PPB_AudioInput_Dev: support multiple audio input devices - Part 1.

ppapi/examples/audio_input/audio_input.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <string.h>
 
 #include <algorithm>
 #include <limits>
+#include <vector>
 
 #include "ppapi/cpp/audio_config.h"
 #include "ppapi/cpp/dev/audio_input_dev.h"
+#include "ppapi/cpp/dev/device_ref_dev.h"
 #include "ppapi/cpp/graphics_2d.h"
 #include "ppapi/cpp/image_data.h"
 #include "ppapi/cpp/instance.h"
 #include "ppapi/cpp/logging.h"
 #include "ppapi/cpp/module.h"
 #include "ppapi/cpp/rect.h"
 #include "ppapi/cpp/size.h"
 #include "ppapi/utility/completion_callback_factory.h"
 
 class MyInstance : public pp::Instance {
  public:
   explicit MyInstance(PP_Instance instance)
       : pp::Instance(instance),
         callback_factory_(this),
         sample_count_(0),
         channel_count_(0),
         samples_(NULL),
         timer_interval_(0),
         pending_paint_(false),
-        waiting_for_flush_completion_(false) {
+        waiting_for_flush_completion_(false),
+        audio_input_0_1_(0),
+        audio_input_interface_0_1_(NULL) {
   }
   virtual ~MyInstance() {
-    audio_input_.StopCapture();
+    if (!audio_input_.is_null()) {
+      audio_input_.Close();
+    } else if (audio_input_0_1_ != 0) {
+      audio_input_interface_0_1_->StopCapture(audio_input_0_1_);
+      pp::Module::Get()->core()->ReleaseResource(audio_input_0_1_);
+    }
+
     delete[] samples_;
   }
 
   virtual bool Init(uint32_t argc, const char* argn[], const char* argv[]) {
     // This sample frequency is guaranteed to work.
     const PP_AudioSampleRate kSampleFrequency = PP_AUDIOSAMPLERATE_44100;
     const uint32_t kSampleCount = 1024;
     const uint32_t kChannelCount = 1;
 
     sample_count_ = pp::AudioConfig::RecommendSampleFrameCount(this,
                                                                kSampleFrequency,
                                                                kSampleCount);
     PP_DCHECK(sample_count_ > 0);
     channel_count_ = kChannelCount;
     pp::AudioConfig config = pp::AudioConfig(this,
                                              kSampleFrequency,
                                              sample_count_);
     samples_ = new int16_t[sample_count_ * channel_count_];
     memset(samples_, 0, sample_count_ * channel_count_ * sizeof(int16_t));
     audio_input_ = pp::AudioInput_Dev(this, config, CaptureCallback, this);
-    if (!audio_input_.StartCapture())
+
+    audio_input_interface_0_1_ = static_cast<const PPB_AudioInput_Dev_0_1*>(
+        pp::Module::Get()->GetBrowserInterface(
+            PPB_AUDIO_INPUT_DEV_INTERFACE_0_1));
+    if (!audio_input_interface_0_1_)
       return false;
 
     // Try to ensure that we pick up a new set of samples between each
     // timer-generated repaint.
     timer_interval_ = (sample_count_ * 1000) / kSampleFrequency + 5;
     ScheduleNextTimer();
 
     return true;
   }
 
   virtual void DidChangeView(const pp::Rect& position, const pp::Rect& clip) {
     if (position.size() == size_)
       return;
 
     size_ = position.size();
     device_context_ = pp::Graphics2D(this, size_, false);
     if (!BindGraphics(device_context_))
       return;
 
     Paint();
   }
 
+  virtual void HandleMessage(const pp::Var& message_data) {
+    if (message_data.is_string()) {
+      std::string event = message_data.AsString();
+      if (event == "PageInitialized") {
+        pp::CompletionCallback callback = callback_factory_.NewCallback(
+            &MyInstance::EnumerateDevicesFinished);
+        audio_input_.EnumerateDevices(&devices_, callback);
+      } else if (event == "UseDefault") {
+        Open(pp::DeviceRef_Dev());
+      } else if (event == "UseDefault(v0.1)") {
+        audio_input_0_1_ = audio_input_interface_0_1_->Create(
+            pp_instance(), audio_input_.config().pp_resource(),
+            CaptureCallback, this);
+        if (audio_input_0_1_ != 0) {
+          audio_input_interface_0_1_->StartCapture(audio_input_0_1_);
+        } else {
+          PostMessage(pp::Var("OpenFailed"));

[viettrungluu, 2012/03/06 19:26:30]

Admittedly, it's a bit strange that you check that Create() succeeded here, but
not the return value of other calls.

