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// 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 <algorithm>
#include <limits>
#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/callback_helpers.h"
#include "base/macros.h"
#include "base/numerics/safe_conversions.h"
#include "base/optional.h"
#include "base/stl_util.h"
#include "media/gpu/h264_decoder.h"
namespace media {
H264Decoder::H264Accelerator::H264Accelerator() {}
H264Decoder::H264Accelerator::~H264Accelerator() {}
H264Decoder::H264Decoder(H264Accelerator* accelerator)
: max_frame_num_(0),
max_pic_num_(0),
max_long_term_frame_idx_(0),
max_num_reorder_frames_(0),
accelerator_(accelerator) {
DCHECK(accelerator_);
Reset();
state_ = kNeedStreamMetadata;
}
H264Decoder::~H264Decoder() {}
void H264Decoder::Reset() {
curr_pic_ = nullptr;
curr_nalu_ = nullptr;
curr_slice_hdr_ = nullptr;
curr_sps_id_ = -1;
curr_pps_id_ = -1;
prev_frame_num_ = -1;
prev_ref_frame_num_ = -1;
prev_frame_num_offset_ = -1;
prev_has_memmgmnt5_ = false;
prev_ref_has_memmgmnt5_ = false;
prev_ref_top_field_order_cnt_ = -1;
prev_ref_pic_order_cnt_msb_ = -1;
prev_ref_pic_order_cnt_lsb_ = -1;
prev_ref_field_ = H264Picture::FIELD_NONE;
ref_pic_list_p0_.clear();
ref_pic_list_b0_.clear();
ref_pic_list_b1_.clear();
dpb_.Clear();
parser_.Reset();
accelerator_->Reset();
last_output_poc_ = std::numeric_limits<int>::min();
// If we are in kDecoding, we can resume without processing an SPS.
if (state_ == kDecoding)
state_ = kAfterReset;
}
void H264Decoder::PrepareRefPicLists(const H264SliceHeader* slice_hdr) {
ConstructReferencePicListsP(slice_hdr);
ConstructReferencePicListsB(slice_hdr);
}
bool H264Decoder::ModifyReferencePicLists(const H264SliceHeader* slice_hdr,
H264Picture::Vector* ref_pic_list0,
H264Picture::Vector* ref_pic_list1) {
ref_pic_list0->clear();
ref_pic_list1->clear();
// Fill reference picture lists for B and S/SP slices.
if (slice_hdr->IsPSlice() || slice_hdr->IsSPSlice()) {
*ref_pic_list0 = ref_pic_list_p0_;
return ModifyReferencePicList(slice_hdr, 0, ref_pic_list0);
} else if (slice_hdr->IsBSlice()) {
*ref_pic_list0 = ref_pic_list_b0_;
*ref_pic_list1 = ref_pic_list_b1_;
return ModifyReferencePicList(slice_hdr, 0, ref_pic_list0) &&
ModifyReferencePicList(slice_hdr, 1, ref_pic_list1);
}
return true;
}
bool H264Decoder::DecodePicture() {
DCHECK(curr_pic_.get());
DVLOG(4) << "Decoding POC " << curr_pic_->pic_order_cnt;
return accelerator_->SubmitDecode(curr_pic_);
}
bool H264Decoder::InitNonexistingPicture(scoped_refptr<H264Picture> pic,
int frame_num) {
pic->nonexisting = true;
pic->nal_ref_idc = 1;
pic->frame_num = pic->pic_num = frame_num;
pic->adaptive_ref_pic_marking_mode_flag = false;
pic->ref = true;
pic->long_term_reference_flag = false;
pic->field = H264Picture::FIELD_NONE;
return CalculatePicOrderCounts(pic);
}
bool H264Decoder::InitCurrPicture(const H264SliceHeader* slice_hdr) {
DCHECK(curr_pic_.get());
curr_pic_->idr = slice_hdr->idr_pic_flag;
if (curr_pic_->idr)
curr_pic_->idr_pic_id = slice_hdr->idr_pic_id;
if (slice_hdr->field_pic_flag) {
curr_pic_->field = slice_hdr->bottom_field_flag ? H264Picture::FIELD_BOTTOM
: H264Picture::FIELD_TOP;
} else {
curr_pic_->field = H264Picture::FIELD_NONE;
}
if (curr_pic_->field != H264Picture::FIELD_NONE) {
DVLOG(1) << "Interlaced video not supported.";
return false;
}
curr_pic_->nal_ref_idc = slice_hdr->nal_ref_idc;
curr_pic_->ref = slice_hdr->nal_ref_idc != 0;
// This assumes non-interlaced stream.
curr_pic_->frame_num = curr_pic_->pic_num = slice_hdr->frame_num;
DCHECK_NE(curr_sps_id_, -1);
const H264SPS* sps = parser_.GetSPS(curr_sps_id_);
if (!sps)
return false;
curr_pic_->pic_order_cnt_type = sps->pic_order_cnt_type;
switch (curr_pic_->pic_order_cnt_type) {
case 0:
curr_pic_->pic_order_cnt_lsb = slice_hdr->pic_order_cnt_lsb;
curr_pic_->delta_pic_order_cnt_bottom =
slice_hdr->delta_pic_order_cnt_bottom;
break;
case 1:
curr_pic_->delta_pic_order_cnt0 = slice_hdr->delta_pic_order_cnt0;
curr_pic_->delta_pic_order_cnt1 = slice_hdr->delta_pic_order_cnt1;
break;
case 2:
break;
default:
NOTREACHED();
return false;
}
if (!CalculatePicOrderCounts(curr_pic_))
return false;
curr_pic_->long_term_reference_flag = slice_hdr->long_term_reference_flag;
curr_pic_->adaptive_ref_pic_marking_mode_flag =
slice_hdr->adaptive_ref_pic_marking_mode_flag;
// If the slice header indicates we will have to perform reference marking
// process after this picture is decoded, store required data for that
// purpose.
if (slice_hdr->adaptive_ref_pic_marking_mode_flag) {
static_assert(sizeof(curr_pic_->ref_pic_marking) ==
sizeof(slice_hdr->ref_pic_marking),
"Array sizes of ref pic marking do not match.");
memcpy(curr_pic_->ref_pic_marking, slice_hdr->ref_pic_marking,
sizeof(curr_pic_->ref_pic_marking));
}
return true;
}
bool H264Decoder::CalculatePicOrderCounts(scoped_refptr<H264Picture> pic) {
const H264SPS* sps = parser_.GetSPS(curr_sps_id_);
if (!sps)
return false;
switch (pic->pic_order_cnt_type) {
case 0: {
// See spec 8.2.1.1.
