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/*
* Copyright (c) 2023 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "common_video/h265/h265_pps_parser.h"
#include <memory>
#include <optional>
#include <vector>
#include "common_video/h265/h265_common.h"
#include "rtc_base/bit_buffer.h"
#include "rtc_base/bitstream_reader.h"
#include "rtc_base/logging.h"
#define IN_RANGE_OR_RETURN_NULL(val, min, max) \
do { \
if (!reader.Ok() || (val) < (min) || (val) > (max)) { \
RTC_LOG(LS_WARNING) << "Error in stream: invalid value, expected " #val \
" to be" \
<< " in range [" << (min) << ":" << (max) << "]" \
<< " found " << (val) << " instead"; \
return std::nullopt; \
} \
} while (0)
#define IN_RANGE_OR_RETURN_FALSE(val, min, max) \
do { \
if (!reader.Ok() || (val) < (min) || (val) > (max)) { \
RTC_LOG(LS_WARNING) << "Error in stream: invalid value, expected " #val \
" to be" \
<< " in range [" << (min) << ":" << (max) << "]" \
<< " found " << (val) << " instead"; \
return false; \
} \
} while (0)
#define TRUE_OR_RETURN(a) \
do { \
if (!reader.Ok() || !(a)) { \
RTC_LOG(LS_WARNING) << "Error in stream: invalid value, expected " \
<< #a; \
return std::nullopt; \
} \
} while (0)
namespace {
constexpr int kMaxNumTileColumnWidth = 19;
constexpr int kMaxNumTileRowHeight = 21;
constexpr int kMaxRefIdxActive = 15;
} // namespace
namespace webrtc {
// General note: this is based off the 08/2021 version of the H.265 standard.
// You can find it on this page:
std::optional<H265PpsParser::PpsState> H265PpsParser::ParsePps(
rtc::ArrayView<const uint8_t> data,
const H265SpsParser::SpsState* sps) {
// First, parse out rbsp, which is basically the source buffer minus emulation
// bytes (the last byte of a 0x00 0x00 0x03 sequence). RBSP is defined in
// section 7.3.1.1 of the H.265 standard.
return ParseInternal(H265::ParseRbsp(data), sps);
}
bool H265PpsParser::ParsePpsIds(rtc::ArrayView<const uint8_t> data,
uint32_t* pps_id,
uint32_t* sps_id) {
RTC_DCHECK(pps_id);
RTC_DCHECK(sps_id);
// First, parse out rbsp, which is basically the source buffer minus emulation
// bytes (the last byte of a 0x00 0x00 0x03 sequence). RBSP is defined in
// section 7.3.1.1 of the H.265 standard.
std::vector<uint8_t> unpacked_buffer = H265::ParseRbsp(data);
BitstreamReader reader(unpacked_buffer);
*pps_id = reader.ReadExponentialGolomb();
IN_RANGE_OR_RETURN_FALSE(*pps_id, 0, 63);
*sps_id = reader.ReadExponentialGolomb();
IN_RANGE_OR_RETURN_FALSE(*sps_id, 0, 15);
return reader.Ok();
}
std::optional<H265PpsParser::PpsState> H265PpsParser::ParseInternal(
rtc::ArrayView<const uint8_t> buffer,
const H265SpsParser::SpsState* sps) {
BitstreamReader reader(buffer);
PpsState pps;
if (!sps) {
return std::nullopt;
}
if (!ParsePpsIdsInternal(reader, pps.pps_id, pps.sps_id)) {
return std::nullopt;
}
// dependent_slice_segments_enabled_flag: u(1)
pps.dependent_slice_segments_enabled_flag = reader.Read<bool>();
// output_flag_present_flag: u(1)
pps.output_flag_present_flag = reader.Read<bool>();
// num_extra_slice_header_bits: u(3)
pps.num_extra_slice_header_bits = reader.ReadBits(3);
IN_RANGE_OR_RETURN_NULL(pps.num_extra_slice_header_bits, 0, 2);
// sign_data_hiding_enabled_flag: u(1)
reader.ConsumeBits(1);
// cabac_init_present_flag: u(1)
pps.cabac_init_present_flag = reader.Read<bool>();
// num_ref_idx_l0_default_active_minus1: ue(v)
pps.num_ref_idx_l0_default_active_minus1 = reader.ReadExponentialGolomb();
IN_RANGE_OR_RETURN_NULL(pps.num_ref_idx_l0_default_active_minus1, 0,
kMaxRefIdxActive - 1);
// num_ref_idx_l1_default_active_minus1: ue(v)
pps.num_ref_idx_l1_default_active_minus1 = reader.ReadExponentialGolomb();
IN_RANGE_OR_RETURN_NULL(pps.num_ref_idx_l1_default_active_minus1, 0,
kMaxRefIdxActive - 1);
// init_qp_minus26: se(v)
pps.init_qp_minus26 = reader.ReadSignedExponentialGolomb();
pps.qp_bd_offset_y = 6 * sps->bit_depth_luma_minus8;
// Sanity-check parsed value
IN_RANGE_OR_RETURN_NULL(pps.init_qp_minus26, -(26 + pps.qp_bd_offset_y), 25);
// constrained_intra_pred_flag: u(1)log2_min_pcm_luma_coding_block_size_minus3
reader.ConsumeBits(1);
// transform_skip_enabled_flag: u(1)
reader.ConsumeBits(1);
// cu_qp_delta_enabled_flag: u(1)
