media/base/audio_splicer_unittest.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/memory/scoped_ptr.h"
   6 #include "media/base/audio_buffer.h"
   7 #include "media/base/audio_bus.h"
   8 #include "media/base/audio_splicer.h"
   9 #include "media/base/audio_timestamp_helper.h"
  10 #include "media/base/test_helpers.h"
  11 #include "media/base/timestamp_constants.h"
  12 #include "testing/gtest/include/gtest/gtest.h"
  13
  14 namespace media {
  15
  16 // Do not change this format.  AddInput() and GetValue() only work with float.
  17 static const SampleFormat kSampleFormat = kSampleFormatF32;
  18 static_assert(kSampleFormat == kSampleFormatF32, "invalid splice format");
  19
  20 static const int kChannels = 1;
  21 static const ChannelLayout kChannelLayout = CHANNEL_LAYOUT_MONO;
  22 static const int kDefaultSampleRate = 44100;
  23 static const int kDefaultBufferSize = 100;
  24
  25 class AudioSplicerTest : public ::testing::Test {
  26  public:
  27   AudioSplicerTest()
  28       : splicer_(kDefaultSampleRate, new MediaLog()),
  29         input_timestamp_helper_(kDefaultSampleRate) {
  30     input_timestamp_helper_.SetBaseTimestamp(base::TimeDelta());
  31   }
  32
  33   scoped_refptr<AudioBuffer> GetNextInputBuffer(float value) {
  34     return GetNextInputBuffer(value, kDefaultBufferSize);
  35   }
  36
  37   scoped_refptr<AudioBuffer> GetNextInputBuffer(float value, int frame_size) {
  38     scoped_refptr<AudioBuffer> buffer =
  39         MakeAudioBuffer<float>(kSampleFormat,
  40                                kChannelLayout,
  41                                kChannels,
  42                                kDefaultSampleRate,
  43                                value,
  44                                0.0f,
  45                                frame_size,
  46                                input_timestamp_helper_.GetTimestamp());
  47     input_timestamp_helper_.AddFrames(frame_size);
  48     return buffer;
  49   }
  50
  51   float GetValue(const scoped_refptr<AudioBuffer>& buffer) {
  52     return reinterpret_cast<const float*>(buffer->channel_data()[0])[0];
  53   }
  54
  55   bool VerifyData(const scoped_refptr<AudioBuffer>& buffer, float value) {
  56     int frames = buffer->frame_count();
  57     scoped_ptr<AudioBus> bus = AudioBus::Create(kChannels, frames);
  58     buffer->ReadFrames(frames, 0, 0, bus.get());
  59     for (int ch = 0; ch < buffer->channel_count(); ++ch) {
  60       for (int i = 0; i < frames; ++i) {
  61         if (bus->channel(ch)[i] != value)
  62           return false;
  63       }
  64     }
  65     return true;
  66   }
  67
  68   void VerifyNextBuffer(const scoped_refptr<AudioBuffer>& input) {
  69     ASSERT_TRUE(splicer_.HasNextBuffer());
  70     scoped_refptr<AudioBuffer> output = splicer_.GetNextBuffer();
  71     EXPECT_EQ(input->timestamp(), output->timestamp());
  72     EXPECT_EQ(input->duration(), output->duration());
  73     EXPECT_EQ(input->frame_count(), output->frame_count());
  74     EXPECT_TRUE(VerifyData(output, GetValue(input)));
  75   }
  76
  77   void VerifyPreSpliceOutput(
  78       const scoped_refptr<AudioBuffer>& overlapped_buffer,
  79       const scoped_refptr<AudioBuffer>& overlapping_buffer,
  80       int expected_pre_splice_size,
  81       base::TimeDelta expected_pre_splice_duration) {
  82     ASSERT_TRUE(splicer_.HasNextBuffer());
  83     scoped_refptr<AudioBuffer> pre_splice_output = splicer_.GetNextBuffer();
  84     EXPECT_EQ(overlapped_buffer->timestamp(), pre_splice_output->timestamp());
  85     EXPECT_EQ(expected_pre_splice_size, pre_splice_output->frame_count());
  86     EXPECT_EQ(expected_pre_splice_duration, pre_splice_output->duration());
  87     EXPECT_TRUE(VerifyData(pre_splice_output, GetValue(overlapped_buffer)));
  88   }
  89
  90   void VerifyCrossfadeOutput(
  91       const scoped_refptr<AudioBuffer>& overlapped_buffer_1,
  92       const scoped_refptr<AudioBuffer>& overlapped_buffer_2,
  93       const scoped_refptr<AudioBuffer>& overlapping_buffer,
  94       int second_overlap_index,
  95       int expected_crossfade_size,
  96       base::TimeDelta expected_crossfade_duration) {
  97     ASSERT_TRUE(splicer_.HasNextBuffer());
  98
  99     scoped_refptr<AudioBuffer> crossfade_output = splicer_.GetNextBuffer();
 100     EXPECT_EQ(expected_crossfade_size, crossfade_output->frame_count());
 101     EXPECT_EQ(expected_crossfade_duration, crossfade_output->duration());
 102
 103     // The splice timestamp may be adjusted by a microsecond.