int prev_pic_order_cnt_msb, prev_pic_order_cnt_lsb;
if (pic->idr) {
prev_pic_order_cnt_msb = prev_pic_order_cnt_lsb = 0;
} else {
if (prev_ref_has_memmgmnt5_) {
if (prev_ref_field_ != H264Picture::FIELD_BOTTOM) {
prev_pic_order_cnt_msb = 0;
prev_pic_order_cnt_lsb = prev_ref_top_field_order_cnt_;
} else {
prev_pic_order_cnt_msb = 0;
prev_pic_order_cnt_lsb = 0;
}
} else {
prev_pic_order_cnt_msb = prev_ref_pic_order_cnt_msb_;
prev_pic_order_cnt_lsb = prev_ref_pic_order_cnt_lsb_;
}
}
int max_pic_order_cnt_lsb =
1 << (sps->log2_max_pic_order_cnt_lsb_minus4 + 4);
DCHECK_NE(max_pic_order_cnt_lsb, 0);
if ((pic->pic_order_cnt_lsb < prev_pic_order_cnt_lsb) &&
(prev_pic_order_cnt_lsb - pic->pic_order_cnt_lsb >=
max_pic_order_cnt_lsb / 2)) {
pic->pic_order_cnt_msb = prev_pic_order_cnt_msb + max_pic_order_cnt_lsb;
} else if ((pic->pic_order_cnt_lsb > prev_pic_order_cnt_lsb) &&
(pic->pic_order_cnt_lsb - prev_pic_order_cnt_lsb >
max_pic_order_cnt_lsb / 2)) {
pic->pic_order_cnt_msb = prev_pic_order_cnt_msb - max_pic_order_cnt_lsb;
} else {
pic->pic_order_cnt_msb = prev_pic_order_cnt_msb;
}
if (pic->field != H264Picture::FIELD_BOTTOM) {
pic->top_field_order_cnt =
pic->pic_order_cnt_msb + pic->pic_order_cnt_lsb;
}
if (pic->field != H264Picture::FIELD_TOP) {
if (pic->field == H264Picture::FIELD_NONE) {
pic->bottom_field_order_cnt =
pic->top_field_order_cnt + pic->delta_pic_order_cnt_bottom;
} else {
pic->bottom_field_order_cnt =
pic->pic_order_cnt_msb + pic->pic_order_cnt_lsb;
}
}
break;
}
case 1: {
// See spec 8.2.1.2.
if (prev_has_memmgmnt5_)
prev_frame_num_offset_ = 0;
if (pic->idr)
pic->frame_num_offset = 0;
else if (prev_frame_num_ > pic->frame_num)
pic->frame_num_offset = prev_frame_num_offset_ + max_frame_num_;
else
pic->frame_num_offset = prev_frame_num_offset_;
int abs_frame_num = 0;
if (sps->num_ref_frames_in_pic_order_cnt_cycle != 0)
abs_frame_num = pic->frame_num_offset + pic->frame_num;
else
abs_frame_num = 0;
if (pic->nal_ref_idc == 0 && abs_frame_num > 0)
--abs_frame_num;
int expected_pic_order_cnt = 0;
if (abs_frame_num > 0) {
if (sps->num_ref_frames_in_pic_order_cnt_cycle == 0) {
DVLOG(1) << "Invalid num_ref_frames_in_pic_order_cnt_cycle "
<< "in stream";
return false;
}
int pic_order_cnt_cycle_cnt =
(abs_frame_num - 1) / sps->num_ref_frames_in_pic_order_cnt_cycle;
int frame_num_in_pic_order_cnt_cycle =
(abs_frame_num - 1) % sps->num_ref_frames_in_pic_order_cnt_cycle;
expected_pic_order_cnt = pic_order_cnt_cycle_cnt *
sps->expected_delta_per_pic_order_cnt_cycle;
// frame_num_in_pic_order_cnt_cycle is verified < 255 in parser
for (int i = 0; i <= frame_num_in_pic_order_cnt_cycle; ++i)
expected_pic_order_cnt += sps->offset_for_ref_frame[i];
}
if (!pic->nal_ref_idc)
expected_pic_order_cnt += sps->offset_for_non_ref_pic;
if (pic->field == H264Picture::FIELD_NONE) {
pic->top_field_order_cnt =
expected_pic_order_cnt + pic->delta_pic_order_cnt0;
pic->bottom_field_order_cnt = pic->top_field_order_cnt +
sps->offset_for_top_to_bottom_field +
pic->delta_pic_order_cnt1;
} else if (pic->field != H264Picture::FIELD_BOTTOM) {
pic->top_field_order_cnt =
expected_pic_order_cnt + pic->delta_pic_order_cnt0;
} else {
pic->bottom_field_order_cnt = expected_pic_order_cnt +
sps->offset_for_top_to_bottom_field +
pic->delta_pic_order_cnt0;
}
break;
}
case 2: {
// See spec 8.2.1.3.
if (prev_has_memmgmnt5_)
prev_frame_num_offset_ = 0;
if (pic->idr)
pic->frame_num_offset = 0;
else if (prev_frame_num_ > pic->frame_num)
pic->frame_num_offset = prev_frame_num_offset_ + max_frame_num_;
else
pic->frame_num_offset = prev_frame_num_offset_;
int temp_pic_order_cnt;
if (pic->idr) {
temp_pic_order_cnt = 0;
} else if (!pic->nal_ref_idc) {
temp_pic_order_cnt = 2 * (pic->frame_num_offset + pic->frame_num) - 1;
} else {
temp_pic_order_cnt = 2 * (pic->frame_num_offset + pic->frame_num);
}
if (pic->field == H264Picture::FIELD_NONE) {
pic->top_field_order_cnt = temp_pic_order_cnt;
pic->bottom_field_order_cnt = temp_pic_order_cnt;
} else if (pic->field == H264Picture::FIELD_BOTTOM) {
pic->bottom_field_order_cnt = temp_pic_order_cnt;
} else {
pic->top_field_order_cnt = temp_pic_order_cnt;
}
break;
}
default:
DVLOG(1) << "Invalid pic_order_cnt_type: " << sps->pic_order_cnt_type;
return false;
}
switch (pic->field) {
case H264Picture::FIELD_NONE:
pic->pic_order_cnt =
std::min(pic->top_field_order_cnt, pic->bottom_field_order_cnt);
break;
case H264Picture::FIELD_TOP:
pic->pic_order_cnt = pic->top_field_order_cnt;
break;
case H264Picture::FIELD_BOTTOM:
pic->pic_order_cnt = pic->bottom_field_order_cnt;
break;
}
return true;
}
void H264Decoder::UpdatePicNums(int frame_num) {
for (auto& pic : dpb_) {
if (!pic->ref)
continue;
// 8.2.4.1. Assumes non-interlaced stream.