bool cu_qp_delta_enabled_flag = reader.Read<bool>();
if (cu_qp_delta_enabled_flag) {
// diff_cu_qp_delta_depth: ue(v)
uint32_t diff_cu_qp_delta_depth = reader.ReadExponentialGolomb();
IN_RANGE_OR_RETURN_NULL(diff_cu_qp_delta_depth, 0,
sps->log2_diff_max_min_luma_coding_block_size);
}
// pps_cb_qp_offset: se(v)
int32_t pps_cb_qp_offset = reader.ReadSignedExponentialGolomb();
IN_RANGE_OR_RETURN_NULL(pps_cb_qp_offset, -12, 12);
// pps_cr_qp_offset: se(v)
int32_t pps_cr_qp_offset = reader.ReadSignedExponentialGolomb();
IN_RANGE_OR_RETURN_NULL(pps_cr_qp_offset, -12, 12);
// pps_slice_chroma_qp_offsets_present_flag: u(1)
reader.ConsumeBits(1);
// weighted_pred_flag: u(1)
pps.weighted_pred_flag = reader.Read<bool>();
// weighted_bipred_flag: u(1)
pps.weighted_bipred_flag = reader.Read<bool>();
// transquant_bypass_enabled_flag: u(1)
reader.ConsumeBits(1);
// tiles_enabled_flag: u(1)
bool tiles_enabled_flag = reader.Read<bool>();
// entropy_coding_sync_enabled_flag: u(1)
reader.ConsumeBits(1);
if (tiles_enabled_flag) {
// num_tile_columns_minus1: ue(v)
uint32_t num_tile_columns_minus1 = reader.ReadExponentialGolomb();
IN_RANGE_OR_RETURN_NULL(num_tile_columns_minus1, 0,
sps->pic_width_in_ctbs_y - 1);
TRUE_OR_RETURN(num_tile_columns_minus1 < kMaxNumTileColumnWidth);
// num_tile_rows_minus1: ue(v)
uint32_t num_tile_rows_minus1 = reader.ReadExponentialGolomb();
IN_RANGE_OR_RETURN_NULL(num_tile_rows_minus1, 0,
sps->pic_height_in_ctbs_y - 1);
TRUE_OR_RETURN((num_tile_columns_minus1 != 0) ||
(num_tile_rows_minus1 != 0));
TRUE_OR_RETURN(num_tile_rows_minus1 < kMaxNumTileRowHeight);
// uniform_spacing_flag: u(1)
bool uniform_spacing_flag = reader.Read<bool>();
if (!uniform_spacing_flag) {
int column_width_minus1[kMaxNumTileColumnWidth];
column_width_minus1[num_tile_columns_minus1] =
sps->pic_width_in_ctbs_y - 1;
for (uint32_t i = 0; i < num_tile_columns_minus1; i++) {
// column_width_minus1: ue(v)
column_width_minus1[i] = reader.ReadExponentialGolomb();
IN_RANGE_OR_RETURN_NULL(
column_width_minus1[i], 0,
column_width_minus1[num_tile_columns_minus1] - 1);
column_width_minus1[num_tile_columns_minus1] -=
column_width_minus1[i] + 1;
}
int row_height_minus1[kMaxNumTileRowHeight];
row_height_minus1[num_tile_rows_minus1] = sps->pic_height_in_ctbs_y - 1;
for (uint32_t i = 0; i < num_tile_rows_minus1; i++) {
// row_height_minus1: ue(v)
row_height_minus1[i] = reader.ReadExponentialGolomb();
IN_RANGE_OR_RETURN_NULL(row_height_minus1[i], 0,
row_height_minus1[num_tile_rows_minus1] - 1);
row_height_minus1[num_tile_rows_minus1] -= row_height_minus1[i] + 1;
}
// loop_filter_across_tiles_enabled_flag: u(1)
reader.ConsumeBits(1);
}
}
// pps_loop_filter_across_slices_enabled_flag: u(1)
reader.ConsumeBits(1);
// deblocking_filter_control_present_flag: u(1)
bool deblocking_filter_control_present_flag = reader.Read<bool>();
if (deblocking_filter_control_present_flag) {
// deblocking_filter_override_enabled_flag: u(1)
reader.ConsumeBits(1);
// pps_deblocking_filter_disabled_flag: u(1)
bool pps_deblocking_filter_disabled_flag = reader.Read<bool>();
if (!pps_deblocking_filter_disabled_flag) {
// pps_beta_offset_div2: se(v)
int pps_beta_offset_div2 = reader.ReadSignedExponentialGolomb();
IN_RANGE_OR_RETURN_NULL(pps_beta_offset_div2, -6, 6);
// pps_tc_offset_div2: se(v)
int pps_tc_offset_div2 = reader.ReadSignedExponentialGolomb();
IN_RANGE_OR_RETURN_NULL(pps_tc_offset_div2, -6, 6);
}
}
// pps_scaling_list_data_present_flag: u(1)
bool pps_scaling_list_data_present_flag = 0;
pps_scaling_list_data_present_flag = reader.Read<bool>();
if (pps_scaling_list_data_present_flag) {
// scaling_list_data()
if (!H265SpsParser::ParseScalingListData(reader)) {
return std::nullopt;
}
}
// lists_modification_present_flag: u(1)
pps.lists_modification_present_flag = reader.Read<bool>();
if (!reader.Ok()) {
return std::nullopt;
}
return pps;
}
bool H265PpsParser::ParsePpsIdsInternal(BitstreamReader& reader,
uint32_t& pps_id,
uint32_t& sps_id) {
// pic_parameter_set_id: ue(v)
pps_id = reader.ReadExponentialGolomb();
IN_RANGE_OR_RETURN_FALSE(pps_id, 0, 63);
// seq_parameter_set_id: ue(v)
sps_id = reader.ReadExponentialGolomb();
IN_RANGE_OR_RETURN_FALSE(sps_id, 0, 15);
return true;
}
} // namespace webrtc