Switch OnMoreData() to use AudioBus.

ppapi/native_client/src/shared/ppapi_proxy/plugin_ppb_audio.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 "native_client/src/shared/ppapi_proxy/plugin_ppb_audio.h"
 
 #include <pthread.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/errno.h>
 #include <sys/mman.h>
 #include "native_client/src/include/nacl_scoped_ptr.h"
 #include "native_client/src/include/portability.h"
 #include "native_client/src/shared/ppapi_proxy/plugin_globals.h"
+#include "native_client/src/shared/ppapi_proxy/plugin_ppb_audio_config.h"
 #include "native_client/src/shared/ppapi_proxy/plugin_resource.h"
 #include "native_client/src/shared/ppapi_proxy/utility.h"
 #include "native_client/src/shared/srpc/nacl_srpc.h"
 #include "media/audio/shared_memory_util.h"
 #include "ppapi/c/ppb_audio.h"
 #include "ppapi/c/ppb_audio_config.h"
 #include "ppapi/cpp/module_impl.h"
 #include "srpcgen/ppb_rpc.h"
 #include "srpcgen/ppp_rpc.h"
 
 namespace ppapi_proxy {
 namespace {
 
 // Round size up to next 64k; required for NaCl's version of mmap().
 size_t ceil64k(size_t n) {
   return (n + 0xFFFF) & (~0xFFFF);
 }
 
+// Hard coded values from PepperPlatformAudioOutputImpl.
+// TODO(???): PPAPI shouldn't hard code these values for all clients.
+enum { kChannels = 2, kBytesPerSample = 2 };
+
 }  // namespace
 
 PluginAudio::PluginAudio() :
     resource_(kInvalidResourceId),
     socket_(-1),
     shm_(-1),
     shm_size_(0),
     shm_buffer_(NULL),
     state_(AUDIO_INCOMPLETE),
     thread_id_(),
     thread_active_(false),
     user_callback_(NULL),
-    user_data_(NULL) {
+    user_data_(NULL),
+    audio_buffer_size_bytes_(0) {
   DebugPrintf("PluginAudio::PluginAudio\n");
 }
 
 PluginAudio::~PluginAudio() {
   DebugPrintf("PluginAudio::~PluginAudio\n");
   // Ensure audio thread is not active.
   if (resource_ != kInvalidResourceId)
     GetInterface()->StopPlayback(resource_);
   // Unmap the shared memory buffer, if present.
   if (shm_buffer_) {
+    audio_bus_.reset();
+    audio_buffer_.reset();
     munmap(shm_buffer_,
            ceil64k(media::TotalSharedMemorySizeInBytes(shm_size_)));
     shm_buffer_ = NULL;
     shm_size_ = 0;
+    audio_buffer_size_bytes_ = 0;
   }
   // Close the handles.
   if (shm_ != -1) {
     close(shm_);
     shm_ = -1;
   }
   if (socket_ != -1) {
     close(socket_);
     socket_ = -1;
   }
@@ skipping 10 matching lines @@
   PluginAudio* audio = static_cast<PluginAudio*>(self);
   DebugPrintf("PluginAudio::AudioThread: self=%p\n", self);
   while (true) {
     int32_t sync_value;
     // Block on socket read.
     ssize_t r = read(audio->socket_, &sync_value, sizeof(sync_value));
     // StopPlayback() will send a value of -1 over the sync_socket.
     if ((sizeof(sync_value) != r) || (-1 == sync_value))
       break;
     // Invoke user callback, get next buffer of audio data.
-    audio->user_callback_(audio->shm_buffer_,
-                          audio->shm_size_,
+    audio->user_callback_(audio->audio_buffer_.get(),
+                          audio->audio_buffer_size_bytes_,
                           audio->user_data_);
+
+    // Deinterleave the audio data into the shared memory as float.
+    audio->audio_bus_->FromInterleaved(
+        audio->audio_buffer_.get(), audio->audio_bus_->frames(),
+        kBytesPerSample);
+
     // Signal audio backend by writing buffer length at end of buffer.
     // (Note: NaCl applications will always write the entire buffer.)
-    media::SetActualDataSizeInBytes(audio->shm_buffer_,
-                                    audio->shm_size_,
-                                    audio->shm_size_);
+    // 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(
+        audio->shm_buffer_, audio->shm_size_, audio->audio_bus_->frames() *
+        sizeof(*(audio->audio_bus_->channel(0))) *
+        audio->audio_bus_->channels());