 104     EXPECT_NEAR(overlapping_buffer->timestamp().InMicroseconds(),
 105                 crossfade_output->timestamp().InMicroseconds(),
 106                 1);
 107
 108     // Verify the actual crossfade.
 109     const int frames = crossfade_output->frame_count();
 110     float overlapped_value = GetValue(overlapped_buffer_1);
 111     const float overlapping_value = GetValue(overlapping_buffer);
 112     scoped_ptr<AudioBus> bus = AudioBus::Create(kChannels, frames);
 113     crossfade_output->ReadFrames(frames, 0, 0, bus.get());
 114     for (int ch = 0; ch < crossfade_output->channel_count(); ++ch) {
 115       float cf_ratio = 0;
 116       const float cf_increment = 1.0f / frames;
 117       for (int i = 0; i < frames; ++i, cf_ratio += cf_increment) {
 118         if (overlapped_buffer_2.get() && i >= second_overlap_index)
 119           overlapped_value = GetValue(overlapped_buffer_2);
 120         const float actual = bus->channel(ch)[i];
 121         const float expected =
 122             (1.0f - cf_ratio) * overlapped_value + cf_ratio * overlapping_value;
 123         ASSERT_FLOAT_EQ(expected, actual) << "i=" << i;
 124       }
 125     }
 126   }
 127
 128   bool AddInput(const scoped_refptr<AudioBuffer>& input) {
 129     // Since the splicer doesn't make copies it's working directly on the input
 130     // buffers.  We must make a copy before adding to ensure the original buffer
 131     // is not modified in unexpected ways.
 132     scoped_refptr<AudioBuffer> buffer_copy =
 133         input->end_of_stream()
 134             ? AudioBuffer::CreateEOSBuffer()
 135             : AudioBuffer::CopyFrom(kSampleFormat,
 136                                     input->channel_layout(),
 137                                     input->channel_count(),
 138                                     input->sample_rate(),
 139                                     input->frame_count(),
 140                                     &input->channel_data()[0],
 141                                     input->timestamp());
 142     return splicer_.AddInput(buffer_copy);
 143   }
 144
 145   base::TimeDelta max_crossfade_duration() {
 146     return splicer_.max_crossfade_duration_;
 147   }
 148
 149  protected:
 150   AudioSplicer splicer_;
 151   AudioTimestampHelper input_timestamp_helper_;
 152
 153   DISALLOW_COPY_AND_ASSIGN(AudioSplicerTest);
 154 };
 155
 156 TEST_F(AudioSplicerTest, PassThru) {
 157   EXPECT_FALSE(splicer_.HasNextBuffer());
 158
 159   // Test single buffer pass-thru behavior.
 160   scoped_refptr<AudioBuffer> input_1 = GetNextInputBuffer(0.1f);
 161   EXPECT_TRUE(AddInput(input_1));
 162   VerifyNextBuffer(input_1);
 163   EXPECT_FALSE(splicer_.HasNextBuffer());
 164
 165   // Test that multiple buffers can be queued in the splicer.
 166   scoped_refptr<AudioBuffer> input_2 = GetNextInputBuffer(0.2f);
 167   scoped_refptr<AudioBuffer> input_3 = GetNextInputBuffer(0.3f);
 168   EXPECT_TRUE(AddInput(input_2));
 169   EXPECT_TRUE(AddInput(input_3));
 170   VerifyNextBuffer(input_2);
 171   VerifyNextBuffer(input_3);
 172   EXPECT_FALSE(splicer_.HasNextBuffer());
 173 }
 174
 175 TEST_F(AudioSplicerTest, Reset) {
 176   scoped_refptr<AudioBuffer> input_1 = GetNextInputBuffer(0.1f);
 177   EXPECT_TRUE(AddInput(input_1));
 178   ASSERT_TRUE(splicer_.HasNextBuffer());
 179
 180   splicer_.Reset();
 181   EXPECT_FALSE(splicer_.HasNextBuffer());
 182
 183   // Add some bytes to the timestamp helper so that the
 184   // next buffer starts many frames beyond the end of
 185   // |input_1|. This is to make sure that Reset() actually
 186   // clears its state and doesn't try to insert a gap.
 187   input_timestamp_helper_.AddFrames(100);
 188
 189   // Verify that a new input buffer passes through as expected.
