* be found in the AUTHORS file in the root of the source tree.
*/
+#include <math.h>
#include <stdio.h>
#include "webrtc/modules/audio_coding/neteq/tools/neteq_quality_test.h"
const uint8_t kPayloadType = 95;
const int kOutputSizeMs = 10;
+const int kInitSeed = 0x12345678;
+const int kPacketLossTimeUnitMs = 10;
+
+// Define switch for packet loss rate.
+static bool ValidatePacketLossRate(const char* /* flag_name */, int32_t value) {
+ if (value >= 0 && value <= 100)
+ return true;
+ printf("Invalid packet loss percentile, should be between 0 and 100.");
+ return false;
+}
+
+DEFINE_int32(packet_loss_rate, 10, "Percentile of packet loss.");
+
+static const bool packet_loss_rate_dummy =
+ RegisterFlagValidator(&FLAGS_packet_loss_rate, &ValidatePacketLossRate);
+
+// Define switch for random loss mode.
+static bool ValidateRandomLossMode(const char* /* flag_name */, int32_t value) {
+ if (value >= 0 && value <= 2)
+ return true;
+ printf("Invalid random packet loss mode, should be between 0 and 2.");
+ return false;
+}
+
+DEFINE_int32(random_loss_mode, 1,
+ "Random loss mode: 0--no loss, 1--uniform loss, 2--Gilbert Elliot loss.");
+static const bool random_loss_mode_dummy =
+ RegisterFlagValidator(&FLAGS_random_loss_mode, &ValidateRandomLossMode);
+
+// Define switch for burst length.
+static bool ValidateBurstLength(const char* /* flag_name */, int32_t value) {
+ if (value >= kPacketLossTimeUnitMs)
+ return true;
+ printf("Invalid burst length, should be greater than %d ms.",
+ kPacketLossTimeUnitMs);
+ return false;
+}
+
+DEFINE_int32(burst_length, 30,
+ "Burst length in milliseconds, only valid for Gilbert Elliot loss.");
+
+static const bool burst_length_dummy =
+ RegisterFlagValidator(&FLAGS_burst_length, &ValidateBurstLength);
+
+// Define switch for drift factor.
+static bool ValidateDriftFactor(const char* /* flag_name */, double value) {
+ if (value > -0.1)
+ return true;
+ printf("Invalid drift factor, should be greater than -0.1.");
+ return false;
+}
+
+DEFINE_double(drift_factor, 0.0, "Time drift factor.");
+
+static const bool drift_factor_dummy =
+ RegisterFlagValidator(&FLAGS_drift_factor, &ValidateDriftFactor);
+
+// ProbTrans00Solver() is to calculate the transition probability from no-loss
+// state to itself in a modified Gilbert Elliot packet loss model. The result is
+// to achieve the target packet loss rate |loss_rate|, when a packet is not
+// lost only if all |units| drawings within the duration of the packet result in
+// no-loss.
+static double ProbTrans00Solver(int units, double loss_rate,
+ double prob_trans_10) {
+ if (units == 1)
+ return prob_trans_10 / (1.0f - loss_rate) - prob_trans_10;
+// 0 == prob_trans_00 ^ (units - 1) + (1 - loss_rate) / prob_trans_10 *
+// prob_trans_00 - (1 - loss_rate) * (1 + 1 / prob_trans_10).
+// There is a unique solution between 0.0 and 1.0, due to the monotonicity and
+// an opposite sign at 0.0 and 1.0.
+// For simplicity, we reformulate the equation as
+// f(x) = x ^ (units - 1) + a x + b.
+// Its derivative is
+// f'(x) = (units - 1) x ^ (units - 2) + a.
+// The derivative is strictly greater than 0 when x is between 0 and 1.
