media/gpu/v4l2/v4l2_h264_accelerator.cc - chromium/src - Git at Google

 // Copyright 2018 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 "media/gpu/v4l2/v4l2_h264_accelerator.h"

 #include <linux/videodev2.h>
 #include <type_traits>

 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "media/gpu/macros.h"
 #include "media/gpu/v4l2/v4l2_decode_surface.h"
 #include "media/gpu/v4l2/v4l2_decode_surface_handler.h"
 #include "media/gpu/v4l2/v4l2_device.h"

 namespace media {

 // This struct contains the kernel-specific parts of the H264 acceleration,
 // that we don't want to expose in the .h file since they may differ from
 // upstream.
 struct V4L2H264AcceleratorPrivate {
   // TODO(posciak): This should be queried from hardware once supported.
   static constexpr size_t kMaxSlices = 16;

   struct v4l2_ctrl_h264_slice_param v4l2_slice_params[kMaxSlices];
   struct v4l2_ctrl_h264_decode_param v4l2_decode_param;
 };

 class V4L2H264Picture : public H264Picture {
  public:
   explicit V4L2H264Picture(const scoped_refptr<V4L2DecodeSurface>& dec_surface)
       : dec_surface_(dec_surface) {}

   V4L2H264Picture* AsV4L2H264Picture() override { return this; }
   scoped_refptr<V4L2DecodeSurface> dec_surface() { return dec_surface_; }

  private:
   ~V4L2H264Picture() override {}

   scoped_refptr<V4L2DecodeSurface> dec_surface_;

   DISALLOW_COPY_AND_ASSIGN(V4L2H264Picture);
 };

 V4L2H264Accelerator::V4L2H264Accelerator(
     V4L2DecodeSurfaceHandler* surface_handler,
     V4L2Device* device)
     : num_slices_(0),
       surface_handler_(surface_handler),
       device_(device),
       priv_(std::make_unique<V4L2H264AcceleratorPrivate>()) {
   DCHECK(surface_handler_);
 }

 V4L2H264Accelerator::~V4L2H264Accelerator() {}

 scoped_refptr<H264Picture> V4L2H264Accelerator::CreateH264Picture() {
   scoped_refptr<V4L2DecodeSurface> dec_surface =
       surface_handler_->CreateSurface();
   if (!dec_surface)
     return nullptr;

   return new V4L2H264Picture(dec_surface);
 }

 void V4L2H264Accelerator::H264PictureListToDPBIndicesList(
     const H264Picture::Vector& src_pic_list,
     uint8_t dst_list[kDPBIndicesListSize]) {
   size_t i;
   for (i = 0; i < src_pic_list.size() && i < kDPBIndicesListSize; ++i) {
     const scoped_refptr<H264Picture>& pic = src_pic_list[i];
     dst_list[i] = pic ? pic->dpb_position : VIDEO_MAX_FRAME;
   }

   while (i < kDPBIndicesListSize)
     dst_list[i++] = VIDEO_MAX_FRAME;
 }

 void V4L2H264Accelerator::H264DPBToV4L2DPB(
     const H264DPB& dpb,
     std::vector<scoped_refptr<V4L2DecodeSurface>>* ref_surfaces) {
   memset(priv_->v4l2_decode_param.dpb, 0, sizeof(priv_->v4l2_decode_param.dpb));
   size_t i = 0;
   for (const auto& pic : dpb) {
     if (i >= base::size(priv_->v4l2_decode_param.dpb)) {
       VLOGF(1) << "Invalid DPB size";
       break;
     }

     int index = VIDEO_MAX_FRAME;
     if (!pic->nonexisting) {
       scoped_refptr<V4L2DecodeSurface> dec_surface =
           H264PictureToV4L2DecodeSurface(pic.get());
       index = dec_surface->GetReferenceID();
       ref_surfaces->push_back(dec_surface);
     }

     struct v4l2_h264_dpb_entry& entry = priv_->v4l2_decode_param.dpb[i++];
     entry.buf_index = index;
     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);
   }
 }

