VDA implementation for Exynos, using V4L2

content/common/gpu/media/exynos_video_decode_accelerator.cc

+// Copyright (c) 2012 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 <dlfcn.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/videodev2.h>
+#include <sys/epoll.h>
+#include <sys/eventfd.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+
+#include "base/bind.h"
+#include "base/message_loop.h"
+#include "base/message_loop_proxy.h"
+#include "base/shared_memory.h"
+#include "content/common/gpu/media/exynos_video_decode_accelerator.h"
+#include "third_party/angle/include/GLES2/gl2.h"
+
+namespace content {
+
+#define EXYNOS_MFC_DEVICE "/dev/mfc-dec"
+#define EXYNOS_GSC_DEVICE "/dev/gsc1"
+#define EXYNOS_MALI_DRIVER "libmali.so"
+
+#define NOTIFY_ERROR(x)                                             \
+  do {                                                              \
+    SetDecoderState(kError);                                        \
+    LOG(ERROR) << "calling NotifyError(): " << x;                   \
+    NotifyError(x);                                                 \
+  } while (0)
+
+#define IOCTL_OR_ERROR_RETURN(fd, type, arg)                        \
+  do {                                                              \
+    if (ioctl(fd, type, arg) != 0) {                                \
+      DPLOG(ERROR) << __func__ << "(): ioctl() failed: " << #type;  \
+      NOTIFY_ERROR(PLATFORM_FAILURE);                               \
+      return;                                                       \
+    }                                                               \
+  } while (0)
+
+#define IOCTL_OR_ERROR_RETURN_FALSE(fd, type, arg)                  \
+  do {                                                              \
+    if (ioctl(fd, type, arg) != 0) {                                \
+      DPLOG(ERROR) << __func__ << "(): ioctl() failed: " << #type;  \
+      NOTIFY_ERROR(PLATFORM_FAILURE);                               \
+      return false;                                                 \
+    }                                                               \
+  } while (0)
+
+typedef void* GLeglImageOES;
+static void* libmali_handle = NULL;
+static EGLBoolean(*mali_egl_image_get_buffer_ext_phandle)(
+    EGLImageKHR, EGLint*, void*) = NULL;
+static EGLImageKHR(*egl_create_image_khr)(
+    EGLDisplay, EGLContext, EGLenum, EGLClientBuffer, const EGLint*) = NULL;
+static EGLBoolean(*egl_destroy_image_khr)(
+    EGLDisplay, EGLImageKHR) = NULL;
+static EGLSyncKHR(*egl_create_sync_khr)(
+    EGLDisplay, EGLenum, const EGLint*) = NULL;
+static EGLBoolean(*egl_destroy_sync_khr)(
+    EGLDisplay, EGLSyncKHR) = NULL;
+static EGLint(*egl_client_wait_sync_khr)(
+    EGLDisplay, EGLSyncKHR, EGLint, EGLTimeKHR) = NULL;
+static void(*gl_egl_image_target_texture_2d_oes)(
+    GLenum, GLeglImageOES) = NULL;
+
+ExynosVideoDecodeAccelerator::BitstreamBufferRef::BitstreamBufferRef(
+    base::WeakPtr<Client>& client,
+    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),
+      input_id(input_id) {
+}
+
+ExynosVideoDecodeAccelerator::BitstreamBufferRef::~BitstreamBufferRef() {
+  if (input_id != -1 && client_message_loop_proxy != NULL)
+    client_message_loop_proxy->PostTask(FROM_HERE, base::Bind(
+        &Client::NotifyEndOfBitstreamBuffer, client, input_id));
+}
+
+ExynosVideoDecodeAccelerator::EGLImageKHRArrayRef::EGLImageKHRArrayRef(
+    EGLDisplay egl_display, EGLImageKHR egl_images[], int egl_image_fds[],
+    int egl_images_count)
+    : egl_display(egl_display),
+      egl_images(egl_images),
+      egl_image_fds(egl_image_fds),
+      egl_images_count(egl_images_count) {
+}
+
+ExynosVideoDecodeAccelerator::EGLImageKHRArrayRef::~EGLImageKHRArrayRef() {
+  DCHECK_EQ(egl_images != NULL, egl_image_fds != NULL);
+  if (egl_images == NULL)
+    return;
+
+  for (int i = 0; i < egl_images_count; ++i) {
+    if (egl_images[i] != EGL_NO_IMAGE_KHR)
+      egl_destroy_image_khr(egl_display, egl_images[i]);
+    if (egl_image_fds[i] != -1)
+      close(egl_image_fds[i]);
+  }
+}
+
+ExynosVideoDecodeAccelerator::EGLSyncKHRRef::EGLSyncKHRRef(
+    EGLDisplay egl_display, EGLSyncKHR egl_sync)
+    : egl_display(egl_display),
+      egl_sync(egl_sync) {
+}
+
+ExynosVideoDecodeAccelerator::EGLSyncKHRRef::~EGLSyncKHRRef() {
+  if (egl_sync != EGL_NO_SYNC_KHR)
+    egl_destroy_sync_khr(egl_display, egl_sync);
+}
+
+ExynosVideoDecodeAccelerator::MfcInputRecord::MfcInputRecord()
+    : at_device(false),
+      address(NULL),
+      length(0),
+      bytes_used(0),
+      input_id(-1) {
+}
+
+ExynosVideoDecodeAccelerator::MfcInputRecord::~MfcInputRecord() {
+}
+
+ExynosVideoDecodeAccelerator::MfcOutputRecord::MfcOutputRecord()
+    : at_device(false),
+      input_id(-1) {
+  bytes_used[0] = 0;
+  bytes_used[1] = 0;
+  address[0] = NULL;
+  address[1] = NULL;
+  length[0] = 0;
+  length[1] = 0;
+}
+
+ExynosVideoDecodeAccelerator::MfcOutputRecord::~MfcOutputRecord() {
+}
+
+ExynosVideoDecodeAccelerator::GscInputRecord::GscInputRecord()
+    : at_device(false),
+      mfc_output(-1) {
+}
+
+ExynosVideoDecodeAccelerator::GscInputRecord::~GscInputRecord() {
+}
+
+ExynosVideoDecodeAccelerator::GscOutputRecord::GscOutputRecord()
+    : at_device(false),
+      at_client(false),
+      fd(-1),
+      egl_image(EGL_NO_IMAGE_KHR),
+      egl_sync(EGL_NO_SYNC_KHR),
+      picture_id(-1) {
+}
+
+ExynosVideoDecodeAccelerator::GscOutputRecord::~GscOutputRecord() {
+}
+
+ExynosVideoDecodeAccelerator::ExynosVideoDecodeAccelerator(
+    EGLDisplay egl_display,
+    EGLContext egl_context,
+    Client* client,
+    const base::Callback<bool(void)>& make_context_current)
+    : child_message_loop_proxy_(base::MessageLoopProxy::current()),
+      weak_this_(base::AsWeakPtr(this)),
+      client_ptr_factory_(client),
+      client_(client_ptr_factory_.GetWeakPtr()),
+      decoder_thread_("ExynosDecoderThread"),
+      decoder_state_(kUninitialized),
+      decoder_current_bitstream_buffer_(NULL),
+      decoder_current_input_buffer_(-1),
+      decoder_decode_buffer_tasks_scheduled_(0),
+      decoder_frames_at_client_(0),
+      decoder_flush_notify_requested_(false),
+      mfc_fd_(-1),
+      mfc_input_streamon_(false),
+      mfc_input_buffer_count_(0),
+      mfc_input_buffer_queued_count_(0),
+      mfc_output_streamon_(false),
+      mfc_output_buffer_count_(0),
+      mfc_output_buffer_queued_count_(0),
+      mfc_output_buffer_pixelformat_(0),
+      gsc_fd_(-1),
+      gsc_input_streamon_(false),
+      gsc_input_buffer_count_(0),
+      gsc_input_buffer_queued_count_(0),
+      gsc_output_streamon_(false),
+      gsc_output_buffer_count_(0),
+      gsc_output_buffer_queued_count_(0),
+      frame_buffer_size_(0, 0),
+      device_poll_thread_("ExynosDevicePollThread"),
+      device_poll_epoll_fd_(-1),
+      device_poll_interrupt_fd_(-1),
+      make_context_current_(make_context_current),
+      egl_display_(egl_display),
+      egl_context_(egl_context),
+      video_profile_(media::VIDEO_CODEC_PROFILE_UNKNOWN) {
+}
+
+ExynosVideoDecodeAccelerator::~ExynosVideoDecodeAccelerator() {
+  // Nuke the entire site from orbit -- it's the only way to be sure.
+  if (device_poll_interrupt_fd_ != -1) {
+    close(device_poll_interrupt_fd_);
+    device_poll_interrupt_fd_ = -1;
+  }
+  if (device_poll_epoll_fd_ != -1) {
+    close(device_poll_epoll_fd_);
+    device_poll_epoll_fd_ = -1;
+  }
+  if (gsc_fd_ != -1) {
+    DestroyGscInputBuffers();
+    DestroyGscOutputBuffers();
+    close(gsc_fd_);
+    gsc_fd_ = -1;
+  }
+  if (mfc_fd_ != -1) {
+    DestroyMfcInputBuffers();
+    DestroyMfcOutputBuffers();
+    close(mfc_fd_);
+    mfc_fd_ = -1;
+  }
+
+  // These maps have members that should be manually destroyed, e.g. file
+  // descriptors, mmap() segments, etc.
+  DCHECK(mfc_input_buffer_map_.empty());
+  DCHECK(mfc_output_buffer_map_.empty());
+  DCHECK(gsc_input_buffer_map_.empty());
+  DCHECK(gsc_output_buffer_map_.empty());
+}
+
+bool ExynosVideoDecodeAccelerator::Initialize(
+    media::VideoCodecProfile profile) {
+  DVLOG(3) << "Initialize()";
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+  DCHECK_EQ(decoder_state_, kUninitialized);
+
+  switch (profile) {
+    case media::H264PROFILE_BASELINE:
+      DVLOG(2) << "Initialize(): profile H264PROFILE_BASELINE";
+      break;
+    case media::H264PROFILE_MAIN:
+      DVLOG(2) << "Initialize(): profile H264PROFILE_MAIN";
+      break;
+    case media::H264PROFILE_HIGH:
+      DVLOG(2) << "Initialize(): profile H264PROFILE_HIGH";
+      break;
+    case media::VP8PROFILE_MAIN:
+      DVLOG(2) << "Initialize(): profile VP8PROFILE_MAIN";
+      break;
+    default:
+      DLOG(ERROR) << "Initialize(): unsupported profile=" << profile;
+      return false;
+  };
+  video_profile_ = profile;
+
+  static bool sandbox_initialized = PostSandboxInitialization();
+  if (!sandbox_initialized) {
+    DLOG(ERROR) << "Initialize(): PostSandboxInitialization() failed";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+
+  if (egl_display_ == EGL_NO_DISPLAY) {
+    DLOG(ERROR) << "Initialize(): could not get EGLDisplay";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+
+  if (egl_context_ == EGL_NO_CONTEXT) {
+    DLOG(ERROR) << "Initialize(): could not get EGLContext";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+
+  // Open the video devices.
+  DVLOG(2) << "Initialize(): opening MFC device: " << EXYNOS_MFC_DEVICE;
+  mfc_fd_ = open(EXYNOS_MFC_DEVICE, O_RDWR | O_NONBLOCK | O_CLOEXEC);
+  if (mfc_fd_ == -1) {
+    DPLOG(ERROR) << "Initialize(): could not open MFC device: "
+                 << EXYNOS_MFC_DEVICE;
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+  DVLOG(2) << "Initialize(): opening GSC device: " << EXYNOS_GSC_DEVICE;
+  gsc_fd_ = open(EXYNOS_GSC_DEVICE, O_RDWR | O_NONBLOCK | O_CLOEXEC);
+  if (gsc_fd_ == -1) {
+    DPLOG(ERROR) << "Initialize(): could not open GSC device: "
+                 << EXYNOS_GSC_DEVICE;
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+
+  // Create the interrupt fd.
+  DCHECK_EQ(device_poll_interrupt_fd_, -1);
+  device_poll_interrupt_fd_ = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
+  if (device_poll_interrupt_fd_ == -1) {
+    DPLOG(ERROR) << "StartDevicePoll(): eventfd() failed";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+
+  // Create the epoll fd.
+  DCHECK_EQ(device_poll_epoll_fd_, -1);
+  device_poll_epoll_fd_ = epoll_create1(EPOLL_CLOEXEC);
+  if (device_poll_epoll_fd_ == -1) {
+    DPLOG(ERROR) << "StartDevicePoll(): epoll_create1() failed";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    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(mfc_fd_, VIDIOC_QUERYCAP, &caps);
+  if ((caps.capabilities & kCapsRequired) != kCapsRequired) {
+    DLOG(ERROR) << "Initialize(): ioctl() failed: VIDIOC_QUERYCAP"
+        ", caps check failed: 0x" << std::hex << caps.capabilities;
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+  IOCTL_OR_ERROR_RETURN_FALSE(gsc_fd_, VIDIOC_QUERYCAP, &caps);
+  if ((caps.capabilities & kCapsRequired) != kCapsRequired) {
+    DLOG(ERROR) << "Initialize(): ioctl() failed: VIDIOC_QUERYCAP"
+        ", caps check failed: 0x" << std::hex << caps.capabilities;
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+
+  // Some random ioctls that Exynos requires.
+  struct v4l2_control control;
+  memset(&control, 0, sizeof(control));
+  control.id = V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY; // also VP8
+  control.value = 8; // Magic number from Samsung folks.
+  IOCTL_OR_ERROR_RETURN_FALSE(mfc_fd_, VIDIOC_S_CTRL, &control);
+
+  if (!make_context_current_.Run()) {
+    DLOG(ERROR) << "Initialize(): could not make context current";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+
+  // Add all our fds to the epoll FD.
+  struct epoll_event event;
+  // Interrupt fd.
+  event.events = EPOLLOUT;
+  event.data.fd = device_poll_interrupt_fd_;
+  epoll_ctl(device_poll_epoll_fd_, EPOLL_CTL_ADD, device_poll_interrupt_fd_,

