tor-browser

The Tor Browser
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stream_generator.cc (4077B)

      1 /*
      2 *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
      3 *
      4 *  Use of this source code is governed by a BSD-style license
      5 *  that can be found in the LICENSE file in the root of the source
      6 *  tree. An additional intellectual property rights grant can be found
      7 *  in the file PATENTS.  All contributing project authors may
      8 *  be found in the AUTHORS file in the root of the source tree.
      9 */
     10 
     11 #include "modules/video_coding/deprecated/stream_generator.h"
     12 
     13 #include <cstdint>
     14 #include <cstring>
     15 #include <list>
     16 
     17 #include "api/video/video_frame_type.h"
     18 #include "modules/video_coding/deprecated/packet.h"
     19 #include "rtc_base/checks.h"
     20 
     21 namespace webrtc {
     22 
     23 StreamGenerator::StreamGenerator(uint16_t start_seq_num, int64_t current_time)
     24    : packets_(), sequence_number_(start_seq_num), start_time_(current_time) {}
     25 
     26 void StreamGenerator::Init(uint16_t start_seq_num, int64_t current_time) {
     27  packets_.clear();
     28  sequence_number_ = start_seq_num;
     29  start_time_ = current_time;
     30  memset(packet_buffer_, 0, sizeof(packet_buffer_));
     31 }
     32 
     33 void StreamGenerator::GenerateFrame(VideoFrameType type,
     34                                    int num_media_packets,
     35                                    int num_empty_packets,
     36                                    int64_t time_ms) {
     37  uint32_t timestamp = 90 * (time_ms - start_time_);
     38  for (int i = 0; i < num_media_packets; ++i) {
     39    const int packet_size =
     40        (kFrameSize + num_media_packets / 2) / num_media_packets;
     41    bool marker_bit = (i == num_media_packets - 1);
     42    packets_.push_back(GeneratePacket(sequence_number_, timestamp, packet_size,
     43                                      (i == 0), marker_bit, type));
     44    ++sequence_number_;
     45  }
     46  for (int i = 0; i < num_empty_packets; ++i) {
     47    packets_.push_back(GeneratePacket(sequence_number_, timestamp, 0, false,
     48                                      false, VideoFrameType::kEmptyFrame));
     49    ++sequence_number_;
     50  }
     51 }
     52 
     53 VCMPacket StreamGenerator::GeneratePacket(uint16_t sequence_number,
     54                                          uint32_t timestamp,
     55                                          unsigned int size,
     56                                          bool first_packet,
     57                                          bool marker_bit,
     58                                          VideoFrameType type) {
     59  RTC_CHECK_LT(size, kMaxPacketSize);
     60  VCMPacket packet;
     61  packet.seqNum = sequence_number;
     62  packet.timestamp = timestamp;
     63  packet.video_header.frame_type = type;
     64  packet.video_header.is_first_packet_in_frame = first_packet;
     65  packet.markerBit = marker_bit;
     66  packet.sizeBytes = size;
     67  packet.dataPtr = packet_buffer_;
     68  if (packet.is_first_packet_in_frame())
     69    packet.completeNALU = kNaluStart;
     70  else if (packet.markerBit)
     71    packet.completeNALU = kNaluEnd;
     72  else
     73    packet.completeNALU = kNaluIncomplete;
     74  return packet;
     75 }
     76 
     77 bool StreamGenerator::PopPacket(VCMPacket* packet, int index) {
     78  std::list<VCMPacket>::iterator it = GetPacketIterator(index);
     79  if (it == packets_.end())
     80    return false;
     81  if (packet)
     82    *packet = (*it);
     83  packets_.erase(it);
     84  return true;
     85 }
     86 
     87 bool StreamGenerator::GetPacket(VCMPacket* packet, int index) {
     88  std::list<VCMPacket>::iterator it = GetPacketIterator(index);
     89  if (it == packets_.end())
     90    return false;
     91  if (packet)
     92    *packet = (*it);
     93  return true;
     94 }
     95 
     96 bool StreamGenerator::NextPacket(VCMPacket* packet) {
     97  if (packets_.empty())
     98    return false;
     99  if (packet != nullptr)
    100    *packet = packets_.front();
    101  packets_.pop_front();
    102  return true;
    103 }
    104 
    105 void StreamGenerator::DropLastPacket() {
    106  packets_.pop_back();
    107 }
    108 
    109 uint16_t StreamGenerator::NextSequenceNumber() const {
    110  if (packets_.empty())
    111    return sequence_number_;
    112  return packets_.front().seqNum;
    113 }
    114 
    115 int StreamGenerator::PacketsRemaining() const {
    116  return packets_.size();
    117 }
    118 
    119 std::list<VCMPacket>::iterator StreamGenerator::GetPacketIterator(int index) {
    120  std::list<VCMPacket>::iterator it = packets_.begin();
    121  for (int i = 0; i < index; ++i) {
    122    ++it;
    123    if (it == packets_.end())
    124      break;
    125  }
    126  return it;
    127 }
    128 
    129 }  // namespace webrtc