1 files changed, 144 insertions, 0 deletions
diff --git a/dom/media/platforms/agnostic/BlankDecoderModule.cpp b/dom/media/platforms/agnostic/BlankDecoderModule.cpp
new file mode 100644
index 0000000000..fba07338dc
--- /dev/null
+++ b/dom/media/platforms/agnostic/BlankDecoderModule.cpp
@@ -0,0 +1,144 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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 "BlankDecoderModule.h"
+
+#include "mozilla/CheckedInt.h"
+#include "mozilla/UniquePtrExtensions.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/gfx/Rect.h"
+#include "mozilla/gfx/Point.h"
+#include "ImageContainer.h"
+#include "MediaData.h"
+#include "MediaInfo.h"
+#include "VideoUtils.h"
+
+namespace mozilla {
+
+BlankVideoDataCreator::BlankVideoDataCreator(
+    uint32_t aFrameWidth, uint32_t aFrameHeight,
+    layers::ImageContainer* aImageContainer)
+    : mFrameWidth(aFrameWidth),
+      mFrameHeight(aFrameHeight),
+      mImageContainer(aImageContainer) {
+  mInfo.mDisplay = gfx::IntSize(mFrameWidth, mFrameHeight);
+  mPicture = gfx::IntRect(0, 0, mFrameWidth, mFrameHeight);
+}
+
+already_AddRefed<MediaData> BlankVideoDataCreator::Create(
+    MediaRawData* aSample) {
+  // Create a fake YUV buffer in a 420 format. That is, an 8bpp Y plane,
+  // with a U and V plane that are half the size of the Y plane, i.e 8 bit,
+  // 2x2 subsampled. Have the data pointer of each frame point to the
+  // first plane, they'll always be zero'd memory anyway.
+  const CheckedUint32 size = CheckedUint32(mFrameWidth) * mFrameHeight;
+  if (!size.isValid()) {
+    // Overflow happened.
+    return nullptr;
+  }
+  auto frame = MakeUniqueFallible<uint8_t[]>(size.value());
+  if (!frame) {
+    return nullptr;
+  }
+  memset(frame.get(), 0, mFrameWidth * mFrameHeight);
+  VideoData::YCbCrBuffer buffer;
+
+  // Y plane.
+  buffer.mPlanes[0].mData = frame.get();
+  buffer.mPlanes[0].mStride = mFrameWidth;
+  buffer.mPlanes[0].mHeight = mFrameHeight;
+  buffer.mPlanes[0].mWidth = mFrameWidth;
+  buffer.mPlanes[0].mSkip = 0;
+
+  // Cb plane.
+  buffer.mPlanes[1].mData = frame.get();
+  buffer.mPlanes[1].mStride = (mFrameWidth + 1) / 2;
+  buffer.mPlanes[1].mHeight = (mFrameHeight + 1) / 2;
+  buffer.mPlanes[1].mWidth = (mFrameWidth + 1) / 2;
+  buffer.mPlanes[1].mSkip = 0;
+
+  // Cr plane.
+  buffer.mPlanes[2].mData = frame.get();
+  buffer.mPlanes[2].mStride = (mFrameWidth + 1) / 2;
+  buffer.mPlanes[2].mHeight = (mFrameHeight + 1) / 2;
+  buffer.mPlanes[2].mWidth = (mFrameWidth + 1) / 2;
+  buffer.mPlanes[2].mSkip = 0;
+
+  buffer.mChromaSubsampling = gfx::ChromaSubsampling::HALF_WIDTH_AND_HEIGHT;
+  buffer.mYUVColorSpace = gfx::YUVColorSpace::BT601;
+  buffer.mColorPrimaries = gfx::ColorSpace2::BT709;
+
+  return VideoData::CreateAndCopyData(mInfo, mImageContainer, aSample->mOffset,
+                                      aSample->mTime, aSample->mDuration,
+                                      buffer, aSample->mKeyframe,
+                                      aSample->mTime, mPicture, nullptr);
+}
+
+BlankAudioDataCreator::BlankAudioDataCreator(uint32_t aChannelCount,
+                                             uint32_t aSampleRate)
+    : mFrameSum(0), mChannelCount(aChannelCount), mSampleRate(aSampleRate) {}
+
+already_AddRefed<MediaData> BlankAudioDataCreator::Create(
+    MediaRawData* aSample) {
+  // Convert duration to frames. We add 1 to duration to account for
+  // rounding errors, so we get a consistent tone.
+  CheckedInt64 frames =
+      UsecsToFrames(aSample->mDuration.ToMicroseconds() + 1, mSampleRate);
+  if (!frames.isValid() || !mChannelCount || !mSampleRate ||
+      frames.value() > (UINT32_MAX / mChannelCount)) {
+    return nullptr;
+  }
+  AlignedAudioBuffer samples(frames.value() * mChannelCount);
+  if (!samples) {
+    return nullptr;
+  }
+  // Fill the sound buffer with an A4 tone.
+  static const float pi = 3.14159265f;
+  static const float noteHz = 440.0f;
+  for (int i = 0; i < frames.value(); i++) {
+    float f = sin(2 * pi * noteHz * mFrameSum / mSampleRate);
+    for (unsigned c = 0; c < mChannelCount; c++) {
+      samples[i * mChannelCount + c] = AudioDataValue(f);
+    }
+    mFrameSum++;
+  }
+  RefPtr<AudioData> data(new AudioData(aSample->mOffset, aSample->mTime,
+                                       std::move(samples), mChannelCount,
+                                       mSampleRate));
+  return data.forget();
+}
+
+already_AddRefed<MediaDataDecoder> BlankDecoderModule::CreateVideoDecoder(
+    const CreateDecoderParams& aParams) {
+  const VideoInfo& config = aParams.VideoConfig();
+  UniquePtr<DummyDataCreator> creator = MakeUnique<BlankVideoDataCreator>(
+      config.mDisplay.width, config.mDisplay.height, aParams.mImageContainer);
+  RefPtr<MediaDataDecoder> decoder = new DummyMediaDataDecoder(
+      std::move(creator), "blank media data decoder"_ns, aParams);
+  return decoder.forget();
+}
+
+already_AddRefed<MediaDataDecoder> BlankDecoderModule::CreateAudioDecoder(
+    const CreateDecoderParams& aParams) {
+  const AudioInfo& config = aParams.AudioConfig();
+  UniquePtr<DummyDataCreator> creator =
+      MakeUnique<BlankAudioDataCreator>(config.mChannels, config.mRate);
+  RefPtr<MediaDataDecoder> decoder = new DummyMediaDataDecoder(
+      std::move(creator), "blank media data decoder"_ns, aParams);
+  return decoder.forget();
+}
+
+media::DecodeSupportSet BlankDecoderModule::SupportsMimeType(
+    const nsACString& aMimeType, DecoderDoctorDiagnostics* aDiagnostics) const {
+  return media::DecodeSupport::SoftwareDecode;
+}
+
+/* static */
+already_AddRefed<PlatformDecoderModule> BlankDecoderModule::Create() {
+  return MakeAndAddRef<BlankDecoderModule>();
+}
+
+}  // namespace mozilla