[Pawel Osciak, 2012/11/29 19:19:53]

Should we test the return value for failures?

[sheu, 2012/11/30 23:48:21]

Done.

+            &event);
+  // The device fds are added as EPOLLONESHOT without events to wait on, for
+  // now, as we'll only wait on them once we know there are buffers to wait on.
+  event.events = EPOLLONESHOT;
+  event.data.fd = mfc_fd_;
+  epoll_ctl(device_poll_epoll_fd_, EPOLL_CTL_ADD, mfc_fd_, &event);
+  event.events = EPOLLONESHOT;
+  event.data.fd = gsc_fd_;
+  epoll_ctl(device_poll_epoll_fd_, EPOLL_CTL_ADD, gsc_fd_, &event);
+
+  if (!CreateMfcInputBuffers())
+    return false;
+
+  // MFC output format has to be setup before streaming starts.
+  struct v4l2_format format;
+  memset(&format, 0, sizeof(format));
+  format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+  format.fmt.pix_mp.pixelformat = V4L2_PIX_FMT_NV12MT_16X16;
+  IOCTL_OR_ERROR_RETURN_FALSE(mfc_fd_, VIDIOC_S_FMT, &format);
+
+  if (!decoder_thread_.Start()) {
+    DLOG(ERROR) << "Initialize(): decoder thread failed to start";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+
+  SetDecoderState(kInitialized);
+
+  child_message_loop_proxy_->PostTask(FROM_HERE, base::Bind(
+      &Client::NotifyInitializeDone, client_));
+  return true;
+}
+
+void ExynosVideoDecodeAccelerator::Decode(
+    const media::BitstreamBuffer& bitstream_buffer) {
+  DVLOG(1) << "Decode(): input_id=" << bitstream_buffer.id()
+           << ", size=" << bitstream_buffer.size();
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+
+  scoped_ptr<BitstreamBufferRef> bitstream_record(new BitstreamBufferRef(
+      client_, child_message_loop_proxy_,
+      new base::SharedMemory(bitstream_buffer.handle(), true),
+      bitstream_buffer.size(), bitstream_buffer.id()));
+  if (!bitstream_record->shm->Map(bitstream_buffer.size())) {
+    DLOG(ERROR) << "Decode(): could not map bitstream_buffer";
+    NOTIFY_ERROR(UNREADABLE_INPUT);
+    return;
+  }
+  DVLOG(3) << "Decode(): mapped to addr=" << bitstream_record->shm->memory();
+
+  // DecodeTask() will take care of running a DecodeBufferTask().
+  decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
+      &ExynosVideoDecodeAccelerator::DecodeTask, base::Unretained(this),
+      base::Passed(&bitstream_record)));
+}
+
+void ExynosVideoDecodeAccelerator::AssignPictureBuffers(
+    const std::vector<media::PictureBuffer>& buffers) {
+  DVLOG(3) << "AssignPictureBuffers(): buffer_count=" << buffers.size();
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+
+  if (!make_context_current_.Run()) {
+    DLOG(ERROR) << "AssignPictureBuffers(): could not make context current";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  DCHECK_EQ(gsc_output_buffer_count_, static_cast<int>(buffers.size()));
+  scoped_ptr<EGLImageKHRArrayRef> egl_images_ref(
+      new EGLImageKHRArrayRef(
+          egl_display_, new EGLImageKHR[buffers.size()],
+          new int[buffers.size()], buffers.size()));
+  for (int i = 0; i < egl_images_ref->egl_images_count; ++i) {
+    egl_images_ref->egl_images[i] = EGL_NO_IMAGE_KHR;
+    egl_images_ref->egl_image_fds[i] = -1;
+  }
+
+  const static EGLint kImageAttrs[] = {
+    EGL_IMAGE_PRESERVED_KHR, 0,
+    EGL_NONE,
+  };
+  Display* x_display = base::MessagePumpForUI::GetDefaultXDisplay();
+  glActiveTexture(GL_TEXTURE0);
+  for (int i = 0; i < egl_images_ref->egl_images_count; ++i) {
+    // Create the X pixmap and then create an EGLImageKHR from it, so we can
+    // get dma_buf backing.
+    Pixmap pixmap = XCreatePixmap(x_display, RootWindow(x_display, 0),
+        buffers[i].size().width(), buffers[i].size().height(), 32);
+    if (!pixmap) {
+      DLOG(ERROR) << "AssignPictureBuffers(): could not create X pixmap";
+      NOTIFY_ERROR(PLATFORM_FAILURE);
+      return;
+    }
+    glBindTexture(GL_TEXTURE_2D, buffers[i].texture_id());
+    EGLImageKHR egl_image;
+    egl_image = egl_create_image_khr(
+        egl_display_, EGL_NO_CONTEXT, EGL_NATIVE_PIXMAP_KHR,
+        (EGLClientBuffer)pixmap, kImageAttrs);
+    // We can free the X pixmap immediately -- according to the
+    // EGL_KHR_image_base spec, the backing storage does not go away until the
+    // last referencing EGLImage is destroyed.
+    XFreePixmap(x_display, pixmap);
+    if (egl_image == EGL_NO_IMAGE_KHR) {
+      DLOG(ERROR) << "AssignPictureBuffers(): could not create EGLImageKHR";
+      NOTIFY_ERROR(PLATFORM_FAILURE);
+      return;
+    }
+    egl_images_ref->egl_images[i] = egl_image;
+    int fd;
+    if (!mali_egl_image_get_buffer_ext_phandle(
+        egl_images_ref->egl_images[i], NULL, &fd)) {
+      DLOG(ERROR) << "AssignPictureBuffers(): "
+                  << "could not get EGLImageKHR dmabuf fd";
+      NOTIFY_ERROR(PLATFORM_FAILURE);
+      return;
+    }
+    egl_images_ref->egl_image_fds[i] = fd;
+    gl_egl_image_target_texture_2d_oes(GL_TEXTURE_2D, egl_image);
+  }
+  decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
+      &ExynosVideoDecodeAccelerator::AssignPictureBuffersTask,
+      base::Unretained(this), base::Passed(&egl_images_ref)));
+}
+
+void ExynosVideoDecodeAccelerator::ReusePictureBuffer(int32 picture_buffer_id) {
+  DVLOG(3) << "ReusePictureBuffer(): picture_buffer_id=" << picture_buffer_id;
+  // Must be run on child thread, as we'll insert a sync in the EGL context.
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+
+  if (!make_context_current_.Run()) {
+    DLOG(ERROR) << "ReusePictureBuffer(): could not make context current";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  EGLSyncKHR egl_sync;
+  egl_sync = egl_create_sync_khr(egl_display_, EGL_SYNC_FENCE_KHR, NULL);
+  if (egl_sync == EGL_NO_SYNC_KHR) {
+    DLOG(ERROR) << "ReusePictureBuffer(): eglCreateSyncKHR() failed";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  scoped_ptr<EGLSyncKHRRef> egl_sync_ref(new EGLSyncKHRRef(
+      egl_display_, egl_sync));
+  decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
+      &ExynosVideoDecodeAccelerator::ReusePictureBufferTask,
+      base::Unretained(this), picture_buffer_id, base::Passed(&egl_sync_ref)));
+}
+
+void ExynosVideoDecodeAccelerator::Flush() {
+  DVLOG(3) << "Flush()";
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+  decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
+      &ExynosVideoDecodeAccelerator::FlushTask, base::Unretained(this)));
+}
+
+void ExynosVideoDecodeAccelerator::Reset() {
+  DVLOG(3) << "Reset()";
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+  decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
+      &ExynosVideoDecodeAccelerator::ResetTask, base::Unretained(this)));
+}
+
+void ExynosVideoDecodeAccelerator::Destroy() {
+  DVLOG(3) << "Destroy()";
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+
+  // We're destroying; cancel all callbacks.
+  client_ptr_factory_.InvalidateWeakPtrs();
+
+  // If the decoder thread is running, destroy using posted task.
+  if (decoder_thread_.message_loop() != NULL) {
+    decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
+        &ExynosVideoDecodeAccelerator::DestroyTask, base::Unretained(this)));
+    // DestroyTask() will cause the decoder_thread_ to flush all tasks.
+    decoder_thread_.Stop();
+  } else {
+    // Otherwise, call the destroy task directly.
+    DestroyTask();
+  }
+
+  // Set to kError state just in case.
+  SetDecoderState(kError);
+
+  delete this;
+}
+
+// static
+void ExynosVideoDecodeAccelerator::PreSandboxInitialization() {
+  DVLOG(3) << "PreSandboxInitialization()";
+  dlerror();
+  libmali_handle = dlopen(EXYNOS_MALI_DRIVER, RTLD_LAZY | RTLD_LOCAL);
+  if (libmali_handle == NULL) {
+    DPLOG(ERROR) << "failed to dlopen() " << EXYNOS_MALI_DRIVER
+                 << ": " << dlerror();
+  }
+}
+
+// static
+bool ExynosVideoDecodeAccelerator::PostSandboxInitialization() {
+  DVLOG(3) << "PostSandboxInitialization()";
+  if (libmali_handle == NULL) {
+    DLOG(ERROR) << "PostSandboxInitialization(): no " << EXYNOS_MALI_DRIVER
+                << " driver handle";
+    return false;
+  }
+
+  dlerror();
+  mali_egl_image_get_buffer_ext_phandle =
+      reinterpret_cast<EGLBoolean(*)(EGLImageKHR, EGLint*, void*)>(
+          dlsym(libmali_handle, "mali_egl_image_get_buffer_ext_phandle"));
+  if (mali_egl_image_get_buffer_ext_phandle == NULL) {
+    DPLOG(ERROR) << "PostSandboxInitialization(): failed to dlsym()"
+                 << " mali_egl_image_get_buffer_ext_phandle: " << dlerror();
+    return false;
+  }
+
+  egl_create_image_khr =
+      reinterpret_cast<EGLImageKHR(*)(EGLDisplay, EGLContext, EGLenum,
+                                      EGLClientBuffer, const EGLint*)>(
+          dlsym(libmali_handle, "eglCreateImageKHR"));
+  if (egl_create_image_khr == NULL) {
+    DPLOG(ERROR) << "PostSandBoxInitialization(): failed to dlsym()"
+                 << " eglCreateImageKHR: " << dlerror();
+    return false;
+  }
+
+  egl_destroy_image_khr =
+      reinterpret_cast<EGLBoolean(*)(EGLDisplay, EGLImageKHR)>(
+          dlsym(libmali_handle, "eglDestroyImageKHR"));
+  if (egl_destroy_image_khr == NULL) {
+    DPLOG(ERROR) << "PostSandBoxInitialization(): failed to dlsym()"
+                 << " eglDestroyImageKHR: " << dlerror();
+    return false;
+  }
+
+  egl_create_sync_khr =
+      reinterpret_cast<EGLSyncKHR(*)(EGLDisplay, EGLenum, const EGLint*)>(
+          dlsym(libmali_handle, "eglCreateSyncKHR"));
+  if (egl_create_sync_khr == NULL) {
+    DPLOG(ERROR) << "PostSandboxInitialization(): failed to dlsym()"
+                 << " eglCreateSyncKHR: " << dlerror();
+    return false;
+  }
+
+  egl_destroy_sync_khr =
+      reinterpret_cast<EGLBoolean(*)(EGLDisplay, EGLSyncKHR)>(
+          dlsym(libmali_handle, "eglDestroySyncKHR"));
+  if (egl_destroy_sync_khr == NULL) {
+    DPLOG(ERROR) << "PostSandboxInitialization(): failed to dlsym()"
+                 << " eglDestroySyncKHR: " << dlerror();
+    return false;
+  }
+
+  egl_client_wait_sync_khr =
+      reinterpret_cast<EGLint(*)(EGLDisplay, EGLSyncKHR, EGLint, EGLTimeKHR)>(
+          dlsym(libmali_handle, "eglClientWaitSyncKHR"));
+  if (egl_client_wait_sync_khr == NULL) {
+    DPLOG(ERROR) << "PostSandboxInitialization(): failed to dlsym()"
+                 << " eglClientWaitSyncKHR: " << dlerror();
+    return false;
+  }
+
+  gl_egl_image_target_texture_2d_oes =
+      reinterpret_cast<void(*)(GLenum, GLeglImageOES)>(
+          dlsym(libmali_handle, "glEGLImageTargetTexture2DOES"));
+  if (gl_egl_image_target_texture_2d_oes == NULL) {
+    DPLOG(ERROR) << "PostSandboxInitialization(): failed to dlsym()"
+                 << "glEGLImageTargetTexture2DOES: " << dlerror();
+    return false;
+  }
+
+  return true;
+}
+
+void ExynosVideoDecodeAccelerator::DecodeTask(
+    scoped_ptr<BitstreamBufferRef> bitstream_record) {
+  DVLOG(3) << "DecodeTask(): input_id=" << bitstream_record->input_id;
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+  DCHECK_NE(decoder_state_, kUninitialized);
+
+  if (decoder_state_ == kResetting) {
+    DVLOG(2) << "DecodeTask(): early out: kResetting state";
+    return;
+  } else if (decoder_state_ == kError) {
+    DVLOG(2) << "DecodeTask(): early out: kError state";
+    return;
+  }
+
+  decoder_input_queue_.push_front(
+      linked_ptr<BitstreamBufferRef>(bitstream_record.release()));
+  decoder_decode_buffer_tasks_scheduled_++;
+  DecodeBufferTask();
+}
+
+void ExynosVideoDecodeAccelerator::DecodeBufferTask() {
+  DVLOG(3) << "DecodeBufferTask()";
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+  DCHECK_NE(decoder_state_, kUninitialized);
+
+  decoder_decode_buffer_tasks_scheduled_--;
+
+  if (decoder_state_ == kResetting) {
+    DVLOG(2) << "DecodeBufferTask(): early out: kResetting state";
+    return;
+  } else if (decoder_state_ == kError) {
+    DVLOG(2) << "DecodeBufferTask(): early out: kError state";
+    return;
+  }
+
+  if (decoder_current_bitstream_buffer_ == NULL) {
+    if (decoder_input_queue_.empty()) {
+      // We're waiting for a new buffer -- exit without scheduling a new task.
+      return;
+    }
+    // Setup to use the next buffer.
+    decoder_current_bitstream_buffer_.reset(
+        decoder_input_queue_.back().release());
+    decoder_input_queue_.pop_back();
+    DVLOG(3) << "DecodeBufferTask(): reading input_id="
+             << decoder_current_bitstream_buffer_->input_id
+             << ", addr=" << decoder_current_bitstream_buffer_->shm->memory()
+             << ", size=" << decoder_current_bitstream_buffer_->size;
+  }
+  bool decode_result = false;
+  const size_t size = decoder_current_bitstream_buffer_->size;
+  if (size == 0) {
+    const int32 input_id = decoder_current_bitstream_buffer_->input_id;
+    if (input_id != -1) {
+      // This is a buffer queued from the client that has zero size.  Skip.
+      decode_result = true;
+    } else {
+      // This is a buffer of zero size, queued to flush the pipe.  Flush.
+      DCHECK_EQ(decoder_current_bitstream_buffer_->shm.get(),
+                static_cast<base::SharedMemory*>(NULL));
+      // Flush the current input, enqueue an empty buffer, then flush that down.
+      if (!FlushInputFrame() || !AppendToInputFrame(NULL, 0)
+          || !FlushInputFrame()) {
+        decode_result = false;
+      } else {
+        DVLOG(2) << "DecodeBufferTask(): enqueued flush buffer";
+        decode_result = true;
+      }
+    }
+  } else {
+    // This is a buffer queued from the client, with actual `contents.  Decode.
+    const void* const data = decoder_current_bitstream_buffer_->shm->memory();
+    switch (decoder_state_) {
+      case kInitialized:
+      case kAfterReset:
+        decode_result = DecodeBufferInitial(data, size);
+        break;
+      case kDecoding:
+        decode_result = DecodeBufferContinue(data, size);
+        break;
+      default:
+        NOTIFY_ERROR(ILLEGAL_STATE);
+        return;
+    }
+  }
+  if (decoder_state_ == kError) {
+    // Failed during decode.
+    return;
+  } else if (!decode_result) {
+    // We might not have failed decode completely, but returned false due to
+    // insufficient resources, etc.  Retry this this buffer later; exit without
+    // scheduling another task.
+    return;
+  }
+
+  // Our current bitstream buffer is done; return it.
+  int32 input_id = decoder_current_bitstream_buffer_->input_id;
+  DVLOG(3) << "DecodeBufferTask(): finished input_id=" << input_id;
+  decoder_current_bitstream_buffer_.reset();

