Add accelerated video decoder interface, VP8 and H.264 implementations and hook up to V4L2SVDA.

content/common/gpu/media/v4l2_slice_video_decode_accelerator.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 <fcntl.h>
+#include <linux/videodev2.h>
+#include <poll.h>
+#include <sys/eventfd.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/callback.h"
+#include "base/callback_helpers.h"
+#include "base/command_line.h"
+#include "base/message_loop/message_loop_proxy.h"
+#include "base/numerics/safe_conversions.h"
+#include "base/strings/stringprintf.h"
+#include "content/common/gpu/media/v4l2_slice_video_decode_accelerator.h"
+#include "media/base/bind_to_current_loop.h"
+#include "media/base/media_switches.h"
+#include "ui/gl/scoped_binders.h"
+
+#define LOGF(level) LOG(level) << __FUNCTION__ << "(): "
+#define DVLOGF(level) LOG(ERROR) << __FUNCTION__ << "(): "

[kcwu, 2015/01/12 07:31:46]

level is ignored?

[Pawel Osciak, 2015/01/13 11:33:33]

Just for debugging, sorry.

+
+#define NOTIFY_ERROR(x)                        \
+  do {                                         \
+    LOG(ERROR) << "Setting error state:" << x; \
+    SetErrorState(x);                          \
+  } while (0)
+
+#define IOCTL_OR_ERROR_RETURN_VALUE(type, arg, value)             \
+  do {                                                            \
+    if (device_->Ioctl(type, arg) != 0) {                         \
+      PLOG(ERROR) << __func__ << "(): ioctl() failed: " << #type; \
+      return value;                                               \
+    }                                                             \
+  } while (0)
+
+#define IOCTL_OR_ERROR_RETURN(type, arg) \
+  IOCTL_OR_ERROR_RETURN_VALUE(type, arg, ((void)0))
+
+#define IOCTL_OR_ERROR_RETURN_FALSE(type, arg) \
+  IOCTL_OR_ERROR_RETURN_VALUE(type, arg, false)
+
+#define IOCTL_OR_LOG_ERROR(type, arg)                             \
+  do {                                                            \
+    if (device_->Ioctl(type, arg) != 0)                           \
+      PLOG(ERROR) << __func__ << "(): ioctl() failed: " << #type; \
+  } while (0)
+
+namespace content {
+
+V4L2SliceVideoDecodeAccelerator::V4L2DecodeSurface::V4L2DecodeSurface(
+    int32 bitstream_id,
+    int input_record,
+    int output_record,
+    const ReleaseCB& release_cb)
+    : bitstream_id_(bitstream_id),
+      input_record_(input_record),
+      output_record_(output_record),
+      config_store_(input_record + 1),
+      decoded_(false),
+      release_cb_(release_cb) {
+}
+
+V4L2SliceVideoDecodeAccelerator::V4L2DecodeSurface::~V4L2DecodeSurface() {
+  DVLOGF(5) << "Releasing output record id=" << output_record_;
+  release_cb_.Run(output_record_);
+}
+
+void V4L2SliceVideoDecodeAccelerator::V4L2DecodeSurface::SetReferenceSurfaces(
+    const std::vector<scoped_refptr<V4L2DecodeSurface>>& ref_surfaces) {
+  DCHECK(reference_surfaces_.empty());
+  reference_surfaces_ = ref_surfaces;
+}
+
+void V4L2SliceVideoDecodeAccelerator::V4L2DecodeSurface::SetDecoded() {
+  DCHECK(!decoded_);
+  decoded_ = true;
+
+  // We can now drop references to all reference surfaces for this surface
+  // as we are done with decoding.
+  reference_surfaces_.clear();
+}
+
+std::string V4L2SliceVideoDecodeAccelerator::V4L2DecodeSurface::ToString()
+    const {
+  std::string out;
+  base::StringAppendF(&out, "Buffer %d -> %d. ", input_record_, output_record_);
+  base::StringAppendF(&out, "Reference surfaces:");
+  for (const auto& ref : reference_surfaces_) {
+    DCHECK_NE(ref->output_record(), output_record_);
+    base::StringAppendF(&out, " %d", ref->output_record());
+  }
+  return out;
+}
+
+V4L2SliceVideoDecodeAccelerator::InputRecord::InputRecord()
+    : input_id(-1),
+      address(nullptr),
+      length(0),
+      bytes_used(0),
+      at_device(false) {
+}
+
+V4L2SliceVideoDecodeAccelerator::OutputRecord::OutputRecord()
+    : at_device(false),
+      at_client(false),
+      picture_id(-1),
+      egl_image(EGL_NO_IMAGE_KHR),
+      egl_sync(EGL_NO_SYNC_KHR),
+      cleared(false) {
+}
+
+struct V4L2SliceVideoDecodeAccelerator::BitstreamBufferRef {
+  BitstreamBufferRef(
+      base::WeakPtr<VideoDecodeAccelerator::Client>& client,
+      const scoped_refptr<base::MessageLoopProxy>& client_message_loop_proxy,
+      base::SharedMemory* shm,
+      size_t size,
+      int32 input_id);
+  ~BitstreamBufferRef();
+  const base::WeakPtr<VideoDecodeAccelerator::Client> client;
+  const scoped_refptr<base::MessageLoopProxy> client_message_loop_proxy;
+  const scoped_ptr<base::SharedMemory> shm;
+  const size_t size;
+  off_t bytes_used;
+  const int32 input_id;
+};
+
+V4L2SliceVideoDecodeAccelerator::BitstreamBufferRef::BitstreamBufferRef(
+    base::WeakPtr<VideoDecodeAccelerator::Client>& client,
+    const scoped_refptr<base::MessageLoopProxy>& client_message_loop_proxy,
+    base::SharedMemory* shm,
+    size_t size,
+    int32 input_id)
+    : client(client),
+      client_message_loop_proxy(client_message_loop_proxy),
+      shm(shm),
+      size(size),
+      bytes_used(0),
+      input_id(input_id) {
+}
+
+V4L2SliceVideoDecodeAccelerator::BitstreamBufferRef::~BitstreamBufferRef() {
+  if (input_id >= 0) {
+    DVLOGF(5) << "returning input_id: " << input_id;
+    client_message_loop_proxy->PostTask(
+        FROM_HERE,
+        base::Bind(&VideoDecodeAccelerator::Client::NotifyEndOfBitstreamBuffer,
+                   client, input_id));
+  }
+}
+
+struct V4L2SliceVideoDecodeAccelerator::EGLSyncKHRRef {
+  EGLSyncKHRRef(EGLDisplay egl_display, EGLSyncKHR egl_sync);
+  ~EGLSyncKHRRef();
+  EGLDisplay const egl_display;
+  EGLSyncKHR egl_sync;
+};
+
+V4L2SliceVideoDecodeAccelerator::EGLSyncKHRRef::EGLSyncKHRRef(
+    EGLDisplay egl_display,
+    EGLSyncKHR egl_sync)
+    : egl_display(egl_display), egl_sync(egl_sync) {
+}
+
+V4L2SliceVideoDecodeAccelerator::EGLSyncKHRRef::~EGLSyncKHRRef() {
+  // We don't check for eglDestroySyncKHR failures, because if we get here
+  // with a valid sync object, something went wrong and we are getting
+  // destroyed anyway.
+  if (egl_sync != EGL_NO_SYNC_KHR)
+    eglDestroySyncKHR(egl_display, egl_sync);
+}
+
+struct V4L2SliceVideoDecodeAccelerator::PictureRecord {
+  PictureRecord(bool cleared, const media::Picture& picture);
+  ~PictureRecord();
+  bool cleared;  // Whether the texture is cleared and safe to render from.
+  media::Picture picture;  // The decoded picture.
+};
+
+V4L2SliceVideoDecodeAccelerator::PictureRecord::PictureRecord(
+    bool cleared,
+    const media::Picture& picture)
+    : cleared(cleared), picture(picture) {
+}
+
+V4L2SliceVideoDecodeAccelerator::PictureRecord::~PictureRecord() {
+}
+
+V4L2SliceVideoDecodeAccelerator::V4L2SliceVideoDecodeAccelerator(
+    const scoped_refptr<V4L2Device>& device,
+    EGLDisplay egl_display,
+    EGLContext egl_context,
+    const base::WeakPtr<Client>& io_client,
+    const base::Callback<bool(void)>& make_context_current,
+    const scoped_refptr<base::MessageLoopProxy>& io_message_loop_proxy)
+    : input_planes_count_(0),
+      output_planes_count_(0),
+      child_message_loop_proxy_(base::MessageLoopProxy::current()),
+      io_message_loop_proxy_(io_message_loop_proxy),
+      io_client_(io_client),
+      device_(device),
+      decoder_thread_("V4L2SliceVideoDecodeAcceleratorThread"),
+      device_poll_thread_("V4L2SliceVideoDecodeAcceleratorDevicePollThread"),
+      input_streamon_(false),
+      input_buffer_queued_count_(0),
+      output_streamon_(false),
+      output_buffer_queued_count_(0),
+      video_profile_(media::VIDEO_CODEC_PROFILE_UNKNOWN),
+      output_format_fourcc_(0),
+      output_dpb_size_(0),
+      state_(kUninitialized),
+      decoder_flushing_(false),
+      decoder_resetting_(false),
+      surface_set_change_pending_(false),
+      picture_clearing_count_(0),
+      pictures_assigned_(false, false),
+      make_context_current_(make_context_current),
+      egl_display_(egl_display),
+      egl_context_(egl_context),
+      weak_this_factory_(this) {
+  weak_this_ = weak_this_factory_.GetWeakPtr();
+}
+
+V4L2SliceVideoDecodeAccelerator::~V4L2SliceVideoDecodeAccelerator() {
+  DVLOGF(2);
+
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+  DCHECK(!decoder_thread_.IsRunning());
+  DCHECK(!device_poll_thread_.IsRunning());
+
+  DCHECK(input_buffer_map_.empty());
+  DCHECK(output_buffer_map_.empty());
+}
+
+void V4L2SliceVideoDecodeAccelerator::NotifyError(Error error) {
+  if (!child_message_loop_proxy_->BelongsToCurrentThread()) {
+    child_message_loop_proxy_->PostTask(
+        FROM_HERE, base::Bind(&V4L2SliceVideoDecodeAccelerator::NotifyError,
+                              weak_this_, error));
+    return;
+  }
+
+  if (client_) {
+    client_->NotifyError(error);
+    client_ptr_factory_.reset();
+  }
+}
+
+bool V4L2SliceVideoDecodeAccelerator::Initialize(
+    media::VideoCodecProfile profile,
+    VideoDecodeAccelerator::Client* client) {
+  DVLOGF(3);
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+  DCHECK_EQ(state_, kUninitialized);
+
+  client_ptr_factory_.reset(
+      new base::WeakPtrFactory<VideoDecodeAccelerator::Client>(client));
+  client_ = client_ptr_factory_->GetWeakPtr();
+
+  video_profile_ = profile;
+
+  if (video_profile_ >= media::H264PROFILE_MIN &&
+      video_profile_ <= media::H264PROFILE_MAX) {
+    h264_accelerator_.reset(new V4L2H264Accelerator(this));
+    decoder_.reset(new H264Decoder(h264_accelerator_.get()));
+  } else if (video_profile_ >= media::VP8PROFILE_MIN &&
+             video_profile_ <= media::VP8PROFILE_MAX) {
+    vp8_accelerator_.reset(new V4L2VP8Accelerator(this));
+    decoder_.reset(new VP8Decoder(vp8_accelerator_.get()));
+  } else {
+    DLOG(ERROR) << "Unsupported profile " << video_profile_;
+    return false;
+  }
+
+  // TODO(posciak): This needs to be queried once supported.
+  input_planes_count_ = 1;
+  output_planes_count_ = 1;
+
+  if (egl_display_ == EGL_NO_DISPLAY) {
+    LOG(ERROR) << "Initialize(): could not get EGLDisplay";
+    return false;
+  }
+
+  // We need the context to be initialized to query extensions.
+  if (!make_context_current_.Run()) {
+    LOG(ERROR) << "Initialize(): could not make context current";
+    return false;
+  }
+
+  if (!gfx::g_driver_egl.ext.b_EGL_KHR_fence_sync) {
+    LOG(ERROR) << "Initialize(): context does not have EGL_KHR_fence_sync";
+    return false;
+  }
+
+  // Capabilities check.
+  struct v4l2_capability caps;
+  const __u32 kCapsRequired =
+      V4L2_CAP_VIDEO_CAPTURE_MPLANE |
+      V4L2_CAP_VIDEO_OUTPUT_MPLANE |
+      V4L2_CAP_STREAMING;
+  IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_QUERYCAP, &caps);
+  if ((caps.capabilities & kCapsRequired) != kCapsRequired) {
+    DLOG(ERROR) << "Initialize(): ioctl() failed: VIDIOC_QUERYCAP"
+                   ", caps check failed: 0x" << std::hex << caps.capabilities;
+    return false;
+  }
+
+  if (!SetupFormats())
+    return false;
+
+  if (!decoder_thread_.Start()) {
+    DLOG(ERROR) << "Initialize(): device thread failed to start";
+    return false;
+  }
+  decoder_thread_proxy_ = decoder_thread_.message_loop_proxy();
+
+  state_ = kInitialized;
+
+  // InitializeTask will NOTIFY_ERROR on failure.
+  decoder_thread_proxy_->PostTask(
+      FROM_HERE, base::Bind(&V4L2SliceVideoDecodeAccelerator::InitializeTask,
+                            base::Unretained(this)));
+
+  DVLOGF(1) << "V4L2SliceVideoDecodeAccelerator initialized";
+  return true;
+}
+
+void V4L2SliceVideoDecodeAccelerator::InitializeTask() {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+  DCHECK_EQ(state_, kInitialized);
+
+  if (!CreateInputBuffers())
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+
+  // Output buffers will be created once decoder gives us information
+  // about their size and required count.
+  state_ = kDecoding;
+}
+
+void V4L2SliceVideoDecodeAccelerator::Destroy() {
+  DVLOGF(3);
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+
+  if (decoder_thread_.IsRunning()) {
+    decoder_thread_proxy_->PostTask(
+        FROM_HERE, base::Bind(&V4L2SliceVideoDecodeAccelerator::DestroyTask,
+                              base::Unretained(this)));
+
+    // Wait for tasks to finish/early-exit.
+    decoder_thread_.Stop();
+  }
+
+  delete this;
+  DVLOGF(3) << "Destroyed";
+}
+
+void V4L2SliceVideoDecodeAccelerator::DestroyTask() {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  state_ = kError;
+
+  decoder_->Reset();
+
+  decoder_current_bitstream_buffer_.reset();
+  while (!decoder_input_queue_.empty())
+    decoder_input_queue_.pop();
+
+  // Stop streaming and the device_poll_thread_.
+  StopDevicePoll(false);
+
+  DestroyInputBuffers();
+  DestroyOutputs(false);
+
+  DCHECK(surfaces_at_device_.empty());
+  DCHECK(surfaces_at_display_.empty());
+  DCHECK(decoder_display_queue_.empty());
+}
+
+bool V4L2SliceVideoDecodeAccelerator::SetupFormats() {
+  DCHECK_EQ(state_, kUninitialized);
+
+  __u32 input_format_fourcc =
+      V4L2Device::VideoCodecProfileToV4L2PixFmt(video_profile_, true);
+  if (!input_format_fourcc) {
+    NOTREACHED();
+    return false;
+  }
+
+  size_t input_size;
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kIgnoreResolutionLimitsForAcceleratedVideoDecode))
+    input_size = kInputBufferMaxSizeFor4k;
+  else
+    input_size = kInputBufferMaxSizeFor1080p;
+
+  struct v4l2_format format;
+  memset(&format, 0, sizeof(format));
+  format.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+  format.fmt.pix_mp.pixelformat = input_format_fourcc;
+  format.fmt.pix_mp.plane_fmt[0].sizeimage = input_size;
+  format.fmt.pix_mp.num_planes = input_planes_count_;
+  IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_S_FMT, &format);
+
+  // We have to set up the format for output, because the driver may not allow
+  // changing it once we start streaming; whether it can support our chosen
+  // output format or not may depend on the input format.
+  struct v4l2_fmtdesc fmtdesc;
+  memset(&fmtdesc, 0, sizeof(fmtdesc));
+  fmtdesc.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+  while (device_->Ioctl(VIDIOC_ENUM_FMT, &fmtdesc) == 0) {
+    if (device_->CanCreateEGLImageFrom(fmtdesc.pixelformat)) {
+      output_format_fourcc_ = fmtdesc.pixelformat;
+      break;
+    }
+    ++fmtdesc.index;
+  }
+
+  if (output_format_fourcc_ == 0) {
+    LOG(ERROR) << "Could not find a usable output format";
+    return false;
+  }
+
+  // Only set fourcc for output; resolution, etc., will come from the
+  // driver once it extracts it from the stream.
+  memset(&format, 0, sizeof(format));
+  format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+  format.fmt.pix_mp.pixelformat = output_format_fourcc_;
+  format.fmt.pix_mp.num_planes = output_planes_count_;
+  IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_S_FMT, &format);
+
+  return true;
+}
+
+bool V4L2SliceVideoDecodeAccelerator::CreateInputBuffers() {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+  DCHECK(!input_streamon_);
+  DCHECK(input_buffer_map_.empty());
+
+  struct v4l2_requestbuffers reqbufs;
+  memset(&reqbufs, 0, sizeof(reqbufs));
+  reqbufs.count = kNumInputBuffers;
+  reqbufs.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+  reqbufs.memory = V4L2_MEMORY_MMAP;
+  IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_REQBUFS, &reqbufs);
+  if (reqbufs.count < kNumInputBuffers) {
+    PLOG(ERROR) << "Could not allocate enough output buffers";
+    return false;
+  }
+  input_buffer_map_.resize(reqbufs.count);
+  for (size_t i = 0; i < input_buffer_map_.size(); ++i) {
+    free_input_buffers_.push_back(i);
+
+    // Query for the MEMORY_MMAP pointer.
+    struct v4l2_plane planes[VIDEO_MAX_PLANES];
+    struct v4l2_buffer buffer;
+    memset(&buffer, 0, sizeof(buffer));
+    memset(planes, 0, sizeof(planes));
+    buffer.index    = i;
+    buffer.type     = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+    buffer.memory   = V4L2_MEMORY_MMAP;
+    buffer.m.planes = planes;
+    buffer.length   = input_planes_count_;

