sprang 52033d6ea1 Add H264 bitstream rewriting to limit frame reordering marker in header
The VUI part an SPS may specify max_num_reorder_frames and
max_dec_frame_buffering. These may cause a decoder to buffer a number
of frame prior allowing decode, leading to delays, even if no frames
using such references (ie B-frames) are sent.

Because of this we update any SPS block emitted by the encoder.

Also, a bunch of refactoring of H264-related code to reduce code
duplication.

BUG=

Review-Url: https://codereview.webrtc.org/1979443004
Cr-Commit-Position: refs/heads/master@{#13010}
2016-06-02 09:43:38 +00:00

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1.5 KiB
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/*
* 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.
*/
#ifndef WEBRTC_COMMON_VIDEO_H264_PPS_PARSER_H_
#define WEBRTC_COMMON_VIDEO_H264_PPS_PARSER_H_
#include "webrtc/base/common.h"
#include "webrtc/base/optional.h"
namespace rtc {
class BitBuffer;
}
namespace webrtc {
// A class for parsing out picture parameter set (PPS) data from a H264 NALU.
class PpsParser {
public:
// 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;
uint32_t weighted_bipred_idc = false;
uint32_t redundant_pic_cnt_present_flag = 0;
int pic_init_qp_minus26 = 0;
};
// Unpack RBSP and parse PPS state from the supplied buffer.
static rtc::Optional<PpsState> ParsePps(const uint8_t* data, size_t length);
protected:
// Parse the PPS state, for a bit buffer where RBSP decoding has already been
// performed.
static rtc::Optional<PpsState> ParseInternal(rtc::BitBuffer* bit_buffer);
};
} // namespace webrtc
#endif // WEBRTC_COMMON_VIDEO_H264_PPS_PARSER_H_