+// We use Newton's method to solve the equation, iteration is
+// x(k+1) = x(k) - f(x) / f'(x);
+ const double kPrecision = 0.001f;
+ const int kIterations = 100;
+ const double a = (1.0f - loss_rate) / prob_trans_10;
+ const double b = (loss_rate - 1.0f) * (1.0f + 1.0f / prob_trans_10);
+ double x = 0.0f; // Starting point;
+ double f = b;
+ double f_p;
+ int iter = 0;
+ while ((f >= kPrecision || f <= -kPrecision) && iter < kIterations) {
+ f_p = (units - 1.0f) * pow(x, units - 2) + a;
+ x -= f / f_p;
+ if (x > 1.0f) {
+ x = 1.0f;
+ } else if (x < 0.0f) {
+ x = 0.0f;
+ }
+ f = pow(x, units - 1) + a * x + b;
+ iter ++;
+ }
+ return x;
+}
NetEqQualityTest::NetEqQualityTest(int block_duration_ms,
int in_sampling_khz,
int out_sampling_khz,
enum NetEqDecoder decoder_type,
int channels,
- double drift_factor,
std::string in_filename,
std::string out_filename)
: decoded_time_ms_(0),
decodable_time_ms_(0),
- drift_factor_(drift_factor),
+ drift_factor_(FLAGS_drift_factor),
+ packet_loss_rate_(FLAGS_packet_loss_rate),
block_duration_ms_(block_duration_ms),
in_sampling_khz_(in_sampling_khz),
out_sampling_khz_(out_sampling_khz),
channels_(channels),
in_filename_(in_filename),
out_filename_(out_filename),
+ log_filename_(out_filename + ".log"),
in_size_samples_(in_sampling_khz_ * block_duration_ms_),
out_size_samples_(out_sampling_khz_ * kOutputSizeMs),
payload_size_bytes_(0),
max_payload_bytes_(0),
in_file_(new InputAudioFile(in_filename_)),
out_file_(NULL),
+ log_file_(NULL),
rtp_generator_(new RtpGenerator(in_sampling_khz_, 0, 0,
- decodable_time_ms_)) {
+ decodable_time_ms_)),
+ total_payload_size_bytes_(0) {
NetEq::Config config;
config.sample_rate_hz = out_sampling_khz_ * 1000;
neteq_.reset(NetEq::Create(config));
out_data_.reset(new int16_t[out_size_samples_ * channels_]);
}
+bool NoLoss::Lost() {
+ return false;
+}
+
+UniformLoss::UniformLoss(double loss_rate)
+ : loss_rate_(loss_rate) {
+}
+
+bool UniformLoss::Lost() {
+ int drop_this = rand();
+ return (drop_this < loss_rate_ * RAND_MAX);
+}
+
+GilbertElliotLoss::GilbertElliotLoss(double prob_trans_11, double prob_trans_01)
+ : prob_trans_11_(prob_trans_11),
+ prob_trans_01_(prob_trans_01),
+ lost_last_(false),
+ uniform_loss_model_(new UniformLoss(0)) {
+}
+
+bool GilbertElliotLoss::Lost() {
+ // Simulate bursty channel (Gilbert model).
+ // (1st order) Markov chain model with memory of the previous/last
+ // packet state (lost or received).
+ if (lost_last_) {
+ // Previous packet was not received.
+ uniform_loss_model_->set_loss_rate(prob_trans_11_);
+ return lost_last_ = uniform_loss_model_->Lost();
+ } else {
+ uniform_loss_model_->set_loss_rate(prob_trans_01_);
+ return lost_last_ = uniform_loss_model_->Lost();
+ }
+}
+
void NetEqQualityTest::SetUp() {
out_file_ = fopen(out_filename_.c_str(), "wb");
+ log_file_ = fopen(log_filename_.c_str(), "wt");
ASSERT_TRUE(out_file_ != NULL);
ASSERT_EQ(0, neteq_->RegisterPayloadType(decoder_type_, kPayloadType));
rtp_generator_->set_drift_factor(drift_factor_);
+
+ int units = block_duration_ms_ / kPacketLossTimeUnitMs;
+ switch (FLAGS_random_loss_mode) {
+ case 1: {
+ // |unit_loss_rate| is the packet loss rate for each unit time interval
+ // (kPacketLossTimeUnitMs). Since a packet loss event is generated if any
+ // of |block_duration_ms_ / kPacketLossTimeUnitMs| unit time intervals of
+ // a full packet duration is drawn with a loss, |unit_loss_rate| fulfills
+ // (1 - unit_loss_rate) ^ (block_duration_ms_ / kPacketLossTimeUnitMs) ==
+ // 1 - packet_loss_rate.
+ double unit_loss_rate = (1.0f - pow(1.0f - 0.01f * packet_loss_rate_,
+ 1.0f / units));
+ loss_model_.reset(new UniformLoss(unit_loss_rate));
+ break;
+ }
+ case 2: {
+ // |FLAGS_burst_length| should be integer times of kPacketLossTimeUnitMs.
