blob: d04d9a0f1c8dc83cea98d926baa0c882a3f39a82 [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 "webrtc/base/common.h"
#include "webrtc/base/optional.h"
namespace rtc {
class BitBuffer;
namespace webrtc {
// A class for parsing out sequence parameter set (SPS) data from an H264 NALU.
class SpsParser {
// The parsed state of the SPS. Only some select values are stored.
// Add more as they are actually needed.
struct SpsState {
SpsState() = default;
uint32_t width = 0;
uint32_t height = 0;
uint32_t delta_pic_order_always_zero_flag = 0;
uint32_t separate_colour_plane_flag = 0;
uint32_t frame_mbs_only_flag = 0;
uint32_t log2_max_frame_num_minus4 = 0;
uint32_t log2_max_pic_order_cnt_lsb_minus4 = 0;
uint32_t pic_order_cnt_type = 0;
uint32_t max_num_ref_frames = 0;
uint32_t vui_params_present = 0;
// Unpack RBSP and parse SPS state from the supplied buffer.
static rtc::Optional<SpsState> ParseSps(const uint8_t* data, size_t length);
// Parse the SPS state, up till the VUI part, for a bit buffer where RBSP
// decoding has already been performed.
static rtc::Optional<SpsState> ParseSpsUpToVui(rtc::BitBuffer* buffer);
} // namespace webrtc