[Pawel Osciak, 2012/11/29 19:19:53]

Perhaps IWBN to have a doc saying destructor will call the client?

[sheu, 2012/11/30 23:48:21]

Done.

+
+  ScheduleDecodeBufferTaskIfNeeded();
+}
+
+void ExynosVideoDecodeAccelerator::ScheduleDecodeBufferTaskIfNeeded() {
+  // If we're behind on tasks, schedule another one.
+  int buffers_to_decode = decoder_input_queue_.size();
+  if (decoder_current_bitstream_buffer_ != NULL)
+    buffers_to_decode++;
+  if (decoder_decode_buffer_tasks_scheduled_ < buffers_to_decode) {
+    decoder_decode_buffer_tasks_scheduled_++;
+    decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
+        &ExynosVideoDecodeAccelerator::DecodeBufferTask,
+        base::Unretained(this)));
+  }
+}
+
+bool ExynosVideoDecodeAccelerator::DecodeBufferInitial(
+    const void* data, size_t size) {
+  DVLOG(3) << "DecodeBufferInitial(): data=" << data << ", size=" << size;
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+  DCHECK_NE(decoder_state_, kUninitialized);
+  DCHECK_NE(decoder_state_, kDecoding);
+  DCHECK(!device_poll_thread_.IsRunning());
+  // Initial decode.  We haven't been able to get output stream format info yet.
+  // Get it, and start decoding.
+
+  // Copy in and send to HW.
+  if (!AppendToInputFrame(data, size) || !FlushInputFrame())
+    return false;
+
+  // Recycle buffers.
+  DequeueMfc();
+
+  // Check and see if we have format info yet.
+  struct v4l2_format format;
+  format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+  if (ioctl(mfc_fd_, VIDIOC_G_FMT, &format) != 0) {
+    if (errno == EINVAL) {
+      // We will get EINVAL if we haven't seen sufficient stream to decode the
+      // format.  Return true and go to the next buffer.
+      return true;
+    } else {
+      DPLOG(ERROR) << "DecodeBufferInitial(): ioctl() failed: VIDIOC_G_FMT";
+      NOTIFY_ERROR(PLATFORM_FAILURE);
+      return false;
+    }
+  }
+
+  // Run this initialization only on first startup.
+  if (decoder_state_ == kInitialized) {
+    DVLOG(3) << "DecodeBufferInitial(): running one-time initialization";
+    // Success! Setup our parameters.
+    CHECK_EQ(format.fmt.pix_mp.num_planes, 2);
+    // We don't handle midstream resizes right now.
+    if (!frame_buffer_size_.IsEmpty() && frame_buffer_size_ !=
+        gfx::Size(format.fmt.pix_mp.width, frame_buffer_size_.height())) {
+      // We don't handle mistream resizes right now.
+      NOTIMPLEMENTED();
+      NOTIFY_ERROR(UNREADABLE_INPUT);
+      return false;
+    }
+    frame_buffer_size_.SetSize(
+        format.fmt.pix_mp.width, format.fmt.pix_mp.height);
+    mfc_output_buffer_size_[0] = format.fmt.pix_mp.plane_fmt[0].sizeimage;
+    mfc_output_buffer_size_[1] = format.fmt.pix_mp.plane_fmt[1].sizeimage;
+    mfc_output_buffer_pixelformat_ = format.fmt.pix_mp.pixelformat;
+
+    // Create our other buffers.
+    if (!CreateMfcOutputBuffers() || !CreateGscInputBuffers() ||
+        !CreateGscOutputBuffers())
+      return false;
+  }
+
+  // StartDevicePoll will raise the error if there is one.
+  if (!StartDevicePoll()) {
+    return false;
+  }
+
+  decoder_state_ = kDecoding;
+  ScheduleDecodeBufferTaskIfNeeded();
+  return true;
+}
+
+bool ExynosVideoDecodeAccelerator::DecodeBufferContinue(
+    const void* data, size_t size) {
+  DVLOG(3) << "DecodeBufferContinue(): data=" << data << ", size=" << size;
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+  DCHECK_EQ(decoder_state_, kDecoding);
+
+  // We've already setup our output stream parameters, so just keep on truckin'.
+  return (AppendToInputFrame(data, size) && FlushInputFrame());
+}
+
+bool ExynosVideoDecodeAccelerator::AppendToInputFrame(
+    const void* data, size_t size) {
+  DVLOG(3) << "AppendToInputFrame()";
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+  DCHECK_NE(decoder_state_, kUninitialized);
+  DCHECK_NE(decoder_state_, kResetting);
+  DCHECK_NE(decoder_state_, kError);
+  // This routine should handle data == NULL and size == 0, which occurs when

[Pawel Osciak, 2012/11/29 19:19:53]

Should this be a TODO():? Seems scary not to do this already if it's possible,
since we are doing a memcpy(, data,) below...

