Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: 932d9b36d64da93a2a6a6c1af0ee2ffc7ac0c151
https://github.com/WebKit/WebKit/commit/932d9b36d64da93a2a6a6c1af0ee2ffc7ac0c151
Author: Youenn Fablet <[email protected]>
Date: 2026-06-15 (Mon, 15 Jun 2026)
Changed paths:
A LayoutTests/http/wpt/webrtc/peer-connection-color-space-expected.txt
A LayoutTests/http/wpt/webrtc/peer-connection-color-space-worker.js
A LayoutTests/http/wpt/webrtc/peer-connection-color-space.html
M LayoutTests/platform/glib/TestExpectations
M Source/ThirdParty/libwebrtc/Configurations/libwebrtc.exp
M
Source/ThirdParty/libwebrtc/Source/webrtc/webkit_sdk/WebKit/WebKitDecoder.h
M
Source/ThirdParty/libwebrtc/Source/webrtc/webkit_sdk/WebKit/WebKitDecoder.mm
M Source/WebCore/Headers.cmake
M Source/WebCore/WebCore.xcodeproj/project.pbxproj
M Source/WebCore/platform/SourcesLibWebRTC.txt
M Source/WebCore/platform/libwebrtc/LibWebRTCVPXVideoEncoder.cpp
M Source/WebCore/platform/mediastream/RealtimeOutgoingVideoSource.cpp
A
Source/WebCore/platform/mediastream/libwebrtc/LibWebRTCColorSpaceUtilities.h
A
Source/WebCore/platform/mediastream/libwebrtc/LibWebRTCVideoFrameUtilities.cpp
M
Source/WebCore/platform/mediastream/libwebrtc/LibWebRTCVideoFrameUtilities.h
M Source/WebCore/platform/video-codecs/cocoa/WebRTCVideoDecoder.h
M Source/WebCore/platform/video-codecs/cocoa/WebRTCVideoDecoder.mm
M Source/WebCore/platform/video-codecs/cocoa/WebRTCVideoDecoderVTB.h
M Source/WebCore/platform/video-codecs/cocoa/WebRTCVideoDecoderVTB.mm
M Source/WebKit/GPUProcess/webrtc/LibWebRTCCodecsProxy.h
M Source/WebKit/GPUProcess/webrtc/LibWebRTCCodecsProxy.messages.in
M Source/WebKit/GPUProcess/webrtc/LibWebRTCCodecsProxy.mm
M Source/WebKit/WebProcess/GPU/webrtc/LibWebRTCCodecs.cpp
M Source/WebKit/WebProcess/GPU/webrtc/LibWebRTCCodecs.h
Log Message:
-----------
WebRTC HDR decoding should be enabled via the RTP color space information
rdar://178529773
https://bugs.webkit.org/show_bug.cgi?id=316393
Reviewed by Jean-Yves Avenard.
WebRTC video has two channels for color-space metadata: in-band (the codec
bitstream's own color tags, e.g. VP9's color_space field) and out-of-band
(libwebrtc's WebRTC ColorSpace metadata, populated from the RTP color-space
header extension RFC 7798 §3.4 and surfaced as
EncodedImage::ColorSpace()).
Until now the GPU-process VTB decoder only honored the in-band channel.
For HDR over WebRTC — where senders signal BT.2020/PQ via the RTP
extension while the bitstream may not carry equivalent in-band tags
(or carries an SDR fallback) — frames came out tagged as their bitstream
color space rather than the sender's intended HDR space.
This patch routes the libwebrtc-surfaced per-frame ColorSpace through to
the GPU-side decoder (building on the VideoInfo/colorSpaceOverride
refactoring in the preceding commit) so the receiver tags decoded
VideoFrames with the right color space, and so VTB produces a
CMVideoFormatDescription whose extensions reflect that color space (which
AVSampleBufferDisplayLayer then uses for HDR display routing).
Plumbing, in order:
- WebKitDecoder.h: VideoDecoderDecodeCallback gains a const
webrtc::ColorSpace* parameter (forward-declared in the webrtc namespace).
- WebKitDecoder.mm RemoteVideoDecoder::Decode reads
input_image.ColorSpace() (a const std::optional<ColorSpace>&) and
passes the optional's address (or nullptr) through the callback.
- LibWebRTCVideoFrameUtilities.h: the existing
colorSpaceFromLibWebRTCVideoFrame is refactored to delegate to a new
colorSpaceFromLibWebRTCColorSpace(const webrtc::ColorSpace&), so the
libwebrtc → PlatformVideoColorSpace translation is reusable from the
decode-callback path. A pointer overload is also provided for
convenience.
- LibWebRTCCodecs.cpp's decodeVideoFrame static converts the
webrtc::ColorSpace* to std::optional<PlatformVideoColorSpace> at the
boundary; WebKit code never sees webrtc:: types beyond this point.
- LibWebRTCCodecs::decodeWebRTCFrame compares the surfaced color space
against decoder.colorSpaceOverride. On change (including clearing to
nullopt when the RTP extension is absent), it updates the WebProcess-side
store and sends a new SetDecoderColorSpaceOverride IPC so the GPU-side
decoder applies the override on subsequent frames.
Storing on the WebProcess side also means the override survives a GPU
process bounce — createRemoteDecoder already re-sends CreateDecoder
with decoder.colorSpaceOverride.
- LibWebRTCCodecsProxy gets the new SetDecoderColorSpaceOverride
message + handler, which forwards into
WebRTCVideoDecoder::setColorSpaceOverride.
- WebRTCVideoDecoder gains setColorSpaceOverride() (WEBCORE_EXPORT) and
the colorSpaceOverrideChanged() virtual hook. WebRTCVideoDecoderVTB
implements the hook to call updateFormat() with the stored VideoInfo,
triggering an immediate format description rebuild.