+ ASSERT_EQ(0, FLAGS_burst_length % kPacketLossTimeUnitMs);
+
+ // We do not allow 100 percent packet loss in Gilbert Elliot model, which
+ // makes no sense.
+ ASSERT_GT(100, packet_loss_rate_);
+
+ // To guarantee the overall packet loss rate, transition probabilities
+ // need to satisfy:
+ // pi_0 * (1 - prob_trans_01_) ^ units +
+ // pi_1 * prob_trans_10_ ^ (units - 1) == 1 - loss_rate
+ // pi_0 = prob_trans_10 / (prob_trans_10 + prob_trans_01_)
+ // is the stationary state probability of no-loss
+ // pi_1 = prob_trans_01_ / (prob_trans_10 + prob_trans_01_)
+ // is the stationary state probability of loss
+ // After a derivation prob_trans_00 should satisfy:
+ // prob_trans_00 ^ (units - 1) = (loss_rate - 1) / prob_trans_10 *
+ // prob_trans_00 + (1 - loss_rate) * (1 + 1 / prob_trans_10).
+ double loss_rate = 0.01f * packet_loss_rate_;
+ double prob_trans_10 = 1.0f * kPacketLossTimeUnitMs / FLAGS_burst_length;
+ double prob_trans_00 = ProbTrans00Solver(units, loss_rate, prob_trans_10);
+ loss_model_.reset(new GilbertElliotLoss(1.0f - prob_trans_10,
+ 1.0f - prob_trans_00));
+ break;
+ }
+ default: {
+ loss_model_.reset(new NoLoss);
+ break;
+ }
+ }
+
+ // Make sure that the packet loss profile is same for all derived tests.
+ srand(kInitSeed);
}
void NetEqQualityTest::TearDown() {
fclose(out_file_);
}
+bool NetEqQualityTest::PacketLost() {
+ int cycles = block_duration_ms_ / kPacketLossTimeUnitMs;
+
+ // The loop is to make sure that codecs with different block lengths share the
+ // same packet loss profile.
+ bool lost = false;
+ for (int idx = 0; idx < cycles; idx ++) {
+ if (loss_model_->Lost()) {
+ // The packet will be lost if any of the drawings indicates a loss, but
+ // the loop has to go on to make sure that codecs with different block
+ // lengths keep the same pace.
+ lost = true;
+ }
+ }
+ return lost;
+}
+
int NetEqQualityTest::Transmit() {
int packet_input_time_ms =
rtp_generator_->GetRtpHeader(kPayloadType, in_size_samples_,
&rtp_header_);
- if (!PacketLost(packet_input_time_ms) && payload_size_bytes_ > 0) {
- int ret = neteq_->InsertPacket(rtp_header_, &payload_[0],
- payload_size_bytes_,
- packet_input_time_ms * in_sampling_khz_);
- if (ret != NetEq::kOK)
- return -1;
+ if (payload_size_bytes_ > 0) {
+ fprintf(log_file_, "Packet at %d ms", packet_input_time_ms);
+ if (!PacketLost()) {
+ int ret = neteq_->InsertPacket(rtp_header_, &payload_[0],
+ payload_size_bytes_,
+ packet_input_time_ms * in_sampling_khz_);
+ if (ret != NetEq::kOK)
+ return -1;
+ fprintf(log_file_, " OK.\n");
+ } else {
+ fprintf(log_file_, " Lost.\n");
+ }
}
return packet_input_time_ms;
}
int audio_size_samples;
while (decoded_time_ms_ < end_time_ms) {
- while (decodable_time_ms_ - kOutputSizeMs < decoded_time_ms_) {
+ // Assume 10 packets in packets buffer.
+ while (decodable_time_ms_ - 10 * block_duration_ms_ < decoded_time_ms_) {
ASSERT_TRUE(in_file_->Read(in_size_samples_ * channels_, &in_data_[0]));
payload_size_bytes_ = EncodeBlock(&in_data_[0],
in_size_samples_, &payload_[0],
max_payload_bytes_);
+ total_payload_size_bytes_ += payload_size_bytes_;
decodable_time_ms_ = Transmit() + block_duration_ms_;
}
audio_size_samples = DecodeBlock();
decoded_time_ms_ += audio_size_samples / out_sampling_khz_;
}
}
+ fprintf(log_file_, "%f", 8.0f * total_payload_size_bytes_ / end_time_ms);
}
} // namespace test
projects / platform / framework / web / crosswalk.git / blobdiff