocPolicy:Video", []() {
+                      ClearOnShutdown(&sVideoAllocPolicy,
+                                      ShutdownPhase::XPCOMShutdownThreads);
+                    }));
+            return new SingleAllocPolicy(TrackInfo::TrackType::kVideoTrack,
+                                         taskQueue);
+          }();
+          return AllocationWrapper::CreateDecoder(params, sVideoAllocPolicy)
+              ->Then(
+                  taskQueue, __func__,
+                  [taskQueue, frameRate, shouldResistFingerprinting,
+                   config = std::move(config)](
+                      AllocationWrapper::AllocateDecoderPromise::
+                          ResolveOrRejectValue&& aValue) mutable {
+                    if (aValue.IsReject()) {
+                      return CapabilitiesPromise::CreateAndReject(
+                          std::move(aValue.RejectValue()), __func__);
+                    }
+                    RefPtr<MediaDataDecoder> decoder =
+                        std::move(aValue.ResolveValue());
+                    // We now query the decoder to determine if it's power
+                    // efficient.
+                    RefPtr<CapabilitiesPromise> p = decoder->Init()->Then(
+                        taskQueue, __func__,
+                        [taskQueue, decoder, frameRate,
+                         shouldResistFingerprinting,
+                         config = std::move(config)](
+                            MediaDataDecoder::InitPromise::
+                                ResolveOrRejectValue&& aValue) mutable {
+                          RefPtr<CapabilitiesPromise> p;
+                          if (aValue.IsReject()) {
+                            p = CapabilitiesPromise::CreateAndReject(
+                                std::move(aValue.RejectValue()), __func__);
+                          } else if (shouldResistFingerprinting) {
+                            p = CapabilitiesPromise::CreateAndResolve(
+                                MediaCapabilitiesInfo(true /* supported */,
+                                true /* smooth */, false /* power efficient */),
+                                __func__);
+                          } else {
+                            MOZ_ASSERT(config->IsVideo());
+                            if (StaticPrefs::media_mediacapabilities_from_database()) {
+                              nsAutoCString reason;
+                              bool powerEfficient =
+                                  decoder->IsHardwareAccelerated(reason);
+
+                              int32_t videoFrameRate = std::clamp<int32_t>(frameRate, 1, INT32_MAX);
+
+                              DecoderBenchmarkInfo benchmarkInfo{
+                                  config->mMimeType,
+                                  config->GetAsVideoInfo()->mImage.width,
+                                  config->GetAsVideoInfo()->mImage.height,
+                                  videoFrameRate, 8};
+
+                              p = DecoderBenchmark::Get(benchmarkInfo)->Then(
+                                  GetMainThreadSerialEventTarget(),
+                                  __func__,
+                                  [powerEfficient](int32_t score) {
+                                    // score < 0 means no entry found.
+                                    bool smooth = score < 0 || score >
+                                      StaticPrefs::
+                                        media_mediacapabilities_drop_threshold();
+                                    return CapabilitiesPromise::
+                                        CreateAndResolve(
+                                            MediaCapabilitiesInfo(
+                                                true, smooth,
+                                                powerEfficient),
+                                            __func__);
+                                  },
+                                  [](nsresult rv) {
+                                    return CapabilitiesPromise::
+                                        CreateAndReject(rv, __func__);
+                                  });
+                            } else if (config->GetAsVideoInfo()->mImage.height < 480) {
+                              // Assume that we can do stuff at 480p or less in
+                              // a power efficient manner and smoothly. If
+                              // greater than 480p we assume that if the video
+                              // decoding is hardware accelerated it will be
+                              // smooth and power efficient, otherwise we use
+                              // the benchmark to estimate
+                              p = CapabilitiesPromise::CreateAndResolve(
+                                  MediaCapabilitiesInfo(true, true, true),
+                                  __func__);
+                            } else {
+                              nsAutoCString reason;
+                              bool smooth = true;
+                              bool powerEfficient =
+                                  decoder->IsHardwareAccelerated(reason);
+                              if (!powerEfficient &&
+                                  VPXDecoder::IsVP9(config->mMimeType)) {
+                                smooth = VP9Benchmark::IsVP9DecodeFast(
+                                    true /* default */);
+                                uint32_t fps =
+                                    VP9Benchmark::MediaBenchmarkVp9Fps();
+                                if (!smooth && fps > 0) {
+                                  // The VP9 estimizer decode a 1280x720 video.
+                                  // Let's adjust the result for the resolution
+                                  // and frame rate of what we actually want. If
+                                  // the result is twice that we need we assume
+                                  // it will be smooth.