[sheu, 2012/11/30 23:48:21]

I was relying on memcpy() to handle NULL pointers when the length is 0.  I went
by and read the spec, and it looks like it works for glibc, but I can't rely on
it...

So, fixed up, also because I have to add some other fragment-finding code.

+  // we queue an empty buffer for the purposes of flushing the pipe.
+
+  // Flush if we're too big
+  if (decoder_current_input_buffer_ != -1) {
+    MfcInputRecord& input_record =
+        mfc_input_buffer_map_[decoder_current_input_buffer_];
+    if (input_record.bytes_used + size > input_record.length) {
+      if (!FlushInputFrame())
+        return false;
+      decoder_current_input_buffer_ = -1;
+    }
+  }
+
+  // Try to get an available input buffer
+  if (decoder_current_input_buffer_ == -1) {
+    if (mfc_free_input_buffers_.empty()) {
+      // See if we can get more free buffers from HW
+      DequeueMfc();
+      if (mfc_free_input_buffers_.empty()) {
+        // Nope!
+        DVLOG(2) << "AppendToInputFrame(): stalled for input buffers";
+        return false;
+      }
+    }
+    decoder_current_input_buffer_ = mfc_free_input_buffers_.back();
+    mfc_free_input_buffers_.pop_back();
+    MfcInputRecord& input_record =
+        mfc_input_buffer_map_[decoder_current_input_buffer_];
+    DCHECK_EQ(input_record.bytes_used, 0);
+    DCHECK_EQ(input_record.input_id, -1);
+    DCHECK(decoder_current_bitstream_buffer_ != NULL);
+    input_record.input_id = decoder_current_bitstream_buffer_->input_id;
+  }
+
+  // Copy in to the buffer.
+  MfcInputRecord& input_record =
+      mfc_input_buffer_map_[decoder_current_input_buffer_];
+  if (size > input_record.length - input_record.bytes_used) {
+    LOG(ERROR) << "AppendToInputFrame(): over-size frame, erroring";
+    NOTIFY_ERROR(UNREADABLE_INPUT);
+    return false;
+  }
+  memcpy((char*)input_record.address + input_record.bytes_used, data, size);
+  input_record.bytes_used += size;
+
+  return true;
+}
+
+bool ExynosVideoDecodeAccelerator::FlushInputFrame() {
+  DVLOG(3) << "FlushInputFrame()";
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+  DCHECK_NE(decoder_state_, kUninitialized);
+  DCHECK_NE(decoder_state_, kResetting);
+  DCHECK_NE(decoder_state_, kError);
+
+  if (decoder_current_input_buffer_ == -1)
+    return true;
+
+  MfcInputRecord& input_record =
+      mfc_input_buffer_map_[decoder_current_input_buffer_];
+  // An empty buffer with input_id == -1 is a "flush buffer" that we don't want
+  // to skip.
+  if (input_record.bytes_used == 0 && input_record.input_id != -1) {
+    input_record.input_id = -1;
+    mfc_free_input_buffers_.push_back(decoder_current_input_buffer_);
+    decoder_current_input_buffer_ = -1;
+    return true;
+  }
+
+  // Queue it to MFC.
+  mfc_input_ready_queue_.push_back(decoder_current_input_buffer_);
+  decoder_current_input_buffer_ = -1;
+  DVLOG(3) << "FlushInputFrame(): submitting input_id="
+           << input_record.input_id;
+  // Kick the MFC once since there's new available input for it.
+  EnqueueMfc();
+
+  return (decoder_state_ != kError);
+}
+
+void ExynosVideoDecodeAccelerator::AssignPictureBuffersTask(
+    scoped_ptr<EGLImageKHRArrayRef> egl_images_ref) {
+  DVLOG(3) << "AssignPictureBuffersTask()";
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+  DCHECK_NE(decoder_state_, kUninitialized);
+
+  // We run AssignPictureBuffersTask even if we're in kResetting.
+  if (decoder_state_ == kError) {
+    DVLOG(2) << "AssignPictureBuffersTask(): early out: kError state";
+    return;
+  }
+
+  DCHECK_EQ(egl_images_ref->egl_images_count,
+      static_cast<int>(gsc_output_buffer_map_.size()));
+  for (size_t i = 0; i < gsc_output_buffer_map_.size(); ++i) {
+    // We should be blank right now.
+    GscOutputRecord& output_record = gsc_output_buffer_map_[i];
+    DCHECK_EQ(output_record.fd, -1);
+    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);
+    output_record.fd = egl_images_ref->egl_image_fds[i];
+    output_record.egl_image = egl_images_ref->egl_images[i];
+    output_record.picture_id = i;
+
+    // Take ownership of the EGLImage and fd.
+    egl_images_ref->egl_images[i] = EGL_NO_IMAGE_KHR;
+    egl_images_ref->egl_image_fds[i] = -1;
+    // And add this buffer to the free list.
+    gsc_free_output_buffers_.push_front(i);
+  }
+
+  // StartDevicePoll will raise the error if there is one.
+  StartDevicePoll();
+}
+
+void ExynosVideoDecodeAccelerator::ServiceDeviceTask() {
+  DVLOG(3) << "ServiceDeviceTask()";
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+  DCHECK_NE(decoder_state_, kUninitialized);
+  DCHECK_NE(decoder_state_, kInitialized);
+  DCHECK_NE(decoder_state_, kAfterReset);
+
+  if (decoder_state_ == kResetting) {
+    DVLOG(2) << "ServiceDeviceTask(): early out: kResetting state";
+    return;
+  } else if (decoder_state_ == kError) {
+    DVLOG(2) << "ServiceDeviceTask(): early out: kError state";
+    return;
+  }
+
+  DequeueMfc();
+  DequeueGsc();
+  EnqueueMfc();
+  EnqueueGsc();
+
+  // Clear the interrupt fd.
+  if (!ClearDevicePollInterrupt())
+    return;
+
+  // Activate device_poll_epoll_fd_ for the devices that need a wait.
+  struct epoll_event event;
+  event.events = EPOLLONESHOT;
+  if (mfc_input_buffer_queued_count_ != 0) {

[Pawel Osciak, 2012/11/29 19:19:53]

What if we always said EPOLLOUT | EPOLLIN? If there were no buffers of each
type, wouldn't that be ok anyway, since we wouldn't get any signals?

[sheu, 2012/11/30 23:48:21]

We can't poll if there are no buffers in both input or output (or we return
EPOLLERR right off), but it looks like we can do that if there is at least one
in either.  Fixed this up.

+    event.events |= EPOLLOUT;
+  }

[Pawel Osciak, 2012/11/29 19:19:53]

And nit: no braces needed.

[sheu, 2012/11/30 23:48:21]

Done.

