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 "testing/gtest/include/gtest/gtest.h"
12 #include "webrtc/base/format_macros.h"
13 #include "webrtc/base/scoped_ptr.h"
14 #include "webrtc/modules/audio_coding/codecs/opus/opus_interface.h"
15 #include "webrtc/test/testsupport/fileutils.h"
16 
17 using ::std::string;
18 using ::std::tr1::tuple;
19 using ::std::tr1::get;
20 using ::testing::TestWithParam;
21 
22 namespace webrtc {
23 
24 // Define coding parameter as <channels, bit_rate, filename, extension>.
25 typedef tuple<size_t, int, string, string> coding_param;
26 typedef struct mode mode;
27 
28 struct mode {
29   bool fec;
30   uint8_t target_packet_loss_rate;
31 };
32 
33 const int kOpusBlockDurationMs = 20;
34 const int kOpusSamplingKhz = 48;
35 
36 class OpusFecTest : public TestWithParam<coding_param> {
37  protected:
38   OpusFecTest();
39 
40   virtual void SetUp();
41   virtual void TearDown();
42 
43   virtual void EncodeABlock();
44 
45   virtual void DecodeABlock(bool lost_previous, bool lost_current);
46 
47   int block_duration_ms_;
48   int sampling_khz_;
49   size_t block_length_sample_;
50 
51   size_t channels_;
52   int bit_rate_;
53 
54   size_t data_pointer_;
55   size_t loop_length_samples_;
56   size_t max_bytes_;
57   size_t encoded_bytes_;
58 
59   WebRtcOpusEncInst* opus_encoder_;
60   WebRtcOpusDecInst* opus_decoder_;
61 
62   string in_filename_;
63 
64   rtc::scoped_ptr<int16_t[]> in_data_;
65   rtc::scoped_ptr<int16_t[]> out_data_;
66   rtc::scoped_ptr<uint8_t[]> bit_stream_;
67 };
68 
SetUp()69 void OpusFecTest::SetUp() {
70   channels_ = get<0>(GetParam());
71   bit_rate_ = get<1>(GetParam());
72   printf("Coding %" PRIuS " channel signal at %d bps.\n", channels_, bit_rate_);
73 
74   in_filename_ = test::ResourcePath(get<2>(GetParam()), get<3>(GetParam()));
75 
76   FILE* fp = fopen(in_filename_.c_str(), "rb");
77   ASSERT_FALSE(fp == NULL);
78 
79   // Obtain file size.
80   fseek(fp, 0, SEEK_END);
81   loop_length_samples_ = ftell(fp) / sizeof(int16_t);
82   rewind(fp);
83 
84   // Allocate memory to contain the whole file.
85   in_data_.reset(new int16_t[loop_length_samples_ +
86       block_length_sample_ * channels_]);
87 
88   // Copy the file into the buffer.
89   ASSERT_EQ(fread(&in_data_[0], sizeof(int16_t), loop_length_samples_, fp),
90             loop_length_samples_);
91   fclose(fp);
92 
93   // The audio will be used in a looped manner. To ease the acquisition of an
94   // audio frame that crosses the end of the excerpt, we add an extra block
95   // length of samples to the end of the array, starting over again from the
96   // beginning of the array. Audio frames cross the end of the excerpt always
97   // appear as a continuum of memory.
98   memcpy(&in_data_[loop_length_samples_], &in_data_[0],
99          block_length_sample_ * channels_ * sizeof(int16_t));
100 
101   // Maximum number of bytes in output bitstream.
102   max_bytes_ = block_length_sample_ * channels_ * sizeof(int16_t);
103 
104   out_data_.reset(new int16_t[2 * block_length_sample_ * channels_]);
105   bit_stream_.reset(new uint8_t[max_bytes_]);
106 
107   // If channels_ == 1, use Opus VOIP mode, otherwise, audio mode.
108   int app = channels_ == 1 ? 0 : 1;
109 
110   // Create encoder memory.
111   EXPECT_EQ(0, WebRtcOpus_EncoderCreate(&opus_encoder_, channels_, app));
112   EXPECT_EQ(0, WebRtcOpus_DecoderCreate(&opus_decoder_, channels_));
113   // Set bitrate.
114   EXPECT_EQ(0, WebRtcOpus_SetBitRate(opus_encoder_, bit_rate_));
115 }
116 
TearDown()117 void OpusFecTest::TearDown() {
118   // Free memory.