[kcwu, 2015/01/12 07:31:46]

I think we usually don't align assignment?

[Pawel Osciak, 2015/01/13 11:33:34]

Yup, sorry.

+    IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_QUERYBUF, &buffer);
+    void* address = device_->Mmap(nullptr,
+                                  buffer.m.planes[0].length,
+                                  PROT_READ | PROT_WRITE,
+                                  MAP_SHARED,
+                                  buffer.m.planes[0].m.mem_offset);
+    if (address == MAP_FAILED) {
+      PLOG(ERROR) << "CreateInputBuffers(): mmap() failed";
+      return false;
+    }
+    input_buffer_map_[i].address = address;
+    input_buffer_map_[i].length = buffer.m.planes[0].length;
+  }
+
+  return true;
+}
+
+bool V4L2SliceVideoDecodeAccelerator::CreateOutputBuffers() {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+  DCHECK(!output_streamon_);
+  DCHECK(output_buffer_map_.empty());
+  DCHECK(surfaces_at_display_.empty());
+  DCHECK(surfaces_at_device_.empty());
+
+  frame_buffer_size_ = decoder_->GetPicSize();
+  output_dpb_size_ = decoder_->GetRequiredNumOfPictures();
+
+  DCHECK_GT(output_dpb_size_, 0u);
+  DCHECK(!frame_buffer_size_.IsEmpty());
+
+  struct v4l2_format format;
+  memset(&format, 0, sizeof(format));
+  format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+  format.fmt.pix_mp.pixelformat = output_format_fourcc_;
+  format.fmt.pix_mp.width = frame_buffer_size_.width();
+  format.fmt.pix_mp.height = frame_buffer_size_.height();
+  format.fmt.pix_mp.num_planes = input_planes_count_;
+
+  if (device_->Ioctl(VIDIOC_S_FMT, &format) != 0) {
+    PLOG(ERROR) << "Failed setting format to: " << output_format_fourcc_;
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+
+  struct v4l2_requestbuffers reqbufs;
+  memset(&reqbufs, 0, sizeof(reqbufs));
+  reqbufs.count = output_dpb_size_;
+  reqbufs.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+  reqbufs.memory = V4L2_MEMORY_MMAP;
+  IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_REQBUFS, &reqbufs);
+
+  if (reqbufs.count < output_dpb_size_) {
+    PLOG(ERROR) << "Could not allocate enough output buffers";
+    return false;
+  }
+
+  output_buffer_map_.resize(reqbufs.count);

[kcwu, 2015/01/12 07:31:46]

according to http://linuxtv.org/downloads/v4l-dvb-apis/vidioc-reqbufs.html
reqbufs.count may be larger than output_dpb_size_.
But I don't fully understand that case. 

I'm not sure. Should this line be resize(reqbufs.count) or
resize(output_dpb_size_)?

[Pawel Osciak, 2015/01/13 11:33:33]

In l.524 we check that we got not less than output_dpb_size_, but if we got
more, we can use more. We don't map output buffers directly to dpb.