 190   scoped_refptr<AudioBuffer> input_2 = GetNextInputBuffer(0.2f);
 191   EXPECT_TRUE(AddInput(input_2));
 192   VerifyNextBuffer(input_2);
 193   EXPECT_FALSE(splicer_.HasNextBuffer());
 194 }
 195
 196 TEST_F(AudioSplicerTest, EndOfStream) {
 197   scoped_refptr<AudioBuffer> input_1 = GetNextInputBuffer(0.1f);
 198   scoped_refptr<AudioBuffer> input_2 = AudioBuffer::CreateEOSBuffer();
 199   scoped_refptr<AudioBuffer> input_3 = GetNextInputBuffer(0.2f);
 200   EXPECT_TRUE(input_2->end_of_stream());
 201
 202   EXPECT_TRUE(AddInput(input_1));
 203   EXPECT_TRUE(AddInput(input_2));
 204
 205   VerifyNextBuffer(input_1);
 206
 207   scoped_refptr<AudioBuffer> output_2 = splicer_.GetNextBuffer();
 208   EXPECT_FALSE(splicer_.HasNextBuffer());
 209   EXPECT_TRUE(output_2->end_of_stream());
 210
 211   // Verify that buffers can be added again after Reset().
 212   splicer_.Reset();
 213   EXPECT_TRUE(AddInput(input_3));
 214   VerifyNextBuffer(input_3);
 215   EXPECT_FALSE(splicer_.HasNextBuffer());
 216 }
 217
 218 // Test the gap insertion code.
 219 // +--------------+    +--------------+
 220 // |11111111111111|    |22222222222222|
 221 // +--------------+    +--------------+
 222 // Results in:
 223 // +--------------+----+--------------+
 224 // |11111111111111|0000|22222222222222|
 225 // +--------------+----+--------------+
 226 TEST_F(AudioSplicerTest, GapInsertion) {
 227   scoped_refptr<AudioBuffer> input_1 = GetNextInputBuffer(0.1f);
 228
 229   // Add bytes to the timestamp helper so that the next buffer
 230   // will have a starting timestamp that indicates a gap is
 231   // present.
 232   const int kGapSize = 7;
 233   input_timestamp_helper_.AddFrames(kGapSize);
 234   scoped_refptr<AudioBuffer> input_2 = GetNextInputBuffer(0.2f);
 235
 236   EXPECT_TRUE(AddInput(input_1));
 237   EXPECT_TRUE(AddInput(input_2));
 238
 239   // Verify that the first input buffer passed through unmodified.
 240   VerifyNextBuffer(input_1);
 241
 242   // Verify the contents of the gap buffer.
 243   scoped_refptr<AudioBuffer> output_2 = splicer_.GetNextBuffer();
 244   base::TimeDelta gap_timestamp =
 245       input_1->timestamp() + input_1->duration();
 246   base::TimeDelta gap_duration = input_2->timestamp() - gap_timestamp;
 247   EXPECT_GT(gap_duration, base::TimeDelta());
 248   EXPECT_EQ(gap_timestamp, output_2->timestamp());
 249   EXPECT_NEAR(
 250       gap_duration.InMicroseconds(), output_2->duration().InMicroseconds(), 1);
 251   EXPECT_EQ(kGapSize, output_2->frame_count());
 252   EXPECT_TRUE(VerifyData(output_2, 0.0f));
 253
 254   // Verify that the second input buffer passed through unmodified.
 255   VerifyNextBuffer(input_2);
 256   EXPECT_FALSE(splicer_.HasNextBuffer());
 257 }
 258
 259 // Test that an error is signalled when the gap between input buffers is
 260 // too large.
 261 TEST_F(AudioSplicerTest, GapTooLarge) {
 262   scoped_refptr<AudioBuffer> input_1 = GetNextInputBuffer(0.1f);
 263
 264   // Add a seconds worth of bytes so that an unacceptably large
 265   // gap exists between |input_1| and |input_2|.
 266   const int kGapSize = kDefaultSampleRate;
 267   input_timestamp_helper_.AddFrames(kGapSize);
 268   scoped_refptr<AudioBuffer> input_2 = GetNextInputBuffer(0.2f);
 269
 270   EXPECT_TRUE(AddInput(input_1));
 271   EXPECT_FALSE(AddInput(input_2));
 272
 273   VerifyNextBuffer(input_1);
 274
 275   // Verify that the second buffer is not available.
 276   EXPECT_FALSE(splicer_.HasNextBuffer());
 277
 278   // Reset the timestamp helper so it can generate a buffer that is
 279   // right after |input_1|.
 280   input_timestamp_helper_.SetBaseTimestamp(
 281       input_1->timestamp() + input_1->duration());
 282
 283   // Verify that valid buffers are still accepted.
 284   scoped_refptr<AudioBuffer> input_3 = GetNextInputBuffer(0.3f);
 285   EXPECT_TRUE(AddInput(input_3));
 286   VerifyNextBuffer(input_3);
 287   EXPECT_FALSE(splicer_.HasNextBuffer());
 288 }
 289
 290 // Verifies that an error is signalled if AddInput() is called
 291 // with a timestamp that is earlier than the first buffer added.