[nfullagar, 2012/08/29 18:38:22]

Perhaps cleaner if AudioBus had a member func to return size in bytes of the
buffer (sans padding?)  Or a descriptive temp var?
  media::SetActualDataSizeInBytes(
      audio->shm_buffer_, audio->shm_size_,
      audio->audio_bus_->buffer_size_in_bytes());
...or...
  size_t audio_bus_buffer_size_in_bytes =
      audio->audio_bus_->frames() *
      sizeof(*(audio->audio_bus_->channel(0))) *
      audio->audio_bus_->channels());
  media::SetActualDataSizeInBytes(
      audio->shm_buffer_, audio->shm_size_,
      audio_bus_buffer_size_in_bytes);
...or?

[DaleCurtis, 2012/08/29 18:52:23]

Per the TODO this will just be temporary until I rename the
Get/SetActualDataSize methods to Set/GetActualFrameCount() at which point all
that mess will disappear for SetActualFrameCount(audio->shm_buffer_,
audio->shm_size_, audio_bus->frames());

I'll add a local "bytes_per_frame" temp value for now.

   }
 }
 
 void PluginAudio::StreamCreated(NaClSrpcImcDescType socket,
       NaClSrpcImcDescType shm, size_t shm_size) {
   DebugPrintf("PluginAudio::StreamCreated: shm=%"NACL_PRIu32""
               " shm_size=%"NACL_PRIuS"\n", shm, shm_size);
   socket_ = socket;
   shm_ = shm;
   shm_size_ = shm_size;
   shm_buffer_ = mmap(NULL,
                      ceil64k(media::TotalSharedMemorySizeInBytes(shm_size)),
                      PROT_READ | PROT_WRITE,
                      MAP_SHARED,
                      shm,
                      0);
   if (MAP_FAILED != shm_buffer_) {
+    PP_Resource ac = GetInterface()->GetCurrentConfig(resource_);
+    int frames = PluginAudioConfig::GetInterface()->GetSampleFrameCount(ac);
+
+    audio_bus_ = media::AudioBus::WrapMemory(kChannels, frames, shm_buffer_);
+    // Setup integer audio buffer for user audio data.
+    audio_buffer_size_bytes_ =
+        audio_bus_->frames() * audio_bus_->channels() * kBytesPerSample;
+    audio_buffer_.reset(new uint8_t[audio_buffer_size_bytes_]);
+
     if (state() == AUDIO_PENDING) {
       StartAudioThread();
     } else {
       set_state(AUDIO_READY);
     }
   } else {
     shm_buffer_ = NULL;
   }
 }
 
 bool PluginAudio::StartAudioThread() {
   // clear contents of shm buffer before spinning up audio thread
   DebugPrintf("PluginAudio::StartAudioThread\n");
   memset(shm_buffer_, 0, shm_size_);
+  memset(audio_buffer_.get(), 0, audio_buffer_size_bytes_);
   const struct PP_ThreadFunctions* thread_funcs = GetThreadCreator();
   if (NULL == thread_funcs->thread_create ||
       NULL == thread_funcs->thread_join) {
     return false;
   }
   int ret = thread_funcs->thread_create(&thread_id_, AudioThread, this);
   if (0 == ret) {
     thread_active_ = true;
     set_state(AUDIO_PLAYING);
     return true;
@@ skipping 179 matching lines @@
       GetAs<ppapi_proxy::PluginAudio>(audio_resource);
   if (NULL == audio.get()) {
     // Ignore if no audio_resource -> audio_instance mapping exists,
     // the app may have shutdown audio before StreamCreated() invoked.
     rpc->result = NACL_SRPC_RESULT_OK;
     return;
   }
   audio->StreamCreated(sync_socket, shm, shm_size);
   rpc->result = NACL_SRPC_RESULT_OK;
 }