Make an AudioEncoder subclass for iSAC redundant encoding

Adding unit test, too.

BUG=3926
R=kwiberg@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/36559005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7946 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/audio_coding/codecs/isac/audio_encoder_isac_t.h

@@ -101,9 +101,15 @@ class AudioEncoderDecoderIsacT : public AudioEncoder, public AudioDecoder {
   // Have we accepted input but not yet emitted it in a packet?
   bool packet_in_progress_;
 
+  // Working on the very first output frame.
+  bool first_output_frame_;
+
   // Timestamp of the first input of the currently in-progress packet.
   uint32_t packet_timestamp_;
 
+  // Timestamp of the previously encoded packet.
+  uint32_t last_encoded_timestamp_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioEncoderDecoderIsacT);
 };
 

webrtc/modules/audio_coding/codecs/isac/audio_encoder_isac_t_impl.h

@@ -68,7 +68,8 @@ template <typename T>
 AudioEncoderDecoderIsacT<T>::AudioEncoderDecoderIsacT(const Config& config)
     : payload_type_(config.payload_type),
       lock_(CriticalSectionWrapper::CreateCriticalSection()),
-      packet_in_progress_(false) {
+      packet_in_progress_(false),
+      first_output_frame_(true) {
   CHECK(config.IsOk());
   CHECK_EQ(0, T::Create(&isac_state_));
   CHECK_EQ(0, T::EncoderInit(isac_state_, 1));
@@ -82,7 +83,8 @@ AudioEncoderDecoderIsacT<T>::AudioEncoderDecoderIsacT(
     const ConfigAdaptive& config)
     : payload_type_(config.payload_type),
       lock_(CriticalSectionWrapper::CreateCriticalSection()),
-      packet_in_progress_(false) {
+      packet_in_progress_(false),
+      first_output_frame_(true) {
   CHECK(config.IsOk());
   CHECK_EQ(0, T::Create(&isac_state_));
   CHECK_EQ(0, T::EncoderInit(isac_state_, 0));
@@ -148,13 +150,43 @@ bool AudioEncoderDecoderIsacT<T>::EncodeInternal(uint32_t timestamp,
   CHECK(static_cast<size_t>(r) <= max_encoded_bytes);
 
   info->encoded_bytes = r;
-  if (r > 0) {
+  if (r == 0)
+    return true;
+
   // Got enough input to produce a packet. Return the saved timestamp from
   // the first chunk of input that went into the packet.
   packet_in_progress_ = false;
   info->encoded_timestamp = packet_timestamp_;
   info->payload_type = payload_type_;
+
+  if (!T::has_redundant_encoder)
+    return true;
+
+  if (first_output_frame_) {
+    // Do not emit the first output frame when using redundant encoding.
+    info->encoded_bytes = 0;
+    first_output_frame_ = false;
+  } else {
+    // Call the encoder's method to get redundant encoding.
+    const size_t primary_length = info->encoded_bytes;
+    int16_t secondary_len;
+    {
+      CriticalSectionScoped cs(lock_.get());
+      secondary_len = T::GetRedPayload(isac_state_, &encoded[primary_length]);
     }
+    DCHECK_GE(secondary_len, 0);
+    // |info| will be implicitly cast to an EncodedInfoLeaf struct, effectively
+    // discarding the (empty) vector of redundant information. This is
+    // intentional.
+    info->redundant.push_back(*info);
+    EncodedInfoLeaf secondary_info;
+    secondary_info.payload_type = info->payload_type;
+    secondary_info.encoded_bytes = secondary_len;
+    secondary_info.encoded_timestamp = last_encoded_timestamp_;
+    info->redundant.push_back(secondary_info);
+    info->encoded_bytes += secondary_len;  // Sum of primary and secondary.
+  }
+  last_encoded_timestamp_ = packet_timestamp_;
   return true;
 }
 

webrtc/modules/audio_coding/codecs/isac/fix/interface/audio_encoder_isacfix.h

@@ -19,6 +19,7 @@ namespace webrtc {
 struct IsacFix {
   typedef ISACFIX_MainStruct instance_type;
   static const bool has_32kHz = false;
+  static const bool has_redundant_encoder = false;
   static const uint16_t kFixSampleRate = 16000;
   static inline int16_t Control(instance_type* inst,
                                 int32_t rate,
@@ -100,6 +101,10 @@ struct IsacFix {
     return WebRtcIsacfix_UpdateBwEstimate(inst, encoded, packet_size,
                                           rtp_seq_number, send_ts, arr_ts);
   }
+  static inline int16_t GetRedPayload(instance_type* inst, uint8_t* encoded) {
+    FATAL() << "Should never be called.";
+    return -1;
+  }
 };
 
 typedef AudioEncoderDecoderIsacT<IsacFix> AudioEncoderDecoderIsacFix;

webrtc/modules/audio_coding/codecs/isac/main/interface/audio_encoder_isac.h

@@ -19,6 +19,7 @@ namespace webrtc {
 struct IsacFloat {
   typedef ISACStruct instance_type;
   static const bool has_32kHz = true;
+  static const bool has_redundant_encoder = false;
   static inline int16_t Control(instance_type* inst,
                                 int32_t rate,
                                 int16_t framesize) {
@@ -97,9 +98,23 @@ struct IsacFloat {
     return WebRtcIsac_UpdateBwEstimate(inst, encoded, packet_size,
                                        rtp_seq_number, send_ts, arr_ts);
   }
+  static inline int16_t GetRedPayload(instance_type* inst, uint8_t* encoded) {
+    FATAL() << "Should never be called.";
+    return -1;
+  }
 };
 
 typedef AudioEncoderDecoderIsacT<IsacFloat> AudioEncoderDecoderIsac;
 