+
+  DVLOGF(3) << "buffer_count=" << output_buffer_map_.size()
+            << ", width=" << frame_buffer_size_.width()
+            << ", height=" << frame_buffer_size_.height();
+
+  child_message_loop_proxy_->PostTask(
+      FROM_HERE,
+      base::Bind(&VideoDecodeAccelerator::Client::ProvidePictureBuffers,
+                 client_, output_buffer_map_.size(), frame_buffer_size_,
+                 device_->GetTextureTarget()));
+
+  // Wait for the client to call AssignPictureBuffers() on the Child thread.
+  // We do this, because if we continue decoding without finishing buffer
+  // allocation, we may end up Resetting before AssignPictureBuffers arrives,
+  // resulting in unnecessary complications and subtle bugs.
+  pictures_assigned_.Wait();
+
+  return true;
+}
+
+void V4L2SliceVideoDecodeAccelerator::DestroyInputBuffers() {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread() ||
+         !decoder_thread_.IsRunning());
+  DCHECK(!input_streamon_);
+
+  for (auto& input_record : input_buffer_map_) {
+    if (input_record.address != nullptr)
+      device_->Munmap(input_record.address, input_record.length);
+  }
+
+  struct v4l2_requestbuffers reqbufs;
+  memset(&reqbufs, 0, sizeof(reqbufs));
+  reqbufs.count = 0;
+  reqbufs.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+  reqbufs.memory = V4L2_MEMORY_MMAP;
+  IOCTL_OR_LOG_ERROR(VIDIOC_REQBUFS, &reqbufs);
+
+  input_buffer_map_.clear();
+  free_input_buffers_.clear();
+}
+
+void V4L2SliceVideoDecodeAccelerator::DismissPictures(
+    std::vector<int32> picture_buffer_ids,
+    base::WaitableEvent* done) {
+  DVLOGF(3);
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+
+  for (auto picture_buffer_id : picture_buffer_ids) {
+    DVLOGF(1) << "dismissing PictureBuffer id=" << picture_buffer_id;
+    client_->DismissPictureBuffer(picture_buffer_id);
+  }
+
+  done->Signal();
+}
+
+void V4L2SliceVideoDecodeAccelerator::DevicePollTask(bool poll_device) {
+  DVLOGF(4);
+  DCHECK_EQ(device_poll_thread_.message_loop(), base::MessageLoop::current());
+
+  bool event_pending;
+  if (!device_->Poll(poll_device, &event_pending)) {
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  // All processing should happen on ServiceDeviceTask(), since we shouldn't
+  // touch encoder state from this thread.
+  decoder_thread_proxy_->PostTask(
+      FROM_HERE, base::Bind(&V4L2SliceVideoDecodeAccelerator::ServiceDeviceTask,
+                            base::Unretained(this)));
+}
+
+void V4L2SliceVideoDecodeAccelerator::ServiceDeviceTask() {
+  DVLOGF(4);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  // ServiceDeviceTask() should only ever be scheduled from DevicePollTask().
+
+  Dequeue();
+  SchedulePollIfNeeded();
+}
+
+void V4L2SliceVideoDecodeAccelerator::SchedulePollIfNeeded() {
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  if (!device_poll_thread_.IsRunning()) {
+    DVLOGF(2) << "Device poll thread stopped, will not schedule poll";
+    return;
+  }
+
+  DCHECK(input_streamon_ || output_streamon_);
+
+  if (input_buffer_queued_count_ + output_buffer_queued_count_ == 0) {
+    DVLOGF(4) << "No buffers queued, will not schedule poll";
+    return;
+  }
+
+  DVLOGF(4) << "Scheduling device poll task";
+
+  device_poll_thread_.message_loop()->PostTask(
+      FROM_HERE, base::Bind(&V4L2SliceVideoDecodeAccelerator::DevicePollTask,
+                            base::Unretained(this), true));
+
+  DVLOGF(2) << "buffer counts: "
+            << "INPUT[" << decoder_input_queue_.size() << "]"
+            << " => DEVICE["
+            << free_input_buffers_.size() << "+"
+            << input_buffer_queued_count_ << "/"
+            << input_buffer_map_.size() << "]->["
+            << free_output_buffers_.size() << "+"
+            << output_buffer_queued_count_ << "/"
+            << output_buffer_map_.size() << "]"
+            << " => DISPLAYQ[" << decoder_display_queue_.size() << "]"
+            << " => CLIENT[" << surfaces_at_display_.size() << "]";
+}
+
+void V4L2SliceVideoDecodeAccelerator::Enqueue(
+    const scoped_refptr<V4L2DecodeSurface>& dec_surface) {
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  const int old_inputs_queued = input_buffer_queued_count_;
+  const int old_outputs_queued = output_buffer_queued_count_;
+
+  if (!EnqueueInputRecord(dec_surface->input_record(),
+                          dec_surface->config_store())) {
+    DVLOGF(1) << "Failed queueing an input buffer";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  if (!EnqueueOutputRecord(dec_surface->output_record())) {
+    DVLOGF(1) << "Failed queueing an output buffer";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  bool inserted =
+      surfaces_at_device_.insert(std::make_pair(dec_surface->output_record(),
+                                                dec_surface)).second;
+  DCHECK(inserted);
+
+  if (old_inputs_queued == 0 && old_outputs_queued == 0)
+    SchedulePollIfNeeded();
+}
+
+void V4L2SliceVideoDecodeAccelerator::Dequeue() {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  struct v4l2_buffer dqbuf;
+  struct v4l2_plane planes[VIDEO_MAX_PLANES];
+  while (input_buffer_queued_count_ > 0) {
+    DCHECK(input_streamon_);
+    memset(&dqbuf, 0, sizeof(dqbuf));
+    memset(&planes, 0, sizeof(planes));
+    dqbuf.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+    dqbuf.memory = V4L2_MEMORY_USERPTR;
+    dqbuf.m.planes = planes;
+    dqbuf.length = input_planes_count_;
+    if (device_->Ioctl(VIDIOC_DQBUF, &dqbuf) != 0) {
+      if (errno == EAGAIN) {
+        // EAGAIN if we're just out of buffers to dequeue.
+        break;
+      }
+      PLOG(ERROR) << "ioctl() failed: VIDIOC_DQBUF";
+      NOTIFY_ERROR(PLATFORM_FAILURE);
+      return;
+    }
+    InputRecord& input_record = input_buffer_map_[dqbuf.index];
+    DCHECK(input_record.at_device);
+    input_record.at_device = false;
+    input_record.input_id = -1;
+    input_record.bytes_used = 0;
+    free_input_buffers_.push_back(dqbuf.index);
+    input_buffer_queued_count_--;
+    DVLOGF(4) << "Dequeued input=" << dqbuf.index
+              << " count: " << input_buffer_queued_count_;
+  }
+
+  while (output_buffer_queued_count_ > 0) {
+    DCHECK(output_streamon_);
+    memset(&dqbuf, 0, sizeof(dqbuf));
+    memset(&planes, 0, sizeof(planes));
+    dqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+    dqbuf.memory = V4L2_MEMORY_MMAP;
+    dqbuf.m.planes = planes;
+    dqbuf.length = output_planes_count_;
+    if (device_->Ioctl(VIDIOC_DQBUF, &dqbuf) != 0) {
+      if (errno == EAGAIN) {
+        // EAGAIN if we're just out of buffers to dequeue.
+        break;
+      }
+      PLOG(ERROR) << "ioctl() failed: VIDIOC_DQBUF";
+      NOTIFY_ERROR(PLATFORM_FAILURE);
+      return;
+    }
+    OutputRecord& output_record = output_buffer_map_[dqbuf.index];
+    DCHECK(output_record.at_device);
+    output_record.at_device = false;
+    DCHECK_NE(output_record.picture_id, -1);
+    output_buffer_queued_count_--;
+    DVLOGF(3) << "Dequeued output=" << dqbuf.index
+              << " count " << output_buffer_queued_count_;
+
+    V4L2DecodeSurfaceByOutputId::iterator it =
+        surfaces_at_device_.find(dqbuf.index);
+    if (it == surfaces_at_device_.end()) {
+      DLOG(ERROR) << "Got invalid surface from device.";
+      NOTIFY_ERROR(PLATFORM_FAILURE);
+    }
+
+    it->second->SetDecoded();
+    surfaces_at_device_.erase(it);
+  }
+
+  // A frame was decoded, see if we can output it.
+  TryOutputSurfaces();
+
+  ProcessPendingEventsIfNeeded();
+}
+
+void V4L2SliceVideoDecodeAccelerator::ProcessPendingEventsIfNeeded() {
+  // Process pending events, if any, in the correct order.
+  // We always first process the surface set change, as it is an internal
+  // event from the decoder and interleaving it with external requests would
+  // put the decoder in an undefined state.
+  FinishSurfaceSetChangeIfNeeded();
+
+  // Process external (client) requests.
+  FinishFlushIfNeeded();
+  FinishResetIfNeeded();
+}
+
+void V4L2SliceVideoDecodeAccelerator::ReuseOutputBuffer(int index) {
+  DCHECK_LT(index, static_cast<int>(output_buffer_map_.size()));
+  DVLOGF(4) << "Reusing output buffer, index=" << index;
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  OutputRecord& output_record = output_buffer_map_[index];
+  DCHECK(!output_record.at_device);
+  output_record.at_client = false;
+
+  free_output_buffers_.push_back(index);
+
+  ScheduleDecodeBufferTaskIfNeeded();
+}
+
+bool V4L2SliceVideoDecodeAccelerator::EnqueueInputRecord(
+    int index,
+    uint32_t config_store) {
+  DVLOGF(3);
+  DCHECK_LT(index, static_cast<int>(input_buffer_map_.size()));
+  DCHECK_GT(config_store, 0u);
+
+  // Enqueue an input (VIDEO_OUTPUT) buffer for an input video frame.
+  InputRecord& input_record = input_buffer_map_[index];
+  DCHECK(!input_record.at_device);
+  struct v4l2_buffer qbuf;
+  struct v4l2_plane qbuf_planes[VIDEO_MAX_PLANES];
+  memset(&qbuf, 0, sizeof(qbuf));
+  memset(qbuf_planes, 0, sizeof(qbuf_planes));
+  qbuf.index = index;
+  qbuf.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+  qbuf.memory = V4L2_MEMORY_MMAP;
+  qbuf.m.planes = qbuf_planes;
+  qbuf.m.planes[0].bytesused = input_record.bytes_used;
+  qbuf.length = input_planes_count_;
+  qbuf.config_store = config_store;
+  IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_QBUF, &qbuf);
+  input_record.at_device = true;
+  input_buffer_queued_count_++;
+  DVLOGF(4) << "Enqueued input=" << qbuf.index
+            << " count: " << input_buffer_queued_count_;
+
+  return true;
+}
+
+bool V4L2SliceVideoDecodeAccelerator::EnqueueOutputRecord(int index) {
+  DVLOGF(3);
+  DCHECK_LT(index, static_cast<int>(output_buffer_map_.size()));
+
+  // Enqueue an output (VIDEO_CAPTURE) buffer.
+  OutputRecord& output_record = output_buffer_map_[index];
+  DCHECK(!output_record.at_device);
+  DCHECK(!output_record.at_client);
+  DCHECK_NE(output_record.egl_image, EGL_NO_IMAGE_KHR);
+  DCHECK_NE(output_record.picture_id, -1);
+  if (output_record.egl_sync != EGL_NO_SYNC_KHR) {
+    // If we have to wait for completion, wait.  Note that
+    // free_output_buffers_ is a FIFO queue, so we always wait on the
+    // buffer that has been in the queue the longest.
+    if (eglClientWaitSyncKHR(egl_display_, output_record.egl_sync, 0,
+                             EGL_FOREVER_KHR) == EGL_FALSE) {
+      // This will cause tearing, but is safe otherwise.
+      DVLOGF(1) << "eglClientWaitSyncKHR failed!";
+    }
+    if (eglDestroySyncKHR(egl_display_, output_record.egl_sync) != EGL_TRUE) {
+      LOGF(ERROR) << "eglDestroySyncKHR failed!";
+      NOTIFY_ERROR(PLATFORM_FAILURE);
+      return false;
+    }
+    output_record.egl_sync = EGL_NO_SYNC_KHR;
+  }
+
+  struct v4l2_buffer qbuf;
+  struct v4l2_plane qbuf_planes[VIDEO_MAX_PLANES];
+  memset(&qbuf, 0, sizeof(qbuf));
+  memset(qbuf_planes, 0, sizeof(qbuf_planes));
+  qbuf.index = index;
+  qbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+  qbuf.memory = V4L2_MEMORY_MMAP;
+  qbuf.m.planes = qbuf_planes;
+  qbuf.length = output_planes_count_;
+  IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_QBUF, &qbuf);
+  output_record.at_device = true;
+  output_buffer_queued_count_++;
+  DVLOGF(4) << "Enqueued output=" << qbuf.index
+            << " count: " << output_buffer_queued_count_;
+
+  return true;
+}
+
+bool V4L2SliceVideoDecodeAccelerator::StartDevicePoll() {
+  DVLOGF(3) << "Starting device poll";
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+  DCHECK(!device_poll_thread_.IsRunning());
+
+  // Start up the device poll thread and schedule its first DevicePollTask().
+  if (!device_poll_thread_.Start()) {
+    DLOG(ERROR) << "StartDevicePoll(): Device thread failed to start";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+  if (!input_streamon_) {
+    __u32 type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+    IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_STREAMON, &type);
+    input_streamon_ = true;
+  }
+
+  if (!output_streamon_) {
+    __u32 type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+    IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_STREAMON, &type);
+    output_streamon_ = true;
+  }
+
+  device_poll_thread_.message_loop()->PostTask(
+      FROM_HERE, base::Bind(&V4L2SliceVideoDecodeAccelerator::DevicePollTask,
+                            base::Unretained(this), true));
+
+  return true;
+}
+
+bool V4L2SliceVideoDecodeAccelerator::StopDevicePoll(bool keep_input_state) {
+  DVLOGF(3) << "Stopping device poll";
+  if (decoder_thread_.IsRunning())
+    DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  // Signal the DevicePollTask() to stop, and stop the device poll thread.
+  if (!device_->SetDevicePollInterrupt()) {
+    PLOG(ERROR) << "SetDevicePollInterrupt(): failed";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+  device_poll_thread_.Stop();
+  DVLOGF(3) << "Device poll thread stopped";
+
+  // Clear the interrupt now, to be sure.
+  if (!device_->ClearDevicePollInterrupt()) {
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+
+  if (!keep_input_state) {
+    if (input_streamon_) {
+      __u32 type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+      IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_STREAMOFF, &type);
+    }
+    input_streamon_ = false;
+  }
+
+  if (output_streamon_) {
+    __u32 type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+    IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_STREAMOFF, &type);
+  }
+  output_streamon_ = false;
+
+  if (!keep_input_state) {
+    free_input_buffers_.clear();
+    for (size_t i = 0; i < input_buffer_map_.size(); ++i) {
+      InputRecord& input_record = input_buffer_map_[i];
+      input_record.at_device = false;
+      input_record.bytes_used = 0;
+      input_record.input_id = -1;
+      free_input_buffers_.push_back(i);
+    }
+    input_buffer_queued_count_ = 0;
+  }
+
+  surfaces_at_device_.clear();
+
+  free_output_buffers_.clear();
+  for (size_t i = 0; i < output_buffer_map_.size(); ++i) {
+    OutputRecord& output_record = output_buffer_map_[i];
+    DCHECK(!(output_record.at_client && output_record.at_device));
+    output_record.at_device = false;
+    if (!output_record.at_client)
+      free_output_buffers_.push_back(i);
+  }
+  output_buffer_queued_count_ = 0;
+
+  DVLOGF(3) << "Device poll stopped";
+  return true;
+}
+
+void V4L2SliceVideoDecodeAccelerator::Decode(
+    const media::BitstreamBuffer& bitstream_buffer) {
+  DVLOGF(3) << "input_id=" << bitstream_buffer.id()
+            << ", size=" << bitstream_buffer.size();
+  DCHECK(io_message_loop_proxy_->BelongsToCurrentThread());
+
+  decoder_thread_proxy_->PostTask(
+      FROM_HERE, base::Bind(&V4L2SliceVideoDecodeAccelerator::DecodeTask,
+                            base::Unretained(this), bitstream_buffer));
+}
+
+void V4L2SliceVideoDecodeAccelerator::DecodeTask(
+    const media::BitstreamBuffer& bitstream_buffer) {
+  DVLOGF(3) << "input_id=" << bitstream_buffer.id()
+            << " size=" << bitstream_buffer.size();
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  scoped_ptr<BitstreamBufferRef> bitstream_record(new BitstreamBufferRef(
+      io_client_, io_message_loop_proxy_,
+      new base::SharedMemory(bitstream_buffer.handle(), true),
+      bitstream_buffer.size(), bitstream_buffer.id()));
+  if (!bitstream_record->shm->Map(bitstream_buffer.size())) {
+    LOGF(ERROR) << "Could not map bitstream_buffer";
+    NOTIFY_ERROR(UNREADABLE_INPUT);
+    return;
+  }
+  DVLOGF(3) << "mapped at=" << bitstream_record->shm->memory();
+
+  decoder_input_queue_.push(
+      linked_ptr<BitstreamBufferRef>(bitstream_record.release()));
+
+  ScheduleDecodeBufferTaskIfNeeded();
+}
+
+bool V4L2SliceVideoDecodeAccelerator::TrySetNewBistreamBuffer() {
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+  DCHECK(!decoder_current_bitstream_buffer_);
+
+  if (decoder_input_queue_.empty())
+    return false;
+
+  decoder_current_bitstream_buffer_.reset(
+      decoder_input_queue_.front().release());
+  decoder_input_queue_.pop();
+
+  if (decoder_current_bitstream_buffer_->input_id == kFlushBufferId) {
+    // This is a buffer we queued for ourselves to trigger flush at this time.
+    InitiateFlush();
+    return false;
+  }
+
+  const uint8* const data = reinterpret_cast<const uint8*>(
+      decoder_current_bitstream_buffer_->shm->memory());
+  const size_t data_size = decoder_current_bitstream_buffer_->size;
+  decoder_->SetStream(data, data_size);
+
+  return true;
+}
+
+void V4L2SliceVideoDecodeAccelerator::ScheduleDecodeBufferTaskIfNeeded() {
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+  if (state_ == kDecoding) {
+    decoder_thread_proxy_->PostTask(
+        FROM_HERE,
+        base::Bind(&V4L2SliceVideoDecodeAccelerator::DecodeBufferTask,
+                   base::Unretained(this)));
+  }
+}
+
+void V4L2SliceVideoDecodeAccelerator::DecodeBufferTask() {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  if (state_ != kDecoding) {
+    DVLOGF(3) << "Early exit, not in kDecoding";
+    return;
+  }
+
+  while (true) {
+    AcceleratedVideoDecoder::DecResult res;
+    res = decoder_->Decode();
+    switch (res) {
+      case AcceleratedVideoDecoder::kAllocateNewSurfaces:
+        DVLOGF(2) << "Decoder requesting a new set of surfaces";
+        InitiateSurfaceSetChange();
+        return;
+
+      case AcceleratedVideoDecoder::kRanOutOfStreamData:
+        decoder_current_bitstream_buffer_.reset();
+        if (!TrySetNewBistreamBuffer())
+          return;
+
+        break;
+
+      case AcceleratedVideoDecoder::kRanOutOfSurfaces:
+        // No more surfaces for the decoder, we'll come back once we have more.
+        DVLOGF(4) << "Ran out of surfaces";
+        return;
+
+      case AcceleratedVideoDecoder::kDecodeError:
+        DVLOGF(1) << "Error decoding stream";
+        NOTIFY_ERROR(PLATFORM_FAILURE);
+        return;
+    }
+  }
+}
+
+void V4L2SliceVideoDecodeAccelerator::InitiateSurfaceSetChange() {
+  DVLOGF(2);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+  DCHECK_EQ(state_, kDecoding);
+
+  DCHECK_EQ(state_, kDecoding);

