media_switches.cc | Explore in Territory

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// 2023-10-22: Newly added flags and features should document an owner and
// expiry condition. The expiry condition is freeform and could be a date,
// experiment, bug, the deletion of a file, etc.

#include "media/base/media_switches.h"

#include "base/command_line.h"
#include "base/feature_list.h"
#include "base/strings/string_number_conversions.h"
#include "base/time/time.h"
#include "build/build_config.h"
#include "build/chromecast_buildflags.h"
#include "build/chromeos_buildflags.h"
#include "components/system_media_controls/linux/buildflags/buildflags.h"
#include "gpu/config/gpu_finch_features.h"
#include "media/media_buildflags.h"
#include "ui/gl/gl_features.h"
#include "ui/gl/gl_utils.h"

#if BUILDFLAG(IS_LINUX)
#include "base/cpu.h"
#endif

namespace switches {

// Allow users to specify a custom buffer size for debugging purpose.
const char kAudioBufferSize[] = …;

#if BUILDFLAG(ENABLE_PASSTHROUGH_AUDIO_CODECS)
// Audio codecs supported by the HDMI sink is retrieved from the audio
// service process. EDID contains the Short Audio Descriptors, which list
// the audio decoders supported, and the information is presented as a
// bitmask of supported audio codecs.
const char kAudioCodecsFromEDID[] = "audio-codecs-from-edid";
#endif  // BUILDFLAG(ENABLE_PASSTHROUGH_AUDIO_CODECS)

// Command line flag name to set the autoplay policy.
const char kAutoplayPolicy[] = …;

// Forces input and output stream creation to use fake audio streams.
const char kDisableAudioInput[] = …;
const char kDisableAudioOutput[] = …;

// Causes the AudioManager to fail creating audio streams. Used when testing
// various failure cases.
const char kFailAudioStreamCreation[] = …;

// Set number of threads to use for video decoding.
const char kVideoThreads[] = …;

// Do not immediately suspend media in background tabs.
const char kDisableBackgroundMediaSuspend[] = …;

// Force to report VP9 as an unsupported MIME type.
const char kReportVp9AsAnUnsupportedMimeType[] = …;

#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_FREEBSD) || \
    BUILDFLAG(IS_SOLARIS)
// The Alsa device to use when opening an audio input stream.
const char kAlsaInputDevice[] = …;
// The Alsa device to use when opening an audio stream.
const char kAlsaOutputDevice[] = …;
#endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) ||
        // BUILDFLAG(IS_FREEBSD) || BUILDFLAG(IS_SOLARIS)

#if BUILDFLAG(IS_WIN)
// Use exclusive mode audio streaming for Windows Vista and higher.
// Leads to lower latencies for audio streams which uses the
// AudioParameters::AUDIO_PCM_LOW_LATENCY audio path.
// See http://msdn.microsoft.com/en-us/library/windows/desktop/dd370844.aspx
// for details.
const char kEnableExclusiveAudio[] = "enable-exclusive-audio";

// Use Windows WaveOut/In audio API even if Core Audio is supported.
const char kForceWaveAudio[] = "force-wave-audio";

// Instead of always using the hardware channel layout, check if a driver
// supports the source channel layout.  Avoids outputting empty channels and
// permits drivers to enable stereo to multichannel expansion.  Kept behind a
// flag since some drivers lie about supported layouts and hang when used.  See
// http://crbug.com/259165 for more details.
const char kTrySupportedChannelLayouts[] = "try-supported-channel-layouts";

// Number of buffers to use for WaveOut.
const char kWaveOutBuffers[] = "waveout-buffers";
#endif  // BUILDFLAG(IS_WIN)

#if BUILDFLAG(IS_FUCHSIA)
// Enables protected buffers for encrypted video streams.
const char kEnableProtectedVideoBuffers[] = "enable-protected-video-buffers";

// Forces protected memory for all output video buffers generated by
// FuchsiaVideoDecoder, including unencrypted streams. Ignored unless
// --enable-protected-video-buffers is also specified.
const char kForceProtectedVideoOutputBuffers[] =
    "force-protected-video-output-buffers";

// Minimum size for buffer size used for output video frames in
// FuchsiaVideoDecoder. May be set to avoid re-allocating video buffers when an
// application upgrades video resolution mid-stream.
const char kMinVideoDecoderOutputBufferSize[] =
    "min-video-decoder-output-buffer-size";

// Forces AudioManagerFuchsia to assume that the AudioCapturer implements echo
// cancellation.
// TODO(crbug.com/42050621): Remove this once AudioManagerFuchsia is updated to
// get this information from AudioCapturerFactory.
const char kAudioCapturerWithEchoCancellation[] =
    "audio-capturer-with-echo-cancellation";
#endif  // BUILDFLAG(IS_FUCHSIA)

#if BUILDFLAG(USE_CRAS)
// Use CRAS, the ChromeOS audio server.
const char kUseCras[] = "use-cras";
// Enforce system audio echo cancellation.
const char kSystemAecEnabled[] = "system-aec-enabled";
#endif  // BUILDFLAG(USE_CRAS)

// For automated testing of protected content, this switch allows specific
// domains (e.g. example.com) to always allow the permission to share the
// protected media identifier. In this context, domain does not include the
// port number. User's content settings will not be affected by enabling this
// switch.
// Reference: http://crbug.com/718608
// Example:
// --unsafely-allow-protected-media-identifier-for-domain=a.com,b.ca
const char kUnsafelyAllowProtectedMediaIdentifierForDomain[] = …;

// Skip the permission prompt for Captured Surface Control.
const char kAutoGrantCapturedSurfaceControlPrompt[] = …;

// Use fake device for Media Stream to replace actual camera and microphone.
// For the list of allowed parameters, see
// FakeVideoCaptureDeviceFactory::ParseFakeDevicesConfigFromOptionsString().
const char kUseFakeDeviceForMediaStream[] = …;

// Use an .y4m file to play as the webcam. See the comments in
// media/capture/video/file_video_capture_device.h for more details.
const char kUseFileForFakeVideoCapture[] = …;

// Play a .wav file as the microphone. Note that for WebRTC calls we'll treat
// the bits as if they came from the microphone, which means you should disable
// audio processing (lest your audio file will play back distorted). The input
// file is converted to suit Chrome's audio buses if necessary, so most sane
// .wav files should work. You can pass either <path> to play the file looping
// or <path>%noloop to stop after playing the file to completion.
//
// Must also be used with kDisableAudioInput or kUseFakeDeviceForMediaStream.
const char kUseFileForFakeAudioCapture[] = …;

// Use a fake device for accelerated decoding of MJPEG. This allows, for
// example, testing of the communication to the GPU service without requiring
// actual accelerator hardware to be present.
const char kUseFakeMjpegDecodeAccelerator[] = …;

// Disable hardware acceleration of mjpeg decode for captured frame, where
// available.
const char kDisableAcceleratedMjpegDecode[] = …;

// Mutes audio sent to the audio device so it is not audible during
// automated testing.
const char kMuteAudio[] = …;

// Disables the new rendering algorithm for webrtc, which is designed to improve
// the rendering smoothness.
const char kDisableRTCSmoothnessAlgorithm[] = …;

// Force media player using SurfaceView instead of SurfaceTexture on Android.
const char kForceVideoOverlays[] = …;

// Allows explicitly specifying MSE audio/video buffer sizes as megabytes.
// Default values are 150M for video and 12M for audio.
const char kMSEAudioBufferSizeLimitMb[] = …;
const char kMSEVideoBufferSizeLimitMb[] = …;

// Specifies the path to the Clear Key CDM for testing, which is necessary to
// support External Clear Key key system when library CDM is enabled. Note that
// External Clear Key key system support is also controlled by feature
// kExternalClearKeyForTesting.
const char kClearKeyCdmPathForTesting[] = …;