 292 TEST_F(AudioSplicerTest, BufferAddedBeforeBase) {
 293   input_timestamp_helper_.SetBaseTimestamp(
 294       base::TimeDelta::FromMicroseconds(10));
 295   scoped_refptr<AudioBuffer> input_1 = GetNextInputBuffer(0.1f);
 296
 297   // Reset the timestamp helper so the next buffer will have a timestamp earlier
 298   // than |input_1|.
 299   input_timestamp_helper_.SetBaseTimestamp(base::TimeDelta::FromSeconds(0));
 300   scoped_refptr<AudioBuffer> input_2 = GetNextInputBuffer(0.1f);
 301
 302   EXPECT_GT(input_1->timestamp(), input_2->timestamp());
 303   EXPECT_TRUE(AddInput(input_1));
 304   EXPECT_FALSE(AddInput(input_2));
 305 }
 306
 307 // Test when one buffer partially overlaps another.
 308 // +--------------+
 309 // |11111111111111|
 310 // +--------------+
 311 //            +--------------+
 312 //            |22222222222222|
 313 //            +--------------+
 314 // Results in:
 315 // +--------------+----------+
 316 // |11111111111111|2222222222|
 317 // +--------------+----------+
 318 TEST_F(AudioSplicerTest, PartialOverlap) {
 319   scoped_refptr<AudioBuffer> input_1 = GetNextInputBuffer(0.1f);
 320
 321   // Reset timestamp helper so that the next buffer will have a
 322   // timestamp that starts in the middle of |input_1|.
 323   const int kOverlapSize = input_1->frame_count() / 4;
 324   input_timestamp_helper_.SetBaseTimestamp(input_1->timestamp());
 325   input_timestamp_helper_.AddFrames(input_1->frame_count() - kOverlapSize);
 326
 327   scoped_refptr<AudioBuffer> input_2 = GetNextInputBuffer(0.2f);
 328
 329   EXPECT_TRUE(AddInput(input_1));
 330   EXPECT_TRUE(AddInput(input_2));
 331
 332   // Verify that the first input buffer passed through unmodified.
 333   VerifyNextBuffer(input_1);
 334
 335   ASSERT_TRUE(splicer_.HasNextBuffer());
 336   scoped_refptr<AudioBuffer> output_2 = splicer_.GetNextBuffer();
 337   EXPECT_FALSE(splicer_.HasNextBuffer());
 338
 339   // Verify that the second input buffer was truncated to only contain
 340   // the samples that are after the end of |input_1|.
 341   base::TimeDelta expected_timestamp =
 342       input_1->timestamp() + input_1->duration();
 343   base::TimeDelta expected_duration =
 344       (input_2->timestamp() + input_2->duration()) - expected_timestamp;
 345   EXPECT_EQ(expected_timestamp, output_2->timestamp());
 346   EXPECT_EQ(expected_duration, output_2->duration());
 347   EXPECT_TRUE(VerifyData(output_2, GetValue(input_2)));
 348 }
 349
 350 // Test that an input buffer that is completely overlapped by a buffer
 351 // that was already added is dropped.
 352 // +--------------+
 353 // |11111111111111|
 354 // +--------------+
 355 //       +-----+
 356 //       |22222|
 357 //       +-----+
 358 //                +-------------+
 359 //                |3333333333333|
 360 //                +-------------+
 361 // Results in:
 362 // +--------------+-------------+
 363 // |11111111111111|3333333333333|
 364 // +--------------+-------------+
 365 TEST_F(AudioSplicerTest, DropBuffer) {
 366   scoped_refptr<AudioBuffer> input_1 = GetNextInputBuffer(0.1f);
 367
 368   // Reset timestamp helper so that the next buffer will have a
 369   // timestamp that starts in the middle of |input_1|.
 370   const int kOverlapOffset = input_1->frame_count() / 2;
 371   const int kOverlapSize = input_1->frame_count() / 4;
 372   input_timestamp_helper_.SetBaseTimestamp(input_1->timestamp());
 373   input_timestamp_helper_.AddFrames(kOverlapOffset);
 374
 375   scoped_refptr<AudioBuffer> input_2 = GetNextInputBuffer(0.2f, kOverlapSize);
 376
 377   // Reset the timestamp helper so the next buffer will be right after
 378   // |input_1|.
 379   input_timestamp_helper_.SetBaseTimestamp(input_1->timestamp());
 380   input_timestamp_helper_.AddFrames(input_1->frame_count());
 381   scoped_refptr<AudioBuffer> input_3 = GetNextInputBuffer(0.3f);
 382
 383   EXPECT_TRUE(AddInput(input_1));
 384   EXPECT_TRUE(AddInput(input_2));
 385   EXPECT_TRUE(AddInput(input_3));
 386
 387   VerifyNextBuffer(input_1);
 388   VerifyNextBuffer(input_3);
 389   EXPECT_FALSE(splicer_.HasNextBuffer());
 390 }
 391
 392 // Test crossfade when one buffer partially overlaps another.