[kcwu, 2015/01/12 07:31:46]

code duped

[Pawel Osciak, 2015/01/13 11:33:33]

Done.

+  state_ = kIdle;
+
+  DCHECK(!surface_set_change_pending_);
+  surface_set_change_pending_ = true;
+
+  FinishSurfaceSetChangeIfNeeded();
+}
+
+void V4L2SliceVideoDecodeAccelerator::FinishSurfaceSetChangeIfNeeded() {
+  DVLOGF(2);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  if (!surface_set_change_pending_ || !surfaces_at_device_.empty())
+    return;
+
+  DCHECK_EQ(state_, kIdle);
+  DCHECK(decoder_display_queue_.empty());
+
+  // Keep input queue running while we switch outputs.
+  if (!StopDevicePoll(true)) {
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  // This will return only once all buffers are dismissed and destroyed.
+  // This does not wait until they are displayed however, as display retains
+  // references to the buffers bound to textures and will release them
+  // after displaying.
+  if (!DestroyOutputs(true)) {
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  if (!CreateOutputBuffers()) {
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  if (!StartDevicePoll()) {
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  DVLOGF(3) << "Surface set change finished";
+
+  surface_set_change_pending_ = false;
+  state_ = kDecoding;
+  ScheduleDecodeBufferTaskIfNeeded();
+}
+
+bool V4L2SliceVideoDecodeAccelerator::DestroyOutputs(bool dismiss) {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+  std::vector<EGLImageKHR> egl_images_to_destroy;
+  std::vector<int32> picture_buffers_to_dismiss;
+
+  if (output_buffer_map_.empty())
+    return true;
+
+  for (auto output_record : output_buffer_map_) {
+    DCHECK(!output_record.at_device);
+    output_record.at_client = false;
+
+    if (output_record.egl_sync != EGL_NO_SYNC_KHR) {
+      if (eglDestroySyncKHR(egl_display_, output_record.egl_sync) != EGL_TRUE)
+        DVLOGF(1) << "eglDestroySyncKHR failed.";
+    }
+
+    if (output_record.egl_image != EGL_NO_IMAGE_KHR) {
+      child_message_loop_proxy_->PostTask(
+          FROM_HERE,
+          base::Bind(base::IgnoreResult(&V4L2Device::DestroyEGLImage), device_,
+                     egl_display_, output_record.egl_image));
+    }
+
+    picture_buffers_to_dismiss.push_back(output_record.picture_id);
+  }
+
+  if (dismiss) {
+    DVLOGF(2) << "Scheduling picture dismissal";
+    base::WaitableEvent done(false, false);
+    child_message_loop_proxy_->PostTask(
+        FROM_HERE, base::Bind(&V4L2SliceVideoDecodeAccelerator::DismissPictures,
+                              weak_this_, picture_buffers_to_dismiss, &done));
+    done.Wait();
+  }
+
+  // At this point client can't call ReusePictureBuffer on any of the pictures
+  // anymore, so it's safe to destroy.
+  return DestroyOutputBuffers();
+}
+
+bool V4L2SliceVideoDecodeAccelerator::DestroyOutputBuffers() {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread() ||
+         !decoder_thread_.IsRunning());
+  DCHECK(!output_streamon_);
+  DCHECK(surfaces_at_device_.empty());
+  DCHECK(decoder_display_queue_.empty());
+  DCHECK(surfaces_at_display_.size() + free_output_buffers_.size() ==
+         output_buffer_map_.size());
+
+  if (output_buffer_map_.empty())
+    return true;
+
+  // It's ok to do this, client will retain references to textures, but we are
+  // not interested in reusing the surfaces anymore.
+  // This will prevent us from reusing old surfaces in case we have some
+  // ReusePictureBuffer() pending on ChildThread already. It's ok to ignore
+  // them, because we have already dismissed them (in DestroyOutputs()).
+  surfaces_at_display_.clear();
+  DCHECK_EQ(free_output_buffers_.size(), output_buffer_map_.size());
+
+  free_output_buffers_.clear();
+  output_buffer_map_.clear();
+
+  struct v4l2_requestbuffers reqbufs;
+  memset(&reqbufs, 0, sizeof(reqbufs));
+  reqbufs.count = 0;
+  reqbufs.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+  reqbufs.memory = V4L2_MEMORY_MMAP;
+  IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_REQBUFS, &reqbufs);
+
+  return true;
+}
+
+void V4L2SliceVideoDecodeAccelerator::AssignPictureBuffers(
+    const std::vector<media::PictureBuffer>& buffers) {
+  DVLOGF(3);
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+
+  if (buffers.size() != output_buffer_map_.size()) {
+    DLOG(ERROR) << "Failed to provide requested picture buffers. "
+                << "(Got " << buffers.size()
+                << ", requested " << output_buffer_map_.size() << ")";
+    NOTIFY_ERROR(INVALID_ARGUMENT);
+    return;
+  }
+
+  if (!make_context_current_.Run()) {
+    DLOG(ERROR) << "could not make context current";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  gfx::ScopedTextureBinder bind_restore(GL_TEXTURE_EXTERNAL_OES, 0);
+
+  // It's safe to manipulate all the buffer state here, because the decoder
+  // thread is waiting on pictures_assigned_.
+  DCHECK(free_output_buffers_.empty());
+  for (size_t i = 0; i < output_buffer_map_.size(); ++i) {
+    DCHECK(buffers[i].size() == frame_buffer_size_);
+
+    OutputRecord& output_record = output_buffer_map_[i];
+    DCHECK(!output_record.at_device);
+    DCHECK(!output_record.at_client);
+    DCHECK_EQ(output_record.egl_image, EGL_NO_IMAGE_KHR);
+    DCHECK_EQ(output_record.egl_sync, EGL_NO_SYNC_KHR);
+    DCHECK_EQ(output_record.picture_id, -1);
+    DCHECK_EQ(output_record.cleared, false);
+
+    EGLImageKHR egl_image = device_->CreateEGLImage(egl_display_,
+                                                    egl_context_,
+                                                    buffers[i].texture_id(),
+                                                    frame_buffer_size_,
+                                                    i,
+                                                    output_format_fourcc_,
+                                                    output_planes_count_);
+    if (egl_image == EGL_NO_IMAGE_KHR) {
+      LOGF(ERROR) << "Could not create EGLImageKHR";
+      // Ownership of EGLImages allocated in previous iterations of this loop
+      // has been transferred to output_buffer_map_. After we error-out here
+      // the destructor will handle their cleanup.
+      NOTIFY_ERROR(PLATFORM_FAILURE);
+      return;
+    }
+
+    output_record.egl_image = egl_image;
+    output_record.picture_id = buffers[i].id();
+    free_output_buffers_.push_back(i);
+    DVLOGF(3) << "buffer[" << i << "]: picture_id=" << output_record.picture_id;
+  }
+
+  pictures_assigned_.Signal();
+}
+
+void V4L2SliceVideoDecodeAccelerator::ReusePictureBuffer(
+    int32 picture_buffer_id) {
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+  DVLOGF(4) << "picture_buffer_id=" << picture_buffer_id;
+
+  if (!make_context_current_.Run()) {
+    LOGF(ERROR) << "could not make context current";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  EGLSyncKHR egl_sync =
+      eglCreateSyncKHR(egl_display_, EGL_SYNC_FENCE_KHR, NULL);
+  if (egl_sync == EGL_NO_SYNC_KHR) {
+    LOGF(ERROR) << "eglCreateSyncKHR() failed";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  scoped_ptr<EGLSyncKHRRef> egl_sync_ref(
+      new EGLSyncKHRRef(egl_display_, egl_sync));
+  decoder_thread_proxy_->PostTask(
+      FROM_HERE,
+      base::Bind(&V4L2SliceVideoDecodeAccelerator::ReusePictureBufferTask,
+                 base::Unretained(this), picture_buffer_id,
+                 base::Passed(&egl_sync_ref)));
+}
+
+void V4L2SliceVideoDecodeAccelerator::ReusePictureBufferTask(
+    int32 picture_buffer_id,
+    scoped_ptr<EGLSyncKHRRef> egl_sync_ref) {
+  DVLOGF(3) << "picture_buffer_id=" << picture_buffer_id;
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  V4L2DecodeSurfaceByPictureBufferId::iterator it =
+      surfaces_at_display_.find(picture_buffer_id);
+  if (it == surfaces_at_display_.end()) {
+    // It's possible that we've already posted a DismissPictureBuffer for this
+    // picture, but it has not yet executed when this ReusePictureBuffer was
+    // posted to us by the client. In that case just ignore this (we've already
+    // dismissed it and accounted for that) and let the sync object get
+    // destroyed.
+    DVLOGF(3) << "got picture id= " << picture_buffer_id
+              << " not in use (anymore?).";
+    return;
+  }
+
+  OutputRecord& output_record = output_buffer_map_[it->second->output_record()];
+  if (output_record.at_device || !output_record.at_client) {
+    DVLOGF(1) << "picture_buffer_id not reusable";
+    NOTIFY_ERROR(INVALID_ARGUMENT);
+    return;
+  }
+
+  DCHECK_EQ(output_record.egl_sync, EGL_NO_SYNC_KHR);
+  DCHECK(!output_record.at_device);
+  output_record.at_client = false;
+  output_record.egl_sync = egl_sync_ref->egl_sync;
+  // Take ownership of the EGLSync.
+  egl_sync_ref->egl_sync = EGL_NO_SYNC_KHR;
+  surfaces_at_display_.erase(it);
+}
+
+void V4L2SliceVideoDecodeAccelerator::Flush() {
+  DVLOGF(3);
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+
+  decoder_thread_proxy_->PostTask(
+      FROM_HERE, base::Bind(&V4L2SliceVideoDecodeAccelerator::FlushTask,