// Overrides the default enabled library CDM interface version(s) with the one
// specified with this switch, which will be the only version enabled. For
// example, on a build where CDM 8, CDM 9 and CDM 10 are all supported
// (implemented), but only CDM 8 and CDM 9 are enabled by default:
//  --override-enabled-cdm-interface-version=8 : Only CDM 8 is enabled
//  --override-enabled-cdm-interface-version=9 : Only CDM 9 is enabled
//  --override-enabled-cdm-interface-version=10 : Only CDM 10 is enabled
//  --override-enabled-cdm-interface-version=11 : No CDM interface is enabled
// This can be used for local testing and debugging. It can also be used to
// enable an experimental CDM interface (which is always disabled by default)
// for testing while it's still in development.
const char kOverrideEnabledCdmInterfaceVersion[] = …;

// Overrides hardware secure codecs support for testing. If specified, real
// platform hardware secure codecs check will be skipped. Valid codecs are:
// - video: "vp8", "vp9", "avc1", "hevc", "dolbyvision", "av01"
// - video that does not support clear lead: `<video>-no-clearlead`, where
//   <video> is from the list above.
// - audio: "mp4a", "vorbis"
// Codecs are separated by comma. For example:
//  --override-hardware-secure-codecs-for-testing=vp8,vp9-no-clearlead,vorbis
//  --override-hardware-secure-codecs-for-testing=avc1,mp4a
// CENC encryption scheme is assumed to be supported for the specified codecs.
// If no valid codecs specified, no hardware secure codecs are supported. This
// can be used to disable hardware secure codecs support:
//  --override-hardware-secure-codecs-for-testing
const char kOverrideHardwareSecureCodecsForTesting[] = …;

// Sets the default value for the kLiveCaptionEnabled preference to true.
const char kEnableLiveCaptionPrefForTesting[] = …;

#if BUILDFLAG(IS_CHROMEOS)
// These are flags passed from ash-chrome to lacros-chrome that correspond to
// buildflags for the platform we are running on. lacros-chrome only builds for
// x86/arm differences, so we unconditionally build in the below features into
// the relevant parts of lacros-chrome and then filter the functionality based
// on these command line flags.
MEDIA_EXPORT extern const char kLacrosEnablePlatformHevc[] =
    "lacros-enable-platform-hevc";
MEDIA_EXPORT extern const char kLacrosUseChromeosProtectedMedia[] =
    "lacros-use-chromeos-protected-media";
MEDIA_EXPORT extern const char kLacrosUseChromeosProtectedAv1[] =
    "lacros-use-chromeos-protected-av1";

// Allows remote attestation (RA) in dev mode for testing purpose. Usually RA
// is disabled in dev mode because it will always fail. However, there are cases
// in testing where we do want to go through the permission flow even in dev
// mode. This can be enabled by this flag.
const char kAllowRAInDevMode[] = "allow-ra-in-dev-mode";

// These flags are passed from ash-chrome to lacros-chrome that correspond to
// the directories used for the Widevine CDM (the bundled CDM and the Component
// Updated CDM).
const char kCrosWidevineBundledDir[] = "cros-bundled-widevine";
const char kCrosWidevineComponentUpdatedHintFile[] =
    "cros-component-updated-widevine-hint-file";
#endif  // BUILDFLAG(IS_CHROMEOS)

namespace autoplay {

// Autoplay policy that requires a document user activation.
const char kDocumentUserActivationRequiredPolicy[] = …;

// Autoplay policy that does not require any user gesture.
const char kNoUserGestureRequiredPolicy[] = …;

// Autoplay policy to require a user gesture in order to play.
const char kUserGestureRequiredPolicy[] = …;

}  // namespace autoplay

#if BUILDFLAG(USE_CHROMEOS_MEDIA_ACCELERATION)
// Some (Qualcomm only at the moment) V4L2 video decoders require setting the
// framerate so that the hardware decoder can scale the clocks efficiently.
// This provides a mechanism during testing to lock the decoder framerate
// to a specific value.
const char kHardwareVideoDecodeFrameRate[] = …;
#endif

#if BUILDFLAG(USE_V4L2_CODEC)
// This is needed for V4L2 testing using VISL (virtual driver) on cros VM with
// arm64-generic-vm. Minigbm buffer allocation is done using dumb driver with
// vkms.
const char kEnablePrimaryNodeAccessForVkmsTesting[] =
    "enable-primary-node-access-for-vkms-testing";
#endif

const char kCastStreamingForceDisableHardwareH264[] = …;
const char kCastStreamingForceDisableHardwareVp8[] = …;
const char kCastStreamingForceDisableHardwareVp9[] = …;
const char kCastStreamingForceEnableHardwareH264[] = …;
const char kCastStreamingForceEnableHardwareVp8[] = …;
const char kCastStreamingForceEnableHardwareVp9[] = …;

#if !BUILDFLAG(IS_ANDROID)
const char kCastMirroringTargetPlayoutDelay[] = …;
#endif  // !BUILDFLAG(IS_ANDROID)

}  // namespace switches

namespace media {

// Enables customized AudioRendererAlgorithmParameters.
BASE_FEATURE(…);

const base::FeatureParam<base::TimeDelta>
    kAudioRendererAlgorithmStartingCapacityForEncrypted{ … };

// Only used for disabling overlay fullscreen (aka SurfaceView) in Clank.
BASE_FEATURE(…);

// Pauses muted (and uncaptured) playbacks in the background.
BASE_FEATURE(…);

#if !BUILDFLAG(IS_ANDROID)
// Enables tracking the position of picture-in-picture windows to know when they
// occlude certain widgets.
BASE_FEATURE(…);
#endif  // !BUILDFLAG(IS_ANDROID)

// Enables user control over muting tab audio from the tab strip.
BASE_FEATURE(…);

#if BUILDFLAG(ENABLE_PLATFORM_HEVC)
// Enables HEVC hardware accelerated decoding.
BASE_FEATURE(kPlatformHEVCDecoderSupport,
             "PlatformHEVCDecoderSupport",
             base::FEATURE_ENABLED_BY_DEFAULT);

#if BUILDFLAG(IS_WIN) || BUILDFLAG(IS_APPLE) || BUILDFLAG(IS_ANDROID)
// Enables HEVC hardware accelerated encoding for Windows, Mac, and Android.
BASE_FEATURE(kPlatformHEVCEncoderSupport,
             "PlatformHEVCEncoderSupport",
             base::FEATURE_DISABLED_BY_DEFAULT);
#endif  // BUILDFLAG(IS_WIN) || BUILDFLAG(IS_APPLE) || BUILDFLAG(IS_ANDROID)
#endif  // BUILDFLAG(ENABLE_PLATFORM_HEVC)

// Let videos be resumed via remote controls (for example, the notification)
// when in background.
BASE_FEATURE(…);

#if BUILDFLAG(IS_MAC)
// Enables system audio sharing using ScreenCaptureKit when screen sharing on
// macOS 13.0+.
BASE_FEATURE(kMacLoopbackAudioForScreenShare,
             "MacLoopbackAudioForScreenShare",
             base::FEATURE_ENABLED_BY_DEFAULT);
#endif  // BUILDFLAG(IS_MAC)

#if BUILDFLAG(IS_LINUX)
// Enables system audio mirroring using pulseaudio.
BASE_FEATURE(…);

// Enables system audio sharing using pulseaudio.
BASE_FEATURE(…);
#endif  // BUILDFLAG(IS_LINUX)

// When enabled, MediaCapabilities will check with GPU Video Accelerator
// Factories to determine isPowerEfficient = true/false.
BASE_FEATURE(…);

// Enable Media Capabilities with finch-parameters.
BASE_FEATURE(…);