DCHECK_EQ(pic->field, H264Picture::FIELD_NONE);
if (pic->long_term) {
pic->long_term_pic_num = pic->long_term_frame_idx;
} else {
if (pic->frame_num > frame_num)
pic->frame_num_wrap = pic->frame_num - max_frame_num_;
else
pic->frame_num_wrap = pic->frame_num;
pic->pic_num = pic->frame_num_wrap;
}
}
}
struct PicNumDescCompare {
bool operator()(const scoped_refptr<H264Picture>& a,
const scoped_refptr<H264Picture>& b) const {
return a->pic_num > b->pic_num;
}
};
struct LongTermPicNumAscCompare {
bool operator()(const scoped_refptr<H264Picture>& a,
const scoped_refptr<H264Picture>& b) const {
return a->long_term_pic_num < b->long_term_pic_num;
}
};
void H264Decoder::ConstructReferencePicListsP(
const H264SliceHeader* slice_hdr) {
// RefPicList0 (8.2.4.2.1) [[1] [2]], where:
// [1] shortterm ref pics sorted by descending pic_num,
// [2] longterm ref pics by ascending long_term_pic_num.
ref_pic_list_p0_.clear();
// First get the short ref pics...
dpb_.GetShortTermRefPicsAppending(&ref_pic_list_p0_);
size_t num_short_refs = ref_pic_list_p0_.size();
// and sort them to get [1].
std::sort(ref_pic_list_p0_.begin(), ref_pic_list_p0_.end(),
PicNumDescCompare());
// Now get long term pics and sort them by long_term_pic_num to get [2].
dpb_.GetLongTermRefPicsAppending(&ref_pic_list_p0_);
std::sort(ref_pic_list_p0_.begin() + num_short_refs, ref_pic_list_p0_.end(),
LongTermPicNumAscCompare());
}
struct POCAscCompare {
bool operator()(const scoped_refptr<H264Picture>& a,
const scoped_refptr<H264Picture>& b) const {
return a->pic_order_cnt < b->pic_order_cnt;
}
};
struct POCDescCompare {
bool operator()(const scoped_refptr<H264Picture>& a,
const scoped_refptr<H264Picture>& b) const {
return a->pic_order_cnt > b->pic_order_cnt;
}
};
void H264Decoder::ConstructReferencePicListsB(
const H264SliceHeader* slice_hdr) {
// RefPicList0 (8.2.4.2.3) [[1] [2] [3]], where:
// [1] shortterm ref pics with POC < curr_pic's POC sorted by descending POC,
// [2] shortterm ref pics with POC > curr_pic's POC by ascending POC,
// [3] longterm ref pics by ascending long_term_pic_num.
ref_pic_list_b0_.clear();
ref_pic_list_b1_.clear();
dpb_.GetShortTermRefPicsAppending(&ref_pic_list_b0_);
size_t num_short_refs = ref_pic_list_b0_.size();
// First sort ascending, this will put [1] in right place and finish [2].
std::sort(ref_pic_list_b0_.begin(), ref_pic_list_b0_.end(), POCAscCompare());
// Find first with POC > curr_pic's POC to get first element in [2]...
H264Picture::Vector::iterator iter;
iter = std::upper_bound(ref_pic_list_b0_.begin(), ref_pic_list_b0_.end(),
curr_pic_.get(), POCAscCompare());
// and sort [1] descending, thus finishing sequence [1] [2].
std::sort(ref_pic_list_b0_.begin(), iter, POCDescCompare());
// Now add [3] and sort by ascending long_term_pic_num.
dpb_.GetLongTermRefPicsAppending(&ref_pic_list_b0_);
std::sort(ref_pic_list_b0_.begin() + num_short_refs, ref_pic_list_b0_.end(),
LongTermPicNumAscCompare());
// RefPicList1 (8.2.4.2.4) [[1] [2] [3]], where:
// [1] shortterm ref pics with POC > curr_pic's POC sorted by ascending POC,
// [2] shortterm ref pics with POC < curr_pic's POC by descending POC,
// [3] longterm ref pics by ascending long_term_pic_num.
dpb_.GetShortTermRefPicsAppending(&ref_pic_list_b1_);
num_short_refs = ref_pic_list_b1_.size();
// First sort by descending POC.
std::sort(ref_pic_list_b1_.begin(), ref_pic_list_b1_.end(), POCDescCompare());
// Find first with POC < curr_pic's POC to get first element in [2]...
iter = std::upper_bound(ref_pic_list_b1_.begin(), ref_pic_list_b1_.end(),
curr_pic_.get(), POCDescCompare());
// and sort [1] ascending.
std::sort(ref_pic_list_b1_.begin(), iter, POCAscCompare());
// Now add [3] and sort by ascending long_term_pic_num
dpb_.GetShortTermRefPicsAppending(&ref_pic_list_b1_);
std::sort(ref_pic_list_b1_.begin() + num_short_refs, ref_pic_list_b1_.end(),
LongTermPicNumAscCompare());
// If lists identical, swap first two entries in RefPicList1 (spec 8.2.4.2.3)
if (ref_pic_list_b1_.size() > 1 &&
std::equal(ref_pic_list_b0_.begin(), ref_pic_list_b0_.end(),
ref_pic_list_b1_.begin()))
std::swap(ref_pic_list_b1_[0], ref_pic_list_b1_[1]);
}
// See 8.2.4
int H264Decoder::PicNumF(const scoped_refptr<H264Picture>& pic) {
if (!pic)
return -1;
if (!pic->long_term)
return pic->pic_num;
else
return max_pic_num_;
}
// See 8.2.4
int H264Decoder::LongTermPicNumF(const scoped_refptr<H264Picture>& pic) {
if (pic->ref && pic->long_term)
return pic->long_term_pic_num;
else
return 2 * (max_long_term_frame_idx_ + 1);
}
// Shift elements on the |v| starting from |from| to |to|, inclusive,
// one position to the right and insert pic at |from|.
static void ShiftRightAndInsert(H264Picture::Vector* v,
int from,
int to,
const scoped_refptr<H264Picture>& pic) {
// Security checks, do not disable in Debug mode.