+                                  const auto& videoConfig =
+                                      *config->GetAsVideoInfo();
+                                  double needed = ((1280.0 * 720.0) /
+                                                   (videoConfig.mImage.width *
+                                                    videoConfig.mImage.height) *
+                                                   fps) /
+                                                  frameRate;
+                                  smooth = needed > 2;
+                                }
+                              }
+
+                              p = CapabilitiesPromise::CreateAndResolve(
+                                  MediaCapabilitiesInfo(true /* supported */,
+                                                        smooth, powerEfficient),
+                                  __func__);
+                            }
+                          }
+                          MOZ_ASSERT(p.get(), "the promise has been created");
+                          // Let's keep alive the decoder and the config object
+                          // until the decoder has shutdown.
+                          decoder->Shutdown()->Then(
+                              taskQueue, __func__,
+                              [taskQueue, decoder, config = std::move(config)](
+                                  const ShutdownPromise::ResolveOrRejectValue&
+                                      aValue) {});
+                          return p;
+                        });
+                    return p;
+                  });
+        }));
+    // clang-format on
+  }
+
+  auto holder = MakeRefPtr<
+      DOMMozPromiseRequestHolder<CapabilitiesPromise::AllPromiseType>>(mParent);
+  RefPtr<nsISerialEventTarget> targetThread;
+  RefPtr<StrongWorkerRef> workerRef;
+
+  if (NS_IsMainThread()) {
+    targetThread = GetMainThreadSerialEventTarget();
+  } else {
+    WorkerPrivate* wp = GetCurrentThreadWorkerPrivate();
+    MOZ_ASSERT(wp, "Must be called from a worker thread");
+    targetThread = wp->HybridEventTarget();
+    workerRef = StrongWorkerRef::Create(
+        wp, "MediaCapabilities", [holder, targetThread]() {
+          MOZ_ASSERT(targetThread->IsOnCurrentThread());
+          holder->DisconnectIfExists();
+        });
+    if (NS_WARN_IF(!workerRef)) {
+      // The worker is shutting down.
+      aRv.Throw(NS_ERROR_FAILURE);
+      return nullptr;
+    }
+  }
+
+  MOZ_ASSERT(targetThread);
+
+  // this is only captured for use with the LOG macro.
+  RefPtr<MediaCapabilities> self = this;
+
+  CapabilitiesPromise::All(targetThread, promises)
+      ->Then(targetThread, __func__,
+             [promise, tracks = std::move(tracks), workerRef, holder,
+              aConfiguration, self,
+              this](CapabilitiesPromise::AllPromiseType::ResolveOrRejectValue&&
+                        aValue) {
+               holder->Complete();
+               if (aValue.IsReject()) {
+                 auto info = MakeUnique<MediaCapabilitiesInfo>(
+                     false /* supported */, false /* smooth */,
+                     false /* power efficient */);
+                 LOG("%s -> %s",
+                     MediaDecodingConfigurationToStr(aConfiguration).get(),
+                     MediaCapabilitiesInfoToStr(info.get()).get());
+                 promise->MaybeResolve(std::move(info));
+                 return;
+               }
+               bool powerEfficient = true;
+               bool smooth = true;
+               for (auto&& capability : aValue.ResolveValue()) {
+                 smooth &= capability.Smooth();
+                 powerEfficient &= capability.PowerEfficient();
+               }
+               auto info = MakeUnique<MediaCapabilitiesInfo>(
+                   true /* supported */, smooth, powerEfficient);
+               LOG("%s -> %s",
+                   MediaDecodingConfigurationToStr(aConfiguration).get(),
+                   MediaCapabilitiesInfoToStr(info.get()).get());
+               promise->MaybeResolve(std::move(info));
+             })
+      ->Track(*holder);
+
+  return promise.forget();
+}
+
+already_AddRefed<Promise> MediaCapabilities::EncodingInfo(
+    const MediaEncodingConfiguration& aConfiguration, ErrorResult& aRv) {
+  RefPtr<Promise> promise = Promise::Create(mParent, aRv);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  // If configuration is not a valid MediaConfiguration, return a Promise
+  // rejected with a TypeError.
+  if (!aConfiguration.mVideo.WasPassed() &&
+      !aConfiguration.mAudio.WasPassed()) {
+    aRv.ThrowTypeError<MSG_MISSING_REQUIRED_DICTIONARY_MEMBER>(
+        "'audio' or 'video' member of argument of "
+        "MediaCapabilities.encodingInfo");
+    return nullptr;
+  }
+
+  bool supported = true;
+
+  // If configuration.video is present and is not a valid video configuration,
+  // return a Promise rejected with a TypeError.
+  if (aConfiguration.mVideo.WasPassed()) {
+    if (!CheckVideoConfiguration(aConfiguration.mVideo.Value())) {
+      aRv.ThrowTypeError<MSG_INVALID_MEDIA_VIDEO_CONFIGURATION>();
+      return nullptr;
+    }
+    // We have a video configuration and it is valid. Check if it is supported.
+    supported &=
+        CheckTypeForEncoder(aConfiguration.mVideo.Value().mContentType);
+  }
+  if (aConfiguration.mAudio.WasPassed()) {
+    if (!CheckAudioConfiguration(aConfiguration.mAudio.Value())) {
+      aRv.ThrowTypeError<MSG_INVALID_MEDIA_AUDIO_CONFIGURATION>();
+      return nullptr;
+    }
+    // We have an audio configuration and it is valid. Check if it is supported.