 H264Decoder::H264Accelerator::Status V4L2H264Accelerator::SubmitFrameMetadata(
     const H264SPS* sps,
     const H264PPS* pps,
     const H264DPB& dpb,
     const H264Picture::Vector& ref_pic_listp0,
     const H264Picture::Vector& ref_pic_listb0,
     const H264Picture::Vector& ref_pic_listb1,
     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);

   static_assert(std::extent<decltype(v4l2_sps.offset_for_ref_frame)>() ==
                     std::extent<decltype(sps->offset_for_ref_frame)>(),
                 "offset_for_ref_frame arrays must be same size");
   for (size_t i = 0; i < base::size(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_V4L2_SPS_FLAG_IF
   memset(&ctrl, 0, sizeof(ctrl));
   ctrl.id = V4L2_CID_MPEG_VIDEO_H264_SPS;
   ctrl.size = sizeof(v4l2_sps);
   ctrl.ptr = &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.ptr = &v4l2_pps;
   ctrls.push_back(ctrl);

   struct v4l2_ctrl_h264_scaling_matrix v4l2_scaling_matrix;
   memset(&v4l2_scaling_matrix, 0, sizeof(v4l2_scaling_matrix));

   static_assert(
       std::extent<decltype(v4l2_scaling_matrix.scaling_list_4x4)>() <=
               std::extent<decltype(pps->scaling_list4x4)>() &&
           std::extent<decltype(v4l2_scaling_matrix.scaling_list_4x4[0])>() <=
               std::extent<decltype(pps->scaling_list4x4[0])>() &&
           std::extent<decltype(v4l2_scaling_matrix.scaling_list_8x8)>() <=
               std::extent<decltype(pps->scaling_list8x8)>() &&
           std::extent<decltype(v4l2_scaling_matrix.scaling_list_8x8[0])>() <=
               std::extent<decltype(pps->scaling_list8x8[0])>(),
       "scaling_lists must be of correct size");
   static_assert(
       std::extent<decltype(v4l2_scaling_matrix.scaling_list_4x4)>() <=
               std::extent<decltype(sps->scaling_list4x4)>() &&
           std::extent<decltype(v4l2_scaling_matrix.scaling_list_4x4[0])>() <=
               std::extent<decltype(sps->scaling_list4x4[0])>() &&
           std::extent<decltype(v4l2_scaling_matrix.scaling_list_8x8)>() <=
               std::extent<decltype(sps->scaling_list8x8)>() &&
           std::extent<decltype(v4l2_scaling_matrix.scaling_list_8x8[0])>() <=
               std::extent<decltype(sps->scaling_list8x8[0])>(),
       "scaling_lists must be of correct size");

   const auto* scaling_list4x4 = &sps->scaling_list4x4[0];
   const auto* scaling_list8x8 = &sps->scaling_list8x8[0];
   if (pps->pic_scaling_matrix_present_flag) {
     scaling_list4x4 = &pps->scaling_list4x4[0];
     scaling_list8x8 = &pps->scaling_list8x8[0];
   }

   for (size_t i = 0; i < base::size(v4l2_scaling_matrix.scaling_list_4x4);
        ++i) {
     for (size_t j = 0; j < base::size(v4l2_scaling_matrix.scaling_list_4x4[i]);
          ++j) {
       v4l2_scaling_matrix.scaling_list_4x4[i][j] = scaling_list4x4[i][j];
     }
   }
   for (size_t i = 0; i < base::size(v4l2_scaling_matrix.scaling_list_8x8);
        ++i) {
     for (size_t j = 0; j < base::size(v4l2_scaling_matrix.scaling_list_8x8[i]);
          ++j) {
       v4l2_scaling_matrix.scaling_list_8x8[i][j] = 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.ptr = &v4l2_scaling_matrix;
   ctrls.push_back(ctrl);

   scoped_refptr<V4L2DecodeSurface> dec_surface =
       H264PictureToV4L2DecodeSurface(pic.get());

   struct v4l2_ext_controls ext_ctrls;
   memset(&ext_ctrls, 0, sizeof(ext_ctrls));
   ext_ctrls.count = ctrls.size();
   ext_ctrls.controls = &ctrls[0];
   dec_surface->PrepareSetCtrls(&ext_ctrls);
   if (device_->Ioctl(VIDIOC_S_EXT_CTRLS, &ext_ctrls) != 0) {
     VPLOGF(1) << "ioctl() failed: VIDIOC_S_EXT_CTRLS";
     return Status::kFail;
   }