+  if (mfc_output_buffer_queued_count_ != 0) {
+    event.events |= EPOLLIN;
+  }
+  event.data.fd = mfc_fd_;
+  epoll_ctl(device_poll_epoll_fd_, EPOLL_CTL_MOD, mfc_fd_, &event);
+  event.events = EPOLLONESHOT;
+  if (gsc_input_buffer_queued_count_ != 0) {
+    event.events |= EPOLLOUT;
+  }
+  if (gsc_output_buffer_queued_count_ != 0) {
+    event.events |= EPOLLIN;
+  }
+  event.data.fd = gsc_fd_;
+  epoll_ctl(device_poll_epoll_fd_, EPOLL_CTL_MOD, gsc_fd_, &event);
+
+  // ServiceDeviceTask() should only ever be scheduled from DevicePollTask(),
+  // so either:
+  // * device_poll_thread_ is running normally
+  // * device_poll_thread_ scheduled us, but then a ResetTask() or DestroyTask()
+  //   shut it down, in which case we're either in kResetting or kError states
+  //   respectively, and we should have early-outed already.
+  DCHECK(device_poll_thread_.message_loop());
+  // Queue the DevicePollTask() now.
+  device_poll_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
+      &ExynosVideoDecodeAccelerator::DevicePollTask, base::Unretained(this)));
+
+  DVLOG(1) << "ServiceDeviceTask(): buffer counts: DEC["
+           << decoder_input_queue_.size() << "->"
+           << mfc_input_ready_queue_.size() << "] => MFC["
+           << mfc_free_input_buffers_.size() << "/"
+           << mfc_input_buffer_count_ << "->"
+           << mfc_free_output_buffers_.size() << "/"
+           << mfc_output_buffer_count_ << "] => "
+           << mfc_output_gsc_input_queue_.size() << " => GSC["
+           << gsc_free_input_buffers_.size() << "/"
+           << gsc_input_buffer_count_ << "->"
+           << gsc_free_output_buffers_.size() << "/"
+           << gsc_output_buffer_count_ << "] => VDA["
+           << decoder_frames_at_client_ << "]";
+
+  ScheduleDecodeBufferTaskIfNeeded();
+}
+
+void ExynosVideoDecodeAccelerator::EnqueueMfc() {
+  DVLOG(3) << "EnqueueMfc()";
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+  DCHECK_NE(decoder_state_, kUninitialized);
+
+  // Drain the pipe of completed decode buffers.
+  const int old_mfc_inputs_queued_ = mfc_input_buffer_queued_count_;
+  while (!mfc_input_ready_queue_.empty()) {
+    // Enqueue a MFC input (VIDEO_OUTPUT) buffer.
+    int buffer = mfc_input_ready_queue_.back();
+    MfcInputRecord& input_record = mfc_input_buffer_map_[buffer];
+    DCHECK(!input_record.at_device);
+    struct v4l2_buffer qbuf;
+    struct v4l2_plane qbuf_plane;
+    memset(&qbuf, 0, sizeof(qbuf));
+    memset(&qbuf_plane, 0, sizeof(qbuf_plane));
+    qbuf.index                 = buffer;
+    qbuf.type                  = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+    qbuf.timestamp.tv_sec      = input_record.input_id;
+    qbuf.memory                = V4L2_MEMORY_MMAP;
+    qbuf.m.planes              = &qbuf_plane;
+    qbuf.m.planes[0].bytesused = input_record.bytes_used;
+    qbuf.length                = 1;
+    IOCTL_OR_ERROR_RETURN(mfc_fd_, VIDIOC_QBUF, &qbuf);
+    mfc_input_ready_queue_.pop_back();
+    input_record.at_device = true;
+    mfc_input_buffer_queued_count_++;
+    DVLOG(3) << "EnqueueMfc(): enqueued input_id=" << input_record.input_id;
+  }
+  if (old_mfc_inputs_queued_ == 0 && mfc_input_buffer_queued_count_ != 0) {
+    // We just started up a previously empty queue.
+    // Queue state changed; signal interrupt.
+    if (!SetDevicePollInterrupt())
+      return;
+    // Start VIDIOC_STREAMON if we haven't yet.
+    if (!mfc_input_streamon_) {
+      __u32 type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+      IOCTL_OR_ERROR_RETURN(mfc_fd_, VIDIOC_STREAMON, &type);
+      mfc_input_streamon_ = true;
+    }
+  }
+
+  // Enqueue all the MFC outputs we can.
+  while (!mfc_free_output_buffers_.empty()) {
+    const int old_mfc_outputs_queued_ = mfc_output_buffer_queued_count_;
+    int buffer = mfc_free_output_buffers_.back();
+    MfcOutputRecord& output_record = mfc_output_buffer_map_[buffer];
+    DCHECK(!output_record.at_device);
+    DCHECK_EQ(output_record.input_id, -1);
+    struct v4l2_buffer qbuf;
+    struct v4l2_plane qbuf_planes[2];
+    memset(&qbuf, 0, sizeof(qbuf));
+    memset(qbuf_planes, 0, sizeof(qbuf_planes));
+    qbuf.index    = buffer;
+    qbuf.type     = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+    qbuf.memory   = V4L2_MEMORY_MMAP;
+    qbuf.m.planes = qbuf_planes;
+    qbuf.length   = 2;
+    IOCTL_OR_ERROR_RETURN(mfc_fd_, VIDIOC_QBUF, &qbuf);
+    mfc_free_output_buffers_.pop_back();
+    output_record.at_device = true;
+    mfc_output_buffer_queued_count_++;
+    if (old_mfc_outputs_queued_ == 0 && mfc_output_buffer_queued_count_ != 0) {
+      // We just started up a previously empty queue.
+      // Queue state changed; signal interrupt.
+      if (!SetDevicePollInterrupt())
+        return;
+      // Start VIDIOC_STREAMON if we haven't yet.
+      if (!mfc_output_streamon_) {
+        __u32 type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+        IOCTL_OR_ERROR_RETURN(mfc_fd_, VIDIOC_STREAMON, &type);
+        mfc_output_streamon_ = true;
+      }
+    }
+  }
+}
+
+void ExynosVideoDecodeAccelerator::DequeueMfc() {
+  DVLOG(3) << "DequeueMfc()";
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+  DCHECK_NE(decoder_state_, kUninitialized);
+
+  // Dequeue completed MFC input (VIDEO_OUTPUT) buffers, and recycle to the free
+  // list.
+  struct v4l2_buffer dqbuf;
+  struct v4l2_plane planes[2];
+  while (mfc_input_buffer_queued_count_ > 0) {
+    DCHECK(mfc_input_streamon_);
+    memset(&dqbuf, 0, sizeof(dqbuf));
+    dqbuf.type   = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+    dqbuf.memory = V4L2_MEMORY_MMAP;
+    if (ioctl(mfc_fd_, VIDIOC_DQBUF, &dqbuf) != 0) {
+      if (errno == EAGAIN) {
+        // EAGAIN if we're just out of buffers to dequeue.
+        break;
+      }
+      DPLOG(ERROR) << "DequeueMfc(): ioctl() failed: VIDIOC_DQBUF";
+      NOTIFY_ERROR(PLATFORM_FAILURE);
+      return;
+    }
+    MfcInputRecord& input_record = mfc_input_buffer_map_[dqbuf.index];
+    DCHECK(input_record.at_device);
+    mfc_free_input_buffers_.push_back(dqbuf.index);
+    input_record.at_device = false;
+    input_record.bytes_used = 0;
+    input_record.input_id = -1;
+    mfc_input_buffer_queued_count_--;
+  }
+
+  // Dequeue completed MFC output (VIDEO_CAPTURE) buffers, and queue to the
+  // completed queue.
+  while (mfc_output_buffer_queued_count_ > 0) {
+    DCHECK(mfc_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 = 2;
+    if (ioctl(mfc_fd_, VIDIOC_DQBUF, &dqbuf) != 0) {
+      if (errno == EAGAIN) {
+        // EAGAIN if we're just out of buffers to dequeue.
+        break;
+      }
+      DPLOG(ERROR) << "DequeueMfc(): ioctl() failed: VIDIOC_DQBUF";
+      NOTIFY_ERROR(PLATFORM_FAILURE);
+      return;
+    }
+    const long int input_id = dqbuf.timestamp.tv_sec;
+    MfcOutputRecord& output_record = mfc_output_buffer_map_[dqbuf.index];
+    DCHECK(output_record.at_device);
+    if (dqbuf.m.planes[0].bytesused + dqbuf.m.planes[1].bytesused == 0) {
+      // This is an empty output buffer returned as part of a flush.
+      mfc_free_output_buffers_.push_back(dqbuf.index);
+      output_record.at_device = false;
+      output_record.input_id = -1;
+      output_record.bytes_used[0] = 0;
+      output_record.bytes_used[1] = 0;
+      mfc_output_buffer_queued_count_--;
+    } else {
+      // This is an output buffer with contents to pass down the pipe.
+      mfc_output_gsc_input_queue_.push_front(dqbuf.index);
+      output_record.at_device = false;
+      output_record.input_id = input_id;
+      output_record.bytes_used[0] = dqbuf.m.planes[0].bytesused;
+      output_record.bytes_used[1] = dqbuf.m.planes[1].bytesused;
+      DVLOG(3) << "DequeueMfc(): dequeued input_id=" << input_id;
+      // We don't count this output buffer dequeued yet, or add it to the free
+      // list, as it has data GSC needs to process.
+    }
+  }
+}
+
+void ExynosVideoDecodeAccelerator::EnqueueGsc() {
+  DVLOG(3) << "EnqueueGsc()";
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+  DCHECK_NE(decoder_state_, kUninitialized);
+  DCHECK_NE(decoder_state_, kInitialized);
+
+  // Drain the pipe of completed MFC output buffers.
+  const int old_gsc_inputs_queued_ = gsc_input_buffer_queued_count_;
+  while (!mfc_output_gsc_input_queue_.empty()) {
+    if (gsc_free_input_buffers_.empty())
+      break;
+    // Enqueue a GSC input (VIDEO_OUTPUT) buffer for a complete MFC output

[Pawel Osciak, 2012/11/29 19:19:53]

TBH I liked the old Enqueue*() functions, even if they were to be called only
once, I feel they would improve the readability of these functions...

[sheu, 2012/11/30 23:48:21]

Fine :-P

[Pawel Osciak, 2012/12/01 00:11:20]

Thanks :) Much easier to read now :)