+struct IsacRed : public IsacFloat {
+  static const bool has_redundant_encoder = true;
+
+  static inline int16_t GetRedPayload(instance_type* inst, uint8_t* encoded) {
+    return WebRtcIsac_GetRedPayload(inst, encoded);
+  }
+};
+
+typedef AudioEncoderDecoderIsacT<IsacRed> AudioEncoderDecoderIsacRed;
+
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_AUDIO_CODING_CODECS_ISAC_MAIN_INTERFACE_AUDIO_ENCODER_ISAC_H_

webrtc/modules/audio_coding/codecs/isac/main/source/audio_encoder_isac.cc

@@ -18,4 +18,8 @@ namespace webrtc {
 // AudioEncoderDecoderIsac.
 template class AudioEncoderDecoderIsacT<IsacFloat>;
 
+// Explicit instantiation of AudioEncoderDecoderIsacT<IsacRed>, a.k.a.
+// AudioEncoderDecoderIsacRed.
+template class AudioEncoderDecoderIsacT<IsacRed>;
+
 }  // namespace webrtc

webrtc/modules/audio_coding/codecs/isac/main/source/audio_encoder_isac_red_unittest.cc

@@ -0,0 +1,76 @@
+/*
+ *  Copyright (c) 2014 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 <stdlib.h>
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/modules/audio_coding/codecs/isac/main/interface/audio_encoder_isac.h"
+#include "webrtc/system_wrappers/interface/scoped_ptr.h"
+
+namespace webrtc {
+
+// Simply check that AudioEncoderDecoderIsacRed produces more encoded bytes
+// than AudioEncoderDecoderIsac. Also check that the redundancy information is
+// populated in the EncodedInfo.
+TEST(AudioEncoderIsacRedTest, CompareRedAndNoRed) {
+  static const int kSampleRateHz = 16000;
+  static const int k10MsSamples = kSampleRateHz / 100;
+  // Fill the input array with pseudo-random noise in the range [-1000, 1000].
+  int16_t input[k10MsSamples];
+  srand(1418811752);
+  for (int i = 0; i < k10MsSamples; ++i) {
+    double r = rand();  // NOLINT(runtime/threadsafe_fn)
+    input[i] = (r / RAND_MAX) * 2000 - 1000;
+  }
+  static const size_t kMaxEncodedSizeBytes = 1000;
+  uint8_t encoded[kMaxEncodedSizeBytes];
+  uint8_t red_encoded[kMaxEncodedSizeBytes];
+  AudioEncoderDecoderIsac::Config config;
+  config.sample_rate_hz = kSampleRateHz;
+  AudioEncoderDecoderIsac isac_encoder(config);
+  AudioEncoderDecoderIsacRed::Config red_config;
+  red_config.sample_rate_hz = kSampleRateHz;
+  AudioEncoderDecoderIsacRed isac_red_encoder(red_config);
+  AudioEncoder::EncodedInfo info, red_info;
+
+  // Note that we are not expecting any output from the redundant encoder until
+  // the 6th block of 10 ms has been processed. This is because in RED mode,
+  // iSAC will not output the first 30 ms frame.
+  for (int i = 0; i < 6; ++i) {
+    EXPECT_EQ(0u, red_info.encoded_bytes);
+    EXPECT_EQ(0u, red_info.redundant.size());
+    const uint32_t timestamp = static_cast<uint32_t>(i);
+    EXPECT_TRUE(isac_encoder.Encode(timestamp, input, k10MsSamples,
+                                    kMaxEncodedSizeBytes, encoded, &info));
+    EXPECT_TRUE(isac_red_encoder.Encode(timestamp, input, k10MsSamples,
+                                        kMaxEncodedSizeBytes, red_encoded,
+                                        &red_info));
+  }
+  EXPECT_GT(info.encoded_bytes, 0u)
+      << "Regular codec did not produce any output";
+  EXPECT_GT(red_info.encoded_bytes, info.encoded_bytes)
+      << "Redundant payload seems to be missing";
+  ASSERT_EQ(2u, red_info.redundant.size()) << "Redundancy vector not populated";
+  ASSERT_EQ(info.encoded_bytes, red_info.redundant[0].encoded_bytes)
+      << "Primary payload should be same length as non-redundant payload";
+  // Check that |encoded| and the primary part of |red_encoded| are identical.
+  EXPECT_EQ(0, memcmp(encoded, red_encoded, info.encoded_bytes));
+  EXPECT_GT(red_info.redundant[0].encoded_bytes,
+            red_info.redundant[1].encoded_bytes)
+      << "Redundant payload should be smaller than primary";
+  EXPECT_EQ(red_info.encoded_bytes, red_info.redundant[0].encoded_bytes +
+                                        red_info.redundant[1].encoded_bytes)
+      << "Encoded sizes don't add up";
+  EXPECT_EQ(3u, red_info.redundant[0].encoded_timestamp)
+      << "Primary timestamp is wrong";
+  EXPECT_EQ(0u, red_info.redundant[1].encoded_timestamp)
+      << "Secondary timestamp is wrong";
+}
+}  // namespace webrtc

webrtc/modules/modules.gyp

@@ -119,6 +119,7 @@
             'audio_coding/codecs/isac/fix/source/lpc_masking_model_unittest.cc',
             'audio_coding/codecs/isac/fix/source/transform_unittest.cc',
             'audio_coding/codecs/isac/main/source/isac_unittest.cc',
+            'audio_coding/codecs/isac/main/source/audio_encoder_isac_red_unittest.cc',
             'audio_coding/codecs/opus/opus_unittest.cc',
             'audio_coding/codecs/red/audio_encoder_copy_red_unittest.cc',
             'audio_coding/neteq/audio_classifier_unittest.cc',