// Used to set a few tunable parameters for the WebRTC Media Capabilities
// implementation.
BASE_FEATURE(…);

// Display the Cast overlay button on the media controls.
BASE_FEATURE(…);

// Use AndroidOverlay only if required for secure video playback. This requires
// that |kOverlayFullscreenVideo| is true, else it is ignored.
BASE_FEATURE(…);

// Allows usage of OS-level (platform) audio encoders.
// TODO(crbug.com/41495931): re-enable platform audio encoders on arm64 win when
//                          querying for OS support works as expected.
BASE_FEATURE(…);

// If enabled, RTCVideoDecoderAdapter will wrap a DecoderStream as a video
// decoder, rather than using MojoVideoDecoder.  This causes the RTC external
// decoder to have all the decoder selection / fallback/forward logic of the
// non-RTC pipeline.
// TODO(liberato): This also causes the external decoder to use software
// decoding sometimes, which changes the interpretation of "ExternalDecoder".
BASE_FEATURE(…);

// If enabled, when RTCVideoDecoderAdapter is used then SW decoders will be
// exposed directly to WebRTC.
BASE_FEATURE(…);

// CDM host verification is enabled by default. Can be disabled for testing.
// Has no effect if ENABLE_CDM_HOST_VERIFICATION buildflag is false.
BASE_FEATURE(…);

// Use per-CDM-type, per-user and per-site CDM processes (for library CDM). If
// disabled, the CDM processes are only per-CDM-type, meaning different sites
// using the same CDM type would share one CDM process.
BASE_FEATURE(…);

// Enables the "Copy Video Frame" context menu item.
BASE_FEATURE(…);

// Enables the "Save Video Frame As" context menu item.
BASE_FEATURE(…);

// Enables the "Search Video Frame with <Search Provider>" context menu item.
BASE_FEATURE(…);

#if BUILDFLAG(CHROME_WIDE_ECHO_CANCELLATION)
// If echo cancellation for a mic signal is requested, mix and cancel all audio
// playback going to a specific output device in the audio service.
BASE_FEATURE(…);

// When audio processing is done in the audio process, at the renderer side IPC
// is set up to receive audio at the processing sample rate. This is a
// kill-switch to fallback to receiving audio at the default sample rate of the
// audio capture device.
const base::FeatureParam<bool> kChromeWideEchoCancellationMinimizeResampling{ … };

// Dynamically sets audio::SyncReader's timeout based off of a percentage of
// buffer duration, in an attempt to minimize glitches.
// The default negative value indicates that no experiment is running, and
// we shouldn't use a mixing specific timeout value.
// If the similar kDynamicAudioTimeout feature is enabled and this value is set,
// this parameter will override kDynamicAudioTimeout values when we are mixing.
const base::FeatureParam<double>
    kChromeWideEchoCancellationDynamicMixingTimeout{ … };

// Allows all sample rates to be used for audio processing. If disabled, only
// sample rates divisible by 100 are allowed; a request for a media stream with
// enabled audio processing will fail otherwise. For context see
// https://crbug.com/1332484.
const base::FeatureParam<bool> kChromeWideEchoCancellationAllowAllSampleRates{ … };

// https://crbug.com/1420568
// Applicable only if kChromeWideEchoCancellation is enabled.
// If disabled, the ProcessingAudioFifo size defaults to 110.
// If enabled, the ProcessingAudioFifo size is set to the value of the fifo_size
// parameter.
//
// If the ProcessingAudioFifo size is non-zero, audio processing is done on a
// dedicated processing thread which receives audio from the audio capture
// thread via a fifo of a specified size.
// If the ProcessingAudioFifo size is zero, the usage of this processing thread
// is disabled and processing is done on the audio capture thread itself.
BASE_FEATURE(…);

const base::FeatureParam<int> kDecreaseProcessingAudioFifoSizeValue{ … };

#endif

#if BUILDFLAG(IS_CHROMEOS)
// To control running audio communication effect on Chrome OS Audio Server.
BASE_FEATURE(kCrOSSystemAEC,
             "CrOSSystemAECWithBoardTuningsAllowed",
             base::FEATURE_ENABLED_BY_DEFAULT);
BASE_FEATURE(kCrOSSystemAECDeactivatedGroups,
             "CrOSSystemAECDeactivatedGroups",
             base::FEATURE_ENABLED_BY_DEFAULT);
BASE_FEATURE(kCrOSEnforceSystemAecNsAgc,
             "CrOSEnforceSystemAecNsAgc",
             base::FEATURE_DISABLED_BY_DEFAULT);
BASE_FEATURE(kCrOSEnforceSystemAecNs,
             "CrOSEnforceSystemAecNs",
             base::FEATURE_DISABLED_BY_DEFAULT);
BASE_FEATURE(kCrOSEnforceSystemAecAgc,
             "CrOSEnforceSystemAecAgc",
             base::FEATURE_DISABLED_BY_DEFAULT);
BASE_FEATURE(kCrOSEnforceSystemAec,
             "CrOSEnforceSystemAec",
             base::FEATURE_ENABLED_BY_DEFAULT);

BASE_FEATURE(kCrOSDspBasedAecDeactivatedGroups,
             "CrOSDspBasedAecDeactivatedGroups",
             base::FEATURE_ENABLED_BY_DEFAULT);
BASE_FEATURE(kCrOSDspBasedNsDeactivatedGroups,
             "CrOSDspBasedNsDeactivatedGroups",
             base::FEATURE_ENABLED_BY_DEFAULT);
BASE_FEATURE(kCrOSDspBasedAgcDeactivatedGroups,
             "CrOSDspBasedAgcDeactivatedGroups",
             base::FEATURE_ENABLED_BY_DEFAULT);

BASE_FEATURE(kCrOSDspBasedAecAllowed,
             "CrOSDspBasedAecAllowed",
             base::FEATURE_ENABLED_BY_DEFAULT);
BASE_FEATURE(kCrOSDspBasedNsAllowed,
             "CrOSDspBasedNsAllowed",
             base::FEATURE_ENABLED_BY_DEFAULT);
BASE_FEATURE(kCrOSDspBasedAgcAllowed,
             "CrOSDspBasedAgcAllowed",
             base::FEATURE_ENABLED_BY_DEFAULT);

BASE_FEATURE(kIgnoreUiGains, "IgnoreUiGains", base::FEATURE_ENABLED_BY_DEFAULT);
BASE_FEATURE(kShowForceRespectUiGainsToggle,
             "ShowForceRespectUiGainsToggle",
             base::FEATURE_ENABLED_BY_DEFAULT);

BASE_FEATURE(kCrOSSystemVoiceIsolationOption,
             "CrOSSystemVoiceIsolationOption",
             base::FEATURE_DISABLED_BY_DEFAULT);

BASE_FEATURE(kAudioFlexibleLoopbackForSystemLoopback,
             "AudioFlexibleLoopbackForSystemLoopback",
             base::FEATURE_ENABLED_BY_DEFAULT);
#endif

// Make MSE garbage collection algorithm more aggressive when we are under
// moderate or critical memory pressure. This will relieve memory pressure by
// releasing stale data from MSE buffers.
BASE_FEATURE(…);

// Controls whether the Mirroring Service will fetch, analyze, and store
// information on the quality of the session using RTCP logs.
BASE_FEATURE(…);