CHECK(from <= to);
CHECK(to <= std::numeric_limits<int>::max() - 2);
// Additional checks. Debug mode ok.
DCHECK(v);
DCHECK(pic);
DCHECK((to + 1 == static_cast<int>(v->size())) ||
(to + 2 == static_cast<int>(v->size())));
v->resize(to + 2);
for (int i = to + 1; i > from; --i)
(*v)[i] = (*v)[i - 1];
(*v)[from] = pic;
}
bool H264Decoder::ModifyReferencePicList(const H264SliceHeader* slice_hdr,
int list,
H264Picture::Vector* ref_pic_listx) {
bool ref_pic_list_modification_flag_lX;
int num_ref_idx_lX_active_minus1;
const H264ModificationOfPicNum* list_mod;
// This can process either ref_pic_list0 or ref_pic_list1, depending on
// the list argument. Set up pointers to proper list to be processed here.
if (list == 0) {
ref_pic_list_modification_flag_lX =
slice_hdr->ref_pic_list_modification_flag_l0;
num_ref_idx_lX_active_minus1 = slice_hdr->num_ref_idx_l0_active_minus1;
list_mod = slice_hdr->ref_list_l0_modifications;
} else {
ref_pic_list_modification_flag_lX =
slice_hdr->ref_pic_list_modification_flag_l1;
num_ref_idx_lX_active_minus1 = slice_hdr->num_ref_idx_l1_active_minus1;
list_mod = slice_hdr->ref_list_l1_modifications;
}
// Resize the list to the size requested in the slice header.
// Note that per 8.2.4.2 it's possible for num_ref_idx_lX_active_minus1 to
// indicate there should be more ref pics on list than we constructed.
// Those superfluous ones should be treated as non-reference and will be
// initialized to nullptr, which must be handled by clients.
DCHECK_GE(num_ref_idx_lX_active_minus1, 0);
ref_pic_listx->resize(num_ref_idx_lX_active_minus1 + 1);
if (!ref_pic_list_modification_flag_lX)
return true;
// Spec 8.2.4.3:
// Reorder pictures on the list in a way specified in the stream.
int pic_num_lx_pred = curr_pic_->pic_num;
int ref_idx_lx = 0;
int pic_num_lx_no_wrap;
int pic_num_lx;
bool done = false;
scoped_refptr<H264Picture> pic;
for (int i = 0; i < H264SliceHeader::kRefListModSize && !done; ++i) {
switch (list_mod->modification_of_pic_nums_idc) {
case 0:
case 1:
// Modify short reference picture position.
if (list_mod->modification_of_pic_nums_idc == 0) {
// Subtract given value from predicted PicNum.
pic_num_lx_no_wrap =
pic_num_lx_pred -
(static_cast<int>(list_mod->abs_diff_pic_num_minus1) + 1);
// Wrap around max_pic_num_ if it becomes < 0 as result
// of subtraction.
if (pic_num_lx_no_wrap < 0)
pic_num_lx_no_wrap += max_pic_num_;
} else {
// Add given value to predicted PicNum.
pic_num_lx_no_wrap =
pic_num_lx_pred +
(static_cast<int>(list_mod->abs_diff_pic_num_minus1) + 1);
// Wrap around max_pic_num_ if it becomes >= max_pic_num_ as result
// of the addition.
if (pic_num_lx_no_wrap >= max_pic_num_)
pic_num_lx_no_wrap -= max_pic_num_;
}
// For use in next iteration.
pic_num_lx_pred = pic_num_lx_no_wrap;
if (pic_num_lx_no_wrap > curr_pic_->pic_num)
pic_num_lx = pic_num_lx_no_wrap - max_pic_num_;
else
pic_num_lx = pic_num_lx_no_wrap;
DCHECK_LT(num_ref_idx_lX_active_minus1 + 1,
H264SliceHeader::kRefListModSize);
pic = dpb_.GetShortRefPicByPicNum(pic_num_lx);
if (!pic) {
DVLOG(1) << "Malformed stream, no pic num " << pic_num_lx;
return false;
}
ShiftRightAndInsert(ref_pic_listx, ref_idx_lx,
num_ref_idx_lX_active_minus1, pic);
ref_idx_lx++;
for (int src = ref_idx_lx, dst = ref_idx_lx;
src <= num_ref_idx_lX_active_minus1 + 1; ++src) {
if (PicNumF((*ref_pic_listx)[src]) != pic_num_lx)
(*ref_pic_listx)[dst++] = (*ref_pic_listx)[src];
}
break;
case 2:
// Modify long term reference picture position.
DCHECK_LT(num_ref_idx_lX_active_minus1 + 1,
H264SliceHeader::kRefListModSize);
pic = dpb_.GetLongRefPicByLongTermPicNum(list_mod->long_term_pic_num);
if (!pic) {
DVLOG(1) << "Malformed stream, no pic num "
<< list_mod->long_term_pic_num;
return false;
}
ShiftRightAndInsert(ref_pic_listx, ref_idx_lx,
num_ref_idx_lX_active_minus1, pic);
ref_idx_lx++;
for (int src = ref_idx_lx, dst = ref_idx_lx;
src <= num_ref_idx_lX_active_minus1 + 1; ++src) {
if (LongTermPicNumF((*ref_pic_listx)[src]) !=
static_cast<int>(list_mod->long_term_pic_num))
(*ref_pic_listx)[dst++] = (*ref_pic_listx)[src];
}
break;
case 3:
// End of modification list.
done = true;
break;
default:
// May be recoverable.
DVLOG(1) << "Invalid modification_of_pic_nums_idc="
<< list_mod->modification_of_pic_nums_idc
<< " in position " << i;
break;
}
++list_mod;
}
// Per NOTE 2 in 8.2.4.3.2, the ref_pic_listx size in the above loop is
// temporarily made one element longer than the required final list.