   H264PictureListToDPBIndicesList(ref_pic_listp0,
                                   priv_->v4l2_decode_param.ref_pic_list_p0);
   H264PictureListToDPBIndicesList(ref_pic_listb0,
                                   priv_->v4l2_decode_param.ref_pic_list_b0);
   H264PictureListToDPBIndicesList(ref_pic_listb1,
                                   priv_->v4l2_decode_param.ref_pic_list_b1);

   std::vector<scoped_refptr<V4L2DecodeSurface>> ref_surfaces;
   H264DPBToV4L2DPB(dpb, &ref_surfaces);
   dec_surface->SetReferenceSurfaces(ref_surfaces);

   return Status::kOk;
 }

 H264Decoder::H264Accelerator::Status V4L2H264Accelerator::SubmitSlice(
     const H264PPS* pps,
     const H264SliceHeader* slice_hdr,
     const H264Picture::Vector& ref_pic_list0,
     const H264Picture::Vector& ref_pic_list1,
     scoped_refptr<H264Picture> pic,
     const uint8_t* data,
     size_t size,
     const std::vector<SubsampleEntry>& subsamples) {
   if (num_slices_ == priv_->kMaxSlices) {
     VLOGF(1) << "Over limit of supported slices per frame";
     return Status::kFail;
   }

   struct v4l2_ctrl_h264_slice_param& v4l2_slice_param =
       priv_->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.get());

   priv_->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;
   std::unique_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 surface_handler_->SubmitSlice(dec_surface, data_copy.get(),
                                        data_copy_size)
              ? Status::kOk
              : Status::kFail;
 }

 H264Decoder::H264Accelerator::Status V4L2H264Accelerator::SubmitDecode(
     scoped_refptr<H264Picture> pic) {
   scoped_refptr<V4L2DecodeSurface> dec_surface =
       H264PictureToV4L2DecodeSurface(pic.get());

   priv_->v4l2_decode_param.num_slices = num_slices_;
   priv_->v4l2_decode_param.idr_pic_flag = pic->idr;
   priv_->v4l2_decode_param.top_field_order_cnt = pic->top_field_order_cnt;
   priv_->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(priv_->v4l2_slice_params);
   ctrl.ptr = priv_->v4l2_slice_params;
   ctrls.push_back(ctrl);

   memset(&ctrl, 0, sizeof(ctrl));
   ctrl.id = V4L2_CID_MPEG_VIDEO_H264_DECODE_PARAM;
   ctrl.size = sizeof(priv_->v4l2_decode_param);
   ctrl.ptr = &priv_->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];
   dec_surface->PrepareSetCtrls(&ext_ctrls);
   if (device_->Ioctl(VIDIOC_S_EXT_CTRLS, &ext_ctrls) != 0) {
     VPLOGF(1) << "ioctl() failed: VIDIOC_S_EXT_CTRLS";
     return Status::kFail;
   }

   Reset();

   DVLOGF(4) << "Submitting decode for surface: " << dec_surface->ToString();
   surface_handler_->DecodeSurface(dec_surface);
   return Status::kOk;
 }

 bool V4L2H264Accelerator::OutputPicture(scoped_refptr<H264Picture> pic) {
   // TODO(crbug.com/647725): Insert correct color space.
   surface_handler_->SurfaceReady(H264PictureToV4L2DecodeSurface(pic.get()),
                                  pic->bitstream_id(), pic->visible_rect(),
                                  VideoColorSpace());
   return true;
 }

 void V4L2H264Accelerator::Reset() {
   num_slices_ = 0;
   memset(&priv_->v4l2_decode_param, 0, sizeof(priv_->v4l2_decode_param));
   memset(&priv_->v4l2_slice_params, 0, sizeof(priv_->v4l2_slice_params));
 }

 scoped_refptr<V4L2DecodeSurface>
 V4L2H264Accelerator::H264PictureToV4L2DecodeSurface(H264Picture* pic) {
   V4L2H264Picture* v4l2_pic = pic->AsV4L2H264Picture();
   CHECK(v4l2_pic);
   return v4l2_pic->dec_surface();
 }