// Approach original pre-REC MSE object URL autorevoking behavior, though await
// actual attempt to use the object URL for attachment to perform revocation.
// This will hopefully reduce runtime memory bloat for pages that do not
// explicitly detach their HTMLME+MSE object collections nor explicitly revoke
// the object URLs used to attach HTMLME+MSE. When disabled, revocation only
// occurs when application explicitly revokes the object URL, or upon the
// execution context teardown for the MediaSource object. When enabled,
// revocation occurs upon successful start of attachment of HTMLME to the object
// URL. Note, rather than immediately scheduling a task to revoke upon the URL's
// creation, as at least one other browser does and the original File API
// pattern used to follow, this delay until attachment start enables new
// scenarios that could use the object URL for attaching HTMLME+MSE cross-thread
// (MSE-in-workers), where there could be significant delay between the worker
// thread creation of the object URL and the main thread usage of the object URL
// for starting attachment to HTMLME.
BASE_FEATURE(…);

BASE_FEATURE(…);

// Runs the media service in the GPU process on a dedicated thread.
BASE_FEATURE(…);

// Defer requesting persistent audio focus until the WebContents is audible.
// The goal is to prevent silent playback from taking audio focus from
// background apps on android, where focus is typically exclusive.
BASE_FEATURE(…);

// Adds an animation to document picture-in-picture resizes.
BASE_FEATURE(…);

// Allows document picture-in-picture pages to request capture.
BASE_FEATURE(…);

// Falls back to other decoders after audio/video decode error happens. The
// implementation may choose different strategies on when to fallback. See
// DecoderStream for details. When disabled, playback will fail immediately
// after a decode error happens. This can be useful in debugging and testing
// because the behavior is simpler and more predictable.
BASE_FEATURE(…);

// FeatureManagement gate for Live Translate on ChromeOS devices. No impact
// outside of CrOS.
BASE_FEATURE(…);

// Show toolbar button that opens dialog for controlling media sessions.
BASE_FEATURE(…);

// Auto-dismiss global media controls.
BASE_FEATURE(…);

#if !BUILDFLAG(IS_CHROMEOS)
// Updated global media controls UI for all the non-CrOS desktop platforms.
BASE_FEATURE(…);
#endif  // !BUILDFLAG(IS_CHROMEOS)

#if !BUILDFLAG(IS_ANDROID)
// If enabled, users can request Media Remoting without fullscreen-in-tab.
BASE_FEATURE(…);
#endif

// Show picture-in-picture button in Global Media Controls.
BASE_FEATURE(…);

// Enable selection of audio output device in Global Media Controls.
BASE_FEATURE(…);

// CanPlayThrough issued according to standard.
BASE_FEATURE(…);

// Disables the real audio output stream after silent audio has been delivered
// for too long. Should save quite a bit of power in the muted video case.
BASE_FEATURE(…);

// Enables the Unified Autoplay policy by overriding the platform's default
// autoplay policy.
BASE_FEATURE(…);

#if BUILDFLAG(IS_LINUX)
// Enable vaapi video decoding on linux. This is already enabled by default on
// chromeos, but needs an experiment on linux.
BASE_FEATURE(…);

BASE_FEATURE(…);

BASE_FEATURE(…);

// Ignore the non-intel driver blacklist for VaapiVideoDecoder implementations.
// Intended for manual usage only in order to gague the status of newer driver
// implementations.
BASE_FEATURE(…);
#endif  // BUILDFLAG(IS_LINUX)

// NVIDIA VA-API drivers do not support Chromium and can sometimes cause
// crashes, disable VA-API on NVIDIA GPUs by default. See crbug.com/1492880.
BASE_FEATURE(…);

// Enable VA-API hardware low power encoder for all codecs on intel Gen9x gpu.
BASE_FEATURE(…);

// Reject creation of encode/decode VAContexts when the requested resolution is
// outside the enumerated minimum and maximum. TODO(b/171041334): Remove and
// enable by default once the ARC++ hw codecs issue is fixed.
BASE_FEATURE(…);

// Ensure the advertised minimum supported resolution is larger than or equal to
// a given one (likely QVGA + 1) for certain codecs/modes and platforms, for
// performance reasons. This does not affect JPEG decoding.
BASE_FEATURE(…);

// Enable VA-API hardware encode acceleration for VP8.
BASE_FEATURE(…);

// Enable VA-API hardware encode acceleration for VP9.
BASE_FEATURE(…);

// Enable VA-API hardware encode acceleration for AV1.
BASE_FEATURE(…);

// Enable global VA-API lock. Disable this to use lock-free VA-API function
// calls for thread safe backends.
BASE_FEATURE(…);

#if defined(ARCH_CPU_X86_FAMILY) && BUILDFLAG(IS_CHROMEOS)
// TODO(b/214589754): revisit the need for the BUILDFLAG(IS_CHROMEOS) guard (as
// opposed to BUILDFLAG(IS_CHROMEOS_ASH)) when the final design for HW
// encoding is implemented for lacros-chrome.
// Enable H264 temporal layer encoding with HW encoder on ChromeOS.
BASE_FEATURE(kVaapiH264TemporalLayerHWEncoding,
             "VaapiH264TemporalLayerEncoding",
             base::FEATURE_ENABLED_BY_DEFAULT);
// Enable software bitrate controller for H264 temporal layer encoding with HW
// encoder on ChromeOS.
BASE_FEATURE(kVaapiH264SWBitrateController,
             "VaapiH264SWBitrateController",
             base::FEATURE_DISABLED_BY_DEFAULT);
// Enable VP8 temporal layer encoding with HW encoder on ChromeOS.
BASE_FEATURE(kVaapiVp8TemporalLayerHWEncoding,
             "VaapiVp8TemporalLayerEncoding",
             base::FEATURE_ENABLED_BY_DEFAULT);
// Enable VP9 S-mode encoding with HW encoder for webrtc use case on ChromeOS.
BASE_FEATURE(kVaapiVp9SModeHWEncoding,
             "VaapiVp9SModeHWEncoding",
             base::FEATURE_ENABLED_BY_DEFAULT);
// Enables VSync aligned MJPEG decoding.
BASE_FEATURE(kVSyncMjpegDecoding,
             "VSyncMjpegDecoding",
             base::FEATURE_DISABLED_BY_DEFAULT);
#endif  // defined(ARCH_CPU_X86_FAMILY) && BUILDFLAG(IS_CHROMEOS)
#if BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_LINUX)
// Enables the new V4L2StatefulVideoDecoder instead of V4L2VideoDecoder.
// Owners: [email protected], [email protected]
// Expiry: When the |V4L2FlatVideoDecoder| flag handles stateful decoding on
// all platforms.
BASE_FEATURE(…);
// Enable H264 temporal layer encoding with V4L2 HW encoder on ChromeOS.
BASE_FEATURE(…);
#endif

// Inform video blitter of video color space.
BASE_FEATURE(…);

// Controls whether VideoFrames created by WrapSharedImage(s) get the
// texture target to use from the ClientSharedImage(s) that they are passed
// rather than the explicit texture target parameter(s) that they are passed.
// Serves as a killswitch while we roll out this change.
// TODO(crbug.com/346197746): Remove post-safe rollout.
BASE_FEATURE(…);

// Displays new video picture-in-picture controls for the 2024 UI update.
BASE_FEATURE(…);

// A video encoder is allowed to drop a frame in cast mirroring.
BASE_FEATURE(…);

// A video encoder is allowed to drop a frame in WebCodecs.
BASE_FEATURE(…);

// A hardware video encoder is allowed to drop a frame in WebRTC.
BASE_FEATURE(…);

// Inform webrtc with correct video color space information whenever
// possible.
BASE_FEATURE(…);

// Enables support for External Clear Key (ECK) key system for testing on
// supported platforms. On platforms that do not support ECK, this feature has
// no effect.
BASE_FEATURE(…);

#if BUILDFLAG(IS_WIN)
// Specifies the path to the MediaFoundation Clear Key CDM for testing.
const base::FeatureParam<std::string> kMediaFoundationClearKeyCdmPathForTesting{
    &kExternalClearKeyForTesting, "media_foundation_cdm_path", ""};

