Switch OnMoreData() to use AudioBus.

As titled, with this change we're now piping float data around the pipeline from
end to end. This change is in preparation for browser side channel remixing and
resampling.

As a consequence of this change the shared memory now represents the
contents of an AudioBus object, which is essentially audio data in a float
planar format.

BUG=114700
TEST=Should be no audible change. Ran all existing tests. Compiled ran
WebAudio/HTML5/WebRTC on all platforms and PPAPI on Linux.


Review URL: https://chromiumcodereview.appspot.com/10832285

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@154951 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 41 insertions, 7 deletions

diff --git a/ppapi/shared_impl/ppb_audio_shared.cc b/ppapi/shared_impl/ppb_audio_shared.cc
index d131bb3..f275559 100644
--- a/ppapi/shared_impl/ppb_audio_shared.cc
+++ b/ppapi/shared_impl/ppb_audio_shared.cc
@@ -8,6 +8,10 @@
 #include "media/audio/shared_memory_util.h"
 #include "ppapi/shared_impl/ppapi_globals.h"
 
+// Hard coded values from PepperPlatformAudioOutputImpl.
+// TODO(dalecurtis): PPAPI shouldn't hard code these values for all clients.
+enum { kChannels = 2, kBytesPerSample = 2 };
+
 namespace ppapi {
 
 #if defined(OS_NACL)
@@ -25,7 +29,8 @@ PPB_Audio_Shared::PPB_Audio_Shared()
       thread_active_(false),
 #endif
       callback_(NULL),
-      user_data_(NULL) {
+      user_data_(NULL),
+      client_buffer_size_bytes_(0) {
 }
 
 PPB_Audio_Shared::~PPB_Audio_Shared() {
@@ -67,7 +72,8 @@ void PPB_Audio_Shared::SetStreamInfo(
     PP_Instance instance,
     base::SharedMemoryHandle shared_memory_handle,
     size_t shared_memory_size,
-    base::SyncSocket::Handle socket_handle) {
+    base::SyncSocket::Handle socket_handle,
+    int sample_frame_count) {
   socket_.reset(new base::CancelableSyncSocket(socket_handle));
   shared_memory_.reset(new base::SharedMemory(shared_memory_handle, false));
   shared_memory_size_ = shared_memory_size;
@@ -76,6 +82,13 @@ void PPB_Audio_Shared::SetStreamInfo(
           media::TotalSharedMemorySizeInBytes(shared_memory_size_))) {
     PpapiGlobals::Get()->LogWithSource(instance, PP_LOGLEVEL_WARNING, "",
       "Failed to map shared memory for PPB_Audio_Shared.");
+  } else {
+    audio_bus_ = media::AudioBus::WrapMemory(
+        kChannels, sample_frame_count, shared_memory_->memory());
+    // Setup integer audio buffer for user audio data.
+    client_buffer_size_bytes_ =
+        audio_bus_->frames() * audio_bus_->channels() * kBytesPerSample;
+    client_buffer_.reset(new uint8_t[client_buffer_size_bytes_]);
   }
 
   StartThread();
@@ -83,12 +96,14 @@ void PPB_Audio_Shared::SetStreamInfo(
 
 void PPB_Audio_Shared::StartThread() {
   // Don't start the thread unless all our state is set up correctly.
-  if (!playing_ || !callback_ || !socket_.get() || !shared_memory_->memory())
+  if (!playing_ || !callback_ || !socket_.get() || !shared_memory_->memory() ||
+      !audio_bus_.get() || !client_buffer_.get())
     return;
   // Clear contents of shm buffer before starting audio thread. This will
   // prevent a burst of static if for some reason the audio thread doesn't
   // start up quickly enough.
   memset(shared_memory_->memory(), 0, shared_memory_size_);
+  memset(client_buffer_.get(), 0, client_buffer_size_bytes_);
 #if !defined(OS_NACL)
   DCHECK(!audio_thread_.get());
   audio_thread_.reset(new base::DelegateSimpleThread(
@@ -140,16 +155,26 @@ void PPB_Audio_Shared::CallRun(void* self) {
 
 void PPB_Audio_Shared::Run() {
   int pending_data;
-  void* buffer = shared_memory_->memory();
+  const int bytes_per_frame =
+      sizeof(*audio_bus_->channel(0)) * audio_bus_->channels();
 
   while (sizeof(pending_data) ==
       socket_->Receive(&pending_data, sizeof(pending_data)) &&
       pending_data != media::kPauseMark) {
-    callback_(buffer, shared_memory_size_, user_data_);
+    callback_(client_buffer_.get(), client_buffer_size_bytes_, user_data_);
+
+    // Deinterleave the audio data into the shared memory as float.
+    audio_bus_->FromInterleaved(
+        client_buffer_.get(), audio_bus_->frames(), kBytesPerSample);
 
     // Let the host know we are done.
+    // TODO(dalecurtis): Technically this is not the exact size.  Due to channel
+    // padding for alignment, there may be more data available than this.  We're
+    // relying on AudioSyncReader::Read() to parse this with that in mind.
+    // Rename these methods to Set/GetActualFrameCount().
     media::SetActualDataSizeInBytes(
-        shared_memory_.get(), shared_memory_size_, shared_memory_size_);
+        shared_memory_.get(), shared_memory_size_,
+        audio_bus_->frames() * bytes_per_frame);
   }
 }
 
diff --git a/ppapi/shared_impl/ppb_audio_shared.h b/ppapi/shared_impl/ppb_audio_shared.h
index ed3a5c2..0b6afd4 100644
--- a/ppapi/shared_impl/ppb_audio_shared.h
+++ b/ppapi/shared_impl/ppb_audio_shared.h
@@ -9,6 +9,7 @@
 #include "base/shared_memory.h"
 #include "base/sync_socket.h"
 #include "base/threading/simple_thread.h"
+#include "media/base/audio_bus.h"
 #include "ppapi/c/ppb_audio.h"
 #include "ppapi/shared_impl/resource.h"
 #include "ppapi/thunk/ppb_audio_api.h"
@@ -53,7 +54,8 @@ class PPAPI_SHARED_EXPORT PPB_Audio_Shared
   void SetStreamInfo(PP_Instance instance,
                      base::SharedMemoryHandle shared_memory_handle,
                      size_t shared_memory_size,
-                     base::SyncSocket::Handle socket_handle);
+                     base::SyncSocket::Handle socket_handle,
+                     int sample_frame_count);
 
 #if defined(OS_NACL)
   // NaCl has a special API for IRT code to create threads that can call back
@@ -102,6 +104,13 @@ class PPAPI_SHARED_EXPORT PPB_Audio_Shared
   // User data pointer passed verbatim to the callback function.
   void* user_data_;
 
+  // AudioBus for shuttling data across the shared memory.
+  scoped_ptr<media::AudioBus> audio_bus_;
+
+  // Internal buffer for client's integer audio data.
+  int client_buffer_size_bytes_;
+  scoped_array<uint8_t> client_buffer_;
+
   DISALLOW_COPY_AND_ASSIGN(PPB_Audio_Shared);
 };