MJPEG acceleration for video capture using VAAPI

content/browser/renderer_host/gpu_jpeg_decoder.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/browser/renderer_host/gpu_jpeg_decoder.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "content/browser/gpu/browser_gpu_channel_host_factory.h"
+#include "content/common/gpu/client/gpu_jpeg_decode_accelerator_host.h"
+#include "content/public/browser/browser_thread.h"
+#include "media/base/video_frame.h"
+
+namespace content {
+
+// static
+bool GpuJpegDecoder::Supported() {
+  // A lightweight check for caller to avoid IPC latency for known unsupported
+  // platform. Initialize() can do the real platform supporting check but it
+  // requires an IPC.

[wuchengli, 2015/04/24 05:54:23]

s/IPC/IPC even for platforms that do not support HW decoder/

[kcwu, 2015/04/30 19:25:39]

Done.

+  // TODO(kcwu): move this logic to GpuInfo.

[wuchengli, 2015/04/24 05:54:23]

s/logic/information/

[kcwu, 2015/04/30 19:25:39]

Done.

+#if defined(OS_CHROMEOS) && defined(ARCH_CPU_X86_FAMILY)
+  return true;
+#endif
+  return false;
+}
+
+GpuJpegDecoder::GpuJpegDecoder(
+    media::VideoCaptureDevice::Client* device_client)
+    : device_client_(device_client),
+      main_task_runner_(base::MessageLoopProxy::current()),
+      fail_state_(NOT_FAIL),
+      next_bitstream_buffer_id_(0),
+      in_buffer_(media::JpegDecodeAccelerator::kInvalidBitstreamBufferId,
+                 base::SharedMemory::NULLHandle(),
+                 0) {
+}
+
+GpuJpegDecoder::~GpuJpegDecoder() {
+  DCHECK(main_task_runner_->BelongsToCurrentThread());
+}
+
+bool GpuJpegDecoder::IsDecoding() {
+  base::AutoLock lock(lock_);
+  return out_frame_ != nullptr;
+}
+
+bool GpuJpegDecoder::IsExpectedDecodeResponse(
+    int32 bitstream_buffer_id) {
+  if (bitstream_buffer_id ==
+      media::JpegDecodeAccelerator::kInvalidBitstreamBufferId)
+    return false;
+
+  if (!IsDecoding()) {
+    LOG(ERROR) << "Got decode response while not decoding";
+    return false;
+  }
+
+  if (bitstream_buffer_id != in_buffer_.id()) {
+    LOG(ERROR) << "Unexpected bitstream_buffer_id " << bitstream_buffer_id
+               << ", expected " << in_buffer_.id();
+    return false;
+  }
+
+  return true;
+}
+
+void GpuJpegDecoder::DecodeDone() {
+  base::AutoLock lock(lock_);
+  memset(&captured_data_, 0, sizeof(captured_data_));
+  out_buffer_ = nullptr;
+  out_frame_ = nullptr;
+}
+
+bool GpuJpegDecoder::Initialize() {
+  DVLOG(3) << __func__;
+  DCHECK(main_task_runner_->BelongsToCurrentThread());
+  GpuChannelHost* const host =
+      BrowserGpuChannelHostFactory::instance()->GetGpuChannel();
+  decoder_ = host->CreateJpegDecoder(
+      BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO));
+  if (!decoder_->Initialize(this)) {
+    decoder_.reset();
+    fail_state_ = FAILED;
+    return false;
+  }
+  return true;
+}
+
+bool GpuJpegDecoder::IsFailed() {
+  base::AutoLock lock(lock_);
+  return fail_state_ == FAILED;
+}
+
+void GpuJpegDecoder::VideoFrameReady(
+    int32_t bitstream_buffer_id) {
+  DVLOG(3) << __func__;
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  if (!IsExpectedDecodeResponse(bitstream_buffer_id))
+    return;
+
+  device_client_->OnIncomingCapturedVideoFrame(out_buffer_, out_frame_,
+                                               captured_data_.timestamp);
+
+  DecodeDone();
+}
+
+void GpuJpegDecoder::FallbackToSoftwareDecode() {
+  DVLOG(1) << "Fallback to software decode";
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO) ||
+         main_task_runner_->BelongsToCurrentThread());
+  DCHECK_EQ(BrowserThread::CurrentlyOn(BrowserThread::IO), IsDecoding());
+
+  CapturedData captured_data;
+  {
+    base::AutoLock lock(lock_);
+    // See comment below.
+    if (BrowserThread::CurrentlyOn(BrowserThread::IO))
+      fail_state_ = FAILING;
+    else
+      fail_state_ = FAILED;
+    captured_data = captured_data_;
+  }
+
+  // If we are on |main_task_runner_| thread, OnIncomingCapturedData is
+  // reentrant. But it's okay since |fail_state_| is FAILED and it won't go
+  // hardware decoding route this time.
+  // If we are on IO thread and next frame is coming on |main_task_runner_|
+  // thread, the next frame will call DecodeCapturedData() and drop immediately

[wuchengli, 2015/04/24 05:54:23]

Hmm. If we may still drop a frame, I prefer dropping this frame and we don't
need to remember all these |captured_data|.