// Resize the list back to its required size.
ref_pic_listx->resize(num_ref_idx_lX_active_minus1 + 1);
return true;
}
void H264Decoder::OutputPic(scoped_refptr<H264Picture> pic) {
DCHECK(!pic->outputted);
pic->outputted = true;
if (pic->nonexisting) {
DVLOG(4) << "Skipping output, non-existing frame_num: " << pic->frame_num;
return;
}
DVLOG_IF(1, pic->pic_order_cnt < last_output_poc_)
<< "Outputting out of order, likely a broken stream: "
<< last_output_poc_ << " -> " << pic->pic_order_cnt;
last_output_poc_ = pic->pic_order_cnt;
DVLOG(4) << "Posting output task for POC: " << pic->pic_order_cnt;
accelerator_->OutputPicture(pic);
}
void H264Decoder::ClearDPB() {
// Clear DPB contents, marking the pictures as unused first.
dpb_.Clear();
last_output_poc_ = std::numeric_limits<int>::min();
}
bool H264Decoder::OutputAllRemainingPics() {
// Output all pictures that are waiting to be outputted.
FinishPrevFrameIfPresent();
H264Picture::Vector to_output;
dpb_.GetNotOutputtedPicsAppending(&to_output);
// Sort them by ascending POC to output in order.
std::sort(to_output.begin(), to_output.end(), POCAscCompare());
for (auto& pic : to_output)
OutputPic(pic);
return true;
}
bool H264Decoder::Flush() {
DVLOG(2) << "Decoder flush";
if (!OutputAllRemainingPics())
return false;
ClearDPB();
DVLOG(2) << "Decoder flush finished";
return true;
}
bool H264Decoder::StartNewFrame(const H264SliceHeader* slice_hdr) {
// TODO posciak: add handling of max_num_ref_frames per spec.
CHECK(curr_pic_.get());
DCHECK(slice_hdr);
curr_pps_id_ = slice_hdr->pic_parameter_set_id;
const H264PPS* pps = parser_.GetPPS(curr_pps_id_);
if (!pps)
return false;
curr_sps_id_ = pps->seq_parameter_set_id;
const H264SPS* sps = parser_.GetSPS(curr_sps_id_);
if (!sps)
return false;
max_frame_num_ = 1 << (sps->log2_max_frame_num_minus4 + 4);
int frame_num = slice_hdr->frame_num;
if (slice_hdr->idr_pic_flag)
prev_ref_frame_num_ = 0;
// 7.4.3
if (frame_num != prev_ref_frame_num_ &&
frame_num != (prev_ref_frame_num_ + 1) % max_frame_num_) {
if (!HandleFrameNumGap(frame_num))
return false;
}
if (!InitCurrPicture(slice_hdr))
return false;
UpdatePicNums(frame_num);
PrepareRefPicLists(slice_hdr);
if (!accelerator_->SubmitFrameMetadata(sps, pps, dpb_, ref_pic_list_p0_,
ref_pic_list_b0_, ref_pic_list_b1_,
curr_pic_.get()))
return false;
return true;
}
bool H264Decoder::HandleMemoryManagementOps(scoped_refptr<H264Picture> pic) {
// 8.2.5.4
for (size_t i = 0; i < arraysize(pic->ref_pic_marking); ++i) {
// Code below does not support interlaced stream (per-field pictures).
H264DecRefPicMarking* ref_pic_marking = &pic->ref_pic_marking[i];
scoped_refptr<H264Picture> to_mark;
int pic_num_x;
switch (ref_pic_marking->memory_mgmnt_control_operation) {
case 0:
// Normal end of operations' specification.
return true;
case 1:
// Mark a short term reference picture as unused so it can be removed
// if outputted.
pic_num_x =
pic->pic_num - (ref_pic_marking->difference_of_pic_nums_minus1 + 1);
to_mark = dpb_.GetShortRefPicByPicNum(pic_num_x);
if (to_mark) {
to_mark->ref = false;
} else {
DVLOG(1) << "Invalid short ref pic num to unmark";
return false;
}
break;
case 2:
// Mark a long term reference picture as unused so it can be removed
// if outputted.
to_mark = dpb_.GetLongRefPicByLongTermPicNum(
ref_pic_marking->long_term_pic_num);
if (to_mark) {
to_mark->ref = false;
} else {
DVLOG(1) << "Invalid long term ref pic num to unmark";
return false;
}
break;
case 3:
// Mark a short term reference picture as long term reference.
pic_num_x =
pic->pic_num - (ref_pic_marking->difference_of_pic_nums_minus1 + 1);
to_mark = dpb_.GetShortRefPicByPicNum(pic_num_x);
if (to_mark) {
DCHECK(to_mark->ref && !to_mark->long_term);
to_mark->long_term = true;
to_mark->long_term_frame_idx = ref_pic_marking->long_term_frame_idx;
} else {
DVLOG(1) << "Invalid short term ref pic num to mark as long ref";
return false;
}
break;
case 4: {
// Unmark all reference pictures with long_term_frame_idx over new max.
max_long_term_frame_idx_ =
ref_pic_marking->max_long_term_frame_idx_plus1 - 1;
H264Picture::Vector long_terms;
dpb_.GetLongTermRefPicsAppending(&long_terms);
for (size_t i = 0; i < long_terms.size(); ++i) {
scoped_refptr<H264Picture>& long_term_pic = long_terms[i];
DCHECK(long_term_pic->ref && long_term_pic->long_term);
// Ok to cast, max_long_term_frame_idx is much smaller than 16bit.
if (long_term_pic->long_term_frame_idx >
static_cast<int>(max_long_term_frame_idx_))
long_term_pic->ref = false;
}
break;
}
case 5:
// Unmark all reference pictures.
dpb_.MarkAllUnusedForRef();
max_long_term_frame_idx_ = -1;
pic->mem_mgmt_5 = true;
break;
case 6: {
// Replace long term reference pictures with current picture.
// First unmark if any existing with this long_term_frame_idx...