 393 // +--------------+
 394 // |11111111111111|
 395 // +--------------+
 396 //            +--------------+
 397 //            |22222222222222|
 398 //            +--------------+
 399 // Results in:
 400 // +----------+----+----------+
 401 // |1111111111|xxxx|2222222222|
 402 // +----------+----+----------+
 403 // Where "xxxx" represents the crossfaded portion of the signal.
 404 TEST_F(AudioSplicerTest, PartialOverlapCrossfade) {
 405   const int kCrossfadeSize =
 406       input_timestamp_helper_.GetFramesToTarget(max_crossfade_duration());
 407   const int kBufferSize = kCrossfadeSize * 2;
 408
 409   scoped_refptr<AudioBuffer> extra_pre_splice_buffer =
 410       GetNextInputBuffer(0.2f, kBufferSize);
 411   scoped_refptr<AudioBuffer> overlapped_buffer =
 412       GetNextInputBuffer(1.0f, kBufferSize);
 413
 414   // Reset timestamp helper so that the next buffer will have a timestamp that
 415   // starts in the middle of |overlapped_buffer|.
 416   input_timestamp_helper_.SetBaseTimestamp(overlapped_buffer->timestamp());
 417   input_timestamp_helper_.AddFrames(overlapped_buffer->frame_count() -
 418                                     kCrossfadeSize);
 419   splicer_.SetSpliceTimestamp(input_timestamp_helper_.GetTimestamp());
 420   scoped_refptr<AudioBuffer> overlapping_buffer =
 421       GetNextInputBuffer(0.0f, kBufferSize);
 422
 423   // |extra_pre_splice_buffer| is entirely before the splice and should be ready
 424   // for output.
 425   EXPECT_TRUE(AddInput(extra_pre_splice_buffer));
 426   VerifyNextBuffer(extra_pre_splice_buffer);
 427
 428   // The splicer should be internally queuing input since |overlapped_buffer| is
 429   // part of the splice.
 430   EXPECT_TRUE(AddInput(overlapped_buffer));
 431   EXPECT_FALSE(splicer_.HasNextBuffer());
 432
 433   // |overlapping_buffer| completes the splice.
 434   splicer_.SetSpliceTimestamp(kNoTimestamp());
 435   EXPECT_TRUE(AddInput(overlapping_buffer));
 436   ASSERT_TRUE(splicer_.HasNextBuffer());
 437
 438   // Add one more buffer to make sure it's passed through untouched.
 439   scoped_refptr<AudioBuffer> extra_post_splice_buffer =
 440       GetNextInputBuffer(0.5f, kBufferSize);
 441   EXPECT_TRUE(AddInput(extra_post_splice_buffer));
 442
 443   VerifyPreSpliceOutput(overlapped_buffer,
 444                         overlapping_buffer,
 445                         221,
 446                         base::TimeDelta::FromMicroseconds(5011));
 447
 448   // Due to rounding the crossfade size may vary by up to a frame.
 449   const int kExpectedCrossfadeSize = 220;
 450   EXPECT_NEAR(kExpectedCrossfadeSize, kCrossfadeSize, 1);
 451
 452   VerifyCrossfadeOutput(overlapped_buffer,
 453                         NULL,
 454                         overlapping_buffer,
 455                         0,
 456                         kExpectedCrossfadeSize,
 457                         base::TimeDelta::FromMicroseconds(4988));
 458
 459   // Retrieve the remaining portion after crossfade.
 460   ASSERT_TRUE(splicer_.HasNextBuffer());
 461   scoped_refptr<AudioBuffer> post_splice_output = splicer_.GetNextBuffer();
 462   EXPECT_EQ(base::TimeDelta::FromMicroseconds(20022),
 463             post_splice_output->timestamp());
 464   EXPECT_EQ(overlapping_buffer->frame_count() - kExpectedCrossfadeSize,
 465             post_splice_output->frame_count());
 466   EXPECT_EQ(base::TimeDelta::FromMicroseconds(5034),
 467             post_splice_output->duration());
 468
 469   EXPECT_TRUE(VerifyData(post_splice_output, GetValue(overlapping_buffer)));
 470
 471   VerifyNextBuffer(extra_post_splice_buffer);
 472   EXPECT_FALSE(splicer_.HasNextBuffer());
 473 }
 474
 475 // Test crossfade when one buffer partially overlaps another, but an end of
 476 // stream buffer is received before the crossfade duration is reached.