+                            base::Unretained(this)));
+}
+
+void V4L2SliceVideoDecodeAccelerator::FlushTask() {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  if (!decoder_input_queue_.empty()) {
+    // We are not done with pending inputs, so queue an empty buffer,
+    // which - when reached - will trigger flush sequence.
+    decoder_input_queue_.push(
+        linked_ptr<BitstreamBufferRef>(new BitstreamBufferRef(
+            io_client_, io_message_loop_proxy_, nullptr, 0, kFlushBufferId)));
+    return;
+  }
+
+  // No more inputs pending, so just finish flushing here.
+  InitiateFlush();
+}
+
+void V4L2SliceVideoDecodeAccelerator::InitiateFlush() {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  DCHECK(!decoder_flushing_);
+  DCHECK_EQ(state_, kDecoding);
+  state_ = kIdle;
+
+  // This will trigger output for all remaining surfaces in the decoder.
+  // However, not all of them may be decoded yet (they would be queued
+  // in hardware then).
+  if (!decoder_->Flush()) {
+    DVLOGF(1) << "Failed flushing the decoder.";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  // Put the decoder in an idle state, ready to resume.
+  decoder_->Reset();
+
+  decoder_flushing_ = true;
+
+  decoder_thread_proxy_->PostTask(
+      FROM_HERE,
+      base::Bind(&V4L2SliceVideoDecodeAccelerator::FinishFlushIfNeeded,
+                 base::Unretained(this)));
+}
+
+void V4L2SliceVideoDecodeAccelerator::FinishFlushIfNeeded() {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  if (!decoder_flushing_ || !surfaces_at_device_.empty())
+    return;
+
+  DCHECK_EQ(state_, kIdle);
+
+  // At this point, all remaining surfaces are decoded and dequeued, and since
+  // we have already scheduled output for them in InitiateFlush(), their
+  // respective PictureReady calls have been posted (or they have been queued on
+  // pending_picture_ready_). So at this time, once we SendPictureReady(),
+  // we will have all remaining PictureReady() posted to the client and we
+  // can post NotifyFlushDone().
+  DCHECK(decoder_display_queue_.empty());
+  SendPictureReady();
+
+  child_message_loop_proxy_->PostTask(
+      FROM_HERE, base::Bind(&Client::NotifyFlushDone, client_));
+
+  decoder_flushing_ = false;
+
+  DVLOGF(3) << "Flush finished";
+  state_ = kDecoding;
+  ScheduleDecodeBufferTaskIfNeeded();
+}
+
+void V4L2SliceVideoDecodeAccelerator::Reset() {
+  DVLOGF(3);
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+
+  decoder_thread_proxy_->PostTask(
+      FROM_HERE, base::Bind(&V4L2SliceVideoDecodeAccelerator::ResetTask,
+                            base::Unretained(this)));
+}
+
+void V4L2SliceVideoDecodeAccelerator::ResetTask() {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  if (decoder_resetting_) {
+    // This is a bug in the client, multiple Reset()s before NotifyResetDone()
+    // are not allowed.
+    NOTREACHED() << "Client should not be requesting multiple Reset()s";
+    return;
+  }
+
+  DCHECK_EQ(state_, kDecoding);
+  state_ = kIdle;
+
+  // Put the decoder in an idle state, ready to resume.
+  decoder_->Reset();
+
+  decoder_resetting_ = true;
+
+  // Drop all remaining inputs.
+  decoder_current_bitstream_buffer_.reset();
+  while (!decoder_input_queue_.empty())
+    decoder_input_queue_.pop();
+
+  FinishResetIfNeeded();
+}
+
+void V4L2SliceVideoDecodeAccelerator::FinishResetIfNeeded() {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  if (!decoder_resetting_ || !surfaces_at_device_.empty())
+    return;
+
+  DCHECK_EQ(state_, kIdle);
+  DCHECK(!decoder_flushing_);
+
+  // Drop any pending outputs.
+  while (!decoder_display_queue_.empty())
+    decoder_display_queue_.pop();
+
+  SendPictureReady();
+  decoder_resetting_ = false;
+
+  child_message_loop_proxy_->PostTask(
+      FROM_HERE, base::Bind(&Client::NotifyResetDone, client_));
+
+  DVLOGF(3) << "Reset finished";
+
+  state_ = kDecoding;
+  ScheduleDecodeBufferTaskIfNeeded();
+}
+
+void V4L2SliceVideoDecodeAccelerator::SetErrorState(Error error) {
+  // We can touch decoder_state_ only if this is the decoder thread or the
+  // decoder thread isn't running.
+  if (decoder_thread_.IsRunning() &&
+      !decoder_thread_proxy_->BelongsToCurrentThread()) {
+    decoder_thread_proxy_->PostTask(
+        FROM_HERE, base::Bind(&V4L2SliceVideoDecodeAccelerator::SetErrorState,
+                              base::Unretained(this), error));
+    return;
+  }
+
+  // Post NotifyError only if we are already initialized, as the API does
+  // not allow doing so before that.
+  if (state_ != kError && state_ != kUninitialized)
+    NotifyError(error);
+
+  state_ = kError;
+}
+
+V4L2SliceVideoDecodeAccelerator::V4L2H264Accelerator::V4L2H264Accelerator(
+    V4L2SliceVideoDecodeAccelerator* v4l2_dec)
+    : num_slices_(0), v4l2_dec_(v4l2_dec) {
+  DCHECK(v4l2_dec_);
+}
+
+scoped_refptr<H264Picture>
+V4L2SliceVideoDecodeAccelerator::V4L2H264Accelerator::CreateH264Picture() {
+  scoped_refptr<V4L2DecodeSurface> dec_surface = v4l2_dec_->CreateSurface();
+  if (!dec_surface)
+    return nullptr;
+
+  return new V4L2H264Picture(dec_surface);
+}
+
+void V4L2SliceVideoDecodeAccelerator::V4L2H264Accelerator::
+    H264PictureListToDPBIndicesList(const H264Picture::Vector& src_pic_list,
+                                    uint8_t dst_list[32]) {
+  size_t i = 0;
+  for (auto& pic : src_pic_list)
+    dst_list[i++] = pic ? pic->dpb_position : VIDEO_MAX_FRAME;
+
+  while (i < 32)
+    dst_list[i++] = VIDEO_MAX_FRAME;
+}
+
+void V4L2SliceVideoDecodeAccelerator::V4L2H264Accelerator::H264DPBToV4L2DPB(
+    const H264DPB& dpb,
+    std::vector<scoped_refptr<V4L2DecodeSurface>>* ref_surfaces) {
+  memset(v4l2_decode_param_.dpb, 0, sizeof(v4l2_decode_param_.dpb));
+  size_t i = 0;
+  for (const auto& pic : dpb) {
+    struct v4l2_h264_dpb_entry& entry = v4l2_decode_param_.dpb[i++];
+    scoped_refptr<V4L2DecodeSurface> dec_surface =
+        H264PictureToV4L2DecodeSurface(pic);
+    entry.buf_index = dec_surface->output_record();
+    entry.frame_num = pic->frame_num;
+    entry.pic_num = pic->pic_num;
+    entry.top_field_order_cnt = pic->top_field_order_cnt;
+    entry.bottom_field_order_cnt = pic->bottom_field_order_cnt;
+    entry.flags = (pic->ref ? V4L2_H264_DPB_ENTRY_FLAG_ACTIVE : 0) |
+                  (pic->long_term ? V4L2_H264_DPB_ENTRY_FLAG_LONG_TERM : 0);
+
+    ref_surfaces->push_back(dec_surface);
+  }
+}
+
+bool V4L2SliceVideoDecodeAccelerator::V4L2H264Accelerator::SubmitFrameMetadata(
+    const media::H264SPS* sps,
+    const media::H264PPS* pps,
+    const H264DPB& dpb,
+    const H264Picture::Vector& ref_pic_listp0,
+    const H264Picture::Vector& ref_pic_listb0,
+    const H264Picture::Vector& ref_pic_listb1,
+    const scoped_refptr<H264Picture>& pic) {
+  struct v4l2_ext_control ctrl;
+  std::vector<struct v4l2_ext_control> ctrls;
+
+  struct v4l2_ctrl_h264_sps v4l2_sps;
+  memset(&v4l2_sps, 0, sizeof(v4l2_sps));
+  v4l2_sps.constraint_set_flags =
+    sps->constraint_set0_flag ? V4L2_H264_SPS_CONSTRAINT_SET0_FLAG : 0 |
+    sps->constraint_set1_flag ? V4L2_H264_SPS_CONSTRAINT_SET1_FLAG : 0 |
+    sps->constraint_set2_flag ? V4L2_H264_SPS_CONSTRAINT_SET2_FLAG : 0 |
+    sps->constraint_set3_flag ? V4L2_H264_SPS_CONSTRAINT_SET3_FLAG : 0 |
+    sps->constraint_set4_flag ? V4L2_H264_SPS_CONSTRAINT_SET4_FLAG : 0 |
+    sps->constraint_set5_flag ? V4L2_H264_SPS_CONSTRAINT_SET5_FLAG : 0;
+#define SPS_TO_V4L2SPS(a) v4l2_sps.a = sps->a
+  SPS_TO_V4L2SPS(profile_idc);
+  SPS_TO_V4L2SPS(level_idc);
+  SPS_TO_V4L2SPS(seq_parameter_set_id);
+  SPS_TO_V4L2SPS(chroma_format_idc);
+  SPS_TO_V4L2SPS(bit_depth_luma_minus8);
+  SPS_TO_V4L2SPS(bit_depth_chroma_minus8);
+  SPS_TO_V4L2SPS(log2_max_frame_num_minus4);
+  SPS_TO_V4L2SPS(pic_order_cnt_type);
+  SPS_TO_V4L2SPS(log2_max_pic_order_cnt_lsb_minus4);
+  SPS_TO_V4L2SPS(offset_for_non_ref_pic);
+  SPS_TO_V4L2SPS(offset_for_top_to_bottom_field);
+  SPS_TO_V4L2SPS(num_ref_frames_in_pic_order_cnt_cycle);
+
+  COMPILE_ASSERT(arraysize(v4l2_sps.offset_for_ref_frame) ==
+                 arraysize(sps->offset_for_ref_frame),
+                 offset_for_ref_frame_arrays_must_be_same_size);
+  for (size_t i = 0; i < arraysize(v4l2_sps.offset_for_ref_frame); ++i)
+    v4l2_sps.offset_for_ref_frame[i] = sps->offset_for_ref_frame[i];
+  SPS_TO_V4L2SPS(max_num_ref_frames);
+  SPS_TO_V4L2SPS(pic_width_in_mbs_minus1);
+  SPS_TO_V4L2SPS(pic_height_in_map_units_minus1);
+#undef SPS_TO_V4L2SPS
+
+#define SET_V4L2_SPS_FLAG_IF(cond, flag) \
+  v4l2_sps.flags |= ((sps->cond) ? (flag) : 0)
+  SET_V4L2_SPS_FLAG_IF(separate_colour_plane_flag,
+                       V4L2_H264_SPS_FLAG_SEPARATE_COLOUR_PLANE);
+  SET_V4L2_SPS_FLAG_IF(qpprime_y_zero_transform_bypass_flag,
+                       V4L2_H264_SPS_FLAG_QPPRIME_Y_ZERO_TRANSFORM_BYPASS);
+  SET_V4L2_SPS_FLAG_IF(delta_pic_order_always_zero_flag,
+                       V4L2_H264_SPS_FLAG_DELTA_PIC_ORDER_ALWAYS_ZERO);
+  SET_V4L2_SPS_FLAG_IF(gaps_in_frame_num_value_allowed_flag,
