Returning correct duration estimate on Opus DTX packets.

webrtc/modules/audio_coding/neteq/neteq_impl.cc

Index: webrtc/modules/audio_coding/neteq/neteq_impl.cc
diff --git a/webrtc/modules/audio_coding/neteq/neteq_impl.cc b/webrtc/modules/audio_coding/neteq/neteq_impl.cc
index e6f7e60dbdafb5e29738b3ebf8f9b1379e977851..d6a61763df7168f766ca4fed6e9f2456dbb474ff 100644
--- a/webrtc/modules/audio_coding/neteq/neteq_impl.cc
+++ b/webrtc/modules/audio_coding/neteq/neteq_impl.cc
@@ -1645,21 +1645,23 @@ int NetEqImpl::DoRfc3389Cng(PacketList* packet_list, bool play_dtmf) {
 
 void NetEqImpl::DoCodecInternalCng() {
   int length = 0;
-  // TODO(hlundin): Will probably need a longer buffer for multi-channel.
-  int16_t decoded_buffer[kMaxFrameSize];
   AudioDecoder* decoder = decoder_database_->GetActiveDecoder();
   if (decoder) {
     const uint8_t* dummy_payload = NULL;
     AudioDecoder::SpeechType speech_type;
     length = decoder->Decode(
-        dummy_payload, 0, fs_hz_, kMaxFrameSize * sizeof(int16_t),
-        decoded_buffer, &speech_type);
+        dummy_payload, 0, fs_hz_, decoded_buffer_length_ * sizeof(int16_t),
+        decoded_buffer_.get(), &speech_type);
   }
   assert(mute_factor_array_.get());
-  normal_->Process(decoded_buffer, length, last_mode_, mute_factor_array_.get(),
-                   algorithm_buffer_.get());
-  last_mode_ = kModeCodecInternalCng;
-  expand_->Reset();
+  if (length > 0) {

[hlundin-webrtc, 2015/09/15 13:05:09]

I think you'll have to handle the error differently. If the decoder returns an
error, we should probably set the output to zero; use decoder_frame_length_ as
default packet size. And then call normal_->Process anyway. But, it is still
good to LOG.

[minyue-webrtc, 2015/09/16 08:05:31]

May I suggest yet another solution? When normal decoding fails, it uses
expansion, see line 1255.
*operation = kExpand;  // Do expansion to get data instead.

I think DoCodecInternalCng belongs there. I gave myself an action item of moving
these lines into Decode() (or DecodeLoop). I did not apply it since I wanted to
make a quick fix. Maybe good to do it. WDYT

+    normal_->Process(decoded_buffer_.get(), length, last_mode_,
+                     mute_factor_array_.get(), algorithm_buffer_.get());
+    last_mode_ = kModeCodecInternalCng;
+    expand_->Reset();
+  } else {
+    LOG(LS_WARNING) << "Codec internal Cng decode error.";
+  }
 }
 
 int NetEqImpl::DoDtmf(const DtmfEvent& dtmf_event, bool* play_dtmf) {