tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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rtp_descriptor_authentication.cc (2301B)

      1 /*
      2 *  Copyright (c) 2020 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/rtp_rtcp/source/rtp_descriptor_authentication.h"
     12 
     13 #include <cstdint>
     14 #include <vector>
     15 
     16 #include "modules/rtp_rtcp/source/rtp_generic_frame_descriptor.h"
     17 #include "modules/rtp_rtcp/source/rtp_generic_frame_descriptor_extension.h"
     18 #include "modules/rtp_rtcp/source/rtp_video_header.h"
     19 
     20 namespace webrtc {
     21 
     22 std::vector<uint8_t> RtpDescriptorAuthentication(
     23    const RTPVideoHeader& rtp_video_header) {
     24  if (!rtp_video_header.generic) {
     25    return {};
     26  }
     27  const RTPVideoHeader::GenericDescriptorInfo& descriptor =
     28      *rtp_video_header.generic;
     29  // Default way of creating additional data for an encrypted frame.
     30  if (descriptor.spatial_index < 0 || descriptor.temporal_index < 0 ||
     31      descriptor.spatial_index >=
     32          RtpGenericFrameDescriptor::kMaxSpatialLayers ||
     33      descriptor.temporal_index >=
     34          RtpGenericFrameDescriptor::kMaxTemporalLayers ||
     35      descriptor.dependencies.size() >
     36          RtpGenericFrameDescriptor::kMaxNumFrameDependencies) {
     37    return {};
     38  }
     39  RtpGenericFrameDescriptor frame_descriptor;
     40  frame_descriptor.SetFirstPacketInSubFrame(true);
     41  frame_descriptor.SetLastPacketInSubFrame(false);
     42  frame_descriptor.SetTemporalLayer(descriptor.temporal_index);
     43  frame_descriptor.SetSpatialLayersBitmask(1 << descriptor.spatial_index);
     44  frame_descriptor.SetFrameId(descriptor.frame_id & 0xFFFF);
     45  for (int64_t dependency : descriptor.dependencies) {
     46    frame_descriptor.AddFrameDependencyDiff(descriptor.frame_id - dependency);
     47  }
     48  if (descriptor.dependencies.empty()) {
     49    frame_descriptor.SetResolution(rtp_video_header.width,
     50                                   rtp_video_header.height);
     51  }
     52  std::vector<uint8_t> result(
     53      RtpGenericFrameDescriptorExtension00::ValueSize(frame_descriptor));
     54  RtpGenericFrameDescriptorExtension00::Write(result, frame_descriptor);
     55  return result;
     56 }
     57 
     58 }  // namespace webrtc