 }  // namespace media
	// Copyright 2018 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 "media/gpu/v4l2/v4l2_h264_accelerator.h"

	#include <linux/videodev2.h>
	#include <type_traits>

	#include "base/logging.h"
	#include "base/stl_util.h"
	#include "media/gpu/macros.h"
	#include "media/gpu/v4l2/v4l2_decode_surface.h"
	#include "media/gpu/v4l2/v4l2_decode_surface_handler.h"
	#include "media/gpu/v4l2/v4l2_device.h"

	namespace media {

	// This struct contains the kernel-specific parts of the H264 acceleration,
	// that we don't want to expose in the .h file since they may differ from
	// upstream.
	struct V4L2H264AcceleratorPrivate {
	// TODO(posciak): This should be queried from hardware once supported.
	static constexpr size_t kMaxSlices = 16;

	struct v4l2_ctrl_h264_slice_param v4l2_slice_params[kMaxSlices];
	struct v4l2_ctrl_h264_decode_param v4l2_decode_param;
	};

	class V4L2H264Picture : public H264Picture {
	public:
	explicit V4L2H264Picture(const scoped_refptr<V4L2DecodeSurface>& dec_surface)
	: dec_surface_(dec_surface) {}

	V4L2H264Picture* AsV4L2H264Picture() override { return this; }
	scoped_refptr<V4L2DecodeSurface> dec_surface() { return dec_surface_; }

	private:
	~V4L2H264Picture() override {}

	scoped_refptr<V4L2DecodeSurface> dec_surface_;

	DISALLOW_COPY_AND_ASSIGN(V4L2H264Picture);
	};

	V4L2H264Accelerator::V4L2H264Accelerator(
	V4L2DecodeSurfaceHandler* surface_handler,
	V4L2Device* device)
	: num_slices_(0),
	surface_handler_(surface_handler),
	device_(device),
	priv_(std::make_unique<V4L2H264AcceleratorPrivate>()) {
	DCHECK(surface_handler_);
	}

	V4L2H264Accelerator::~V4L2H264Accelerator() {}

	scoped_refptr<H264Picture> V4L2H264Accelerator::CreateH264Picture() {
	scoped_refptr<V4L2DecodeSurface> dec_surface =
	surface_handler_->CreateSurface();
	if (!dec_surface)
	return nullptr;

	return new V4L2H264Picture(dec_surface);
	}

	void V4L2H264Accelerator::H264PictureListToDPBIndicesList(
	const H264Picture::Vector& src_pic_list,
	uint8_t dst_list[kDPBIndicesListSize]) {
	size_t i;
	for (i = 0; i < src_pic_list.size() && i < kDPBIndicesListSize; ++i) {
	const scoped_refptr<H264Picture>& pic = src_pic_list[i];
	dst_list[i] = pic ? pic->dpb_position : VIDEO_MAX_FRAME;
	}

	while (i < kDPBIndicesListSize)
	dst_list[i++] = VIDEO_MAX_FRAME;
	}

	void V4L2H264Accelerator::H264DPBToV4L2DPB(
	const H264DPB& dpb,
	std::vector<scoped_refptr<V4L2DecodeSurface>>* ref_surfaces) {
	memset(priv_->v4l2_decode_param.dpb, 0, sizeof(priv_->v4l2_decode_param.dpb));
	size_t i = 0;
	for (const auto& pic : dpb) {
	if (i >= base::size(priv_->v4l2_decode_param.dpb)) {
	VLOGF(1) << "Invalid DPB size";
	break;
	}

	int index = VIDEO_MAX_FRAME;
	if (!pic->nonexisting) {
	scoped_refptr<V4L2DecodeSurface> dec_surface =
	H264PictureToV4L2DecodeSurface(pic.get());
	index = dec_surface->GetReferenceID();
	ref_surfaces->push_back(dec_surface);
	}

	struct v4l2_h264_dpb_entry& entry = priv_->v4l2_decode_param.dpb[i++];
	entry.buf_index = index;
	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);
	}
	}

