1 /*
2 * Copyright (c) 2014 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/modules/audio_coding/neteq/tools/constant_pcm_packet_source.h"
12
13 #include <algorithm>
14
15 #include "webrtc/base/checks.h"
16 #include "webrtc/modules/audio_coding/codecs/pcm16b/pcm16b.h"
17 #include "webrtc/modules/audio_coding/neteq/tools/packet.h"
18
19 namespace webrtc {
20 namespace test {
21
ConstantPcmPacketSource(size_t payload_len_samples,int16_t sample_value,int sample_rate_hz,int payload_type)22 ConstantPcmPacketSource::ConstantPcmPacketSource(size_t payload_len_samples,
23 int16_t sample_value,
24 int sample_rate_hz,
25 int payload_type)
26 : payload_len_samples_(payload_len_samples),
27 packet_len_bytes_(2 * payload_len_samples_ + kHeaderLenBytes),
28 samples_per_ms_(sample_rate_hz / 1000),
29 next_arrival_time_ms_(0.0),
30 payload_type_(payload_type),
31 seq_number_(0),
32 timestamp_(0),
33 payload_ssrc_(0xABCD1234) {
34 size_t encoded_len = WebRtcPcm16b_Encode(&sample_value, 1, encoded_sample_);
35 RTC_CHECK_EQ(2U, encoded_len);
36 }
37
NextPacket()38 Packet* ConstantPcmPacketSource::NextPacket() {
39 RTC_CHECK_GT(packet_len_bytes_, kHeaderLenBytes);
40 uint8_t* packet_memory = new uint8_t[packet_len_bytes_];
41 // Fill the payload part of the packet memory with the pre-encoded value.
42 for (unsigned i = 0; i < 2 * payload_len_samples_; ++i)
43 packet_memory[kHeaderLenBytes + i] = encoded_sample_[i % 2];
44 WriteHeader(packet_memory);
45 // |packet| assumes ownership of |packet_memory|.
46 Packet* packet =
47 new Packet(packet_memory, packet_len_bytes_, next_arrival_time_ms_);
48 next_arrival_time_ms_ += payload_len_samples_ / samples_per_ms_;
49 return packet;
50 }
51
WriteHeader(uint8_t * packet_memory)52 void ConstantPcmPacketSource::WriteHeader(uint8_t* packet_memory) {
53 packet_memory[0] = 0x80;
54 packet_memory[1] = static_cast<uint8_t>(payload_type_);
55 packet_memory[2] = seq_number_ >> 8;
56 packet_memory[3] = seq_number_ & 0xFF;
57 packet_memory[4] = timestamp_ >> 24;
58 packet_memory[5] = (timestamp_ >> 16) & 0xFF;
59 packet_memory[6] = (timestamp_ >> 8) & 0xFF;
60 packet_memory[7] = timestamp_ & 0xFF;
61 packet_memory[8] = payload_ssrc_ >> 24;
62 packet_memory[9] = (payload_ssrc_ >> 16) & 0xFF;
63 packet_memory[10] = (payload_ssrc_ >> 8) & 0xFF;
64 packet_memory[11] = payload_ssrc_ & 0xFF;
65 ++seq_number_;
66 timestamp_ += static_cast<uint32_t>(payload_len_samples_);
67 }
68
69 } // namespace test
70 } // namespace webrtc
71