119   EXPECT_EQ(0, WebRtcOpus_EncoderFree(opus_encoder_));
120   EXPECT_EQ(0, WebRtcOpus_DecoderFree(opus_decoder_));
121 }
122 
OpusFecTest()123 OpusFecTest::OpusFecTest()
124     : block_duration_ms_(kOpusBlockDurationMs),
125       sampling_khz_(kOpusSamplingKhz),
126       block_length_sample_(
127           static_cast<size_t>(block_duration_ms_ * sampling_khz_)),
128       data_pointer_(0),
129       max_bytes_(0),
130       encoded_bytes_(0),
131       opus_encoder_(NULL),
132       opus_decoder_(NULL) {
133 }
134 
EncodeABlock()135 void OpusFecTest::EncodeABlock() {
136   int value = WebRtcOpus_Encode(opus_encoder_,
137                                 &in_data_[data_pointer_],
138                                 block_length_sample_,
139                                 max_bytes_, &bit_stream_[0]);
140   EXPECT_GT(value, 0);
141 
142   encoded_bytes_ = static_cast<size_t>(value);
143 }
144 
DecodeABlock(bool lost_previous,bool lost_current)145 void OpusFecTest::DecodeABlock(bool lost_previous, bool lost_current) {
146   int16_t audio_type;
147   int value_1 = 0, value_2 = 0;
148 
149   if (lost_previous) {
150     // Decode previous frame.
151     if (!lost_current &&
152         WebRtcOpus_PacketHasFec(&bit_stream_[0], encoded_bytes_) == 1) {
153       value_1 = WebRtcOpus_DecodeFec(opus_decoder_, &bit_stream_[0],
154                                      encoded_bytes_, &out_data_[0],
155                                      &audio_type);
156     } else {
157       value_1 = WebRtcOpus_DecodePlc(opus_decoder_, &out_data_[0], 1);
158     }
159     EXPECT_EQ(static_cast<int>(block_length_sample_), value_1);
160   }
161 
162   if (!lost_current) {
163     // Decode current frame.
164     value_2 = WebRtcOpus_Decode(opus_decoder_, &bit_stream_[0], encoded_bytes_,
165                                 &out_data_[value_1 * channels_], &audio_type);
166     EXPECT_EQ(static_cast<int>(block_length_sample_), value_2);
167   }
168 }
169 
TEST_P(OpusFecTest,RandomPacketLossTest)170 TEST_P(OpusFecTest, RandomPacketLossTest) {
171   const int kDurationMs = 200000;
172   int time_now_ms, fec_frames;
173   int actual_packet_loss_rate;
174   bool lost_current, lost_previous;
175   mode mode_set[3] = {{true, 0},
176                       {false, 0},
177                       {true, 50}};
178 
179   lost_current = false;
180   for (int i = 0; i < 3; i++) {
181     if (mode_set[i].fec) {
182       EXPECT_EQ(0, WebRtcOpus_EnableFec(opus_encoder_));
183       EXPECT_EQ(0, WebRtcOpus_SetPacketLossRate(opus_encoder_,
184           mode_set[i].target_packet_loss_rate));
185       printf("FEC is ON, target at packet loss rate %d percent.\n",
186              mode_set[i].target_packet_loss_rate);
187     } else {
188       EXPECT_EQ(0, WebRtcOpus_DisableFec(opus_encoder_));
189       printf("FEC is OFF.\n");
190     }
191     // In this test, we let the target packet loss rate match the actual rate.
192     actual_packet_loss_rate = mode_set[i].target_packet_loss_rate;
193     // Run every mode a certain time.
194     time_now_ms = 0;
195     fec_frames = 0;
196     while (time_now_ms < kDurationMs) {
197       // Encode & decode.
198       EncodeABlock();
199 
200       // Check if payload has FEC.
201       int fec = WebRtcOpus_PacketHasFec(&bit_stream_[0], encoded_bytes_);
202 
203       // If FEC is disabled or the target packet loss rate is set to 0, there
204       // should be no FEC in the bit stream.
205       if (!mode_set[i].fec || mode_set[i].target_packet_loss_rate == 0) {
206         EXPECT_EQ(fec, 0);
207       } else if (fec == 1) {
208         fec_frames++;
209       }
210 
211       lost_previous = lost_current;
212       lost_current = rand() < actual_packet_loss_rate * (RAND_MAX / 100);
213       DecodeABlock(lost_previous, lost_current);
214 
215       time_now_ms += block_duration_ms_;
216 
217       // |data_pointer_| is incremented and wrapped across
218       // |loop_length_samples_|.
219       data_pointer_ = (data_pointer_ + block_length_sample_ * channels_) %
220         loop_length_samples_;
221     }
222     if (mode_set[i].fec) {
223       printf("%.2f percent frames has FEC.\n",
224              static_cast<float>(fec_frames) * block_duration_ms_ / 2000);
225     }
226   }
227 }
228 
229 const coding_param param_set[] =
230     {::std::tr1::make_tuple(1, 64000, string("audio_coding/testfile32kHz"),
231                             string("pcm")),
232      ::std::tr1::make_tuple(1, 32000, string("audio_coding/testfile32kHz"),
233                             string("pcm")),
234      ::std::tr1::make_tuple(2, 64000, string("audio_coding/teststereo32kHz"),
235                             string("pcm"))};
236 
237 // 64 kbps, stereo
238 INSTANTIATE_TEST_CASE_P(AllTest, OpusFecTest,
239                         ::testing::ValuesIn(param_set));
240 
241 }  // namespace webrtc
242