[yzshen1, 2012/03/07 00:30:36]

More checks added.

On 2012/03/06 19:26:30, viettrungluu wrote:

+        }
+
+        audio_input_ = pp::AudioInput_Dev();
+      } else if (event == "Stop") {
+        Stop();
+      }
+    } else if (message_data.is_number()) {
+      int index = message_data.AsInt();
+      if (index >= 0 && index < static_cast<int>(devices_.size())) {
+        Open(devices_[index]);
+      } else {
+        assert(false);

[viettrungluu, 2012/03/06 19:26:30]

You should probably include some header for this. Or, better, use the macros in
ppapi/cpp/logging.h.

[yzshen1, 2012/03/07 00:30:36]

Done.

+      }
+    }
+  }
+
  private:
   void ScheduleNextTimer() {
     PP_DCHECK(timer_interval_ > 0);
     pp::Module::Get()->core()->CallOnMainThread(
         timer_interval_,
         callback_factory_.NewRequiredCallback(&MyInstance::OnTimer),
         0);
   }
 
   void OnTimer(int32_t) {
@@ skipping 66 matching lines @@
   // writing to a valid region of memory.
   static void CaptureCallback(const void* samples,
                               uint32_t num_bytes,
                               void* ctx) {
     MyInstance* thiz = static_cast<MyInstance*>(ctx);
     PP_DCHECK(num_bytes ==
               thiz->sample_count_ * thiz->channel_count_ * sizeof(int16_t));
     memcpy(thiz->samples_, samples, num_bytes);
   }
 
+  void Open(const pp::DeviceRef_Dev& device) {
+    pp::CompletionCallback callback = callback_factory_.NewCallback(
+        &MyInstance::OpenFinished);
+    audio_input_.Open(device, callback);
+  }
+
+  void Stop() {
+    if (!audio_input_.is_null()) {
+      audio_input_.StopCapture();
+    } else if (audio_input_0_1_ != 0) {
+      audio_input_interface_0_1_->StopCapture(audio_input_0_1_);
+    }
+  }
+
+  void EnumerateDevicesFinished(int32_t result) {
+    static const char* const kDelimiter = "#__#";
+
+    if (result == PP_OK) {
+      std::string device_names;
+      for (size_t index = 0; index < devices_.size(); ++index) {
+        pp::Var name = devices_[index].GetName();
+        assert(name.is_string());
+
+        if (index != 0)
+          device_names += kDelimiter;
+        device_names += name.AsString();
+      }
+      PostMessage(pp::Var(device_names));
+    } else {
+      PostMessage(pp::Var("EnumerationFailed"));
+    }
+  }
+
+  void OpenFinished(int32_t result) {
+    if (result == PP_OK) {
+      audio_input_.StartCapture();
+    } else {
+      PostMessage(pp::Var("OpenFailed"));
+    }
+  }
+
   pp::CompletionCallbackFactory<MyInstance> callback_factory_;
 
   uint32_t sample_count_;
   uint32_t channel_count_;
   int16_t* samples_;
 
   int32_t timer_interval_;
 
   // Painting stuff.
   pp::Size size_;
   pp::Graphics2D device_context_;
   bool pending_paint_;
   bool waiting_for_flush_completion_;
 
   pp::AudioInput_Dev audio_input_;
+
+  PP_Resource audio_input_0_1_;
+  const PPB_AudioInput_Dev_0_1* audio_input_interface_0_1_;
+
+  std::vector<pp::DeviceRef_Dev> devices_;
 };
 
 class MyModule : public pp::Module {
  public:
   virtual pp::Instance* CreateInstance(PP_Instance instance) {
     return new MyInstance(instance);
   }
 };
 
 namespace pp {
 
 // Factory function for your specialization of the Module object.
 Module* CreateModule() {
   return new MyModule();
 }
 
 }  // namespace pp