| // Copyright 2020 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "media/base/video_encoder.h" |
| |
| #include <algorithm> |
| |
| #include "base/numerics/checked_math.h" |
| #include "base/numerics/clamped_math.h" |
| #include "base/system/sys_info.h" |
| #include "media/base/media_switches.h" |
| #include "media/base/video_frame.h" |
| |
| namespace media { |
| |
| uint8_t GetDefaultVideoEncoderDropFrameThreshold() { |
| // This function is to be invoked only in WebCodecs usage. |
| // The drop frame threshold is the same as WebRTC. |
| // https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/modules/video_coding/codecs/vp9/libvpx_vp9_encoder.cc |
| return base::FeatureList::IsEnabled(kWebCodecsVideoEncoderFrameDrop) ? 30 : 0; |
| } |
| |
| uint32_t GetDefaultVideoEncodeBitrate(gfx::Size frame_size, |
| uint32_t framerate) { |
| // Let's default to 2M bps for HD at 30 fps. |
| const uint32_t kDefaultBitrateForHD30fps = 2'000'000u; |
| const uint32_t kHDArea = 1280u * 720u; |
| const int kMaxArea = 8000 * 8000; |
| const uint64_t kMinBitrate = 10000; |
| const uint64_t kMaxBitrate = std::numeric_limits<uint32_t>::max(); |
| |
| // Scale default bitrate to the given frame size and fps |
| base::ClampedNumeric<uint64_t> result = kDefaultBitrateForHD30fps; |
| result *= std::clamp(framerate, 1u, 300u); |
| result *= std::clamp(frame_size.GetArea(), 1, kMaxArea); |
| result /= kHDArea * 30u; // HD resolution, 30 fps |
| return std::clamp(result.RawValue(), kMinBitrate, kMaxBitrate); |
| } |
| |
| int GetNumberOfThreadsForSoftwareEncoding(gfx::Size frame_size) { |
| int area = frame_size.GetCheckedArea().ValueOrDefault(1); |
| // Default to 1 thread for less than VGA. |
| int desired_threads = 1; |
| |
| if (area >= 3840 * 2160) { |
| desired_threads = 16; |
| } else if (area >= 1920 * 1080) { |
| desired_threads = 8; |
| } else if (area >= 1280 * 720) { |
| desired_threads = 4; |
| } else if (area >= 640 * 480) { |
| desired_threads = 2; |
| } |
| |
| // Clamp to the number of available logical processors/cores. |
| desired_threads = |
| std::min(desired_threads, base::SysInfo::NumberOfProcessors()); |
| |
| return desired_threads; |
| } |
| |
| VideoEncoderOutput::VideoEncoderOutput() = default; |
| VideoEncoderOutput::VideoEncoderOutput(VideoEncoderOutput&&) = default; |
| VideoEncoderOutput::~VideoEncoderOutput() = default; |
| |
| VideoEncoder::VideoEncoder() = default; |
| VideoEncoder::~VideoEncoder() = default; |
| |
| VideoEncoder::Options::Options() = default; |
| VideoEncoder::Options::Options(const Options&) = default; |
| VideoEncoder::Options::~Options() = default; |
| |
| VideoEncoder::PendingEncode::PendingEncode() = default; |
| VideoEncoder::PendingEncode::PendingEncode(PendingEncode&&) = default; |
| VideoEncoder::PendingEncode::~PendingEncode() = default; |
| |
| VideoEncoder::EncodeOptions::EncodeOptions(bool key_frame) |
| : key_frame(key_frame) {} |
| VideoEncoder::EncodeOptions::EncodeOptions() = default; |
| VideoEncoder::EncodeOptions::EncodeOptions(const EncodeOptions&) = default; |
| VideoEncoder::EncodeOptions::~EncodeOptions() = default; |
| |
| void VideoEncoder::DisablePostedCallbacks() { |
| post_callbacks_ = false; |
| } |
| |
| } // namespace media |