 477 // +--------------+
 478 // |11111111111111|
 479 // +--------------+
 480 //            +---------++---+
 481 //            |222222222||EOS|
 482 //            +---------++---+
 483 // Results in:
 484 // +----------+----+----++---+
 485 // |1111111111|xxxx|2222||EOS|
 486 // +----------+----+----++---+
 487 // Where "x" represents the crossfaded portion of the signal.
 488 TEST_F(AudioSplicerTest, PartialOverlapCrossfadeEndOfStream) {
 489   const int kCrossfadeSize =
 490       input_timestamp_helper_.GetFramesToTarget(max_crossfade_duration());
 491
 492   scoped_refptr<AudioBuffer> overlapped_buffer =
 493       GetNextInputBuffer(1.0f, kCrossfadeSize * 2);
 494
 495   // Reset timestamp helper so that the next buffer will have a timestamp that
 496   // starts 3/4 of the way into |overlapped_buffer|.
 497   input_timestamp_helper_.SetBaseTimestamp(overlapped_buffer->timestamp());
 498   input_timestamp_helper_.AddFrames(3 * overlapped_buffer->frame_count() / 4);
 499   splicer_.SetSpliceTimestamp(input_timestamp_helper_.GetTimestamp());
 500   scoped_refptr<AudioBuffer> overlapping_buffer =
 501       GetNextInputBuffer(0.0f, kCrossfadeSize / 3);
 502
 503   // The splicer should be internally queuing input since |overlapped_buffer| is
 504   // part of the splice.
 505   EXPECT_TRUE(AddInput(overlapped_buffer));
 506   EXPECT_FALSE(splicer_.HasNextBuffer());
 507
 508   // |overlapping_buffer| should not have enough data to complete the splice, so
 509   // ensure output is not available.
 510   splicer_.SetSpliceTimestamp(kNoTimestamp());
 511   EXPECT_TRUE(AddInput(overlapping_buffer));
 512   EXPECT_FALSE(splicer_.HasNextBuffer());
 513
 514   // Now add an EOS buffer which should complete the splice.
 515   EXPECT_TRUE(AddInput(AudioBuffer::CreateEOSBuffer()));
 516
 517   VerifyPreSpliceOutput(overlapped_buffer,
 518                         overlapping_buffer,
 519                         331,
 520                         base::TimeDelta::FromMicroseconds(7505));
 521   VerifyCrossfadeOutput(overlapped_buffer,
 522                         NULL,
 523                         overlapping_buffer,
 524                         0,
 525                         overlapping_buffer->frame_count(),
 526                         overlapping_buffer->duration());
 527
 528   // Ensure the last buffer is an EOS buffer.
 529   ASSERT_TRUE(splicer_.HasNextBuffer());
 530   scoped_refptr<AudioBuffer> post_splice_output = splicer_.GetNextBuffer();
 531   EXPECT_TRUE(post_splice_output->end_of_stream());
 532
 533   EXPECT_FALSE(splicer_.HasNextBuffer());
 534 }
 535
 536 // Test crossfade when one buffer partially overlaps another, but the amount of
 537 // overlapped data is less than the crossfade duration.
 538 // +------------+
 539 // |111111111111|
 540 // +------------+
 541 //            +--------------+
 542 //            |22222222222222|
 543 //            +--------------+
 544 // Results in:
 545 // +----------+-+------------+
 546 // |1111111111|x|222222222222|
 547 // +----------+-+------------+
 548 // Where "x" represents the crossfaded portion of the signal.
 549 TEST_F(AudioSplicerTest, PartialOverlapCrossfadeShortPreSplice) {
 550   const int kCrossfadeSize =
 551       input_timestamp_helper_.GetFramesToTarget(max_crossfade_duration());
 552
 553   scoped_refptr<AudioBuffer> overlapped_buffer =
 554       GetNextInputBuffer(1.0f, kCrossfadeSize / 2);
 555
 556   // Reset timestamp helper so that the next buffer will have a timestamp that
 557   // starts in the middle of |overlapped_buffer|.
 558   input_timestamp_helper_.SetBaseTimestamp(overlapped_buffer->timestamp());
 559   input_timestamp_helper_.AddFrames(overlapped_buffer->frame_count() / 2);
 560   splicer_.SetSpliceTimestamp(input_timestamp_helper_.GetTimestamp());
 561   scoped_refptr<AudioBuffer> overlapping_buffer =
 562       GetNextInputBuffer(0.0f, kCrossfadeSize * 2);
 563
 564   // The splicer should be internally queuing input since |overlapped_buffer| is
 565   // part of the splice.
 566   EXPECT_TRUE(AddInput(overlapped_buffer));
 567   EXPECT_FALSE(splicer_.HasNextBuffer());
 568
 569   // |overlapping_buffer| completes the splice.
