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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 17:32:43 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 17:32:43 +0000
commit6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch)
treea68f146d7fa01f0134297619fbe7e33db084e0aa /dom/media/webm/EbmlComposer.cpp
parentInitial commit. (diff)
downloadthunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.tar.xz
thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.zip
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'dom/media/webm/EbmlComposer.cpp')
-rw-r--r--dom/media/webm/EbmlComposer.cpp185
1 files changed, 185 insertions, 0 deletions
diff --git a/dom/media/webm/EbmlComposer.cpp b/dom/media/webm/EbmlComposer.cpp
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
+/* 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 "EbmlComposer.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/EndianUtils.h"
+#include "libmkv/EbmlIDs.h"
+#include "libmkv/EbmlWriter.h"
+#include "libmkv/WebMElement.h"
+#include "prtime.h"
+#include "limits.h"
+
+namespace mozilla {
+
+// Timecode scale in nanoseconds
+constexpr unsigned long TIME_CODE_SCALE = 1000000;
+// The WebM header size without audio CodecPrivateData
+constexpr int32_t DEFAULT_HEADER_SIZE = 1024;
+// Number of milliseconds after which we flush audio-only clusters
+constexpr int32_t FLUSH_AUDIO_ONLY_AFTER_MS = 1000;
+
+void EbmlComposer::GenerateHeader() {
+ MOZ_RELEASE_ASSERT(!mMetadataFinished);
+ MOZ_RELEASE_ASSERT(mHasAudio || mHasVideo);
+
+ // Write the EBML header.
+ EbmlGlobal ebml;
+ // The WEbM header default size usually smaller than 1k.
+ auto buffer =
+ MakeUnique<uint8_t[]>(DEFAULT_HEADER_SIZE + mCodecPrivateData.Length());
+ ebml.buf = buffer.get();
+ ebml.offset = 0;
+ writeHeader(&ebml);
+ {
+ EbmlLoc segEbmlLoc, ebmlLocseg, ebmlLoc;
+ Ebml_StartSubElement(&ebml, &segEbmlLoc, Segment);
+ {
+ Ebml_StartSubElement(&ebml, &ebmlLocseg, SeekHead);
+ // Todo: We don't know the exact sizes of encoded data and
+ // ignore this section.
+ Ebml_EndSubElement(&ebml, &ebmlLocseg);
+ writeSegmentInformation(&ebml, &ebmlLoc, TIME_CODE_SCALE, 0);
+ {
+ EbmlLoc trackLoc;
+ Ebml_StartSubElement(&ebml, &trackLoc, Tracks);
+ {
+ // Video
+ if (mWidth > 0 && mHeight > 0) {
+ writeVideoTrack(&ebml, 0x1, 0, "V_VP8", mWidth, mHeight,
+ mDisplayWidth, mDisplayHeight);
+ }
+ // Audio
+ if (mCodecPrivateData.Length() > 0) {
+ // Extract the pre-skip from mCodecPrivateData
+ // then convert it to nanoseconds.
+ // For more details see
+ // https://tools.ietf.org/html/rfc7845#section-4.2
+ uint64_t codecDelay = (uint64_t)LittleEndian::readUint16(
+ mCodecPrivateData.Elements() + 10) *
+ PR_NSEC_PER_SEC / 48000;
+ // Fixed 80ms, convert into nanoseconds.
+ uint64_t seekPreRoll = 80 * PR_NSEC_PER_MSEC;
+ writeAudioTrack(&ebml, 0x2, 0x0, "A_OPUS", mSampleFreq, mChannels,
+ codecDelay, seekPreRoll,
+ mCodecPrivateData.Elements(),
+ mCodecPrivateData.Length());
+ }
+ }
+ Ebml_EndSubElement(&ebml, &trackLoc);
+ }
+ }
+ // The Recording length is unknown and
+ // ignore write the whole Segment element size
+ }
+ MOZ_ASSERT(ebml.offset <= DEFAULT_HEADER_SIZE + mCodecPrivateData.Length(),
+ "write more data > EBML_BUFFER_SIZE");
+ auto block = mBuffer.AppendElement();
+ block->SetLength(ebml.offset);
+ memcpy(block->Elements(), ebml.buf, ebml.offset);
+ mMetadataFinished = true;
+}
+
+nsresult EbmlComposer::WriteSimpleBlock(EncodedFrame* aFrame) {
+ MOZ_RELEASE_ASSERT(mMetadataFinished);
+ auto frameType = aFrame->mFrameType;
+ const bool isVP8IFrame = (frameType == EncodedFrame::FrameType::VP8_I_FRAME);
+ const bool isVP8PFrame = (frameType == EncodedFrame::FrameType::VP8_P_FRAME);
+ const bool isOpus = (frameType == EncodedFrame::FrameType::OPUS_AUDIO_FRAME);
+
+ MOZ_ASSERT_IF(isVP8IFrame, mHasVideo);
+ MOZ_ASSERT_IF(isVP8PFrame, mHasVideo);
+ MOZ_ASSERT_IF(isOpus, mHasAudio);
+
+ if (isVP8PFrame && !mHasWrittenCluster) {
+ // We ensure there is a cluster header and an I-frame prior to any P-frame.