[kcwu, 2015/04/30 19:25:39]

the behavior changed to always drop current frame if anything failed.

+  // due to |fail_state_| is FAILING. This is to avoid next frame decoded
+  // before this frame.
+  device_client_->OnIncomingCapturedData(captured_data.data,
+                                         captured_data.length,
+                                         captured_data.frame_format,
+                                         captured_data.rotation,
+                                         captured_data.timestamp);
+  {
+    base::AutoLock lock(lock_);
+    fail_state_ = FAILED;
+  }
+}
+
+void GpuJpegDecoder::NotifyError(
+    int32_t bitstream_buffer_id,
+    media::JpegDecodeAccelerator::Error error) {
+  DVLOG(3) << __func__;
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  // Error not associated to any bitstream buffer. For example, GPU channel
+  // is broken.
+  if (bitstream_buffer_id ==
+      media::JpegDecodeAccelerator::kInvalidBitstreamBufferId) {
+    {
+      base::AutoLock lock(lock_);
+      fail_state_ = FAILED;
+    }
+    DecodeDone();
+    return;
+  }
+
+  if (!IsExpectedDecodeResponse(bitstream_buffer_id))
+    return;
+
+  FallbackToSoftwareDecode();
+  DecodeDone();
+}
+
+void GpuJpegDecoder::DecodeCapturedData(
+    const uint8* data,
+    int length,
+    const media::VideoCaptureFormat& frame_format,
+    int rotation,
+    const base::TimeTicks& timestamp) {
+  DCHECK(main_task_runner_->BelongsToCurrentThread());
+  DCHECK(decoder_);
+  if (IsDecoding()) {
+    DVLOG(1) << "Drop captured frame. Previous jpeg frame is still decoding";
+    return;
+  }
+  {
+    base::AutoLock lock(lock_);
+    if (fail_state_ != NOT_FAIL)
+      return;
+  }
+
+  // Since IsDecoding() is false here and we only decode a frame at a time,
+  // after this point, the only possible multithread access to this class is
+  // NotifyError. This means |fail_state_| may be set to FAILED when running
+  // following code.
+
+  const gfx::Size dimensions = frame_format.frame_size;
+  scoped_refptr<media::VideoCaptureDevice::Client::Buffer> out_buffer =
+      device_client_->ReserveOutputBuffer(media::PIXEL_FORMAT_I420, dimensions);
+  if (!out_buffer.get()) {
+    DVLOG(1) << "Drop captured frame. No available buffers"
+             << " (all buffers are still queued to display)";
+    return;
+  }
+
+  CapturedData captured_data;
+  captured_data.data = const_cast<uint8*>(data);
+  captured_data.length = length;
+  captured_data.frame_format = frame_format;
+  captured_data.rotation = rotation;
+  captured_data.timestamp = timestamp;
+
+  size_t in_buffer_size = captured_data.length;
+
+  scoped_ptr<base::SharedMemory> in_shared_memory;
+  {
+    // Swap out to local variable in order to reduce lock time on IO thread.
+    base::AutoLock lock(lock_);
+    std::swap(in_shared_memory, in_shared_memory_);
+  }
+  // Enlarge input buffer if necessary.
+  if (!in_shared_memory.get() ||
+      in_buffer_size > in_shared_memory->mapped_size()) {
+    in_shared_memory.reset(new base::SharedMemory);
+    if (!in_shared_memory->CreateAndMapAnonymous(in_buffer_size)) {
+      DLOG(ERROR) << "CreateAndMapAnonymous failed, size=" << in_buffer_size;
+      captured_data_ = captured_data;
+      FallbackToSoftwareDecode();
+      return;
+    }
+  }
+
+  media::BitstreamBuffer in_buffer(next_bitstream_buffer_id_,
+                                   in_shared_memory->handle(), in_buffer_size);
+  // Mask against 30 bits, to avoid (undefined) wraparound on signed integer.
+  next_bitstream_buffer_id_ = (next_bitstream_buffer_id_ + 1) & 0x3FFFFFFF;
+
+  scoped_refptr<media::VideoFrame> out_frame =
+      media::VideoFrame::WrapExternalPackedMemory(
+          media::VideoFrame::I420,
+          dimensions,
+          gfx::Rect(dimensions),
+          dimensions,
+          reinterpret_cast<uint8*>(out_buffer->data()),
+          out_buffer->size(),
+          out_buffer->handle(),
+          0,
+          base::TimeDelta(),
+          base::Closure());
+  DCHECK(out_frame.get());
+
+  out_frame->metadata()->SetDouble(media::VideoFrameMetadata::FRAME_RATE,
+                                   captured_data.frame_format.frame_rate);
+
+  memcpy(in_shared_memory->memory(), captured_data.data, in_buffer_size);
+  captured_data.data = reinterpret_cast<uint8*>(in_shared_memory->memory());
+
+  base::AutoLock lock(lock_);
+  if (fail_state_ != NOT_FAIL)
+    return;
+  captured_data_ = captured_data;
+  in_buffer_ = in_buffer;
+  std::swap(in_shared_memory_, in_shared_memory);
+  out_buffer_ = out_buffer;
+  out_frame_ = out_frame;
+
+  decoder_->Decode(in_buffer_, out_frame_);
+}
+
+}  // namespace content