+    // (VIDEO_CAPTURE) buffer.
+    int mfc_buffer, gsc_buffer;
+    mfc_buffer = mfc_output_gsc_input_queue_.back();
+    gsc_buffer = gsc_free_input_buffers_.back();
+    MfcOutputRecord& output_record = mfc_output_buffer_map_[mfc_buffer];
+    DCHECK(!output_record.at_device);
+    GscInputRecord& input_record = gsc_input_buffer_map_[gsc_buffer];
+    DCHECK(!input_record.at_device);
+    DCHECK_EQ(input_record.mfc_output, -1);
+    struct v4l2_buffer qbuf;
+    struct v4l2_plane qbuf_planes[2];
+    memset(&qbuf, 0, sizeof(qbuf));
+    memset(qbuf_planes, 0, sizeof(qbuf_planes));
+    qbuf.index                 = gsc_buffer;
+    qbuf.type                  = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+    qbuf.timestamp.tv_sec      = output_record.input_id;
+    qbuf.memory                = V4L2_MEMORY_USERPTR;
+    qbuf.m.planes              = qbuf_planes;
+    qbuf.m.planes[0].bytesused = output_record.bytes_used[0];
+    qbuf.m.planes[0].length    = mfc_output_buffer_size_[0];
+    qbuf.m.planes[0].m.userptr = (unsigned long)output_record.address[0];
+    qbuf.m.planes[1].bytesused = output_record.bytes_used[1];
+    qbuf.m.planes[1].length    = mfc_output_buffer_size_[1];
+    qbuf.m.planes[1].m.userptr = (unsigned long)output_record.address[1];
+    qbuf.length                = 2;
+    IOCTL_OR_ERROR_RETURN(gsc_fd_, VIDIOC_QBUF, &qbuf);
+    mfc_output_gsc_input_queue_.pop_back();
+    gsc_free_input_buffers_.pop_back();
+    input_record.at_device = true;
+    input_record.mfc_output = mfc_buffer;
+    output_record.bytes_used[0] = 0;
+    output_record.bytes_used[1] = 0;
+    gsc_input_buffer_queued_count_++;
+    DVLOG(3) << "EnqueueGsc(): enqueued input_id=" << output_record.input_id;
+  }
+  if (old_gsc_inputs_queued_ == 0 && gsc_input_buffer_queued_count_ != 0) {
+    // We just started up a previously empty queue.
+    // Queue state changed; signal interrupt.
+    if (!SetDevicePollInterrupt())
+      return;
+    // Start VIDIOC_STREAMON if we haven't yet.
+    if (!gsc_input_streamon_) {
+      __u32 type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+      IOCTL_OR_ERROR_RETURN(gsc_fd_, VIDIOC_STREAMON, &type);
+      gsc_input_streamon_ = true;
+    }
+  }
+
+  // Enqueue a GSC output (VIDEO_CAPTURE) buffer, only if we need one
+  if (gsc_input_buffer_queued_count_ != 0 &&
+      gsc_output_buffer_queued_count_ == 0 &&
+      !gsc_free_output_buffers_.empty()) {
+    const int old_gsc_outputs_queued_ = gsc_output_buffer_queued_count_;
+    int buffer = gsc_free_output_buffers_.back();
+    GscOutputRecord& output_record = gsc_output_buffer_map_[buffer];
+    DCHECK(!output_record.at_device);
+    DCHECK(!output_record.at_client);
+    if (output_record.egl_sync != EGL_NO_SYNC_KHR) {
+      // If we have to wait for completion, wait.  Note that
+      // gsc_free_output_buffers_ is a FIFO queue, so we always wait on the
+      // buffer that has been in th queue the longest.
+      egl_client_wait_sync_khr(egl_display_, output_record.egl_sync, 0,
+          EGL_FOREVER_KHR);
+      egl_destroy_sync_khr(egl_display_, output_record.egl_sync);
+      output_record.egl_sync = EGL_NO_SYNC_KHR;
+    }
+    struct v4l2_buffer qbuf;
+    struct v4l2_plane qbuf_plane;
+    memset(&qbuf, 0, sizeof(qbuf));
+    memset(&qbuf_plane, 0, sizeof(qbuf_plane));
+    qbuf.index            = buffer;
+    qbuf.type             = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+    qbuf.memory           = V4L2_MEMORY_DMABUF;
+    qbuf.m.planes         = &qbuf_plane;
+    qbuf.m.planes[0].m.fd = output_record.fd;
+    qbuf.length           = 1;
+    IOCTL_OR_ERROR_RETURN(gsc_fd_, VIDIOC_QBUF, &qbuf);
+    gsc_free_output_buffers_.pop_back();
+    output_record.at_device = true;
+    gsc_output_buffer_queued_count_++;
+    if (old_gsc_outputs_queued_ == 0 && gsc_output_buffer_queued_count_ != 0) {
+      // We just started up a previously empty queue.
+      // Queue state changed; signal interrupt.
+      if (!SetDevicePollInterrupt())
+        return;
+      // Start VIDIOC_STREAMON if we haven't yet.
+      if (!gsc_output_streamon_) {
+        __u32 type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+        IOCTL_OR_ERROR_RETURN(gsc_fd_, VIDIOC_STREAMON, &type);
+        gsc_output_streamon_ = true;
+      }
+    }
+  }
+  // Bug check: GSC is liable to race conditions if more than one buffer is
+  // simultaneously queued.
+  DCHECK_GE(1, gsc_output_buffer_queued_count_);
+}
+
+void ExynosVideoDecodeAccelerator::DequeueGsc() {
+  DVLOG(3) << "DequeueGsc()";
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+  DCHECK_NE(decoder_state_, kUninitialized);
+  DCHECK_NE(decoder_state_, kInitialized);
+  DCHECK_NE(decoder_state_, kAfterReset);
+
+  // Dequeue completed GSC input (VIDEO_OUTPUT) buffers, and recycle to the free
+  // list.  Also recycle the corresponding MFC output buffers at this time.
+  struct v4l2_buffer dqbuf;
+  while (gsc_input_buffer_queued_count_ > 0) {
+    DCHECK(gsc_input_streamon_);
+    memset(&dqbuf, 0, sizeof(dqbuf));
+    dqbuf.type   = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+    dqbuf.memory = V4L2_MEMORY_DMABUF;
+    if (ioctl(gsc_fd_, VIDIOC_DQBUF, &dqbuf) != 0) {
+      if (errno == EAGAIN) {
+        // EAGAIN if we're just out of buffers to dequeue.
+        break;
+      }
+      DPLOG(ERROR) << "DequeueGsc(): ioctl() failed: VIDIOC_DQBUF";
+      NOTIFY_ERROR(PLATFORM_FAILURE);
+      return;
+    }
+    GscInputRecord& input_record = gsc_input_buffer_map_[dqbuf.index];
+    MfcOutputRecord& output_record =
+        mfc_output_buffer_map_[input_record.mfc_output];
+    DCHECK(input_record.at_device);
+    gsc_free_input_buffers_.push_back(dqbuf.index);
+    mfc_free_output_buffers_.push_back(input_record.mfc_output);
+    input_record.at_device = false;
+    input_record.mfc_output = -1;
+    output_record.input_id = -1;
+    gsc_input_buffer_queued_count_--;
+    mfc_output_buffer_queued_count_--;
+  }
+
+  // Dequeue completed GSC output (VIDEO_CAPTURE) buffers, and send them off to
+  // the client.  Don't recycle to its free list yet -- we can't do that until
+  // ReusePictureBuffer() returns it to us.
+  while (gsc_output_buffer_queued_count_ > 0) {
+    DCHECK(gsc_output_streamon_);
+    memset(&dqbuf, 0, sizeof(dqbuf));
+    dqbuf.type   = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+    dqbuf.memory = V4L2_MEMORY_DMABUF;
+    if (ioctl(gsc_fd_, VIDIOC_DQBUF, &dqbuf) != 0) {
+      if (errno == EAGAIN) {
+        // EAGAIN if we're just out of buffers to dequeue.
+        break;
+      }
+      DPLOG(ERROR) << "DequeueGsc(): ioctl() failed: VIDIOC_DQBUF";
+      NOTIFY_ERROR(PLATFORM_FAILURE);
+      return;
+    }
+    GscOutputRecord& output_record = gsc_output_buffer_map_[dqbuf.index];
+    DCHECK(output_record.at_device);
+    DCHECK(!output_record.at_client);
+    DCHECK_EQ(output_record.egl_sync, EGL_NO_SYNC_KHR);
+    output_record.at_device = false;
+    output_record.at_client = true;
+    gsc_output_buffer_queued_count_--;
+    child_message_loop_proxy_->PostTask(FROM_HERE, base::Bind(
+        &Client::PictureReady, client_, media::Picture(
+            output_record.picture_id, dqbuf.timestamp.tv_sec)));
+    decoder_frames_at_client_++;
+    DVLOG(1) << "DequeueGsc(): dequeued input_id=" << dqbuf.timestamp.tv_sec
+             << " as picture_id=" << output_record.picture_id;
+  }
+  if (decoder_flush_notify_requested_ && IsPipelineEmpty()) {
+    // We were asked for a flush notification, so let's do it.
+    decoder_flush_notify_requested_ = false;
+    child_message_loop_proxy_->PostTask(FROM_HERE, base::Bind(
+        &Client::NotifyFlushDone, client_));
+  }
+}
+
+void ExynosVideoDecodeAccelerator::ReusePictureBufferTask(
+    int32 picture_buffer_id, scoped_ptr<EGLSyncKHRRef> egl_sync_ref) {
+  DVLOG(3) << "ReusePictureBufferTask(): picture_buffer_id="
+           << picture_buffer_id;
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+
+  // We run ReusePictureBufferTask even if we're in kResetting.
+  if (decoder_state_ == kError) {
+    DVLOG(2) << "ReusePictureBufferTask(): early out: kError state";
+    return;
+  }
+
+  size_t index;
+  for (index = 0; index < gsc_output_buffer_map_.size(); ++index)
+    if (gsc_output_buffer_map_[index].picture_id == picture_buffer_id)
+      break;
+
+  if (index >= gsc_output_buffer_map_.size()) {
+    DLOG(ERROR) << "ReusePictureBufferTask(): picture_buffer_id not found";
+    NOTIFY_ERROR(INVALID_ARGUMENT);
+    return;
+  }
+
+  GscOutputRecord& output_record = gsc_output_buffer_map_[index];
+  DCHECK(!output_record.at_device);
+  DCHECK(output_record.at_client);
+  DCHECK_EQ(output_record.egl_sync, EGL_NO_SYNC_KHR);
+  output_record.at_client = false;
+  output_record.egl_sync = egl_sync_ref->egl_sync;
+  gsc_free_output_buffers_.push_front(index);
+  decoder_frames_at_client_--;
+  // Take ownership of the EGLSync.
+  egl_sync_ref->egl_sync = EGL_NO_SYNC_KHR;
+  // We got a buffer back, so kick the GSC.
+  EnqueueGsc();
+}
+
+void ExynosVideoDecodeAccelerator::FlushTask() {
+  DVLOG(3) << "FlushTask()";
+  // Flush the currently-building frame.
+
+  if (decoder_state_ == kResetting) {
+    DVLOG(2) << "FlushTask(): early out: kResetting state";
+    return;
+  } else if (decoder_state_ == kError) {
+    DVLOG(2) << "FlushTask(): early out: kError state";
+    return;
+  }
+
+  // Queue up an empty buffer -- this triggers the flush.
+  decoder_input_queue_.push_front(linked_ptr<BitstreamBufferRef>(
+      new BitstreamBufferRef(client_, child_message_loop_proxy_, NULL, 0, -1)));
+  // We'll flag that we want a flush-finished notification, and just return.
+  decoder_flush_notify_requested_ = true;
+}
+
+bool ExynosVideoDecodeAccelerator::IsPipelineEmpty() {
+  // Pipeline is empty when:
+  // * Decoder input holding queue is empty.
+  // * There is no currently filling input buffer.
+  // * MFC input holding queue is empty.
+  // * All MFC input (VIDEO_OUTPUT) buffers are returned.
+  // * MFC -> GSC holding queue is empty.
+  // * All GSC input (VIDEO_OUTPUT) buffers are returned.
+  if (decoder_current_input_buffer_ != -1)
+    return false;
+  return ((decoder_input_queue_.size() + mfc_input_ready_queue_.size() +
+      mfc_input_buffer_queued_count_ + mfc_output_gsc_input_queue_.size() +
+      gsc_input_buffer_queued_count_) == 0);
+}
+
+void ExynosVideoDecodeAccelerator::ResetTask() {
+  DVLOG(3) << "ResetTask()";
