layer_filtering_transport.cc revision ff761fba8274d93bd73e76c8b8a1f2d0776dd840 
1/*
2 *  Copyright (c) 2015 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 "webrtc/base/checks.h"
12#include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
13#include "webrtc/modules/rtp_rtcp/source/byte_io.h"
14#include "webrtc/modules/rtp_rtcp/source/rtp_format.h"
15#include "webrtc/modules/rtp_rtcp/source/rtp_utility.h"
16#include "webrtc/test/layer_filtering_transport.h"
17
18namespace webrtc {
19namespace test {
20
21LayerFilteringTransport::LayerFilteringTransport(
22    const FakeNetworkPipe::Config& config,
23    Call* send_call,
24    uint8_t vp8_video_payload_type,
25    uint8_t vp9_video_payload_type,
26    int selected_tl,
27    int selected_sl)
28    : test::DirectTransport(config, send_call),
29      vp8_video_payload_type_(vp8_video_payload_type),
30      vp9_video_payload_type_(vp9_video_payload_type),
31      selected_tl_(selected_tl),
32      selected_sl_(selected_sl),
33      discarded_last_packet_(false) {}
34
35bool LayerFilteringTransport::DiscardedLastPacket() const {
36  return discarded_last_packet_;
37}
38
39bool LayerFilteringTransport::SendRtp(const uint8_t* packet,
40                                      size_t length,
41                                      const PacketOptions& options) {
42  if (selected_tl_ == -1 && selected_sl_ == -1) {
43    // Nothing to change, forward the packet immediately.
44    return test::DirectTransport::SendRtp(packet, length, options);
45  }
46
47  bool set_marker_bit = false;
48  RtpUtility::RtpHeaderParser parser(packet, length);
49  RTPHeader header;
50  parser.Parse(header);
51
52  RTC_DCHECK_LE(length, static_cast<size_t>(IP_PACKET_SIZE));
53  uint8_t temp_buffer[IP_PACKET_SIZE];
54  memcpy(temp_buffer, packet, length);
55
56  if (header.payloadType == vp8_video_payload_type_ ||
57      header.payloadType == vp9_video_payload_type_) {
58    const uint8_t* payload = packet + header.headerLength;
59    RTC_DCHECK_GT(length, header.headerLength);
60    const size_t payload_length = length - header.headerLength;
61    RTC_DCHECK_GT(payload_length, header.paddingLength);
62    const size_t payload_data_length = payload_length - header.paddingLength;
63
64    const bool is_vp8 = header.payloadType == vp8_video_payload_type_;
65    rtc::scoped_ptr<RtpDepacketizer> depacketizer(
66        RtpDepacketizer::Create(is_vp8 ? kRtpVideoVp8 : kRtpVideoVp9));
67    RtpDepacketizer::ParsedPayload parsed_payload;
68    if (depacketizer->Parse(&parsed_payload, payload, payload_data_length)) {
69      const int temporal_idx = static_cast<int>(
70          is_vp8 ? parsed_payload.type.Video.codecHeader.VP8.temporalIdx
71                 : parsed_payload.type.Video.codecHeader.VP9.temporal_idx);
72      const int spatial_idx = static_cast<int>(
73          is_vp8 ? kNoSpatialIdx
74                 : parsed_payload.type.Video.codecHeader.VP9.spatial_idx);
75      if (selected_sl_ >= 0 && spatial_idx == selected_sl_ &&
76          parsed_payload.type.Video.codecHeader.VP9.end_of_frame) {
77        // This layer is now the last in the superframe.
78        set_marker_bit = true;
79      } else if ((selected_tl_ >= 0 && temporal_idx != kNoTemporalIdx &&
80                  temporal_idx > selected_tl_) ||
81                 (selected_sl_ >= 0 && spatial_idx != kNoSpatialIdx &&
82                  spatial_idx > selected_sl_)) {
83        // Truncate packet to a padding packet.
84        length = header.headerLength + 1;
85        temp_buffer[0] |= (1 << 5);  // P = 1.
86        temp_buffer[1] &= 0x7F;      // M = 0.
87        discarded_last_packet_ = true;
88        temp_buffer[header.headerLength] = 1;  // One byte of padding.
89      }
90    } else {
91      RTC_NOTREACHED() << "Parse error";
92    }
93  }
94
95  // We are discarding some of the packets (specifically, whole layers), so
96  // make sure the marker bit is set properly, and that sequence numbers are
97  // continuous.
98  if (set_marker_bit)
99    temp_buffer[1] |= kRtpMarkerBitMask;
100
101  return test::DirectTransport::SendRtp(temp_buffer, length, options);
102}
103
104}  // namespace test
105}  // namespace webrtc
106