	H264Decoder::H264Accelerator::Status V4L2H264Accelerator::SubmitFrameMetadata(
	const H264SPS* sps,
	const H264PPS* pps,
	const H264DPB& dpb,
	const H264Picture::Vector& ref_pic_listp0,
	const H264Picture::Vector& ref_pic_listb0,
	const H264Picture::Vector& ref_pic_listb1,
	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);

	static_assert(std::extent<decltype(v4l2_sps.offset_for_ref_frame)>() ==
	std::extent<decltype(sps->offset_for_ref_frame)>(),
	"offset_for_ref_frame arrays must be same size");
	for (size_t i = 0; i < base::size(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_V4L2_SPS_FLAG_IF
	memset(&ctrl, 0, sizeof(ctrl));
	ctrl.id = V4L2_CID_MPEG_VIDEO_H264_SPS;
	ctrl.size = sizeof(v4l2_sps);
	ctrl.ptr = &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.ptr = &v4l2_pps;
	ctrls.push_back(ctrl);

	struct v4l2_ctrl_h264_scaling_matrix v4l2_scaling_matrix;
	memset(&v4l2_scaling_matrix, 0, sizeof(v4l2_scaling_matrix));

	static_assert(
	std::extent<decltype(v4l2_scaling_matrix.scaling_list_4x4)>() <=
	std::extent<decltype(pps->scaling_list4x4)>() &&
	std::extent<decltype(v4l2_scaling_matrix.scaling_list_4x4[0])>() <=
	std::extent<decltype(pps->scaling_list4x4[0])>() &&
	std::extent<decltype(v4l2_scaling_matrix.scaling_list_8x8)>() <=
	std::extent<decltype(pps->scaling_list8x8)>() &&
	std::extent<decltype(v4l2_scaling_matrix.scaling_list_8x8[0])>() <=
	std::extent<decltype(pps->scaling_list8x8[0])>(),
	"scaling_lists must be of correct size");
	static_assert(
	std::extent<decltype(v4l2_scaling_matrix.scaling_list_4x4)>() <=
	std::extent<decltype(sps->scaling_list4x4)>() &&
	std::extent<decltype(v4l2_scaling_matrix.scaling_list_4x4[0])>() <=
	std::extent<decltype(sps->scaling_list4x4[0])>() &&
	std::extent<decltype(v4l2_scaling_matrix.scaling_list_8x8)>() <=
	std::extent<decltype(sps->scaling_list8x8)>() &&
	std::extent<decltype(v4l2_scaling_matrix.scaling_list_8x8[0])>() <=
	std::extent<decltype(sps->scaling_list8x8[0])>(),
	"scaling_lists must be of correct size");

	const auto* scaling_list4x4 = &sps->scaling_list4x4[0];
	const auto* scaling_list8x8 = &sps->scaling_list8x8[0];
	if (pps->pic_scaling_matrix_present_flag) {
	scaling_list4x4 = &pps->scaling_list4x4[0];
	scaling_list8x8 = &pps->scaling_list8x8[0];
	}

	for (size_t i = 0; i < base::size(v4l2_scaling_matrix.scaling_list_4x4);
	++i) {
	for (size_t j = 0; j < base::size(v4l2_scaling_matrix.scaling_list_4x4[i]);
	++j) {
	v4l2_scaling_matrix.scaling_list_4x4[i][j] = scaling_list4x4[i][j];
	}
	}
	for (size_t i = 0; i < base::size(v4l2_scaling_matrix.scaling_list_8x8);
	++i) {
	for (size_t j = 0; j < base::size(v4l2_scaling_matrix.scaling_list_8x8[i]);
	++j) {
	v4l2_scaling_matrix.scaling_list_8x8[i][j] = 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.ptr = &v4l2_scaling_matrix;
	ctrls.push_back(ctrl);

	scoped_refptr<V4L2DecodeSurface> dec_surface =
	H264PictureToV4L2DecodeSurface(pic.get());

	struct v4l2_ext_controls ext_ctrls;
	memset(&ext_ctrls, 0, sizeof(ext_ctrls));
	ext_ctrls.count = ctrls.size();
	ext_ctrls.controls = &ctrls[0];
	dec_surface->PrepareSetCtrls(&ext_ctrls);
	if (device_->Ioctl(VIDIOC_S_EXT_CTRLS, &ext_ctrls) != 0) {
	VPLOGF(1) << "ioctl() failed: VIDIOC_S_EXT_CTRLS";
	return Status::kFail;
	}