// Enables the use of a faulty GPU for MediaFoundation. This is used for testing
// purposes only.
BASE_FEATURE(kEnableFaultyGPUForMediaFoundation,
             "EnableFaultyGPUForMediaFoundation",
             base::FEATURE_DISABLED_BY_DEFAULT);
#endif  // BUILDFLAG(IS_WIN)

// Enables the On-Device Web Speech feature on supported devices.
BASE_FEATURE(…);

#if BUILDFLAG(IS_CHROMEOS)
// Enables Lacros Chrome to use the Ash Chrome Widevine CDM.
BASE_FEATURE(kLacrosUseAshWidevine,
             "LacrosUseAshWidevine",
             base::FEATURE_ENABLED_BY_DEFAULT);
#endif

// Enables the Live Caption feature on supported devices.
BASE_FEATURE(…);

// Controls whether a "Share this tab instead" button should be shown for
// getDisplayMedia captures. Note: This flag does not control if the "Share this
// tab instead" button is shown for chrome.desktopCapture captures.
BASE_FEATURE(…);

// If kShareThisTabInsteadButtonGetDisplayMedia is ENABLED, this flag controls
// whether a "Share this tab instead" button should be enabled for
// getDisplayMedia captures with audio.
// If kShareThisTabInsteadButtonGetDisplayMedia is DISABLED, this flag has no
// effect.
// Note: This flag does not control if the "Share this tab instead" button is
// shown for chrome.desktopCapture captures.
BASE_FEATURE(…);

// Enable the Speaker Change Detection feature, which inserts a line break when
// the Speech On-Device API (SODA) detects a speaker change.
BASE_FEATURE(…);

// Log the amount of flickering between partial results. This measures how often
// the system revises earlier outputs, to quantify the system's output
// instability or flicker. Intuitively, it measures how many tokens must be
// truncated from the previous text before appending any new text. The erasure
// of the current timestep can be calculated from its longest common prefix with
// the previous timestep.
BASE_FEATURE(…);

// Use a greedy text stabilizer to reduce flickering when translating partial
// speech recognition results.
BASE_FEATURE(…);

// Use a wait-k approach to reduce flickering when translating partial speech
// recognition results.
BASE_FEATURE(…);

// Live Caption can be used in multiple languages, as opposed to just English.
BASE_FEATURE(…);

// Enable experimental Live Caption languages.
BASE_FEATURE(…);

// Enable automatic downloading of speech recognition language packs.
BASE_FEATURE(…);

// Enable or disable Live Caption from the right click menu.
BASE_FEATURE(…);

// Enable or disable Live Caption support for WebAudio.
BASE_FEATURE(…);

// Live Translate translates captions generated by Live Caption.
BASE_FEATURE(…);

// Prevents UrlProvisionFetcher from making a provisioning request. If
// specified, any provisioning request made will not be sent to the provisioning
// server, and the response will indicate a failure to communicate with the
// provisioning server.
BASE_FEATURE(…);

// Enables hardware secure decryption if supported by hardware and CDM.
// TODO(xhwang): Currently this is only used for development of new features.
// Apply this to Android and ChromeOS as well where hardware secure decryption
// is already available.
BASE_FEATURE(…);

// By default, a codec is not supported for hardware secure decryption if it
// does not support clear lead. This option forces the support for testing.
const base::FeatureParam<bool> kHardwareSecureDecryptionForceSupportClearLead{ … };

// Same as `kHardwareSecureDecryption` above, but only enable experimental
// sub key systems. Which sub key system is experimental is key system specific.
BASE_FEATURE(…);

// Allows automatically disabling hardware secure Content Decryption Module
// (CDM) after failures or crashes to fallback to software secure CDMs. If this
// feature is disabled, the fallback will never happen and users could be stuck
// in playback failures.
BASE_FEATURE(…);

// Whether disabling hardware secure Content Decryption Module
// (CDM) after failures or crashes to fallback to software secure CDMs should
// use per site logic.
const base::FeatureParam<bool> kHardwareSecureDecryptionFallbackPerSite{ … };

// The minimum and maximum number of days to disable hardware secure Content
// Decryption Module (CDM) as part of the fallback logic.
const base::FeatureParam<int> kHardwareSecureDecryptionFallbackMinDisablingDays{ … };
const base::FeatureParam<int> kHardwareSecureDecryptionFallbackMaxDisablingDays{ … };

// Whether selected HardwareContextReset events should be considered as failures
// in the hardware secure decryption fallback logic.
const base::FeatureParam<bool>
    kHardwareSecureDecryptionFallbackOnHardwareContextReset{ … };

// If active, enable HiDPI mode that increases the display scale factor
// while capturing a low-resolution tab.
BASE_FEATURE(…);

// Enables handling of hardware media keys for controlling media.
BASE_FEATURE(…);

// Enables a platform-specific resolution cutoff for prioritizing platform
// decoders over software decoders or vice-versa.
BASE_FEATURE(…);

// Forces use of hardware (platform) video decoders in
// `media::DecoderSelector`.
BASE_FEATURE(…);

// Forces use of hardware (platform) audio decoders in
// `media::DecoderSelector`.
BASE_FEATURE(…);

// Enables low-delay video rendering in media pipeline on "live" stream.
BASE_FEATURE(…);

// Allows the AutoPictureInPictureTabHelper to automatically enter
// picture-in-picture for websites with video playback (instead of only websites
// using camera or microphone).
BASE_FEATURE(…);

// Whether we should show a setting to disable autoplay policy.
BASE_FEATURE(…);

// Whether we should allow color space changes to flush AcceleratedVideoDecoder.
BASE_FEATURE(…);

// Whether FFmpeg supports decoding H.264 video in software. Has no effect if
// BUILDFLAG(ENABLE_FFMPEG_VIDEO_DECODERS) is false.
BASE_FEATURE(…);

#if BUILDFLAG(IS_ANDROID)
// Should we allow video playback to use an overlay if it's not needed for
// security?  Normally, we'd always want to allow this, except as part of the
// power testing A/B experiment.  https://crbug.com/1081346 .
BASE_FEATURE(kAllowNonSecureOverlays,
             "AllowNonSecureOverlays",
             base::FEATURE_ENABLED_BY_DEFAULT);

// Allow FrameInfoHelper to guess coded size information for MediaCodec frames.
BASE_FEATURE(kMediaCodecCodedSizeGuessing,
             "MediaCodecCodedSizeGuessing",
             base::FEATURE_ENABLED_BY_DEFAULT);

// Enable a gesture to make the media controls expanded into the display cutout.
// TODO(beccahughes): Remove this.
BASE_FEATURE(kMediaControlsExpandGesture,
             "MediaControlsExpandGesture",
             base::FEATURE_ENABLED_BY_DEFAULT);

// An experimental feature to enable persistent-license type support in MediaDrm
// when using Encrypted Media Extensions (EME) API.
// TODO(xhwang): Remove this after feature launch. See http://crbug.com/493521
BASE_FEATURE(kMediaDrmPersistentLicense,
             "MediaDrmPersistentLicense",
             base::FEATURE_ENABLED_BY_DEFAULT);

// Enables MediaDrmOriginIdManager to provide preprovisioned origin IDs for
// MediaDrmBridge. If disabled, MediaDrmBridge will get unprovisioned origin IDs
// which will trigger provisioning process after MediaDrmBridge is created.
BASE_FEATURE(kMediaDrmPreprovisioning,
             "MediaDrmPreprovisioning",
             base::FEATURE_ENABLED_BY_DEFAULT);

