Changed mixing api and removed resampler

webrtc/modules/audio_mixer/source/new_audio_conference_mixer_impl.cc

Index: webrtc/modules/audio_mixer/source/new_audio_conference_mixer_impl.cc
diff --git a/webrtc/modules/audio_mixer/source/new_audio_conference_mixer_impl.cc b/webrtc/modules/audio_mixer/source/new_audio_conference_mixer_impl.cc
index 47eac8fff56edb5653a766ef2e345f78de64c64a..086cb74e43a91b05d54940fb3a3b3021cce33a7a 100644
--- a/webrtc/modules/audio_mixer/source/new_audio_conference_mixer_impl.cc
+++ b/webrtc/modules/audio_mixer/source/new_audio_conference_mixer_impl.cc
@@ -19,6 +19,7 @@
 #include "webrtc/modules/utility/include/audio_frame_operations.h"
 #include "webrtc/system_wrappers/include/critical_section_wrapper.h"
 #include "webrtc/system_wrappers/include/trace.h"
+#include "webrtc/voice_engine/utility.h"
 
 namespace webrtc {
 namespace {
@@ -189,7 +190,11 @@ bool NewAudioConferenceMixerImpl::Init() {
   return true;
 }
 
-void NewAudioConferenceMixerImpl::Mix(AudioFrame* audio_frame_for_mixing) {
+void NewAudioConferenceMixerImpl::Mix(int sample_rate,
+                                      size_t number_of_channels,
+                                      void* audio_data) {
+  AudioFrame* audio_frame_for_mixing =
+      reinterpret_cast<AudioFrame*>(audio_data);

[aleloi, 2016/08/05 09:52:22]

It's still an AudioFrame on the inside yet...

   size_t remainingAudioSourcesAllowedToMix = kMaximumAmountOfMixedAudioSources;
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   AudioFrameList mixList;
@@ -277,6 +282,16 @@ void NewAudioConferenceMixerImpl::Mix(AudioFrame* audio_frame_for_mixing) {
       LimitMixedAudio(audio_frame_for_mixing);
     }
   }
+

[aleloi, 2016/08/05 09:52:21]

Resampling copied from OutputMixer. It would be nice to know how often the code
enters the if statement.

+  if (audio_frame_for_mixing->num_channels_ != number_of_channels ||
+      audio_frame_for_mixing->sample_rate_hz_ != sample_rate) {
+    audio_frame_for_mixing->num_channels_ = number_of_channels;
+    audio_frame_for_mixing->sample_rate_hz_ = sample_rate;
+    // TODO(andrew): Ideally the downmixing would occur much earlier, in
+    // AudioCodingModule.
+    voe::RemixAndResample(*audio_frame_for_mixing, &resampler_,

[aleloi, 2016/08/05 09:52:21]

I *think* it's OK for RemixAndResample to put data in the same buffer. I will
double check that some test covers it, and upload a new test in another patch
set if it's not.

+                          audio_frame_for_mixing);
+  }
   return;
 }