+    supported &=
+        CheckTypeForEncoder(aConfiguration.mAudio.Value().mContentType);
+  }
+
+  auto info = MakeUnique<MediaCapabilitiesInfo>(supported, supported, false);
+  promise->MaybeResolve(std::move(info));
+
+  return promise.forget();
+}
+
+Maybe<MediaContainerType> MediaCapabilities::CheckVideoConfiguration(
+    const VideoConfiguration& aConfig) const {
+  Maybe<MediaExtendedMIMEType> container = MakeMediaExtendedMIMEType(aConfig);
+  if (!container) {
+    return Nothing();
+  }
+  // A valid video MIME type is a string that is a valid media MIME type and for
+  // which the type per [RFC7231] is either video or application.
+  if (!container->Type().HasVideoMajorType() &&
+      !container->Type().HasApplicationMajorType()) {
+    return Nothing();
+  }
+
+  // If the MIME type does not imply a codec, the string MUST also have one and
+  // only one parameter that is named codecs with a value describing a single
+  // media codec. Otherwise, it MUST contain no parameters.
+  // TODO (nsIMOMEHeaderParam doesn't provide backend to count number of
+  // parameters)
+
+  return Some(MediaContainerType(std::move(*container)));
+}
+
+Maybe<MediaContainerType> MediaCapabilities::CheckAudioConfiguration(
+    const AudioConfiguration& aConfig) const {
+  Maybe<MediaExtendedMIMEType> container = MakeMediaExtendedMIMEType(aConfig);
+  if (!container) {
+    return Nothing();
+  }
+  // A valid audio MIME type is a string that is valid media MIME type and for
+  // which the type per [RFC7231] is either audio or application.
+  if (!container->Type().HasAudioMajorType() &&
+      !container->Type().HasApplicationMajorType()) {
+    return Nothing();
+  }
+
+  // If the MIME type does not imply a codec, the string MUST also have one and
+  // only one parameter that is named codecs with a value describing a single
+  // media codec. Otherwise, it MUST contain no parameters.
+  // TODO (nsIMOMEHeaderParam doesn't provide backend to count number of
+  // parameters)
+
+  return Some(MediaContainerType(std::move(*container)));
+}
+
+bool MediaCapabilities::CheckTypeForMediaSource(const nsAString& aType) {
+  IgnoredErrorResult rv;
+  MediaSource::IsTypeSupported(aType, nullptr /* DecoderDoctorDiagnostics */,
+                               rv);
+
+  return !rv.Failed();
+}
+
+bool MediaCapabilities::CheckTypeForFile(const nsAString& aType) {
+  Maybe<MediaContainerType> containerType = MakeMediaContainerType(aType);
+  if (!containerType) {
+    return false;
+  }
+
+  return DecoderTraits::CanHandleContainerType(
+             *containerType, nullptr /* DecoderDoctorDiagnostics */) !=
+         CANPLAY_NO;
+}
+
+bool MediaCapabilities::CheckTypeForEncoder(const nsAString& aType) {
+  return MediaRecorder::IsTypeSupported(aType);
+}
+
+already_AddRefed<layers::KnowsCompositor> MediaCapabilities::GetCompositor() {
+  nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(GetParentObject());
+  if (NS_WARN_IF(!window)) {
+    return nullptr;
+  }
+
+  nsCOMPtr<Document> doc = window->GetExtantDoc();
+  if (NS_WARN_IF(!doc)) {
+    return nullptr;
+  }
+  WindowRenderer* renderer = nsContentUtils::WindowRendererForDocument(doc);
+  if (NS_WARN_IF(!renderer)) {
+    return nullptr;
+  }
+  RefPtr<layers::KnowsCompositor> knows = renderer->AsKnowsCompositor();
+  if (NS_WARN_IF(!knows)) {
+    return nullptr;
+  }
+  return knows->GetForMedia().forget();
+}
+
+bool MediaCapabilities::Enabled(JSContext* aCx, JSObject* aGlobal) {
+  return StaticPrefs::media_media_capabilities_enabled();
+}
+
+JSObject* MediaCapabilities::WrapObject(JSContext* aCx,
+                                        JS::Handle<JSObject*> aGivenProto) {
+  return MediaCapabilities_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaCapabilities)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(MediaCapabilities)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(MediaCapabilities)
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(MediaCapabilities, mParent)
+
+// MediaCapabilitiesInfo
+bool MediaCapabilitiesInfo::WrapObject(
+    JSContext* aCx, JS::Handle<JSObject*> aGivenProto,
+    JS::MutableHandle<JSObject*> aReflector) {
+  return MediaCapabilitiesInfo_Binding::Wrap(aCx, this, aGivenProto,
+                                             aReflector);
+}
+
+}  // namespace mozilla::dom