iSAC: Functions for importing and exporting bandwidth est. info

webrtc/modules/audio_coding/codecs/isac/unittest.cc

+/*
+ *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <algorithm>
+#include <sstream>
+#include <vector>
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/buffer.h"
+#include "webrtc/modules/audio_coding/codecs/isac/fix/interface/audio_encoder_isacfix.h"
+#include "webrtc/modules/audio_coding/codecs/isac/main/interface/audio_encoder_isac.h"
+#include "webrtc/modules/audio_coding/neteq/tools/input_audio_file.h"
+#include "webrtc/test/testsupport/fileutils.h"
+
+namespace webrtc {
+
+namespace {
+
+std::vector<int16_t> LoadSpeechData() {
+  webrtc::test::InputAudioFile input_file(
+      webrtc::test::ResourcePath("audio_coding/testfile32kHz", "pcm"));
+  static const int kIsacNumberOfSamples = 32 * 60;  // 60 ms at 32 kHz
+  std::vector<int16_t> speech_data(kIsacNumberOfSamples);
+  input_file.Read(kIsacNumberOfSamples, speech_data.data());
+  return speech_data;
+}
+
+template <typename T>
+IsacBandwidthInfo GetBwInfo(typename T::instance_type* inst) {
+  IsacBandwidthInfo bi;
+  T::GetBandwidthInfo(inst, &bi);
+  EXPECT_TRUE(bi.in_use);
+  return bi;
+}
+
+template <typename T>
+rtc::Buffer EncodePacket(typename T::instance_type* inst,
+                         const IsacBandwidthInfo* bi,
+                         const int16_t* speech_data,
+                         int framesize_ms) {
+  rtc::Buffer output(1000);
+  for (int i = 0;; ++i) {
+    if (bi)
+      T::SetBandwidthInfo(inst, bi);
+    int encoded_bytes = T::Encode(inst, speech_data, output.data());
+    if (i + 1 == framesize_ms / 10) {
+      EXPECT_GT(encoded_bytes, 0);
+      EXPECT_LE(static_cast<size_t>(encoded_bytes), output.size());
+      output.SetSize(encoded_bytes);
+      return output;
+    }
+    EXPECT_EQ(0, encoded_bytes);
+  }
+}
+
+class BoundedCapacityChannel final {
+ public:
+  BoundedCapacityChannel(int rate_bps)

[hlundin-webrtc, 2015/07/02 14:04:36]

Suggest you call the parameter rate_bits_per_second, since bytes per sample
share the same acronym.

[kwiberg-webrtc, 2015/07/03 00:27:53]

Done, for the whole file.

+      : current_time_rtp_(0),
+        channel_rate_bytes_per_sample_(rate_bps / (8.0 * kSamplesPerSecond)) {}
+
+  // Simulate sending the given number of bytes at the given RTP time. Returns
+  // the

[hlundin-webrtc, 2015/07/02 14:04:36]

Re-flow the line breaks.

[kwiberg-webrtc, 2015/07/03 00:27:53]

Done.

+  // new current RTP time after the sending is done.
+  int Send(int send_time_rtp, int nbytes) {
+    current_time_rtp_ = std::max(current_time_rtp_, send_time_rtp) +
+                        nbytes / channel_rate_bytes_per_sample_;
+    return current_time_rtp_;
+  }
+
+ private:
+  int current_time_rtp_;
+  // The somewhat strange unit for channel rate, bytes per sample, is because
+  // RTP time is measured in samples:
+  const double channel_rate_bytes_per_sample_;
+  static const int kSamplesPerSecond = 16000;
+};
+
+template <typename T, bool adaptive>
+struct TestParam {};
+
+template <>
+struct TestParam<IsacFloat, true> {
+  static const int time_to_settle = 200;
+  static int ExpectedRateBps(int rate_bps) { return rate_bps; }
+};
+
+template <>
+struct TestParam<IsacFix, true> {
+  static const int time_to_settle = 350;
+  static int ExpectedRateBps(int rate_bps) {
+    // For some reason, IsacFix fails to adapt to the channel's actual
+    // bandwidth. Instead, it settles on a few hundred packets at 10kbit/s,
+    // then a few hundred at 5kbit/s, then a few hundred at 10kbit/s, and so
+    // on. The 200 packets starting at 350 are in the middle of the first
+    // 10kbit/s run.
+    return 10000;
+  }
+};
+
+template <>
+struct TestParam<IsacFloat, false> {
+  static const int time_to_settle = 0;
+  static int ExpectedRateBps(int rate_bps) { return 16000; }
+};
+
+template <>
+struct TestParam<IsacFix, false> {
+  static const int time_to_settle = 0;
+  static int ExpectedRateBps(int rate_bps) { return 8000; }
+};
+
+// Test that the iSAC encoder produces identical output whether or not we use a
+// conjoined encoder+decoder pair or a separate encoder and decoder that
+// communicate BW estimation info explicitly.
+template <typename T, bool adaptive>
+void TestGetSetBandwidthInfo(const int16_t* speech_data, int rate_bps) {
+  using Param = TestParam<T, adaptive>;
+
+  // Conjoined encoder/decoder pair:
+  typename T::instance_type* encdec;
+  ASSERT_EQ(0, T::Create(&encdec));
+  ASSERT_EQ(0, T::EncoderInit(encdec, adaptive ? 0 : 1));
+  ASSERT_EQ(0, T::DecoderInit(encdec));
+
+  // Disjoint encoder/decoder pair:
+  typename T::instance_type* enc;
+  ASSERT_EQ(0, T::Create(&enc));
+  ASSERT_EQ(0, T::EncoderInit(enc, adaptive ? 0 : 1));
+  typename T::instance_type* dec;
+  ASSERT_EQ(0, T::Create(&dec));
+  ASSERT_EQ(0, T::DecoderInit(dec));
+
+  // 0. Get initial BW info from decoder.
+  auto bi = GetBwInfo<T>(dec);
+
+  BoundedCapacityChannel channel1(rate_bps), channel2(rate_bps);
+  std::vector<size_t> packet_sizes;
+  for (int i = 0; i < Param::time_to_settle + 200; ++i) {
+    std::ostringstream ss;
+    ss << " i = " << i;
+    SCOPED_TRACE(ss.str());
+
+    // 1. Encode 6 * 10 ms (adaptive) or 3 * 10 ms (nonadaptive). The separate
+    // encoder is given the BW info before each encode call.
+    const int framesize_ms = adaptive ? 60 : 30;
+    auto bitstream1 =
+        EncodePacket<T>(encdec, nullptr, speech_data, framesize_ms);
+    auto bitstream2 = EncodePacket<T>(enc, &bi, speech_data, framesize_ms);
+    EXPECT_EQ(bitstream1, bitstream2);
+    if (i > Param::time_to_settle)
+      packet_sizes.push_back(bitstream1.size());
+
+    // 2. Deliver the encoded data to the decoders (but don't actually ask them
+    // to decode it; that's not necessary). Then get new BW info from the
+    // separate decoder.
+    const int samples_per_packet = 16 * framesize_ms;
+    const int send_time = i * samples_per_packet;
+    EXPECT_EQ(0, T::UpdateBwEstimate(
+                     encdec, bitstream1.data(), bitstream1.size(), i, send_time,
+                     channel1.Send(send_time, bitstream1.size())));
+    EXPECT_EQ(0, T::UpdateBwEstimate(
+                     dec, bitstream2.data(), bitstream2.size(), i, send_time,
+                     channel2.Send(send_time, bitstream2.size())));
+    bi = GetBwInfo<T>(dec);
+  }
+
+  EXPECT_EQ(0, T::Free(encdec));
+  EXPECT_EQ(0, T::Free(enc));
+  EXPECT_EQ(0, T::Free(dec));
+
+  // The average send bitrate is close to the channel's capacity.
+  double avg_size =
+      std::accumulate(packet_sizes.begin(), packet_sizes.end(), 0) /
+      static_cast<double>(packet_sizes.size());
+  double avg_rate_bps = 8.0 * avg_size / 60e-3;