// Determines if MediaDrmOriginIdManager should attempt to pre-provision origin
// IDs at startup (whenever a profile is loaded). Also used by tests that
// disable it so that the tests can setup before pre-provisioning is done.
// Note: Has no effect if kMediaDrmPreprovisioning feature is disabled.
BASE_FEATURE(kMediaDrmPreprovisioningAtStartup,
             "MediaDrmPreprovisioningAtStartup",
             base::FEATURE_ENABLED_BY_DEFAULT);

// Enables MediaDrmBridge to call into MediaDrm API to query HDCP Status to
// support the CDM API GetStatusForPolicy.
BASE_FEATURE(kMediaDrmGetStatusForPolicy,
             "MediaDrmGetStatusForPolicy",
             base::FEATURE_ENABLED_BY_DEFAULT);

// Enables the use of MediaPlayerRenderer for HLS playback. When disabled,
// HLS manifests will fail to load (triggering source fallback or load error).
BASE_FEATURE(kHlsPlayer, "HlsPlayer", base::FEATURE_ENABLED_BY_DEFAULT);

// When enabled, Playing media sessions will request audio focus from the
// Android system.
BASE_FEATURE(kRequestSystemAudioFocus,
             "RequestSystemAudioFocus",
             base::FEATURE_ENABLED_BY_DEFAULT);

// Use the (hacky) AudioManager.getOutputLatency() call to get the estimated
// hardware latency for a stream for OpenSLES playback.  This is normally not
// needed, except for some Android TV devices.
BASE_FEATURE(kUseAudioLatencyFromHAL,
             "UseAudioLatencyFromHAL",
             base::FEATURE_DISABLED_BY_DEFAULT);

// Enable pooling of AndroidVideoImageBacking objects for use by MCVD, to save a
// hop to the GPU main thread during VideoFrame construction.
BASE_FEATURE(kUsePooledSharedImageVideoProvider,
             "UsePooledSharedImageVideoProvider",
             base::FEATURE_ENABLED_BY_DEFAULT);

// Allow the media pipeline to prioritize the software decoder provided by
// MediaCodec, instead of the built-in software decoders. This is only enabled
// for platforms which shows worse performance when using the built-in software
// decoders, e.g. Cast on ATV.
BASE_FEATURE(kAllowMediaCodecSoftwareDecoder,
             "AllowMediaCodecSoftwareDecoder",
             base::FEATURE_DISABLED_BY_DEFAULT);

// This feature allows for some MediaDrm functions to be executed in a separate
// process so that crashes do not bring down the browser. Flag is available so
// that it can be disabled for WebView as separate processes are not allowed.
BASE_FEATURE(kAllowMediaCodecCallsInSeparateProcess,
             "AllowMediaCodecCallsInSeparateProcess",
             base::FEATURE_ENABLED_BY_DEFAULT);

#endif  // BUILDFLAG(IS_ANDROID)

#if BUILDFLAG(ENABLE_HLS_DEMUXER)
BASE_FEATURE(kBuiltInHlsPlayer,
             "BuiltInHlsPlayer",
             base::FEATURE_DISABLED_BY_DEFAULT
);

BASE_FEATURE(kBuiltInHlsMP4,
             "BuiltInHlsMP4",
             base::FEATURE_DISABLED_BY_DEFAULT);

BASE_FEATURE(kMediaPlayerHlsStatistics,
             "MediaPlayerHlsStatistics",
             base::FEATURE_ENABLED_BY_DEFAULT);
#endif  // BUILDFLAG(ENABLE_HLS_DEMUXER)

#if BUILDFLAG(USE_CHROMEOS_MEDIA_ACCELERATION)
// Enable hardware AV1 decoder on ChromeOS.
BASE_FEATURE(…);

// Enable Variable Bitrate encoding with hardware accelerated encoders on
// ChromeOS.
BASE_FEATURE(…);

// Limit the number of concurrent hardware decoder instances on ChromeOS.
BASE_FEATURE(…);

// Use SequencedTaskRunner for VideoEncodeAccelerator
BASE_FEATURE(…);

#if defined(ARCH_CPU_ARM_FAMILY)
// Experimental support for GL based scaling for NV12 on Trogdor.
// Normally LibYUV is used to scale these frames. This flag enables
// an experimental GL-based scaling method.
// Owner: [email protected]
// Expiry: When GLImageProcessor is deleted
BASE_FEATURE(kUseGLForScaling,
             "UseGLForScaling",
             base::FEATURE_ENABLED_BY_DEFAULT);
// Experimental support for GL based image processing. On some architectures,
// the hardware accelerated video decoder outputs frames in a format not
// understood by the display controller. We usually use LibYUV to convert these
// frames. This flag enables an experimental GL-based conversion method.
BASE_FEATURE(kPreferGLImageProcessor,
             "PreferGLImageProcessor",
             base::FEATURE_DISABLED_BY_DEFAULT);
// Experimental support for software based MT21 conversion. On some (older)
// architectures, the hardware video decoder outputs frames in a pixel format
// known as MT21. Normally a hardware block performs to the conversion between
// this pixel format and NV12, but this flag will use a software equivalent
// instead.
BASE_FEATURE(kPreferSoftwareMT21,
             "PreferSoftwareMT21",
             base::FEATURE_DISABLED_BY_DEFAULT);
// Enable populating the |needs_detiling| field in |VideoFrameMetadata|. This in
// turn triggers Skia to use the |VulkanImageProcessor| for detiling protected
// content.
// Owner: [email protected]
// Expiry: When Vulkan detiling is thoroughly tested and verified to work.
BASE_FEATURE(kEnableProtectedVulkanDetiling,
             "EnableProtectedVulkanDetiling",
             base::FEATURE_ENABLED_BY_DEFAULT);
// Enable AR30 overlays for 10-bit ARM HWDRM content. If disabled, we will use
// ARGB8888 instead.
// Owner: [email protected]
// Expiry: When AR30 overlays are stable on devices that support them.
BASE_FEATURE(kEnableArmHwdrm10bitOverlays,
             "EnableArmHwdrm10bitOverlays",
             base::FEATURE_ENABLED_BY_DEFAULT);
#if BUILDFLAG(USE_CHROMEOS_PROTECTED_MEDIA)
// Enable use of HW based L1 Widevine DRM via the cdm-oemcrypto daemon on
// ChromeOS. This flag is temporary while we finish development.
// Expiry: M128
BASE_FEATURE(kEnableArmHwdrm,
             "EnableArmHwdrm",
             base::FEATURE_DISABLED_BY_DEFAULT);
#endif  // BUILDFLAG(USE_CHROMEOS_PROTECTED_MEDIA)
#endif  // defined(ARCH_CPU_ARM_FAMILY)
#endif  // BUILDFLAG(USE_CHROMEOS_MEDIA_ACCELERATION)

#if BUILDFLAG(IS_WIN)
// Enables DirectShow GetPhotoState implementation
// Created to act as a kill switch by disabling it, in the case of the
// resurgence of https://crbug.com/722038
BASE_FEATURE(kDirectShowGetPhotoState,
             "DirectShowGetPhotoState",
             base::FEATURE_ENABLED_BY_DEFAULT);

// Includes Infrared cameras in the list returned for EnumerateDevices() on
// Windows.
BASE_FEATURE(kIncludeIRCamerasInDeviceEnumeration,
             "IncludeIRCamerasInDeviceEnumeration",
             base::FEATURE_DISABLED_BY_DEFAULT);

// Enables software rate controller encoding acceleration for Windows.
BASE_FEATURE(kMediaFoundationUseSoftwareRateCtrl,
             "MediaFoundationUseSoftwareRateCtrl",
             base::FEATURE_ENABLED_BY_DEFAULT);

// Enables MediaFoundation based video capture
BASE_FEATURE(kMediaFoundationVideoCapture,
             "MediaFoundationVideoCapture",
             base::FEATURE_ENABLED_BY_DEFAULT);