 570   splicer_.SetSpliceTimestamp(kNoTimestamp());
 571   EXPECT_TRUE(AddInput(overlapping_buffer));
 572
 573   const int kExpectedPreSpliceSize = 55;
 574   const base::TimeDelta kExpectedPreSpliceDuration =
 575       base::TimeDelta::FromMicroseconds(1247);
 576   VerifyPreSpliceOutput(overlapped_buffer,
 577                         overlapping_buffer,
 578                         kExpectedPreSpliceSize,
 579                         kExpectedPreSpliceDuration);
 580   VerifyCrossfadeOutput(overlapped_buffer,
 581                         NULL,
 582                         overlapping_buffer,
 583                         0,
 584                         kExpectedPreSpliceSize,
 585                         kExpectedPreSpliceDuration);
 586
 587   // Retrieve the remaining portion after crossfade.
 588   ASSERT_TRUE(splicer_.HasNextBuffer());
 589   scoped_refptr<AudioBuffer> post_splice_output = splicer_.GetNextBuffer();
 590   EXPECT_EQ(overlapping_buffer->timestamp() + kExpectedPreSpliceDuration,
 591             post_splice_output->timestamp());
 592   EXPECT_EQ(overlapping_buffer->frame_count() - kExpectedPreSpliceSize,
 593             post_splice_output->frame_count());
 594   EXPECT_EQ(overlapping_buffer->duration() - kExpectedPreSpliceDuration,
 595             post_splice_output->duration());
 596
 597   EXPECT_TRUE(VerifyData(post_splice_output, GetValue(overlapping_buffer)));
 598   EXPECT_FALSE(splicer_.HasNextBuffer());
 599 }
 600
 601 // Test behavior when a splice frame is incorrectly marked and does not actually
 602 // overlap.
 603 // +----------+
 604 // |1111111111|
 605 // +----------+
 606 //            +--------------+
 607 //            |22222222222222|
 608 //            +--------------+
 609 // Results in:
 610 // +----------+--------------+
 611 // |1111111111|22222222222222|
 612 // +----------+--------------+
 613 TEST_F(AudioSplicerTest, IncorrectlyMarkedSplice) {
 614   const int kBufferSize =
 615       input_timestamp_helper_.GetFramesToTarget(max_crossfade_duration()) * 2;
 616
 617   scoped_refptr<AudioBuffer> first_buffer =
 618       GetNextInputBuffer(1.0f, kBufferSize);
 619   // Fuzz the duration slightly so that the buffer overlaps the splice timestamp
 620   // by a microsecond, which is not enough to crossfade.
 621   const base::TimeDelta kSpliceTimestamp =
 622       input_timestamp_helper_.GetTimestamp() -
 623       base::TimeDelta::FromMicroseconds(1);
 624   splicer_.SetSpliceTimestamp(kSpliceTimestamp);
 625   scoped_refptr<AudioBuffer> second_buffer =
 626       GetNextInputBuffer(0.0f, kBufferSize);
 627   second_buffer->set_timestamp(kSpliceTimestamp);
 628
 629   // The splicer should be internally queuing input since |first_buffer| is part
 630   // of the supposed splice.
 631   EXPECT_TRUE(AddInput(first_buffer));
 632   EXPECT_FALSE(splicer_.HasNextBuffer());
 633
 634   // |second_buffer| should complete the supposed splice, so ensure output is
 635   // now available.
 636   splicer_.SetSpliceTimestamp(kNoTimestamp());
 637   EXPECT_TRUE(AddInput(second_buffer));
 638
 639   VerifyNextBuffer(first_buffer);
 640   VerifyNextBuffer(second_buffer);
 641   EXPECT_FALSE(splicer_.HasNextBuffer());
 642 }
 643
 644 // Test behavior when a splice frame is incorrectly marked and there is a gap
 645 // between whats in the pre splice and post splice.
 646 // +--------+
 647 // |11111111|
 648 // +--------+
 649 //            +--------------+
 650 //            |22222222222222|
 651 //            +--------------+
 652 // Results in:
 653 // +--------+-+--------------+
 654 // |11111111|0|22222222222222|
 655 // +--------+-+--------------+
 656 TEST_F(AudioSplicerTest, IncorrectlyMarkedSpliceWithGap) {
 657   const int kBufferSize =
 658       input_timestamp_helper_.GetFramesToTarget(max_crossfade_duration()) * 2;
 659   const int kGapSize = 2;
 660
 661   scoped_refptr<AudioBuffer> first_buffer =
 662       GetNextInputBuffer(1.0f, kBufferSize - kGapSize);
 663   scoped_refptr<AudioBuffer> gap_buffer =
 664       GetNextInputBuffer(0.0f, kGapSize);
 665   splicer_.SetSpliceTimestamp(input_timestamp_helper_.GetTimestamp());
 666   scoped_refptr<AudioBuffer> second_buffer =
 667       GetNextInputBuffer(0.0f, kBufferSize);
 668
 669   // The splicer should pass through the first buffer since it's not part of the
 670   // splice.