	H264PictureListToDPBIndicesList(ref_pic_listp0,
	priv_->v4l2_decode_param.ref_pic_list_p0);
	H264PictureListToDPBIndicesList(ref_pic_listb0,
	priv_->v4l2_decode_param.ref_pic_list_b0);
	H264PictureListToDPBIndicesList(ref_pic_listb1,
	priv_->v4l2_decode_param.ref_pic_list_b1);

	std::vector<scoped_refptr<V4L2DecodeSurface>> ref_surfaces;
	H264DPBToV4L2DPB(dpb, &ref_surfaces);
	dec_surface->SetReferenceSurfaces(ref_surfaces);

	return Status::kOk;
	}

	H264Decoder::H264Accelerator::Status V4L2H264Accelerator::SubmitSlice(
	const H264PPS* pps,
	const H264SliceHeader* slice_hdr,
	const H264Picture::Vector& ref_pic_list0,
	const H264Picture::Vector& ref_pic_list1,
	scoped_refptr<H264Picture> pic,
	const uint8_t* data,
	size_t size,
	const std::vector<SubsampleEntry>& subsamples) {
	if (num_slices_ == priv_->kMaxSlices) {
	VLOGF(1) << "Over limit of supported slices per frame";
	return Status::kFail;
	}

	struct v4l2_ctrl_h264_slice_param& v4l2_slice_param =
	priv_->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.get());

	priv_->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;
	std::unique_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 surface_handler_->SubmitSlice(dec_surface, data_copy.get(),
	data_copy_size)
	? Status::kOk
	: Status::kFail;
	}

	H264Decoder::H264Accelerator::Status V4L2H264Accelerator::SubmitDecode(
	scoped_refptr<H264Picture> pic) {
	scoped_refptr<V4L2DecodeSurface> dec_surface =
	H264PictureToV4L2DecodeSurface(pic.get());

	priv_->v4l2_decode_param.num_slices = num_slices_;
	priv_->v4l2_decode_param.idr_pic_flag = pic->idr;
	priv_->v4l2_decode_param.top_field_order_cnt = pic->top_field_order_cnt;
	priv_->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(priv_->v4l2_slice_params);
	ctrl.ptr = priv_->v4l2_slice_params;
	ctrls.push_back(ctrl);

	memset(&ctrl, 0, sizeof(ctrl));
	ctrl.id = V4L2_CID_MPEG_VIDEO_H264_DECODE_PARAM;
	ctrl.size = sizeof(priv_->v4l2_decode_param);
	ctrl.ptr = &priv_->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];
	dec_surface->PrepareSetCtrls(&ext_ctrls);
	if (device_->Ioctl(VIDIOC_S_EXT_CTRLS, &ext_ctrls) != 0) {
	VPLOGF(1) << "ioctl() failed: VIDIOC_S_EXT_CTRLS";
	return Status::kFail;
	}

	Reset();

	DVLOGF(4) << "Submitting decode for surface: " << dec_surface->ToString();
	surface_handler_->DecodeSurface(dec_surface);
	return Status::kOk;
	}

	bool V4L2H264Accelerator::OutputPicture(scoped_refptr<H264Picture> pic) {
	// TODO(crbug.com/647725): Insert correct color space.
	surface_handler_->SurfaceReady(H264PictureToV4L2DecodeSurface(pic.get()),
	pic->bitstream_id(), pic->visible_rect(),
	VideoColorSpace());
	return true;
	}

	void V4L2H264Accelerator::Reset() {
	num_slices_ = 0;
	memset(&priv_->v4l2_decode_param, 0, sizeof(priv_->v4l2_decode_param));
	memset(&priv_->v4l2_slice_params, 0, sizeof(priv_->v4l2_slice_params));
	}

	scoped_refptr<V4L2DecodeSurface>
	V4L2H264Accelerator::H264PictureToV4L2DecodeSurface(H264Picture* pic) {
	V4L2H264Picture* v4l2_pic = pic->AsV4L2H264Picture();
	CHECK(v4l2_pic);
	return v4l2_pic->dec_surface();
	}

	} // namespace media