// Enables MediaFoundation based video capture with D3D11
// For feature check of kMediaFoundationD3D11VideoCapture at runtime,
// please use IsMediaFoundationD3D11VideoCaptureEnabled() instead.
BASE_FEATURE(kMediaFoundationD3D11VideoCapture,
             "MediaFoundationD3D11VideoCapture",
             base::FEATURE_ENABLED_BY_DEFAULT);

// Enable zero-copy based on MediaFoundation video capture with D3D11.
BASE_FEATURE(kMediaFoundationD3D11VideoCaptureZeroCopy,
             "MediaFoundationD3D11VideoCaptureZeroCopy",
             base::FEATURE_DISABLED_BY_DEFAULT);

// Enables VP8 decode acceleration for Windows.
BASE_FEATURE(kMediaFoundationVP8Decoding,
             "MediaFoundationVP8Decoding",
             base::FEATURE_DISABLED_BY_DEFAULT);

// Enables the use of MediaFoundationRenderer for clear content on supported
// systems.
BASE_FEATURE(kMediaFoundationClearPlayback,
             "MediaFoundationClearPlayback",
             base::FEATURE_DISABLED_BY_DEFAULT);

// Enable VP9 kSVC decoding with HW decoder for webrtc use case on Windows.
BASE_FEATURE(kD3D11Vp9kSVCHWDecoding,
             "D3D11Vp9kSVCHWDecoding",
             base::FEATURE_DISABLED_BY_DEFAULT);

// The Media Foundation Rendering Strategy determines which presentation mode
// Media Foundation Renderer should use for presenting clear content. This
// strategy has no impact for protected content, which must always use Direct
// Composition.
//
// The strategy may be one of the following options:
// 1.) Direct Composition: Media Foundation Renderer will use a Windowsless
//     Swapchain to present directly to a Direct Composition surface.
// 2.) Frame Server: Media Foundation Renderer will produce Video Frames that
//     may be passed through the Chromium video frame rendering pipeline.
// 3.) Dynamic: Media Foundation Renderer may freely switch between Direct
//     Composition & Frame Server mode based on the current operating
//     conditions.
//
// Command line invocation:
// --enable-features=MediaFoundationClearRendering:strategy/direct-composition
// --enable-features=MediaFoundationClearRendering:strategy/frame-server
// --enable-features=MediaFoundationClearRendering:strategy/dynamic
BASE_FEATURE(kMediaFoundationClearRendering,
             "MediaFoundationClearRendering",
             base::FEATURE_ENABLED_BY_DEFAULT);

constexpr base::FeatureParam<MediaFoundationClearRenderingStrategy>::Option
    kMediaFoundationClearRenderingStrategyOptions[] = {
        {MediaFoundationClearRenderingStrategy::kDirectComposition,
         "direct-composition"},
        {MediaFoundationClearRenderingStrategy::kFrameServer, "frame-server"},
        {MediaFoundationClearRenderingStrategy::kDynamic, "dynamic"}};

const base::FeatureParam<MediaFoundationClearRenderingStrategy>
    kMediaFoundationClearRenderingStrategyParam{
        &kMediaFoundationClearRendering, "strategy",
        MediaFoundationClearRenderingStrategy::kDynamic,
        &kMediaFoundationClearRenderingStrategyOptions};

BASE_FEATURE(kMediaFoundationBatchRead,
             "MediaFoundationBatchRead",
             base::FEATURE_DISABLED_BY_DEFAULT);

const base::FeatureParam<int> kBatchReadCount{&kMediaFoundationBatchRead,
                                              "batch_read_count", 1};
#endif  // BUILDFLAG(IS_WIN)

#if BUILDFLAG(ENABLE_PLATFORM_ENCRYPTED_DOLBY_VISION)
// When ENABLE_PLATFORM_ENCRYPTED_DOLBY_VISION is enabled at build time, allow
// the support of encrypted Dolby Vision. Have no effect when
// ENABLE_PLATFORM_ENCRYPTED_DOLBY_VISION is disabled.
BASE_FEATURE(kPlatformEncryptedDolbyVision,
             "PlatformEncryptedDolbyVision",
             base::FEATURE_DISABLED_BY_DEFAULT);

// When ENABLE_PLATFORM_ENCRYPTED_DOLBY_VISION is enabled at build time and
// `kPlatformEncryptedDolbyVision` is enabled at run time, encrypted Dolby
// Vision is allowed in Media Source while clear Dolby Vision is not allowed.
// In this case, this feature allows the support of clear Dolby Vision in Media
// Source, which is useful to work around some JavaScript player limitations.
// Otherwise, this feature has no effect and neither encrypted nor clear Dolby
// Vision is allowed.
BASE_FEATURE(kAllowClearDolbyVisionInMseWhenPlatformEncryptedDvEnabled,
             "AllowClearDolbyVisionInMseWhenPlatformEncryptedDvEnabled",
             base::FEATURE_DISABLED_BY_DEFAULT);
#endif

#if BUILDFLAG(IS_CHROMEOS_ASH)
// Expose the out-of-process video decoding feature from ash-chrome to
// lacros-chrome through the crosapi.
BASE_FEATURE(kExposeOutOfProcessVideoDecodingToLacros,
             "ExposeOutOfProcessVideoDecodingToLacros",
             base::FEATURE_ENABLED_BY_DEFAULT);

// Enables the new media player features.
BASE_FEATURE(kBackgroundListening,
             "BackgroundListening",
             base::FEATURE_DISABLED_BY_DEFAULT);
#endif  // BUILDFLAG(IS_CHROMEOS_ASH)

#if BUILDFLAG(ALLOW_OOP_VIDEO_DECODER)
// Spawn utility processes to perform hardware decode acceleration on behalf of
// renderer processes (instead of using the GPU process). The GPU process will
// still be used as a proxy between renderers and utility processes (see
// go/oop-vd-dd). This feature and |kUseGTFOOutOfProcessVideoDecoding| are
// mutually exclusive.
BASE_FEATURE(…);

// Spawn utility processes to perform hardware decode acceleration on behalf of
// renderer processes (instead of using the GPU process). The GPU process will
// NOT be used as a proxy between renderers and utility processes (see
// go/oopvd-gtfo-dd). This feature and |kUseOutOfProcessVideoDecoding| are
// mutually exclusive.
// Owner: [email protected]
// Expiry: one milestone after this path is enabled by default
BASE_FEATURE(…);
#endif  // BUILDFLAG(ALLOW_OOP_VIDEO_DECODER)

#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
// Spawn utility processes to perform hardware encode acceleration instead of
// using the GPU process.
BASE_FEATURE(…);
#endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)

// Use SequencedTaskRunner for MediaService.
BASE_FEATURE(…);

// SequencedTaskRunner isn't supported on Windows since the accelerator requires
// a COM STA TaskRunner.
#if !BUILDFLAG(IS_WIN)
// Use SequencedTaskRunner for MojoVideoEncodeAcceleratorProvider.
BASE_FEATURE(…);
#endif  // !BUILDFLAG(IS_WIN)

// Use TaskRunner for each MojoVideoEncodeAcceleratorService. Replaces
// per-accelerator encoding task runner.
BASE_FEATURE(…);

// Feature flag to run the MojoAudioDecoderService in a sequence different than
// the other mojo media services. On some Android devices, MediaCodec may block
// the thread which leads to frequent audio decoder underrun in renderer.
// Running the audio decoder in a separate sequence can improve the performance.
// Note: running audio decoder in a separate thread/sequence will cause
// multithread access to mojo media services. For Android audio decoder, the
// thread safety is easier to guarantee because:
//   1. The audio decoder and most of the other mojo media services don't cross
//   reference each other.
//   2. The only exception is CDM so we use a lock inside MojoCdmServiceContext
//   for thread safety.
BASE_FEATURE(…);

std::string GetEffectiveAutoplayPolicy(const base::CommandLine& command_line) { … }