+ return NS_ERROR_INVALID_ARG;
+ }
+
+ int64_t timeCode = aFrame->mTime.ToMicroseconds() / PR_USEC_PER_MSEC -
+ mCurrentClusterTimecode;
+
+ const bool needClusterHeader =
+ !mHasWrittenCluster ||
+ (!mHasVideo && timeCode >= FLUSH_AUDIO_ONLY_AFTER_MS) || isVP8IFrame;
+
+ auto block = mBuffer.AppendElement();
+ block->SetLength(aFrame->mFrameData->Length() + DEFAULT_HEADER_SIZE);
+
+ EbmlGlobal ebml;
+ ebml.offset = 0;
+ ebml.buf = block->Elements();
+
+ if (needClusterHeader) {
+ mHasWrittenCluster = true;
+ EbmlLoc ebmlLoc;
+ // This starts the Cluster element. Note that we never end this element
+ // through Ebml_EndSubElement. What the ending would allow us to do is write
+ // the full length of the cluster in the element header. That would also
+ // force us to keep the entire cluster in memory until we know where it
+ // ends. Now it instead ends through the start of the next cluster. This
+ // allows us to stream the muxed data with much lower latency than if we
+ // would have to wait for clusters to end.
+ Ebml_StartSubElement(&ebml, &ebmlLoc, Cluster);
+ // if timeCode didn't under/overflow before, it shouldn't after this
+ mCurrentClusterTimecode = aFrame->mTime.ToMicroseconds() / PR_USEC_PER_MSEC;
+ Ebml_SerializeUnsigned(&ebml, Timecode, mCurrentClusterTimecode);
+
+ // Can't under-/overflow now
+ timeCode = 0;
+ }
+
+ if (MOZ_UNLIKELY(timeCode < SHRT_MIN || timeCode > SHRT_MAX)) {
+ MOZ_CRASH_UNSAFE_PRINTF(
+ "Invalid cluster timecode! audio=%d, video=%d, timeCode=%" PRId64
+ "ms, currentClusterTimecode=%" PRIu64 "ms",
+ mHasAudio, mHasVideo, timeCode, mCurrentClusterTimecode);
+ }
+
+ writeSimpleBlock(&ebml, isOpus ? 0x2 : 0x1, static_cast<short>(timeCode),
+ isVP8IFrame, 0, 0,
+ (unsigned char*)aFrame->mFrameData->Elements(),
+ aFrame->mFrameData->Length());
+ MOZ_ASSERT(ebml.offset <= DEFAULT_HEADER_SIZE + aFrame->mFrameData->Length(),
+ "write more data > EBML_BUFFER_SIZE");
+ block->SetLength(ebml.offset);
+
+ return NS_OK;
+}
+
+void EbmlComposer::SetVideoConfig(uint32_t aWidth, uint32_t aHeight,
+ uint32_t aDisplayWidth,
+ uint32_t aDisplayHeight) {
+ MOZ_RELEASE_ASSERT(!mMetadataFinished);
+ MOZ_ASSERT(aWidth > 0, "Width should > 0");
+ MOZ_ASSERT(aHeight > 0, "Height should > 0");
+ MOZ_ASSERT(aDisplayWidth > 0, "DisplayWidth should > 0");
+ MOZ_ASSERT(aDisplayHeight > 0, "DisplayHeight should > 0");
+ mWidth = aWidth;
+ mHeight = aHeight;
+ mDisplayWidth = aDisplayWidth;
+ mDisplayHeight = aDisplayHeight;
+ mHasVideo = true;
+}
+
+void EbmlComposer::SetAudioConfig(uint32_t aSampleFreq, uint32_t aChannels) {
+ MOZ_RELEASE_ASSERT(!mMetadataFinished);
+ MOZ_ASSERT(aSampleFreq > 0, "SampleFreq should > 0");
+ MOZ_ASSERT(aChannels > 0, "Channels should > 0");
+ mSampleFreq = aSampleFreq;
+ mChannels = aChannels;
+ mHasAudio = true;
+}
+
+void EbmlComposer::ExtractBuffer(nsTArray<nsTArray<uint8_t> >* aDestBufs,
+ uint32_t aFlag) {
+ if (!mMetadataFinished) {
+ return;
+ }
+ aDestBufs->AppendElements(std::move(mBuffer));
+ MOZ_ASSERT(mBuffer.IsEmpty());
+}
+
+} // namespace mozilla