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+
+  if (decoder_state_ == kError) {
+    DVLOG(2) << "DecodeTask(): early out: kError state";
+    return;
+  }
+
+  // We stop streaming, but we _don't_ destroy our buffers.
+  if (!StopDevicePoll())
+    return;
+
+  decoder_current_bitstream_buffer_.reset();
+  decoder_input_queue_.clear();
+
+  decoder_current_input_buffer_ = -1;
+  decoder_decode_buffer_tasks_scheduled_ = 0;
+  decoder_flush_notify_requested_ = false;
+
+  // Mark that we're resetting, then enqueue a ResetDoneTask().  All intervening
+  // jobs will early-out in the kResetting state.
+  decoder_state_ = kResetting;
+  decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
+     &ExynosVideoDecodeAccelerator::ResetDoneTask, base::Unretained(this)));
+}
+
+void ExynosVideoDecodeAccelerator::ResetDoneTask() {
+  DVLOG(3) << "ResetDoneTask()";
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+
+  if (decoder_state_ == kError) {
+    DVLOG(2) << "DecodeTask(): early out: kError state";
+    return;
+  }
+
+  // Jobs drained, we're finished resetting.
+  DCHECK_EQ(decoder_state_, kResetting);
+  decoder_state_ = kAfterReset;
+  child_message_loop_proxy_->PostTask(FROM_HERE, base::Bind(
+      &Client::NotifyResetDone, client_));
+}
+
+void ExynosVideoDecodeAccelerator::DestroyTask() {
+  DVLOG(3) << "DestroyTask()";
+
+  // DestroyTask() should run regardless of decoder_state_.
+
+  // Stop streaming and the device_poll_thread_.
+  StopDevicePoll();
+
+  decoder_current_bitstream_buffer_.reset();
+  decoder_current_input_buffer_ = -1;
+  decoder_decode_buffer_tasks_scheduled_ = 0;
+  decoder_frames_at_client_ = 0;
+  decoder_flush_notify_requested_ = false;
+  decoder_input_queue_.clear();
+
+  // Set our state to kError.  This will cause all subsequent tasks to
+  // early-exit.
+  decoder_state_ = kError;
+}
+
+bool ExynosVideoDecodeAccelerator::StartDevicePoll() {
+  DVLOG(3) << "StartDevicePoll()";
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+
+  // Early-out if we're already running.
+  if (device_poll_thread_.IsRunning()) {
+    DVLOG(2) << "StartDevicePoll(): early out: "
+             << "device poll thread already running";
+    return true;
+  }
+
+  // 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;
+  }
+  device_poll_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
+      &ExynosVideoDecodeAccelerator::DevicePollTask, base::Unretained(this)));
+
+  return true;
+}
+
+bool ExynosVideoDecodeAccelerator::StopDevicePoll() {
+  DVLOG(3) << "StopDevicePoll()";
+  DCHECK_EQ(decoder_thread_.message_loop(), MessageLoop::current());
+
+  // Signal the DevicePollTask() to stop, and stop the device poll thread.
+  if (!SetDevicePollInterrupt())
+    return false;
+  device_poll_thread_.Stop();
+  // Clear the interrupt now, to be sure.
+  if (!ClearDevicePollInterrupt())
+    return false;
+
+  // Stop streaming.
+  if (mfc_input_streamon_) {
+    __u32 type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+    IOCTL_OR_ERROR_RETURN_FALSE(mfc_fd_, VIDIOC_STREAMOFF, &type);
+  }
+  mfc_input_streamon_ = false;
+  if (mfc_output_streamon_) {
+    __u32 type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+    IOCTL_OR_ERROR_RETURN_FALSE(mfc_fd_, VIDIOC_STREAMOFF, &type);
+  }
+  mfc_output_streamon_ = false;
+  if (gsc_input_streamon_) {
+    __u32 type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+    IOCTL_OR_ERROR_RETURN_FALSE(gsc_fd_, VIDIOC_STREAMOFF, &type);
+  }
+  gsc_input_streamon_ = false;
+  if (gsc_output_streamon_) {
+    __u32 type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+    IOCTL_OR_ERROR_RETURN_FALSE(gsc_fd_, VIDIOC_STREAMOFF, &type);
+  }
+  gsc_output_streamon_ = false;
+
+  // Reset all our accounting info.
+  mfc_input_ready_queue_.clear();
+  mfc_free_input_buffers_.clear();
+  DCHECK_EQ(mfc_input_buffer_count_,
+      static_cast<int>(mfc_input_buffer_map_.size()));
+  for (size_t i = 0; i < mfc_input_buffer_map_.size(); ++i) {
+    mfc_free_input_buffers_.push_back(i);
+    mfc_input_buffer_map_[i].at_device = false;
+    mfc_input_buffer_map_[i].bytes_used = 0;
+    mfc_input_buffer_map_[i].input_id = -1;
+  }
+  mfc_input_buffer_queued_count_ = 0;
+  mfc_free_output_buffers_.clear();
+  DCHECK_EQ(mfc_output_buffer_count_,
+     static_cast<int>(mfc_output_buffer_map_.size()));
+  for (size_t i = 0; i < mfc_output_buffer_map_.size(); ++i) {
+    mfc_free_output_buffers_.push_back(i);
+    mfc_output_buffer_map_[i].at_device = false;
+    mfc_output_buffer_map_[i].input_id = -1;
+  }
+  mfc_output_buffer_queued_count_ = 0;
+  mfc_output_gsc_input_queue_.clear();
+  gsc_free_input_buffers_.clear();
+  DCHECK_EQ(gsc_input_buffer_count_,
+      static_cast<int>(gsc_input_buffer_map_.size()));
+  for (size_t i = 0; i < gsc_input_buffer_map_.size(); ++i) {
+    gsc_free_input_buffers_.push_back(i);
+    gsc_input_buffer_map_[i].at_device = false;
+    gsc_input_buffer_map_[i].mfc_output = -1;
+  }
+  gsc_input_buffer_queued_count_ = 0;
+  gsc_free_output_buffers_.clear();
+  DCHECK_EQ(gsc_output_buffer_count_,
+      static_cast<int>(gsc_output_buffer_map_.size()));
+  for (size_t i = 0; i < gsc_output_buffer_map_.size(); ++i) {
+    // Only mark those free that aren't being held by the VDA.
+    if (!gsc_output_buffer_map_[i].at_client) {
+      gsc_free_output_buffers_.push_back(i);
+      gsc_output_buffer_map_[i].at_device = false;
+    }
+    if (gsc_output_buffer_map_[i].egl_sync != EGL_NO_SYNC_KHR) {
+      egl_destroy_sync_khr(egl_display_, gsc_output_buffer_map_[i].egl_sync);
+      gsc_output_buffer_map_[i].egl_sync = EGL_NO_SYNC_KHR;
+    }
+  }
+  gsc_output_buffer_queued_count_ = 0;
+
+  DVLOG(3) << "StopDevicePoll(): device poll stopped";
+  return true;
+}
+
+bool ExynosVideoDecodeAccelerator::SetDevicePollInterrupt() {
+  ssize_t ret;
+  const uint64 buf = 1;
+  ret = write(device_poll_interrupt_fd_, &buf, sizeof(buf));
+  if (ret == -1) {
+    DPLOG(ERROR) << "SetDevicePollInterrupt(): write() failed";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return false;
+  }
+  return true;
+}
+
+bool ExynosVideoDecodeAccelerator::ClearDevicePollInterrupt() {
+  int ret;
+  uint64 buf;
+  ret = read(device_poll_interrupt_fd_, &buf, sizeof(buf));
+  if (ret == -1) {
+    if (errno == EAGAIN) {
+      // No interrupt flag set, and we're reading nonblocking.  Not an error.
+      return true;
+    } else {
+      DPLOG(ERROR) << "ClearDevicePollInterrupt(): read() failed";
+      NOTIFY_ERROR(PLATFORM_FAILURE);
+      return false;
+    }
+  }
+  return true;
+}
+
+void ExynosVideoDecodeAccelerator::DevicePollTask() {
+  DVLOG(3) << "DevicePollTask()";
+  DCHECK_EQ(device_poll_thread_.message_loop(), MessageLoop::current());
+  // This routine just polls on device_poll_epoll_fd_, and schedules a
+  // ServiceDeviceTask() on decoder_thread_ when processing needs to occur.
+  // Other threads may notify this task to return early by writing to
+  // device_poll_interrupt_fd_, which is part of the epoll set waited on.
+  struct epoll_event event;
+  int ret;
+  do {
+    ret = epoll_wait(device_poll_epoll_fd_, &event, 1, -1);
+  } while (ret < 1 && errno == EINTR);
+  if (ret == -1) {
+    DPLOG(ERROR) << "DevicePollTask(): epoll_wait() failed";
+    NOTIFY_ERROR(PLATFORM_FAILURE);
+    return;
+  }
+
+  // All processing should happen on ServiceDeviceTask(), since we shouldn't
+  // touch decoder state from this thread.
+  decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
+      &ExynosVideoDecodeAccelerator::ServiceDeviceTask,
+      base::Unretained(this)));
+}
+
+void ExynosVideoDecodeAccelerator::NotifyError(Error error) {
+  DVLOG(2) << "NotifyError()";
+
+  if (!child_message_loop_proxy_->BelongsToCurrentThread()) {
+    child_message_loop_proxy_->PostTask(FROM_HERE, base::Bind(
+        &ExynosVideoDecodeAccelerator::NotifyError, weak_this_, error));
+    return;
+  }
+
+  if (client_) {
+    client_->NotifyError(error);
+    client_ptr_factory_.InvalidateWeakPtrs();
+  }
+}
+
+void ExynosVideoDecodeAccelerator::SetDecoderState(State state) {
+  DVLOG(3) << "SetDecoderState()";
+
+  // We can touch decoder_state_ only if this is the decoder thread or the
+  // decoder thread isn't running.
+  if (decoder_thread_.message_loop() != NULL &&
+      decoder_thread_.message_loop() != MessageLoop::current()) {
+    decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
+        &ExynosVideoDecodeAccelerator::SetDecoderState,
+        base::Unretained(this), state));
+  } else {
+    decoder_state_ = state;
+  }
+}
+
+bool ExynosVideoDecodeAccelerator::CreateMfcInputBuffers() {
+  DVLOG(3) << "CreateMfcInputBuffers()";
+  // We always run this as we prepare to initialize.
+  DCHECK_EQ(decoder_state_, kUninitialized);
+  DCHECK(!mfc_input_streamon_);
+  DCHECK_EQ(mfc_input_buffer_count_, 0);
+
+  __u32 pixelformat = 0;
+  if (video_profile_ >= media::H264PROFILE_MIN &&
+      video_profile_ <= media::H264PROFILE_MAX) {
+    pixelformat = V4L2_PIX_FMT_H264;
+  } else if (video_profile_ >= media::VP8PROFILE_MIN &&
+             video_profile_ <= media::VP8PROFILE_MAX) {
+    pixelformat = V4L2_PIX_FMT_VP8;
+  } else {
+    NOTREACHED();
+  }
+
+  struct v4l2_format format;
+  memset(&format, 0, sizeof(format));
+  format.type                              = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+  format.fmt.pix_mp.pixelformat            = pixelformat;
+  format.fmt.pix_mp.plane_fmt[0].sizeimage = kMfcInputBufferMaxSize;
+  format.fmt.pix_mp.num_planes             = 1;
+  IOCTL_OR_ERROR_RETURN_FALSE(mfc_fd_, VIDIOC_S_FMT, &format);
+
+  struct v4l2_requestbuffers reqbufs;
+  memset(&reqbufs, 0, sizeof(reqbufs));
+  reqbufs.count  = kMfcInputBufferCount;
+  reqbufs.type   = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+  reqbufs.memory = V4L2_MEMORY_MMAP;
+  IOCTL_OR_ERROR_RETURN_FALSE(mfc_fd_, VIDIOC_REQBUFS, &reqbufs);
+  mfc_input_buffer_count_ = reqbufs.count;
+  mfc_input_buffer_map_.resize(mfc_input_buffer_count_);
+  for (int i = 0; i < mfc_input_buffer_count_; ++i) {
+    mfc_free_input_buffers_.push_back(i);
+
+    // Query for the MEMORY_MMAP pointer.
+    struct v4l2_plane planes[1];
+    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   = 1;
+    IOCTL_OR_ERROR_RETURN_FALSE(mfc_fd_, VIDIOC_QUERYBUF, &buffer);
+    void* address = mmap(NULL, buffer.m.planes[0].length,
+        PROT_READ | PROT_WRITE, MAP_SHARED, mfc_fd_,
+        buffer.m.planes[0].m.mem_offset);