Test: http/wpt/webrtc/peer-connection-color-space.html
The test creates two VideoTrackGenerator-backed tracks in a worker —
one tagged BT.601, one BT.709 — runs them through a loopback PC over
VP9, and reads the receiver-side color space via MediaStreamTrackProcessor
(also worker-only). Then it swaps which generator carries which color
space and verifies the change propagates end-to-end.
The test runs twice: once without modification, exercising the
in-bitstream path; and once with a sender-side RTCRtpScriptTransform
that overwrites the VP9 keyframe's color_space field with CS_UNKNOWN
before transmission. The second run is what specifically exercises the
new RTP-metadata path through the plumbing above — bitstream tags are
gone, so the receiver's only source of color-space info is libwebrtc's
EncodedImage::ColorSpace().
The test also runs with AV1 for completeness and to handle change of
color space outside of a key frame.
We also update LibWebRTC color space utilities so that we can use them in
WebKit.
We split LibWebRTCVideoFrameUtilities.h in LibWebRTCVideoFrameUtilities.cpp and
LibWebRTCColorSpaceUtilities.h to limit header dependencies.
Test: http/wpt/webrtc/peer-connection-color-space.html
* LayoutTests/http/wpt/webrtc/peer-connection-color-space-expected.txt: Added.
* LayoutTests/http/wpt/webrtc/peer-connection-color-space-worker.js: Added.
* LayoutTests/http/wpt/webrtc/peer-connection-color-space.html: Added.
* LayoutTests/platform/glib/TestExpectations:
* Source/ThirdParty/libwebrtc/Configurations/libwebrtc.exp:
* Source/ThirdParty/libwebrtc/Source/webrtc/webkit_sdk/WebKit/WebKitDecoder.h:
* Source/ThirdParty/libwebrtc/Source/webrtc/webkit_sdk/WebKit/WebKitDecoder.mm:
* Source/WebCore/Headers.cmake:
* Source/WebCore/WebCore.xcodeproj/project.pbxproj:
* Source/WebCore/platform/SourcesLibWebRTC.txt:
* Source/WebCore/platform/libwebrtc/LibWebRTCVPXVideoEncoder.cpp:
* Source/WebCore/platform/mediastream/LibWebRTCColorSpaceUtilities.h: Copied
from
Source/WebCore/platform/mediastream/libwebrtc/LibWebRTCVideoFrameUtilities.h.
* Source/WebCore/platform/mediastream/LibWebRTCVideoFrameUtilities.cpp: Copied
from
Source/WebCore/platform/mediastream/libwebrtc/LibWebRTCVideoFrameUtilities.h.
(WebCore::colorSpaceFromLibWebRTCColorSpace):
(WebCore::colorSpaceFromLibWebRTCVideoFrame):
(WebCore::videoRotationFromLibWebRTCVideoFrame):
* Source/WebCore/platform/mediastream/RealtimeOutgoingVideoSource.cpp:
* Source/WebCore/platform/mediastream/libwebrtc/LibWebRTCColorSpaceUtilities.h:
Copied from
Source/WebCore/platform/mediastream/libwebrtc/LibWebRTCVideoFrameUtilities.h.
(WebCore::toWebRTCColorSpace):
(WebCore::colorSpaceFromLibWebRTCColorSpace):
(WebCore::colorSpaceFromLibWebRTCVideoFrame):
(WebCore::videoRotationFromLibWebRTCVideoFrame):
*
Source/WebCore/platform/mediastream/libwebrtc/LibWebRTCVideoFrameUtilities.cpp:
Copied from
Source/WebCore/platform/mediastream/libwebrtc/LibWebRTCVideoFrameUtilities.h.
(WebCore::colorSpaceFromLibWebRTCColorSpace):
(WebCore::colorSpaceFromLibWebRTCVideoFrame):
(WebCore::videoRotationFromLibWebRTCVideoFrame):
* Source/WebCore/platform/mediastream/libwebrtc/LibWebRTCVideoFrameUtilities.h:
(WebCore::colorSpaceFromLibWebRTCColorSpace):
(WebCore::toWebRTCColorSpace): Deleted.
(WebCore::colorSpaceFromLibWebRTCVideoFrame): Deleted.
(WebCore::videoRotationFromLibWebRTCVideoFrame): Deleted.
* Source/WebCore/platform/video-codecs/cocoa/WebRTCVideoDecoder.h:
(WebCore::WebRTCVideoDecoder::colorSpaceOverrideChanged):
* Source/WebCore/platform/video-codecs/cocoa/WebRTCVideoDecoder.mm:
(WebCore::WebRTCVideoDecoder::setColorSpaceOverride):
* Source/WebCore/platform/video-codecs/cocoa/WebRTCVideoDecoderVTB.h:
* Source/WebCore/platform/video-codecs/cocoa/WebRTCVideoDecoderVTB.mm:
(WebCore::WebRTCVideoDecoderVTB::colorSpaceOverrideChanged):
* Source/WebKit/GPUProcess/webrtc/LibWebRTCCodecsProxy.h:
* Source/WebKit/GPUProcess/webrtc/LibWebRTCCodecsProxy.messages.in:
* Source/WebKit/GPUProcess/webrtc/LibWebRTCCodecsProxy.mm:
(WebKit::LibWebRTCCodecsProxy::setDecoderColorSpaceOverride):
* Source/WebKit/WebProcess/GPU/webrtc/LibWebRTCCodecs.cpp:
(WebKit::decodeVideoFrame):
(WebKit::LibWebRTCCodecs::decodeWebRTCFrame):
* Source/WebKit/WebProcess/GPU/webrtc/LibWebRTCCodecs.h:
Canonical link: https://commits.webkit.org/315272@main
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