// Enables Media Engagement Index recording. This data will be used to determine
// when to bypass autoplay policies. This is recorded on all platforms.
BASE_FEATURE(…);

// Enables Media Engagement Index recording for Web Audio playbacks.
BASE_FEATURE(…);

#if BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_LINUX)
// Reduces the number of buffers needed in the output video frame pool to
// populate the Renderer pipeline for hardware accelerated VideoDecoder in
// non-low latency scenarios.
BASE_FEATURE(…);
#endif

// The following Media Engagement flags are not enabled on mobile platforms:
// - MediaEngagementBypassAutoplayPolicies: enables the Media Engagement Index
//   data to be esude to override autoplay policies. An origin with a high MEI
//   will be allowed to autoplay.
// - PreloadMediaEngagementData: enables a list of origins to be considered as
//   having a high MEI until there is enough local data to determine the user's
//   preferred behaviour.
BASE_FEATURE(…);
BASE_FEATURE(…);

BASE_FEATURE(…);

// Enables experimental local learning for media. Used in the context of media
// capabilities only. Adds reporting only; does not change media behavior.
BASE_FEATURE(…);

// Enables the general purpose media machine learning framework. Adds reporting
// only; does not change media behavior.
BASE_FEATURE(…);

// Enables the smoothness prediction experiment.  Requires
// kMediaLearningFramework to be enabled also, else it does nothing.
BASE_FEATURE(…);

// Enable the prototype global optimization of tuneables via finch.  See
// media/base/tuneable.h for how to create tuneable parameters.
BASE_FEATURE(…);

// Enable aggregate power measurement for media playback.
BASE_FEATURE(…);

// Enables flash to be ducked by audio focus. This is enabled on Chrome OS which
// has audio focus enabled.
BASE_FEATURE(…);

// Only affects Android. Suspends a media session when audio focus is lost; when
// this setting is disabled, an Android media session will not be suspended when
// Audio focus is lost. This is used by Cast which sometimes needs to drive
// multiple media sessions.
BASE_FEATURE(…);

// Hides the media metadata from the OS' media player if running in an Incognito
// session.
BASE_FEATURE(…);

// Enables the internal Media Session logic without enabling the Media Session
// service.
BASE_FEATURE(…);

// Keypress detection which serves as input to noise suppression methods
// in WebRTC clients. This functionality is enabled by default but it can be
// disabled experemantally by using --disable-features=KeyPressMonitoring.
BASE_FEATURE(…);

BASE_FEATURE(…);

#if !BUILDFLAG(IS_ANDROID) && !BUILDFLAG(IS_CHROMEOS) && !BUILDFLAG(IS_FUCHSIA)
// Enables effects for camera and mic streams.
BASE_FEATURE(…);
#endif  // !BUILDFLAG(IS_ANDROID) && !BUILDFLAG(IS_CHROMEOS) &&
        // !BUILDFLAG(IS_FUCHSIA)

// Controls whether system loopback audio can be Cast to audio-only Cast
// receivers, e.g. speakers.
// TODO(crbug.com/40579200): Remove once launched.
BASE_FEATURE(…);

// Controls whether mirroring negotiations will include the AV1 codec for video
// encoding.
//
// NOTE: currently only software AV1 encoding is supported.
// TODO(crbug.com/40246079): hardware AV1 encoding should be added.
BASE_FEATURE(…);

// Controls whether the new exponential bitrate calculate logic is used, or
// the legacy linear algorithm.
BASE_FEATURE(…);

BASE_FEATURE(…);

// Controls whether mirroring negotiations will include the VP9 codec for video
// encoding.
//
// NOTE: this is the default codec for Cast Streaming. Be careful when
// disabling.
BASE_FEATURE(…);

// Controls whether mirroring negotiations will include the VP9 codec for video
// encoding.
//
// NOTE: currently only software VP9 encoding is supported.
// TODO(https://crbug.com/1311770): hardware VP9 encoding should be added.
BASE_FEATURE(…);

#if BUILDFLAG(IS_MAC)
// Controls whether hardware H264 is default enabled on macOS.
BASE_FEATURE(kCastStreamingMacHardwareH264,
             "CastStreamingMacHardwareH264",
             base::FEATURE_ENABLED_BY_DEFAULT);
#endif

#if BUILDFLAG(IS_FUCHSIA)
// Enables use of Fuchsia's Mediacodec service for encoding.
BASE_FEATURE(kFuchsiaMediacodecVideoEncoder,
             "FuchsiaMediacodecVideoEncoder",
             base::FEATURE_DISABLED_BY_DEFAULT);
#endif  // BUILDFLAG(IS_FUCHSIA)

// Controls whether to pre-dispatch more decode tasks when pending decodes is
// smaller than maximum supported decodes as advertiszed by decoder.
BASE_FEATURE(…);

// Safety switch to allow us to revert to the previous behavior of using the
// restored bounds for PiP windows, rather than the window bounds.  If this
// feature is enabled (the default), then we'll use the window bounds.
BASE_FEATURE(…);

// Enables FFmpeg allow lists for supported codecs / containers.
BASE_FEATURE(…);

#if BUILDFLAG(IS_WIN)
// Enables audio offload when supported by endpoints.
BASE_FEATURE(kAudioOffload, "AudioOffload", base::FEATURE_DISABLED_BY_DEFAULT);

// The buffer time in milliseconds for audio offload.
const base::FeatureParam<double> kAudioOffloadBufferTimeMs{
    &kAudioOffload, "buffer_time_ms", 50};
#endif

// Enables sending MediaLog to the log stream, which is useful for easier
// development by ensuring logs can be seen without a remote desktop session.
// Only affects builds when DCHECK is on for non-ERROR logs (ERROR logs are
// always sent to the log stream). Enabled by default on Android and ChromeOS.
BASE_FEATURE(…);

BASE_FEATURE(…);
BASE_FEATURE(…);

#if BUILDFLAG(IS_WIN)
// Controls whether to use D3D12 video decoder instead of D3D11 when supported.
BASE_FEATURE(kD3D12VideoDecoder,
             "D3D12VideoDecoder",
             base::FEATURE_DISABLED_BY_DEFAULT);
#endif

#if BUILDFLAG(IS_WIN) && defined(ARCH_CPU_ARM64)
// Allow MF-accelerated video encoding.
BASE_FEATURE(kMediaFoundationAcceleratedEncodeOnArm64,
             "MediaFoundationAcceleratedEncodeOnArm64",
             base::FEATURE_ENABLED_BY_DEFAULT);
#endif

// Convert SharedBitmap to SharedImage for media resources.
BASE_FEATURE(…);

bool IsChromeWideEchoCancellationEnabled() { … }

bool IsDedicatedMediaServiceThreadEnabled(gl::ANGLEImplementation impl) { … }

int GetProcessingAudioFifoSize() { … }

bool IsHardwareSecureDecryptionEnabled() { … }

bool IsLiveTranslateEnabled() { … }

bool IsVideoCaptureAcceleratedJpegDecodingEnabled() { … }

#if BUILDFLAG(IS_WIN)
bool IsMediaFoundationD3D11VideoCaptureEnabled() {
  return base::FeatureList::IsEnabled(kMediaFoundationD3D11VideoCapture);
}
#endif

#if BUILDFLAG(ALLOW_OOP_VIDEO_DECODER)
OOPVDMode GetOutOfProcessVideoDecodingMode() { … }
#endif  // BUILDFLAG(ALLOW_OOP_VIDEO_DECODER)

// Return bitmask of audio formats supported by EDID.
uint32_t GetPassthroughAudioFormats() { … }

}  // namespace media
chromium/media/base/media_switches.cc