+                       V4L2_H264_SPS_FLAG_GAPS_IN_FRAME_NUM_VALUE_ALLOWED);
+  SET_V4L2_SPS_FLAG_IF(frame_mbs_only_flag, V4L2_H264_SPS_FLAG_FRAME_MBS_ONLY);
+  SET_V4L2_SPS_FLAG_IF(mb_adaptive_frame_field_flag,
+                       V4L2_H264_SPS_FLAG_MB_ADAPTIVE_FRAME_FIELD);
+  SET_V4L2_SPS_FLAG_IF(direct_8x8_inference_flag,
+                       V4L2_H264_SPS_FLAG_DIRECT_8X8_INFERENCE);
+#undef SET_FLAG
+  memset(&ctrl, 0, sizeof(ctrl));
+  ctrl.id = V4L2_CID_MPEG_VIDEO_H264_SPS;
+  ctrl.size = sizeof(v4l2_sps);
+  ctrl.p_h264_sps = &v4l2_sps;
+  ctrls.push_back(ctrl);
+
+  struct v4l2_ctrl_h264_pps v4l2_pps;
+  memset(&v4l2_pps, 0, sizeof(v4l2_pps));
+#define PPS_TO_V4L2PPS(a) v4l2_pps.a = pps->a
+  PPS_TO_V4L2PPS(pic_parameter_set_id);
+  PPS_TO_V4L2PPS(seq_parameter_set_id);
+  PPS_TO_V4L2PPS(num_slice_groups_minus1);
+  PPS_TO_V4L2PPS(num_ref_idx_l0_default_active_minus1);
+  PPS_TO_V4L2PPS(num_ref_idx_l1_default_active_minus1);
+  PPS_TO_V4L2PPS(weighted_bipred_idc);
+  PPS_TO_V4L2PPS(pic_init_qp_minus26);
+  PPS_TO_V4L2PPS(pic_init_qs_minus26);
+  PPS_TO_V4L2PPS(chroma_qp_index_offset);
+  PPS_TO_V4L2PPS(second_chroma_qp_index_offset);
+#undef PPS_TO_V4L2PPS
+
+#define SET_V4L2_PPS_FLAG_IF(cond, flag) \
+  v4l2_pps.flags |= ((pps->cond) ? (flag) : 0)
+  SET_V4L2_PPS_FLAG_IF(entropy_coding_mode_flag,
+                       V4L2_H264_PPS_FLAG_ENTROPY_CODING_MODE);
+  SET_V4L2_PPS_FLAG_IF(
+      bottom_field_pic_order_in_frame_present_flag,
+      V4L2_H264_PPS_FLAG_BOTTOM_FIELD_PIC_ORDER_IN_FRAME_PRESENT);
+  SET_V4L2_PPS_FLAG_IF(weighted_pred_flag, V4L2_H264_PPS_FLAG_WEIGHTED_PRED);
+  SET_V4L2_PPS_FLAG_IF(deblocking_filter_control_present_flag,
+                       V4L2_H264_PPS_FLAG_DEBLOCKING_FILTER_CONTROL_PRESENT);
+  SET_V4L2_PPS_FLAG_IF(constrained_intra_pred_flag,
+                       V4L2_H264_PPS_FLAG_CONSTRAINED_INTRA_PRED);
+  SET_V4L2_PPS_FLAG_IF(redundant_pic_cnt_present_flag,
+                       V4L2_H264_PPS_FLAG_REDUNDANT_PIC_CNT_PRESENT);
+  SET_V4L2_PPS_FLAG_IF(transform_8x8_mode_flag,
+                       V4L2_H264_PPS_FLAG_TRANSFORM_8X8_MODE);
+  SET_V4L2_PPS_FLAG_IF(pic_scaling_matrix_present_flag,
+                       V4L2_H264_PPS_FLAG_PIC_SCALING_MATRIX_PRESENT);
+#undef SET_V4L2_PPS_FLAG_IF
+  memset(&ctrl, 0, sizeof(ctrl));
+  ctrl.id = V4L2_CID_MPEG_VIDEO_H264_PPS;
+  ctrl.size = sizeof(v4l2_pps);
+  ctrl.p_h264_pps = &v4l2_pps;
+  ctrls.push_back(ctrl);
+
+  struct v4l2_ctrl_h264_scaling_matrix v4l2_scaling_matrix;
+  memset(&v4l2_scaling_matrix, 0, sizeof(v4l2_scaling_matrix));
+  COMPILE_ASSERT(arraysize(v4l2_scaling_matrix.scaling_list_4x4) <=
+                 arraysize(pps->scaling_list4x4) &&
+                 arraysize(v4l2_scaling_matrix.scaling_list_4x4[0]) <=
+                 arraysize(pps->scaling_list4x4[0]) &&
+                 arraysize(v4l2_scaling_matrix.scaling_list_8x8) <=
+                 arraysize(pps->scaling_list8x8) &&
+                 arraysize(v4l2_scaling_matrix.scaling_list_8x8[0]) <=
+                 arraysize(pps->scaling_list8x8[0]),
+                 scaling_lists_invalid_size);
+  for (size_t i = 0; i < arraysize(v4l2_scaling_matrix.scaling_list_4x4); ++i) {
+    for (size_t j = 0; j < arraysize(v4l2_scaling_matrix.scaling_list_4x4[i]);
+         ++j) {
+      v4l2_scaling_matrix.scaling_list_4x4[i][j] = pps->scaling_list4x4[i][j];
+    }
+  }
+  for (size_t i = 0; i < arraysize(v4l2_scaling_matrix.scaling_list_8x8); ++i) {
+    for (size_t j = 0; j < arraysize(v4l2_scaling_matrix.scaling_list_8x8[i]);
+         ++j) {
+      v4l2_scaling_matrix.scaling_list_8x8[i][j] = pps->scaling_list8x8[i][j];
+    }
+  }
+  memset(&ctrl, 0, sizeof(ctrl));
+  ctrl.id = V4L2_CID_MPEG_VIDEO_H264_SCALING_MATRIX;
+  ctrl.size = sizeof(v4l2_scaling_matrix);
+  ctrl.p_h264_scal_mtrx = &v4l2_scaling_matrix;
+  ctrls.push_back(ctrl);
+
+  scoped_refptr<V4L2DecodeSurface> dec_surface =
+      H264PictureToV4L2DecodeSurface(pic);
+
+  struct v4l2_ext_controls ext_ctrls;
+  memset(&ext_ctrls, 0, sizeof(ext_ctrls));
+  ext_ctrls.count = ctrls.size();
+  ext_ctrls.controls = &ctrls[0];
+  ext_ctrls.config_store = dec_surface->config_store();
+  v4l2_dec_->SubmitExtControls(&ext_ctrls);
+
+  H264PictureListToDPBIndicesList(ref_pic_listp0,
+                                  v4l2_decode_param_.ref_pic_list_p0);
+  H264PictureListToDPBIndicesList(ref_pic_listb0,
+                                  v4l2_decode_param_.ref_pic_list_b0);
+  H264PictureListToDPBIndicesList(ref_pic_listb1,
+                                  v4l2_decode_param_.ref_pic_list_b1);
+
+  std::vector<scoped_refptr<V4L2DecodeSurface>> ref_surfaces;
+  H264DPBToV4L2DPB(dpb, &ref_surfaces);
+  dec_surface->SetReferenceSurfaces(ref_surfaces);
+
+  return true;
+}
+
+bool V4L2SliceVideoDecodeAccelerator::V4L2H264Accelerator::SubmitSlice(
+    const media::H264PPS* pps,
+    const media::H264SliceHeader* slice_hdr,
+    const H264Picture::Vector& ref_pic_list0,
+    const H264Picture::Vector& ref_pic_list1,
+    const scoped_refptr<H264Picture>& pic,
+    const uint8_t* data,
+    size_t size) {
+  if (num_slices_ == kMaxSlices) {
+    LOGF(ERROR) << "Over limit of supported slices per frame";
+    return false;
+  }
+
+  struct v4l2_ctrl_h264_slice_param& v4l2_slice_param =
+      v4l2_slice_params_[num_slices_++];
+  memset(&v4l2_slice_param, 0, sizeof(v4l2_slice_param));
+
+  v4l2_slice_param.size = size;
+#define SHDR_TO_V4L2SPARM(a) v4l2_slice_param.a = slice_hdr->a
+  SHDR_TO_V4L2SPARM(header_bit_size);
+  SHDR_TO_V4L2SPARM(first_mb_in_slice);
+  SHDR_TO_V4L2SPARM(slice_type);
+  SHDR_TO_V4L2SPARM(pic_parameter_set_id);
+  SHDR_TO_V4L2SPARM(colour_plane_id);
+  SHDR_TO_V4L2SPARM(frame_num);
+  SHDR_TO_V4L2SPARM(idr_pic_id);
+  SHDR_TO_V4L2SPARM(pic_order_cnt_lsb);
+  SHDR_TO_V4L2SPARM(delta_pic_order_cnt_bottom);
+  SHDR_TO_V4L2SPARM(delta_pic_order_cnt0);
+  SHDR_TO_V4L2SPARM(delta_pic_order_cnt1);
+  SHDR_TO_V4L2SPARM(redundant_pic_cnt);
+  SHDR_TO_V4L2SPARM(dec_ref_pic_marking_bit_size);
+  SHDR_TO_V4L2SPARM(cabac_init_idc);
+  SHDR_TO_V4L2SPARM(slice_qp_delta);
+  SHDR_TO_V4L2SPARM(slice_qs_delta);
+  SHDR_TO_V4L2SPARM(disable_deblocking_filter_idc);
+  SHDR_TO_V4L2SPARM(slice_alpha_c0_offset_div2);
+  SHDR_TO_V4L2SPARM(slice_beta_offset_div2);
+  SHDR_TO_V4L2SPARM(num_ref_idx_l0_active_minus1);
+  SHDR_TO_V4L2SPARM(num_ref_idx_l1_active_minus1);
+  SHDR_TO_V4L2SPARM(pic_order_cnt_bit_size);
+#undef SHDR_TO_V4L2SPARM
+
+#define SET_V4L2_SPARM_FLAG_IF(cond, flag) \
+  v4l2_slice_param.flags |= ((slice_hdr->cond) ? (flag) : 0)
+  SET_V4L2_SPARM_FLAG_IF(field_pic_flag, V4L2_SLICE_FLAG_FIELD_PIC);
+  SET_V4L2_SPARM_FLAG_IF(bottom_field_flag, V4L2_SLICE_FLAG_BOTTOM_FIELD);
+  SET_V4L2_SPARM_FLAG_IF(direct_spatial_mv_pred_flag,
+                         V4L2_SLICE_FLAG_DIRECT_SPATIAL_MV_PRED);
+  SET_V4L2_SPARM_FLAG_IF(sp_for_switch_flag, V4L2_SLICE_FLAG_SP_FOR_SWITCH);
+#undef SET_V4L2_SPARM_FLAG_IF
+
+  struct v4l2_h264_pred_weight_table* pred_weight_table =
+      &v4l2_slice_param.pred_weight_table;
+
+  if (((slice_hdr->IsPSlice() || slice_hdr->IsSPSlice()) &&
+       pps->weighted_pred_flag) ||
+      (slice_hdr->IsBSlice() && pps->weighted_bipred_idc == 1)) {
+    pred_weight_table->luma_log2_weight_denom =
+        slice_hdr->luma_log2_weight_denom;
+    pred_weight_table->chroma_log2_weight_denom =
+        slice_hdr->chroma_log2_weight_denom;
+
+    struct v4l2_h264_weight_factors* factorsl0 =
+        &pred_weight_table->weight_factors[0];
+
+    for (int i = 0; i < 32; ++i) {
+      factorsl0->luma_weight[i] =
+          slice_hdr->pred_weight_table_l0.luma_weight[i];
+      factorsl0->luma_offset[i] =
+          slice_hdr->pred_weight_table_l0.luma_offset[i];
+
+      for (int j = 0; j < 2; ++j) {
+        factorsl0->chroma_weight[i][j] =
+            slice_hdr->pred_weight_table_l0.chroma_weight[i][j];
+        factorsl0->chroma_offset[i][j] =
+            slice_hdr->pred_weight_table_l0.chroma_offset[i][j];
+      }
+    }
+
+    if (slice_hdr->IsBSlice()) {
+      struct v4l2_h264_weight_factors* factorsl1 =
+          &pred_weight_table->weight_factors[1];
+
+      for (int i = 0; i < 32; ++i) {
+        factorsl1->luma_weight[i] =
+            slice_hdr->pred_weight_table_l1.luma_weight[i];
+        factorsl1->luma_offset[i] =
+            slice_hdr->pred_weight_table_l1.luma_offset[i];
+
+        for (int j = 0; j < 2; ++j) {
+          factorsl1->chroma_weight[i][j] =
+              slice_hdr->pred_weight_table_l1.chroma_weight[i][j];
+          factorsl1->chroma_offset[i][j] =
+              slice_hdr->pred_weight_table_l1.chroma_offset[i][j];
+        }
+      }
+    }
+  }
+
+  H264PictureListToDPBIndicesList(ref_pic_list0,
+                                  v4l2_slice_param.ref_pic_list0);
+  H264PictureListToDPBIndicesList(ref_pic_list1,
+                                  v4l2_slice_param.ref_pic_list1);
+
+  scoped_refptr<V4L2DecodeSurface> dec_surface =
+      H264PictureToV4L2DecodeSurface(pic);
+