+    if (address == MAP_FAILED) {
+      DPLOG(ERROR) << "CreateMfcInputBuffers(): mmap() failed";
+      return false;
+    }
+    mfc_input_buffer_map_[i].address = address;
+    mfc_input_buffer_map_[i].length = buffer.m.planes[0].length;
+  }
+
+  return true;
+}
+
+bool ExynosVideoDecodeAccelerator::CreateMfcOutputBuffers() {
+  DVLOG(3) << "CreateMfcOutputBuffers()";
+  DCHECK_EQ(decoder_state_, kInitialized);
+  DCHECK(!mfc_output_streamon_);
+  DCHECK_EQ(mfc_output_buffer_count_, 0);
+
+  // Number of MFC output buffers we need.
+  struct v4l2_control ctrl;
+  memset(&ctrl, 0, sizeof(ctrl));
+  ctrl.id = V4L2_CID_MIN_BUFFERS_FOR_CAPTURE;
+  IOCTL_OR_ERROR_RETURN_FALSE(mfc_fd_, VIDIOC_G_CTRL, &ctrl);
+
+  // Output format setup in Initialize().
+
+  // Allocate the output buffers.
+  struct v4l2_requestbuffers reqbufs;
+  memset(&reqbufs, 0, sizeof(reqbufs));
+  reqbufs.count  = ctrl.value + kMfcOutputBufferExtraCount;
+  reqbufs.type   = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+  reqbufs.memory = V4L2_MEMORY_MMAP;
+  IOCTL_OR_ERROR_RETURN_FALSE(mfc_fd_, VIDIOC_REQBUFS, &reqbufs);
+
+  // Fill our free-buffers list, and create DMABUFs from them.
+  mfc_output_buffer_count_ = reqbufs.count;
+  mfc_output_buffer_map_.resize(mfc_output_buffer_count_);
+  for (int i = 0; i < mfc_output_buffer_count_; ++i) {
+    mfc_free_output_buffers_.push_back(i);
+
+    // Query for the MEMORY_MMAP pointer.
+    struct v4l2_plane planes[2];
+    struct v4l2_buffer buffer;
+    memset(&buffer, 0, sizeof(buffer));
+    memset(planes, 0, sizeof(planes));
+    buffer.index    = i;
+    buffer.type     = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+    buffer.memory   = V4L2_MEMORY_MMAP;
+    buffer.m.planes = planes;
+    buffer.length   = 2;
+    IOCTL_OR_ERROR_RETURN_FALSE(mfc_fd_, VIDIOC_QUERYBUF, &buffer);
+
+    // Get their user memory for GSC input.
+    for (int j = 0; j < 2; ++j) {
+      void* address = mmap(NULL, buffer.m.planes[j].length,
+          PROT_READ | PROT_WRITE, MAP_SHARED, mfc_fd_,
+          buffer.m.planes[j].m.mem_offset);
+      if (address == MAP_FAILED) {
+        DPLOG(ERROR) << "CreateMfcInputBuffers(): mmap() failed";
+        return false;
+      }
+      mfc_output_buffer_map_[i].address[j] = address;
+      mfc_output_buffer_map_[i].length[j] = buffer.m.planes[j].length;
+    }
+  }
+
+  return true;
+}
+
+bool ExynosVideoDecodeAccelerator::CreateGscInputBuffers() {
+  DVLOG(3) << "CreateGscInputBuffers()";
+  DCHECK_EQ(decoder_state_, kInitialized);
+  DCHECK(!gsc_input_streamon_);
+  DCHECK_EQ(gsc_input_buffer_count_, 0);
+
+  struct v4l2_format format;
+  memset(&format, 0, sizeof(format));
+  format.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+  format.fmt.pix_mp.width  = frame_buffer_size_.width();
+  format.fmt.pix_mp.height = frame_buffer_size_.height();
+  DCHECK_EQ(mfc_output_buffer_pixelformat_, V4L2_PIX_FMT_NV12MT_16X16);
+  format.fmt.pix_mp.pixelformat = mfc_output_buffer_pixelformat_;
+  format.fmt.pix_mp.plane_fmt[0].sizeimage = mfc_output_buffer_size_[0];
+  format.fmt.pix_mp.plane_fmt[1].sizeimage = mfc_output_buffer_size_[1];
+  // NV12MT_16X16 is a tiled format for which bytesperline doesn't make too much
+  // sense.  Convention seems to be to assume 8bpp for these tiled formats.
+  format.fmt.pix_mp.plane_fmt[0].bytesperline = frame_buffer_size_.width();
+  format.fmt.pix_mp.plane_fmt[1].bytesperline = frame_buffer_size_.width();
+  format.fmt.pix_mp.num_planes = 2;
+  IOCTL_OR_ERROR_RETURN_FALSE(gsc_fd_, VIDIOC_S_FMT, &format);
+
+  struct v4l2_control control;
+  memset(&control, 0, sizeof(control));
+  control.id = V4L2_CID_ROTATE;
+  control.value = 0;
+  IOCTL_OR_ERROR_RETURN_FALSE(gsc_fd_, VIDIOC_S_CTRL, &control);
+
+  memset(&control, 0, sizeof(control));
+  control.id = V4L2_CID_HFLIP;
+  control.value = 0;
+  IOCTL_OR_ERROR_RETURN_FALSE(gsc_fd_, VIDIOC_S_CTRL, &control);
+
+  memset(&control, 0, sizeof(control));
+  control.id = V4L2_CID_VFLIP;
+  control.value = 0;
+  IOCTL_OR_ERROR_RETURN_FALSE(gsc_fd_, VIDIOC_S_CTRL, &control);
+
+  memset(&control, 0, sizeof(control));
+  control.id = V4L2_CID_GLOBAL_ALPHA;
+  control.value = 255;
+  IOCTL_OR_ERROR_RETURN_FALSE(gsc_fd_, VIDIOC_S_CTRL, &control);
+
+  struct v4l2_requestbuffers reqbufs;
+  memset(&reqbufs, 0, sizeof(reqbufs));
+  reqbufs.count = kGscOutputBufferCount;
+  reqbufs.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+  reqbufs.memory = V4L2_MEMORY_USERPTR;
+  IOCTL_OR_ERROR_RETURN_FALSE(gsc_fd_, VIDIOC_REQBUFS, &reqbufs);
+
+  gsc_input_buffer_count_ = reqbufs.count;
+  gsc_input_buffer_map_.resize(gsc_input_buffer_count_);
+  for (int i = 0; i < gsc_input_buffer_count_; ++i) {
+    gsc_free_input_buffers_.push_back(i);
+    gsc_input_buffer_map_[i].mfc_output = -1;
+  }
+
+  return true;
+}
+
+bool ExynosVideoDecodeAccelerator::CreateGscOutputBuffers() {
+  DVLOG(3) << "CreateGscOutputBuffers()";
+  DCHECK_EQ(decoder_state_, kInitialized);
+  DCHECK(!gsc_output_streamon_);
+  DCHECK_EQ(gsc_output_buffer_count_, 0);
+
+  // GSC outputs into the EGLImages we create from the textures we are
+  // assigned.  Assume RGBA8888 format.
+  struct v4l2_format format;
+  memset(&format, 0, sizeof(format));
+  format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+  format.fmt.pix_mp.width  = frame_buffer_size_.width();
+  format.fmt.pix_mp.height = frame_buffer_size_.height();
+  format.fmt.pix_mp.pixelformat = V4L2_PIX_FMT_RGB32;
+  format.fmt.pix_mp.plane_fmt[0].sizeimage =
+      frame_buffer_size_.width() * frame_buffer_size_.height() * 4;
+  format.fmt.pix_mp.plane_fmt[0].bytesperline = frame_buffer_size_.width() * 4;
+  format.fmt.pix_mp.num_planes = 1;
+  IOCTL_OR_ERROR_RETURN_FALSE(gsc_fd_, VIDIOC_S_FMT, &format);
+
+  struct v4l2_requestbuffers reqbufs;
+  memset(&reqbufs, 0, sizeof(reqbufs));
+  reqbufs.count = kGscOutputBufferCount;
+  reqbufs.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+  reqbufs.memory = V4L2_MEMORY_DMABUF;
+  IOCTL_OR_ERROR_RETURN_FALSE(gsc_fd_, VIDIOC_REQBUFS, &reqbufs);
+
+  // We don't actually fill in the freelist or the map here.  That happens once
+  // we have actual usable buffers, after AssignPictureBuffers();
+  gsc_output_buffer_count_ = reqbufs.count;
+  gsc_output_buffer_map_.resize(gsc_output_buffer_count_);
+
+  DVLOG(3) << "CreateGscOutputBuffers(): ProvidePictureBuffers(): "
+           << "buffer_count=" << gsc_output_buffer_count_
+           << ", width=" << frame_buffer_size_.width()
+           << ", height=" << frame_buffer_size_.height();
+  child_message_loop_proxy_->PostTask(FROM_HERE, base::Bind(
+      &Client::ProvidePictureBuffers, client_, gsc_output_buffer_count_,
+      gfx::Size(frame_buffer_size_.width(), frame_buffer_size_.height()),
+      GL_TEXTURE_2D));
+
+  return true;
+}
+
+void ExynosVideoDecodeAccelerator::DestroyMfcInputBuffers() {
+  DVLOG(3) << "DestroyMfcInputBuffers()";
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+  DCHECK(!mfc_input_streamon_);
+
+  for (size_t i = 0; i < mfc_input_buffer_map_.size(); ++i) {
+    if (mfc_input_buffer_map_[i].address != NULL) {
+      munmap(mfc_input_buffer_map_[i].address,
+          mfc_input_buffer_map_[i].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;
+  if (ioctl(mfc_fd_, VIDIOC_REQBUFS, &reqbufs) != 0)
+    DPLOG(ERROR) << "DestroyMfcInputBuffers(): ioctl() failed: VIDIOC_REQBUFS";
+
+  mfc_input_buffer_map_.clear();
+  mfc_free_input_buffers_.clear();
+  mfc_input_buffer_count_ = 0;
+}
+
+void ExynosVideoDecodeAccelerator::DestroyMfcOutputBuffers() {
+  DVLOG(3) << "DestroyMfcOutputBuffers()";
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+  DCHECK(!mfc_output_streamon_);
+
+  for (size_t i = 0; i < mfc_output_buffer_map_.size(); ++i) {
+    if (mfc_output_buffer_map_[i].address[0] != NULL)
+      munmap(mfc_output_buffer_map_[i].address[0],
+          mfc_output_buffer_map_[i].length[0]);
+    if (mfc_output_buffer_map_[i].address[1] != NULL)
+      munmap(mfc_output_buffer_map_[i].address[1],
+          mfc_output_buffer_map_[i].length[1]);
+  }
+
+  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;
+  if (ioctl(mfc_fd_, VIDIOC_REQBUFS, &reqbufs) != 0)
+    DPLOG(ERROR) << "DestroyMfcOutputBuffers() ioctl() failed: VIDIOC_REQBUFS";
+
+  mfc_output_buffer_map_.clear();
+  mfc_free_output_buffers_.clear();
+  mfc_output_buffer_count_ = 0;
+}
+
+void ExynosVideoDecodeAccelerator::DestroyGscInputBuffers() {
+  DVLOG(3) << "DestroyGscInputBuffers()";
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+  DCHECK(!gsc_input_streamon_);
+
+  struct v4l2_requestbuffers reqbufs;
+  memset(&reqbufs, 0, sizeof(reqbufs));
+  reqbufs.count = 0;
+  reqbufs.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+  reqbufs.memory = V4L2_MEMORY_DMABUF;
+  if (ioctl(gsc_fd_, VIDIOC_REQBUFS, &reqbufs) != 0)
+    DPLOG(ERROR) << "DestroyGscInputBuffers(): ioctl() failed: VIDIOC_REQBUFS";
+
+  gsc_input_buffer_map_.clear();
+  gsc_free_input_buffers_.clear();
+  gsc_input_buffer_count_ = 0;
+}
+
+void ExynosVideoDecodeAccelerator::DestroyGscOutputBuffers() {
+  DVLOG(3) << "DestroyGscOutputBuffers()";
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+  DCHECK(!gsc_output_streamon_);
+
+  if (gsc_output_buffer_map_.size() != 0) {
+    if (!make_context_current_.Run())
+      DLOG(ERROR) << "DestroyGscOutputBuffers(): "
+                  << "could not make context current";
+
+    size_t i = 0;
+    do {
+      GscOutputRecord& output_record = gsc_output_buffer_map_[i];
+      if (output_record.fd != -1)
+        close(output_record.fd);
+      if (output_record.egl_image != EGL_NO_IMAGE_KHR)
+        egl_destroy_image_khr(egl_display_, output_record.egl_image);
+      if (output_record.egl_sync != EGL_NO_SYNC_KHR)
+        egl_destroy_sync_khr(egl_display_, output_record.egl_sync);
+      if (client_)
+        client_->DismissPictureBuffer(output_record.picture_id);
+      ++i;
+    } while (i < gsc_output_buffer_map_.size());
+  }
+
+  struct v4l2_requestbuffers reqbufs;
+  memset(&reqbufs, 0, sizeof(reqbufs));
+  reqbufs.count = 0;
+  reqbufs.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+  reqbufs.memory = V4L2_MEMORY_DMABUF;
+  if (ioctl(gsc_fd_, VIDIOC_REQBUFS, &reqbufs) != 0)
+    DPLOG(ERROR) << "DestroyGscOutputBuffers(): ioctl() failed: VIDIOC_REQBUFS";
+
+  gsc_output_buffer_map_.clear();
+  gsc_free_output_buffers_.clear();
+  gsc_output_buffer_count_ = 0;
+}
+
+}  // namespace content