 671   EXPECT_TRUE(AddInput(first_buffer));
 672   VerifyNextBuffer(first_buffer);
 673
 674   // Do not add |gap_buffer|.
 675
 676   // |second_buffer| will complete the supposed splice.
 677   splicer_.SetSpliceTimestamp(kNoTimestamp());
 678   EXPECT_TRUE(AddInput(second_buffer));
 679
 680   VerifyNextBuffer(gap_buffer);
 681   VerifyNextBuffer(second_buffer);
 682   EXPECT_FALSE(splicer_.HasNextBuffer());
 683 }
 684
 685 // Test behavior when a splice frame is incorrectly marked and there is a gap
 686 // between what's in the pre splice and post splice that is too large to recover
 687 // from.
 688 // +--------+
 689 // |11111111|
 690 // +--------+
 691 //                    +------+
 692 //                    |222222|
 693 //                    +------+
 694 // Results in an error and not a crash.
 695 TEST_F(AudioSplicerTest, IncorrectlyMarkedSpliceWithBadGap) {
 696   const int kBufferSize =
 697       input_timestamp_helper_.GetFramesToTarget(max_crossfade_duration()) * 2;
 698   const int kGapSize = kBufferSize +
 699                        input_timestamp_helper_.GetFramesToTarget(
 700                            base::TimeDelta::FromMilliseconds(
 701                                AudioSplicer::kMaxTimeDeltaInMilliseconds + 1));
 702
 703   scoped_refptr<AudioBuffer> first_buffer =
 704       GetNextInputBuffer(1.0f, kBufferSize);
 705   scoped_refptr<AudioBuffer> gap_buffer =
 706       GetNextInputBuffer(0.0f, kGapSize);
 707   splicer_.SetSpliceTimestamp(input_timestamp_helper_.GetTimestamp());
 708   scoped_refptr<AudioBuffer> second_buffer =
 709       GetNextInputBuffer(0.0f, kBufferSize);
 710
 711   // The splicer should pass through the first buffer since it's not part of the
 712   // splice.
 713   EXPECT_TRUE(AddInput(first_buffer));
 714   VerifyNextBuffer(first_buffer);
 715
 716   // Do not add |gap_buffer|.
 717
 718   // |second_buffer| will complete the supposed splice.
 719   splicer_.SetSpliceTimestamp(kNoTimestamp());
 720   EXPECT_FALSE(AddInput(second_buffer));
 721 }
 722
 723 // Ensure we don't crash when a splice frame is incorrectly marked such that the
 724 // splice timestamp has already passed when SetSpliceTimestamp() is called.
 725 // This can happen if the encoded timestamps are too far behind the decoded
 726 // timestamps.
 727 TEST_F(AudioSplicerTest, IncorrectlyMarkedPastSplice) {
 728   const int kBufferSize = 200;
 729
 730   scoped_refptr<AudioBuffer> first_buffer =
 731       GetNextInputBuffer(1.0f, kBufferSize);
 732   EXPECT_TRUE(AddInput(first_buffer));
 733   VerifyNextBuffer(first_buffer);
 734
 735   // Start the splice at a timestamp which has already occurred.
 736   splicer_.SetSpliceTimestamp(base::TimeDelta());
 737
 738   scoped_refptr<AudioBuffer> second_buffer =
 739       GetNextInputBuffer(0.5f, kBufferSize);
 740   EXPECT_TRUE(AddInput(second_buffer));
 741   EXPECT_FALSE(splicer_.HasNextBuffer());
 742
 743   // |third_buffer| will complete the supposed splice.  The buffer size is set
 744   // such that unchecked the splicer would try to trim off a negative number of
 745   // frames.
 746   splicer_.SetSpliceTimestamp(kNoTimestamp());
 747   scoped_refptr<AudioBuffer> third_buffer =
 748       GetNextInputBuffer(0.0f, kBufferSize * 10);
 749   third_buffer->set_timestamp(base::TimeDelta());
 750   EXPECT_TRUE(AddInput(third_buffer));
 751
 752   // The second buffer should come through unmodified.
 753   VerifyNextBuffer(second_buffer);
 754
 755   // The third buffer should be partially dropped since it overlaps the second.
 756   ASSERT_TRUE(splicer_.HasNextBuffer());
 757   const base::TimeDelta second_buffer_end_ts =
 758       second_buffer->timestamp() + second_buffer->duration();
 759   scoped_refptr<AudioBuffer> output = splicer_.GetNextBuffer();
 760   EXPECT_EQ(second_buffer_end_ts, output->timestamp());
 761   EXPECT_EQ(third_buffer->duration() -
 762                 (second_buffer_end_ts - third_buffer->timestamp()),
 763             output->duration());
 764   EXPECT_TRUE(VerifyData(output, GetValue(third_buffer)));
 765 }
 766
 767 }  // namespace media