[hlundin-webrtc, 2015/07/02 14:04:36]

Shouldn't 60e-3 be 30e-3 in the non-adaptive case?

[kwiberg-webrtc, 2015/07/03 00:27:53]

Yes. Done.

+  double expected_rate_bps = Param::ExpectedRateBps(rate_bps);
+  EXPECT_GT(avg_rate_bps / expected_rate_bps, 0.99);
+  EXPECT_LT(avg_rate_bps / expected_rate_bps, 1.06);
+
+  // The largest packet isn't that large, and the smallest not that small.
+  auto minmax_size =
+      std::minmax_element(packet_sizes.begin(), packet_sizes.end());
+  double size_range = *minmax_size.second - *minmax_size.first;
+  EXPECT_LE(size_range / avg_size, 0.16);
+}
+
+}  // namespace
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFloat12kAdaptive) {
+  TestGetSetBandwidthInfo<IsacFloat, true>(LoadSpeechData().data(), 12000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFloat15kAdaptive) {
+  TestGetSetBandwidthInfo<IsacFloat, true>(LoadSpeechData().data(), 15000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFloat19kAdaptive) {
+  TestGetSetBandwidthInfo<IsacFloat, true>(LoadSpeechData().data(), 19000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFloat22kAdaptive) {
+  TestGetSetBandwidthInfo<IsacFloat, true>(LoadSpeechData().data(), 22000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFix12kAdaptive) {
+  TestGetSetBandwidthInfo<IsacFix, true>(LoadSpeechData().data(), 12000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFix15kAdaptive) {
+  TestGetSetBandwidthInfo<IsacFix, true>(LoadSpeechData().data(), 15000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFix19kAdaptive) {
+  TestGetSetBandwidthInfo<IsacFix, true>(LoadSpeechData().data(), 19000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFix22kAdaptive) {
+  TestGetSetBandwidthInfo<IsacFix, true>(LoadSpeechData().data(), 22000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFloat12k) {
+  TestGetSetBandwidthInfo<IsacFloat, false>(LoadSpeechData().data(), 12000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFloat15k) {
+  TestGetSetBandwidthInfo<IsacFloat, false>(LoadSpeechData().data(), 15000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFloat19k) {
+  TestGetSetBandwidthInfo<IsacFloat, false>(LoadSpeechData().data(), 19000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFloat22k) {
+  TestGetSetBandwidthInfo<IsacFloat, false>(LoadSpeechData().data(), 22000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFix12k) {
+  TestGetSetBandwidthInfo<IsacFix, false>(LoadSpeechData().data(), 12000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFix15k) {
+  TestGetSetBandwidthInfo<IsacFix, false>(LoadSpeechData().data(), 15000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFix19k) {
+  TestGetSetBandwidthInfo<IsacFix, false>(LoadSpeechData().data(), 19000);
+}
+
+TEST(IsacCommonTest, GetSetBandwidthInfoFix22k) {
+  TestGetSetBandwidthInfo<IsacFix, false>(LoadSpeechData().data(), 22000);
+}
+
+}  // namespace webrtc