H264Picture::Vector long_terms;
dpb_.GetLongTermRefPicsAppending(&long_terms);
for (size_t i = 0; i < long_terms.size(); ++i) {
scoped_refptr<H264Picture>& long_term_pic = long_terms[i];
DCHECK(long_term_pic->ref && long_term_pic->long_term);
// Ok to cast, long_term_frame_idx is much smaller than 16bit.
if (long_term_pic->long_term_frame_idx ==
static_cast<int>(ref_pic_marking->long_term_frame_idx))
long_term_pic->ref = false;
}
// and mark the current one instead.
pic->ref = true;
pic->long_term = true;
pic->long_term_frame_idx = ref_pic_marking->long_term_frame_idx;
break;
}
default:
// Would indicate a bug in parser.
NOTREACHED();
}
}
return true;
}
// This method ensures that DPB does not overflow, either by removing
// reference pictures as specified in the stream, or using a sliding window
// procedure to remove the oldest one.
// It also performs marking and unmarking pictures as reference.
// See spac 8.2.5.1.
bool H264Decoder::ReferencePictureMarking(scoped_refptr<H264Picture> pic) {
// If the current picture is an IDR, all reference pictures are unmarked.
if (pic->idr) {
dpb_.MarkAllUnusedForRef();
if (pic->long_term_reference_flag) {
pic->long_term = true;
pic->long_term_frame_idx = 0;
max_long_term_frame_idx_ = 0;
} else {
pic->long_term = false;
max_long_term_frame_idx_ = -1;
}
return true;
}
// Not an IDR. If the stream contains instructions on how to discard pictures
// from DPB and how to mark/unmark existing reference pictures, do so.
// Otherwise, fall back to default sliding window process.
if (pic->adaptive_ref_pic_marking_mode_flag) {
DCHECK(!pic->nonexisting);
return HandleMemoryManagementOps(pic);
} else {
return SlidingWindowPictureMarking();
}
}
bool H264Decoder::SlidingWindowPictureMarking() {
const H264SPS* sps = parser_.GetSPS(curr_sps_id_);
if (!sps)
return false;
// 8.2.5.3. Ensure the DPB doesn't overflow by discarding the oldest picture.
int num_ref_pics = dpb_.CountRefPics();
DCHECK_LE(num_ref_pics, std::max<int>(sps->max_num_ref_frames, 1));
if (num_ref_pics == std::max<int>(sps->max_num_ref_frames, 1)) {
// Max number of reference pics reached, need to remove one of the short
// term ones. Find smallest frame_num_wrap short reference picture and mark
// it as unused.
scoped_refptr<H264Picture> to_unmark =
dpb_.GetLowestFrameNumWrapShortRefPic();
if (!to_unmark) {
DVLOG(1) << "Couldn't find a short ref picture to unmark";
return false;
}
to_unmark->ref = false;
}
return true;
}
bool H264Decoder::FinishPicture(scoped_refptr<H264Picture> pic) {
// Finish processing the picture.
// Start by storing previous picture data for later use.
if (pic->ref) {
ReferencePictureMarking(pic);
prev_ref_has_memmgmnt5_ = pic->mem_mgmt_5;
prev_ref_top_field_order_cnt_ = pic->top_field_order_cnt;
prev_ref_pic_order_cnt_msb_ = pic->pic_order_cnt_msb;
prev_ref_pic_order_cnt_lsb_ = pic->pic_order_cnt_lsb;
prev_ref_field_ = pic->field;
prev_ref_frame_num_ = pic->frame_num;
}
prev_frame_num_ = pic->frame_num;
prev_has_memmgmnt5_ = pic->mem_mgmt_5;
prev_frame_num_offset_ = pic->frame_num_offset;
// Remove unused (for reference or later output) pictures from DPB, marking
// them as such.
dpb_.DeleteUnused();
DVLOG(4) << "Finishing picture frame_num: " << pic->frame_num
<< ", entries in DPB: " << dpb_.size();
// The ownership of pic will either be transferred to DPB - if the picture is
// still needed (for output and/or reference) - or we will release it
// immediately if we manage to output it here and won't have to store it for
// future reference.
// Get all pictures that haven't been outputted yet.
H264Picture::Vector not_outputted;
dpb_.GetNotOutputtedPicsAppending(&not_outputted);
// Include the one we've just decoded.
not_outputted.push_back(pic);
// Sort in output order.
std::sort(not_outputted.begin(), not_outputted.end(), POCAscCompare());
// Try to output as many pictures as we can. A picture can be output,
// if the number of decoded and not yet outputted pictures that would remain
// in DPB afterwards would at least be equal to max_num_reorder_frames.
// If the outputted picture is not a reference picture, it doesn't have
// to remain in the DPB and can be removed.
H264Picture::Vector::iterator output_candidate = not_outputted.begin();
size_t num_remaining = not_outputted.size();
while (num_remaining > max_num_reorder_frames_ ||
// If the condition below is used, this is an invalid stream. We should
// not be forced to output beyond max_num_reorder_frames in order to
// make room in DPB to store the current picture (if we need to do so).
// However, if this happens, ignore max_num_reorder_frames and try
// to output more. This may cause out-of-order output, but is not
// fatal, and better than failing instead.
((dpb_.IsFull() && (!pic->outputted || pic->ref)) && num_remaining)) {
DVLOG_IF(1, num_remaining <= max_num_reorder_frames_)
<< "Invalid stream: max_num_reorder_frames not preserved";
OutputPic(*output_candidate);
if (!(*output_candidate)->ref) {
// Current picture hasn't been inserted into DPB yet, so don't remove it
// if we managed to output it immediately.
int outputted_poc = (*output_candidate)->pic_order_cnt;
if (outputted_poc != pic->pic_order_cnt)
dpb_.DeleteByPOC(outputted_poc);
}
++output_candidate;
--num_remaining;
}
// If we haven't managed to output the picture that we just decoded, or if
// it's a reference picture, we have to store it in DPB.
if (!pic->outputted || pic->ref) {
if (dpb_.IsFull()) {
// If we haven't managed to output anything to free up space in DPB
// to store this picture, it's an error in the stream.
