blob: d6c31b06887782f41c4bc09f736abf6fb35802ee [file] [log] [blame]
* Copyright (c) 2016 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 "absl/types/optional.h"
namespace rtc {
class BitBuffer;
namespace webrtc {
// A class for parsing out picture parameter set (PPS) data from a H264 NALU.
class PpsParser {
// The parsed state of the PPS. Only some select values are stored.
// Add more as they are actually needed.
struct PpsState {
PpsState() = default;
bool bottom_field_pic_order_in_frame_present_flag = false;
bool weighted_pred_flag = false;
bool entropy_coding_mode_flag = false;
uint32_t weighted_bipred_idc = false;
uint32_t redundant_pic_cnt_present_flag = 0;
int pic_init_qp_minus26 = 0;
uint32_t id = 0;
uint32_t sps_id = 0;
// Unpack RBSP and parse PPS state from the supplied buffer.
static absl::optional<PpsState> ParsePps(const uint8_t* data, size_t length);
static bool ParsePpsIds(const uint8_t* data,
size_t length,
uint32_t* pps_id,
uint32_t* sps_id);
static absl::optional<uint32_t> ParsePpsIdFromSlice(const uint8_t* data,
size_t length);
// Parse the PPS state, for a bit buffer where RBSP decoding has already been
// performed.
static absl::optional<PpsState> ParseInternal(rtc::BitBuffer* bit_buffer);
static bool ParsePpsIdsInternal(rtc::BitBuffer* bit_buffer,
uint32_t* pps_id,
uint32_t* sps_id);
} // namespace webrtc