+  v4l2_decode_param_.nal_ref_idc = slice_hdr->nal_ref_idc;
+
+  // TODO(posciak): Don't add start code back here, but have it passed from
+  // the parser.
+  size_t data_copy_size = size + 3;
+  scoped_ptr<uint8_t[]> data_copy(new uint8_t[data_copy_size]);
+  memset(data_copy.get(), 0, data_copy_size);
+  data_copy[2] = 0x01;
+  memcpy(data_copy.get() + 3, data, size);
+  return v4l2_dec_->SubmitSlice(dec_surface->input_record(), data_copy.get(),
+                                data_copy_size);
+}
+
+bool V4L2SliceVideoDecodeAccelerator::SubmitSlice(int index,
+                                                  const uint8_t* data,
+                                                  size_t size) {
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  InputRecord& input_record = input_buffer_map_[index];
+
+  if (input_record.bytes_used + size > input_record.length) {
+    DVLOGF(1) << "Input buffer too small";
+    return false;
+  }
+
+  memcpy(static_cast<uint8*>(input_record.address) + input_record.bytes_used,
+         data, size);
+  input_record.bytes_used += size;
+
+  return true;
+}
+
+bool V4L2SliceVideoDecodeAccelerator::SubmitExtControls(
+    struct v4l2_ext_controls* ext_ctrls) {
+  DCHECK_GT(ext_ctrls->config_store, 0u);
+  IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_S_EXT_CTRLS, ext_ctrls);
+  return true;
+}
+
+bool V4L2SliceVideoDecodeAccelerator::V4L2H264Accelerator::SubmitDecode(
+    const scoped_refptr<H264Picture>& pic) {
+  scoped_refptr<V4L2DecodeSurface> dec_surface =
+      H264PictureToV4L2DecodeSurface(pic);
+
+  v4l2_decode_param_.num_slices = num_slices_;
+  v4l2_decode_param_.idr_pic_flag = pic->idr;
+  v4l2_decode_param_.top_field_order_cnt = pic->top_field_order_cnt;
+  v4l2_decode_param_.bottom_field_order_cnt = pic->bottom_field_order_cnt;
+
+  struct v4l2_ext_control ctrl;
+  std::vector<struct v4l2_ext_control> ctrls;
+
+  memset(&ctrl, 0, sizeof(ctrl));
+  ctrl.id = V4L2_CID_MPEG_VIDEO_H264_SLICE_PARAM;
+  ctrl.size = sizeof(v4l2_slice_params_);
+  ctrl.p_h264_slice_param = v4l2_slice_params_;
+  ctrls.push_back(ctrl);
+
+  memset(&ctrl, 0, sizeof(ctrl));
+  ctrl.id = V4L2_CID_MPEG_VIDEO_H264_DECODE_PARAM;
+  ctrl.size = sizeof(v4l2_decode_param_);
+  ctrl.p_h264_decode_param = &v4l2_decode_param_;
+  ctrls.push_back(ctrl);
+
+  struct v4l2_ext_controls ext_ctrls;
+  memset(&ext_ctrls, 0, sizeof(ext_ctrls));
+  ext_ctrls.count = ctrls.size();
+  ext_ctrls.controls = &ctrls[0];
+  ext_ctrls.config_store = dec_surface->config_store();
+  v4l2_dec_->SubmitExtControls(&ext_ctrls);
+
+  num_slices_ = 0;
+  memset(&v4l2_decode_param_, 0, sizeof(v4l2_decode_param_));
+  memset(&v4l2_slice_params_, 0, sizeof(v4l2_slice_params_));
+
+  v4l2_dec_->DecodeSurface(dec_surface);
+  return true;
+}
+
+bool V4L2SliceVideoDecodeAccelerator::V4L2H264Accelerator::OutputPicture(
+    const scoped_refptr<H264Picture>& pic) {
+  scoped_refptr<V4L2DecodeSurface> dec_surface =
+      H264PictureToV4L2DecodeSurface(pic);
+  v4l2_dec_->SurfaceReady(dec_surface);
+  return true;
+}
+
+scoped_refptr<V4L2SliceVideoDecodeAccelerator::V4L2DecodeSurface>
+V4L2SliceVideoDecodeAccelerator::V4L2H264Accelerator::
+    H264PictureToV4L2DecodeSurface(const scoped_refptr<H264Picture>& pic) {
+  V4L2H264Picture* v4l2_pic = pic->AsV4L2H264Picture();
+  CHECK(v4l2_pic);
+  return v4l2_pic->dec_surface();
+}
+
+V4L2SliceVideoDecodeAccelerator::V4L2VP8Accelerator::V4L2VP8Accelerator(
+    V4L2SliceVideoDecodeAccelerator* v4l2_dec)
+    : v4l2_dec_(v4l2_dec) {
+  DCHECK(v4l2_dec_);
+}
+
+scoped_refptr<VP8Picture>
+V4L2SliceVideoDecodeAccelerator::V4L2VP8Accelerator::CreateVP8Picture() {
+  scoped_refptr<V4L2DecodeSurface> dec_surface = v4l2_dec_->CreateSurface();
+  if (!dec_surface)
+    return nullptr;
+
+  return new V4L2VP8Picture(dec_surface);
+}
+
+#define ARRAY_MEMCPY_CHECKED(to, from)                               \
+  do {                                                               \
+    static_assert(sizeof(to) == sizeof(from),                        \
+                  #from " and " #to " arrays must be of same size"); \
+    memcpy(to, from, sizeof(to));                                    \
+  } while (0)
+
+static void FillV4L2SegmentationHeader(
+    const media::Vp8SegmentationHeader& vp8_sgmnt_hdr,
+    struct v4l2_vp8_sgmnt_hdr* v4l2_sgmnt_hdr) {
+#define SET_V4L2_SGMNT_HDR_FLAG_IF(cond, flag) \
+  v4l2_sgmnt_hdr->flags |= ((vp8_sgmnt_hdr.cond) ? (flag) : 0)
+  SET_V4L2_SGMNT_HDR_FLAG_IF(segmentation_enabled,
+                             V4L2_VP8_SEGMNT_HDR_FLAG_ENABLED);
+  SET_V4L2_SGMNT_HDR_FLAG_IF(update_mb_segmentation_map,
+                             V4L2_VP8_SEGMNT_HDR_FLAG_UPDATE_MAP);
+  SET_V4L2_SGMNT_HDR_FLAG_IF(update_segment_feature_data,
+                             V4L2_VP8_SEGMNT_HDR_FLAG_UPDATE_FEATURE_DATA);
+#undef SET_V4L2_SPARM_FLAG_IF
+  v4l2_sgmnt_hdr->segment_feature_mode = vp8_sgmnt_hdr.segment_feature_mode;
+
+  ARRAY_MEMCPY_CHECKED(v4l2_sgmnt_hdr->quant_update,
+                       vp8_sgmnt_hdr.quantizer_update_value);
+  ARRAY_MEMCPY_CHECKED(v4l2_sgmnt_hdr->lf_update,
+                       vp8_sgmnt_hdr.lf_update_value);
+  ARRAY_MEMCPY_CHECKED(v4l2_sgmnt_hdr->segment_probs,
+                       vp8_sgmnt_hdr.segment_prob);
+}
+
+static void FillV4L2LoopfilterHeader(
+    const media::Vp8LoopFilterHeader& vp8_loopfilter_hdr,
+    struct v4l2_vp8_loopfilter_hdr* v4l2_lf_hdr) {
+#define SET_V4L2_LF_HDR_FLAG_IF(cond, flag) \
+  v4l2_lf_hdr->flags |= ((vp8_loopfilter_hdr.cond) ? (flag) : 0)
+  SET_V4L2_LF_HDR_FLAG_IF(loop_filter_adj_enable, V4L2_VP8_LF_HDR_ADJ_ENABLE);
+  SET_V4L2_LF_HDR_FLAG_IF(mode_ref_lf_delta_update,
+                          V4L2_VP8_LF_HDR_DELTA_UPDATE);
+#undef SET_V4L2_SGMNT_HDR_FLAG_IF
+
+#define LF_HDR_TO_V4L2_LF_HDR(a) v4l2_lf_hdr->a = vp8_loopfilter_hdr.a;
+  LF_HDR_TO_V4L2_LF_HDR(type);
+  LF_HDR_TO_V4L2_LF_HDR(level);
+  LF_HDR_TO_V4L2_LF_HDR(sharpness_level);
+#undef LF_HDR_TO_V4L2_LF_HDR
+
+  ARRAY_MEMCPY_CHECKED(v4l2_lf_hdr->ref_frm_delta_magnitude,
+                       vp8_loopfilter_hdr.ref_frame_delta);
+  ARRAY_MEMCPY_CHECKED(v4l2_lf_hdr->mb_mode_delta_magnitude,
+                       vp8_loopfilter_hdr.mb_mode_delta);
+}
+
+static void FillV4L2QuantizationHeader(
+    const media::Vp8QuantizationHeader& vp8_quant_hdr,
+    struct v4l2_vp8_quantization_hdr* v4l2_quant_hdr) {
+  v4l2_quant_hdr->y_ac_qi = vp8_quant_hdr.y_ac_qi;
+  v4l2_quant_hdr->y_dc_delta = vp8_quant_hdr.y_dc_delta;
+  v4l2_quant_hdr->y2_dc_delta = vp8_quant_hdr.y2_dc_delta;
+  v4l2_quant_hdr->y2_ac_delta = vp8_quant_hdr.y2_ac_delta;
+  v4l2_quant_hdr->uv_dc_delta = vp8_quant_hdr.uv_dc_delta;
+  v4l2_quant_hdr->uv_ac_delta = vp8_quant_hdr.uv_ac_delta;
+}
+
+static void FillV4L2EntropyHeader(
+    const media::Vp8EntropyHeader& vp8_entropy_hdr,
+    struct v4l2_vp8_entropy_hdr* v4l2_entropy_hdr) {
+  ARRAY_MEMCPY_CHECKED(v4l2_entropy_hdr->coeff_probs,
+                       vp8_entropy_hdr.coeff_probs);
+  ARRAY_MEMCPY_CHECKED(v4l2_entropy_hdr->y_mode_probs,
+                       vp8_entropy_hdr.y_mode_probs);
+  ARRAY_MEMCPY_CHECKED(v4l2_entropy_hdr->uv_mode_probs,
+                       vp8_entropy_hdr.uv_mode_probs);
+  ARRAY_MEMCPY_CHECKED(v4l2_entropy_hdr->mv_probs,
+                       vp8_entropy_hdr.mv_probs);
+}
+
+bool V4L2SliceVideoDecodeAccelerator::V4L2VP8Accelerator::SubmitDecode(
+    const scoped_refptr<VP8Picture>& pic,
+    const media::Vp8FrameHeader* frame_hdr,
+    const scoped_refptr<VP8Picture>& last_frame,
+    const scoped_refptr<VP8Picture>& golden_frame,
+    const scoped_refptr<VP8Picture>& alt_frame) {
+  struct v4l2_ctrl_vp8_frame_hdr v4l2_frame_hdr;
+  memset(&v4l2_frame_hdr, 0, sizeof(v4l2_frame_hdr));
+
+#define FHDR_TO_V4L2_FHDR(a) v4l2_frame_hdr.a = frame_hdr->a
+  FHDR_TO_V4L2_FHDR(key_frame);
+  FHDR_TO_V4L2_FHDR(version);
+  FHDR_TO_V4L2_FHDR(width);
+  FHDR_TO_V4L2_FHDR(horizontal_scale);
+  FHDR_TO_V4L2_FHDR(height);
+  FHDR_TO_V4L2_FHDR(vertical_scale);
+  FHDR_TO_V4L2_FHDR(sign_bias_golden);
+  FHDR_TO_V4L2_FHDR(sign_bias_alternate);
+  FHDR_TO_V4L2_FHDR(prob_skip_false);
+  FHDR_TO_V4L2_FHDR(prob_intra);
+  FHDR_TO_V4L2_FHDR(prob_last);
+  FHDR_TO_V4L2_FHDR(prob_gf);
+  FHDR_TO_V4L2_FHDR(bool_dec_range);
+  FHDR_TO_V4L2_FHDR(bool_dec_value);
+  FHDR_TO_V4L2_FHDR(bool_dec_count);
+#undef FHDR_TO_V4L2_FHDR
+
+#define SET_V4L2_FRM_HDR_FLAG_IF(cond, flag) \
+  v4l2_frame_hdr.flags |= ((frame_hdr->cond) ? (flag) : 0)
+  SET_V4L2_FRM_HDR_FLAG_IF(is_experimental,
+                           V4L2_VP8_FRAME_HDR_FLAG_EXPERIMENTAL);
+  SET_V4L2_FRM_HDR_FLAG_IF(show_frame, V4L2_VP8_FRAME_HDR_FLAG_SHOW_FRAME);
+  SET_V4L2_FRM_HDR_FLAG_IF(mb_no_skip_coeff,
+                           V4L2_VP8_FRAME_HDR_FLAG_MB_NO_SKIP_COEFF);
+#undef SET_V4L2_FRM_HDR_FLAG_IF
+
+  FillV4L2SegmentationHeader(frame_hdr->segmentation_hdr,
+                             &v4l2_frame_hdr.sgmnt_hdr);
+
+  FillV4L2LoopfilterHeader(frame_hdr->loopfilter_hdr, &v4l2_frame_hdr.lf_hdr);
+