DVLOG(1) << "Could not free up space in DPB!";
return false;
}
dpb_.StorePic(pic);
}
return true;
}
static int LevelToMaxDpbMbs(int level) {
// See table A-1 in spec.
switch (level) {
case 10:
return 396;
case 11:
return 900;
case 12: // fallthrough
case 13: // fallthrough
case 20:
return 2376;
case 21:
return 4752;
case 22: // fallthrough
case 30:
return 8100;
case 31:
return 18000;
case 32:
return 20480;
case 40: // fallthrough
case 41:
return 32768;
case 42:
return 34816;
case 50:
return 110400;
case 51: // fallthrough
case 52:
return 184320;
default:
DVLOG(1) << "Invalid codec level (" << level << ")";
return 0;
}
}
bool H264Decoder::UpdateMaxNumReorderFrames(const H264SPS* sps) {
if (sps->vui_parameters_present_flag && sps->bitstream_restriction_flag) {
max_num_reorder_frames_ =
base::checked_cast<size_t>(sps->max_num_reorder_frames);
if (max_num_reorder_frames_ > dpb_.max_num_pics()) {
DVLOG(1)
<< "max_num_reorder_frames present, but larger than MaxDpbFrames ("
<< max_num_reorder_frames_ << " > " << dpb_.max_num_pics() << ")";
max_num_reorder_frames_ = 0;
return false;
}
return true;
}
// max_num_reorder_frames not present, infer from profile/constraints
// (see VUI semantics in spec).
if (sps->constraint_set3_flag) {
switch (sps->profile_idc) {
case 44:
case 86:
case 100:
case 110:
case 122:
case 244:
max_num_reorder_frames_ = 0;
break;
default:
max_num_reorder_frames_ = dpb_.max_num_pics();
break;
}
} else {
max_num_reorder_frames_ = dpb_.max_num_pics();
}
return true;
}
bool H264Decoder::ProcessSPS(int sps_id, bool* need_new_buffers) {
DVLOG(4) << "Processing SPS id:" << sps_id;
const H264SPS* sps = parser_.GetSPS(sps_id);
if (!sps)
return false;
*need_new_buffers = false;
if (sps->frame_mbs_only_flag == 0) {
DVLOG(1) << "frame_mbs_only_flag != 1 not supported";
return false;
}
gfx::Size new_pic_size = sps->GetCodedSize().value_or(gfx::Size());
if (new_pic_size.IsEmpty()) {
DVLOG(1) << "Invalid picture size";
return false;
}
int width_mb = new_pic_size.width() / 16;
int height_mb = new_pic_size.height() / 16;
// Verify that the values are not too large before multiplying.
if (std::numeric_limits<int>::max() / width_mb < height_mb) {
DVLOG(1) << "Picture size is too big: " << new_pic_size.ToString();
return false;
}
if (new_pic_size == pic_size_) {
// Already have surfaces and this SPS keeps the same resolution,
// no need to request a new set.
return true;
}
pic_size_ = new_pic_size;
DVLOG(1) << "New picture size: " << pic_size_.ToString();
int level = sps->level_idc;
int max_dpb_mbs = LevelToMaxDpbMbs(level);
if (max_dpb_mbs == 0)
return false;
size_t max_dpb_size = std::min(max_dpb_mbs / (width_mb * height_mb),
static_cast<int>(H264DPB::kDPBMaxSize));
DVLOG(1) << "Codec level: " << level << ", DPB size: " << max_dpb_size;
if (max_dpb_size == 0) {
DVLOG(1) << "Invalid DPB Size";
return false;
}
dpb_.set_max_num_pics(max_dpb_size);
if (!UpdateMaxNumReorderFrames(sps))
return false;
DVLOG(1) << "max_num_reorder_frames: " << max_num_reorder_frames_;
*need_new_buffers = true;
return true;
}
bool H264Decoder::FinishPrevFrameIfPresent() {
// If we already have a frame waiting to be decoded, decode it and finish.
if (curr_pic_) {
if (!DecodePicture())
return false;
scoped_refptr<H264Picture> pic = curr_pic_;
curr_pic_ = nullptr;
return FinishPicture(pic);
}
return true;
}
bool H264Decoder::HandleFrameNumGap(int frame_num) {
const H264SPS* sps = parser_.GetSPS(curr_sps_id_);
if (!sps)
return false;
if (!sps->gaps_in_frame_num_value_allowed_flag) {
DVLOG(1) << "Invalid frame_num: " << frame_num;
return false;
}
DVLOG(2) << "Handling frame_num gap: " << prev_ref_frame_num_ << "->"
<< frame_num;
// 7.4.3/7-23
int unused_short_term_frame_num = (prev_ref_frame_num_ + 1) % max_frame_num_;
while (unused_short_term_frame_num != frame_num) {
scoped_refptr<H264Picture> pic = new H264Picture();
if (!InitNonexistingPicture(pic, unused_short_term_frame_num))
return false;
UpdatePicNums(unused_short_term_frame_num);
if (!FinishPicture(pic))
return false;
unused_short_term_frame_num++;
unused_short_term_frame_num %= max_frame_num_;
}
return true;
}
bool H264Decoder::IsNewPrimaryCodedPicture(
const H264SliceHeader* slice_hdr) const {
if (!curr_pic_)
return true;
// 7.4.1.2.4, assumes non-interlaced.
if (slice_hdr->frame_num != curr_pic_->frame_num ||
slice_hdr->pic_parameter_set_id != curr_pps_id_ ||
slice_hdr->nal_ref_idc != curr_pic_->nal_ref_idc ||
slice_hdr->idr_pic_flag != curr_pic_->idr ||
(slice_hdr->idr_pic_flag &&
(slice_hdr->idr_pic_id != curr_pic_->idr_pic_id ||
// If we have two consecutive IDR slices, and the second one has
// first_mb_in_slice == 0, treat it as a new picture.
// Per spec, idr_pic_id should not be equal in this case (and we should
// have hit the condition above instead, see spec 7.4.3 on idr_pic_id),
// but some encoders neglect changing idr_pic_id for two consecutive
// IDRs. Work around this by checking if the next slice contains the
// zeroth macroblock, i.e. data that belongs to the next picture.
slice_hdr->first_mb_in_slice == 0)))
return true;
const H264SPS* sps = parser_.GetSPS(curr_sps_id_);
if (!sps)
return false;
if (sps->pic_order_cnt_type == curr_pic_->pic_order_cnt_type) {
if (curr_pic_->pic_order_cnt_type == 0) {
if (slice_hdr->pic_order_cnt_lsb != curr_pic_->pic_order_cnt_lsb ||
slice_hdr->delta_pic_order_cnt_bottom !=
curr_pic_->delta_pic_order_cnt_bottom)
return true;
} else if (curr_pic_->pic_order_cnt_type == 1) {
if (slice_hdr->delta_pic_order_cnt0 != curr_pic_->delta_pic_order_cnt0 ||
slice_hdr->delta_pic_order_cnt1 != curr_pic_->delta_pic_order_cnt1)
return true;
}
}
return false;
}
bool H264Decoder::PreprocessCurrentSlice() {
const H264SliceHeader* slice_hdr = curr_slice_hdr_.get();
DCHECK(slice_hdr);
if (IsNewPrimaryCodedPicture(slice_hdr)) {
// New picture, so first finish the previous one before processing it.
