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 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 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 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