+  FillV4L2QuantizationHeader(frame_hdr->quantization_hdr,
+                             &v4l2_frame_hdr.quant_hdr);
+
+  FillV4L2EntropyHeader(frame_hdr->entropy_hdr, &v4l2_frame_hdr.entropy_hdr);
+
+  v4l2_frame_hdr.first_part_size =
+      base::checked_cast<__u32>(frame_hdr->first_part_size);
+  v4l2_frame_hdr.first_part_offset =
+      base::checked_cast<__u32>(frame_hdr->first_part_offset);
+  v4l2_frame_hdr.macroblock_bit_offset =
+      base::checked_cast<__u32>(frame_hdr->macroblock_bit_offset);
+  v4l2_frame_hdr.num_dct_parts = frame_hdr->num_of_dct_partitions;
+
+  static_assert(arraysize(v4l2_frame_hdr.dct_part_sizes) ==
+                arraysize(frame_hdr->dct_partition_sizes),
+                "DCT partition size arrays must have equal number of elements");
+  for (size_t i = 0; i < frame_hdr->num_of_dct_partitions &&
+       i < arraysize(v4l2_frame_hdr.dct_part_sizes); ++i)
+    v4l2_frame_hdr.dct_part_sizes[i] = frame_hdr->dct_partition_sizes[i];
+
+  scoped_refptr<V4L2DecodeSurface> dec_surface =
+      VP8PictureToV4L2DecodeSurface(pic);
+  std::vector<scoped_refptr<V4L2DecodeSurface>> ref_surfaces;
+
+  if (last_frame) {
+    scoped_refptr<V4L2DecodeSurface> last_frame_surface =
+        VP8PictureToV4L2DecodeSurface(last_frame);
+    v4l2_frame_hdr.last_frame = last_frame_surface->output_record();
+    ref_surfaces.push_back(last_frame_surface);
+  } else {
+    v4l2_frame_hdr.last_frame = VIDEO_MAX_FRAME;
+  }
+
+  if (golden_frame) {
+    scoped_refptr<V4L2DecodeSurface> golden_frame_surface =
+        VP8PictureToV4L2DecodeSurface(golden_frame);
+    v4l2_frame_hdr.golden_frame = golden_frame_surface->output_record();
+    ref_surfaces.push_back(golden_frame_surface);
+  } else {
+    v4l2_frame_hdr.golden_frame = VIDEO_MAX_FRAME;
+  }
+
+  if (alt_frame) {
+    scoped_refptr<V4L2DecodeSurface> alt_frame_surface =
+        VP8PictureToV4L2DecodeSurface(alt_frame);
+    v4l2_frame_hdr.alt_frame = alt_frame_surface->output_record();
+    ref_surfaces.push_back(alt_frame_surface);
+  } else {
+    v4l2_frame_hdr.alt_frame = VIDEO_MAX_FRAME;
+  }
+
+  struct v4l2_ext_control ctrl;
+  memset(&ctrl, 0, sizeof(ctrl));
+  ctrl.id = V4L2_CID_MPEG_VIDEO_VP8_FRAME_HDR;
+  ctrl.size = sizeof(v4l2_frame_hdr);
+  ctrl.p_vp8_frame_hdr = &v4l2_frame_hdr;
+
+  struct v4l2_ext_controls ext_ctrls;
+  memset(&ext_ctrls, 0, sizeof(ext_ctrls));
+  ext_ctrls.count = 1;
+  ext_ctrls.controls = &ctrl;
+  ext_ctrls.config_store = dec_surface->config_store();
+
+  if (!v4l2_dec_->SubmitExtControls(&ext_ctrls))
+    return false;
+
+  dec_surface->SetReferenceSurfaces(ref_surfaces);
+
+  if (!v4l2_dec_->SubmitSlice(dec_surface->input_record(), frame_hdr->data,
+                              frame_hdr->frame_size))
+    return false;
+
+  v4l2_dec_->DecodeSurface(dec_surface);
+  return true;
+}
+
+bool V4L2SliceVideoDecodeAccelerator::V4L2VP8Accelerator::OutputPicture(
+    const scoped_refptr<VP8Picture>& pic) {
+  scoped_refptr<V4L2DecodeSurface> dec_surface =
+      VP8PictureToV4L2DecodeSurface(pic);
+
+  v4l2_dec_->SurfaceReady(dec_surface);
+  return true;
+}
+
+scoped_refptr<V4L2SliceVideoDecodeAccelerator::V4L2DecodeSurface>
+V4L2SliceVideoDecodeAccelerator::V4L2VP8Accelerator::
+    VP8PictureToV4L2DecodeSurface(const scoped_refptr<VP8Picture>& pic) {
+  V4L2VP8Picture* v4l2_pic = pic->AsV4L2VP8Picture();
+  CHECK(v4l2_pic);
+  return v4l2_pic->dec_surface();
+}
+
+void V4L2SliceVideoDecodeAccelerator::DecodeSurface(
+    const scoped_refptr<V4L2DecodeSurface>& dec_surface) {
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  DVLOGF(3) << "Submitting decode for surface: " << dec_surface->ToString();
+  Enqueue(dec_surface);
+}
+
+void V4L2SliceVideoDecodeAccelerator::SurfaceReady(
+    const scoped_refptr<V4L2DecodeSurface>& dec_surface) {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  decoder_display_queue_.push(dec_surface);
+  TryOutputSurfaces();
+}
+
+void V4L2SliceVideoDecodeAccelerator::TryOutputSurfaces() {
+  while (!decoder_display_queue_.empty()) {
+    scoped_refptr<V4L2DecodeSurface> dec_surface =
+        decoder_display_queue_.front();
+
+    if (!dec_surface->decoded())
+      break;
+
+    decoder_display_queue_.pop();
+    OutputSurface(dec_surface);
+  }
+}
+
+void V4L2SliceVideoDecodeAccelerator::OutputSurface(
+    const scoped_refptr<V4L2DecodeSurface>& dec_surface) {
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  OutputRecord& output_record =
+      output_buffer_map_[dec_surface->output_record()];
+
+  bool inserted =
+      surfaces_at_display_.insert(std::make_pair(output_record.picture_id,
+                                                 dec_surface)).second;
+  DCHECK(inserted);
+
+  DCHECK(!output_record.at_client);
+  DCHECK(!output_record.at_device);
+  DCHECK_NE(output_record.egl_image, EGL_NO_IMAGE_KHR);
+  DCHECK_NE(output_record.picture_id, -1);
+  output_record.at_client = true;
+
+  media::Picture picture(output_record.picture_id, dec_surface->bitstream_id(),
+                         gfx::Rect(frame_buffer_size_));
+  DVLOGF(3) << dec_surface->ToString()
+            << " picture_id: " << picture.picture_buffer_id();
+  pending_picture_ready_.push(PictureRecord(output_record.cleared, picture));
+  SendPictureReady();
+  output_record.cleared = true;
+}
+
+scoped_refptr<V4L2SliceVideoDecodeAccelerator::V4L2DecodeSurface>
+V4L2SliceVideoDecodeAccelerator::CreateSurface() {
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+
+  if (free_input_buffers_.empty() || free_output_buffers_.empty())
+    return nullptr;
+
+  int input = free_input_buffers_.front();
+  free_input_buffers_.pop_front();
+  int output = free_output_buffers_.front();
+  free_output_buffers_.pop_front();
+
+  InputRecord& input_record = input_buffer_map_[input];
+  DCHECK_EQ(input_record.bytes_used, 0u);
+  DCHECK_EQ(input_record.input_id, -1);
+  DCHECK(decoder_current_bitstream_buffer_ != nullptr);
+  input_record.input_id = decoder_current_bitstream_buffer_->input_id;
+
+  scoped_refptr<V4L2DecodeSurface> dec_surface = new V4L2DecodeSurface(
+      decoder_current_bitstream_buffer_->input_id, input, output,
+      base::Bind(&V4L2SliceVideoDecodeAccelerator::ReuseOutputBuffer,
+                 base::Unretained(this)));
+
+  DVLOGF(4) << "Created surface " << input << " -> " << output;
+  return dec_surface;
+}
+
+void V4L2SliceVideoDecodeAccelerator::SendPictureReady() {
+  DVLOGF(3);
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+  bool resetting_or_flushing = (decoder_resetting_ || decoder_flushing_);
+  while (pending_picture_ready_.size() > 0) {
+    bool cleared = pending_picture_ready_.front().cleared;
+    const media::Picture& picture = pending_picture_ready_.front().picture;
+    if (cleared && picture_clearing_count_ == 0) {
+      DVLOGF(4) << "Posting picture ready to IO for: "
+                << picture.picture_buffer_id();
+      // This picture is cleared. Post it to IO thread to reduce latency. This
+      // should be the case after all pictures are cleared at the beginning.
+      io_message_loop_proxy_->PostTask(
+          FROM_HERE, base::Bind(&Client::PictureReady, io_client_, picture));
+      pending_picture_ready_.pop();
+    } else if (!cleared || resetting_or_flushing) {
+      DVLOGF(3) << ". cleared=" << pending_picture_ready_.front().cleared
+                << ", decoder_resetting_=" << decoder_resetting_
+                << ", decoder_flushing_=" << decoder_flushing_
+                << ", picture_clearing_count_=" << picture_clearing_count_;
+      DVLOGF(4) << "Posting picture ready to GPU for: "
+                << picture.picture_buffer_id();
+      // If the picture is not cleared, post it to the child thread because it
+      // has to be cleared in the child thread. A picture only needs to be
+      // cleared once. If the decoder is resetting or flushing, send all
+      // pictures to ensure PictureReady arrive before reset or flush done.
+      child_message_loop_proxy_->PostTaskAndReply(
+          FROM_HERE, base::Bind(&Client::PictureReady, client_, picture),
+          // Unretained is safe. If Client::PictureReady gets to run, |this| is
+          // alive. Destroy() will wait the decode thread to finish.
+          base::Bind(&V4L2SliceVideoDecodeAccelerator::PictureCleared,
+                     base::Unretained(this)));
+      picture_clearing_count_++;
+      pending_picture_ready_.pop();
+    } else {
+      // This picture is cleared. But some pictures are about to be cleared on
+      // the child thread. To preserve the order, do not send this until those
+      // pictures are cleared.
+      break;
+    }
+  }
+}
+
+void V4L2SliceVideoDecodeAccelerator::PictureCleared() {
+  DVLOGF(3) << "clearing count=" << picture_clearing_count_;
+  DCHECK(decoder_thread_proxy_->BelongsToCurrentThread());
+  DCHECK_GT(picture_clearing_count_, 0);
+  picture_clearing_count_--;
+  SendPictureReady();
+}
+
+bool V4L2SliceVideoDecodeAccelerator::CanDecodeOnIOThread() {
+  return true;
+}
+
+}  // namespace content