if (!FinishPrevFrameIfPresent())
return false;
DCHECK(!curr_pic_);
if (slice_hdr->first_mb_in_slice != 0) {
DVLOG(1) << "ASO/invalid stream, first_mb_in_slice: "
<< slice_hdr->first_mb_in_slice;
return false;
}
// If the new picture is an IDR, flush DPB.
if (slice_hdr->idr_pic_flag) {
// Output all remaining pictures, unless we are explicitly instructed
// not to do so.
if (!slice_hdr->no_output_of_prior_pics_flag) {
if (!Flush())
return false;
}
dpb_.Clear();
last_output_poc_ = std::numeric_limits<int>::min();
}
}
return true;
}
bool H264Decoder::ProcessCurrentSlice() {
DCHECK(curr_pic_);
const H264SliceHeader* slice_hdr = curr_slice_hdr_.get();
DCHECK(slice_hdr);
if (slice_hdr->field_pic_flag == 0)
max_pic_num_ = max_frame_num_;
else
max_pic_num_ = 2 * max_frame_num_;
H264Picture::Vector ref_pic_list0, ref_pic_list1;
if (!ModifyReferencePicLists(slice_hdr, &ref_pic_list0, &ref_pic_list1))
return false;
const H264PPS* pps = parser_.GetPPS(curr_pps_id_);
if (!pps)
return false;
if (!accelerator_->SubmitSlice(pps, slice_hdr, ref_pic_list0, ref_pic_list1,
curr_pic_.get(), slice_hdr->nalu_data,
slice_hdr->nalu_size))
return false;
return true;
}
#define SET_ERROR_AND_RETURN() \
do { \
DVLOG(1) << "Error during decode"; \
state_ = kError; \
return H264Decoder::kDecodeError; \
} while (0)
void H264Decoder::SetStream(const uint8_t* ptr, size_t size) {
DCHECK(ptr);
DCHECK(size);
DVLOG(4) << "New input stream at: " << (void*)ptr << " size: " << size;
parser_.SetStream(ptr, size);
}
H264Decoder::DecodeResult H264Decoder::Decode() {
if (state_ == kError) {
DVLOG(1) << "Decoder in error state";
return kDecodeError;
}
while (1) {
H264Parser::Result par_res;
if (!curr_nalu_) {
curr_nalu_.reset(new H264NALU());
par_res = parser_.AdvanceToNextNALU(curr_nalu_.get());
if (par_res == H264Parser::kEOStream)
return kRanOutOfStreamData;
else if (par_res != H264Parser::kOk)
SET_ERROR_AND_RETURN();
DVLOG(4) << "New NALU: " << static_cast<int>(curr_nalu_->nal_unit_type);
}
switch (curr_nalu_->nal_unit_type) {
case H264NALU::kNonIDRSlice:
// We can't resume from a non-IDR slice.
if (state_ != kDecoding)
break;
// else fallthrough
case H264NALU::kIDRSlice: {
// TODO(posciak): the IDR may require an SPS that we don't have
// available. For now we'd fail if that happens, but ideally we'd like
// to keep going until the next SPS in the stream.
if (state_ == kNeedStreamMetadata) {
// We need an SPS, skip this IDR and keep looking.
break;
}
// If after reset, we should be able to recover from an IDR.
state_ = kDecoding;
if (!curr_slice_hdr_) {
curr_slice_hdr_.reset(new H264SliceHeader());
par_res =
parser_.ParseSliceHeader(*curr_nalu_, curr_slice_hdr_.get());
if (par_res != H264Parser::kOk)
SET_ERROR_AND_RETURN();
if (!PreprocessCurrentSlice())
SET_ERROR_AND_RETURN();
}
if (!curr_pic_) {
// New picture/finished previous one, try to start a new one
// or tell the client we need more surfaces.
curr_pic_ = accelerator_->CreateH264Picture();
if (!curr_pic_)
return kRanOutOfSurfaces;
if (!StartNewFrame(curr_slice_hdr_.get()))
SET_ERROR_AND_RETURN();
}
if (!ProcessCurrentSlice())
SET_ERROR_AND_RETURN();
curr_slice_hdr_.reset();
break;
}
case H264NALU::kSPS: {
int sps_id;
if (!FinishPrevFrameIfPresent())
SET_ERROR_AND_RETURN();
par_res = parser_.ParseSPS(&sps_id);
if (par_res != H264Parser::kOk)
SET_ERROR_AND_RETURN();
bool need_new_buffers = false;
if (!ProcessSPS(sps_id, &need_new_buffers))
SET_ERROR_AND_RETURN();
if (state_ == kNeedStreamMetadata)
state_ = kAfterReset;
if (need_new_buffers) {
if (!Flush())
return kDecodeError;
curr_pic_ = nullptr;
curr_nalu_ = nullptr;
ref_pic_list_p0_.clear();
ref_pic_list_b0_.clear();
ref_pic_list_b1_.clear();
return kAllocateNewSurfaces;
}
break;
}
case H264NALU::kPPS: {
int pps_id;
if (!FinishPrevFrameIfPresent())
SET_ERROR_AND_RETURN();
par_res = parser_.ParsePPS(&pps_id);
if (par_res != H264Parser::kOk)
SET_ERROR_AND_RETURN();
break;
}
case H264NALU::kAUD:
case H264NALU::kEOSeq:
case H264NALU::kEOStream:
if (state_ != kDecoding)
break;
if (!FinishPrevFrameIfPresent())
SET_ERROR_AND_RETURN();
break;
default:
DVLOG(4) << "Skipping NALU type: " << curr_nalu_->nal_unit_type;
break;
}
DVLOG(4) << "NALU done";
curr_nalu_.reset();
}
}
gfx::Size H264Decoder::GetPicSize() const {
return pic_size_;
}
size_t H264Decoder::GetRequiredNumOfPictures() const {
return dpb_.max_num_pics() + kPicsInPipeline;
}
} // namespace media