Support for AudioContextOptions latencyHint.

content/renderer/renderer_blink_platform_impl.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 "content/renderer/renderer_blink_platform_impl.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
@@ skipping 69 matching lines @@
 #include "media/filters/stream_parser_factory.h"
 #include "mojo/common/common_type_converters.h"
 #include "mojo/public/cpp/bindings/associated_group.h"
 #include "ppapi/features/features.h"
 #include "services/service_manager/public/cpp/interface_provider.h"
 #include "storage/common/database/database_identifier.h"
 #include "storage/common/quota/quota_types.h"
 #include "third_party/WebKit/public/platform/BlameContext.h"
 #include "third_party/WebKit/public/platform/FilePathConversion.h"
 #include "third_party/WebKit/public/platform/URLConversion.h"
+#include "third_party/WebKit/public/platform/WebAudioLatencyHint.h"
 #include "third_party/WebKit/public/platform/WebBlobRegistry.h"
 #include "third_party/WebKit/public/platform/WebDeviceLightListener.h"
 #include "third_party/WebKit/public/platform/WebFileInfo.h"
 #include "third_party/WebKit/public/platform/WebGamepads.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamCenter.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamCenterClient.h"
 #include "third_party/WebKit/public/platform/WebPluginListBuilder.h"
 #include "third_party/WebKit/public/platform/WebSecurityOrigin.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
 #include "third_party/WebKit/public/platform/WebVector.h"
@@ skipping 35 matching lines @@
 #define WebScrollbarBehaviorImpl blink::WebScrollbarBehavior
 #endif
 
 #if BUILDFLAG(ENABLE_WEBRTC)
 #include "content/renderer/media/rtc_certificate_generator.h"
 #include "content/renderer/media/webrtc/peer_connection_dependency_factory.h"
 #endif
 
 using blink::Platform;
 using blink::WebAudioDevice;
+using blink::WebAudioLatencyHint;
 using blink::WebBlobRegistry;
 using blink::WebCanvasCaptureHandler;
 using blink::WebDatabaseObserver;
 using blink::WebFileInfo;
 using blink::WebFileSystem;
 using blink::WebGamepad;
 using blink::WebGamepads;
 using blink::WebIDBFactory;
 using blink::WebImageCaptureFrameGrabber;
 using blink::WebMIDIAccessor;
@@ skipping 495 matching lines @@
 
 unsigned RendererBlinkPlatformImpl::audioHardwareOutputChannels() {
   return GetAudioHardwareParams().channels();
 }
 
 WebDatabaseObserver* RendererBlinkPlatformImpl::databaseObserver() {
   return web_database_observer_impl_.get();
 }
 
 WebAudioDevice* RendererBlinkPlatformImpl::createAudioDevice(
-    size_t buffer_size,
     unsigned input_channels,
     unsigned channels,
-    double sample_rate,
+    const blink::WebAudioLatencyHint& latency_hint,
     WebAudioDevice::RenderCallback* callback,
     const blink::WebString& input_device_id,
     const blink::WebSecurityOrigin& security_origin) {
   // Use a mock for testing.
   blink::WebAudioDevice* mock_device =
-      GetContentClient()->renderer()->OverrideCreateAudioDevice(sample_rate);
+      GetContentClient()->renderer()->OverrideCreateAudioDevice(
+          GetAudioHardwareParams().sample_rate(),

[o1ka, 2016/11/30 11:46:26]

Make OverrideCreateAudioDevice() parameterless?
It's up to implementation to decide whether is needs real or mock sample
rate/buffer size.

[Andrew MacPherson, 2016/12/01 12:11:56]

rtoy@: Do you know if we can just hardcode these to something reasonable in
layout_test_content_renderer_client.cc or if we need to retrieve actual hardware
values?

[Raymond Toy, 2016/12/01 16:16:27]

I don't think any of the build bots have any actual audio hardware (real or
virtual) so there's nothing to be retrieved.  This is why none of the layout
tests actually use AudioContext because it doesn't really work.

[Andrew MacPherson, 2016/12/02 09:42:55]

Ok, I've removed the parameters from OverrideCreateAudioDevice() and have
hardcoded them to 44100 and 128 in layout_test_content_renderer_client.cc.

+          GetAudioHardwareParams().frames_per_buffer());
   if (mock_device)
     return mock_device;
 
   // The |channels| does not exactly identify the channel layout of the
   // device. The switch statement below assigns a best guess to the channel
   // layout based on number of channels.
   media::ChannelLayout layout = media::CHANNEL_LAYOUT_UNSUPPORTED;
   switch (channels) {
     case 1:
       layout = media::CHANNEL_LAYOUT_MONO;
@@ skipping 13 matching lines @@
     case 6:
       layout = media::CHANNEL_LAYOUT_5_1;
       break;
     case 7:
       layout = media::CHANNEL_LAYOUT_7_0;
       break;
     case 8:
       layout = media::CHANNEL_LAYOUT_7_1;
       break;
     default:
-      // If the layout is not supported (more than 9 channels), falls back to
-      // discrete mode.
-      layout = media::CHANNEL_LAYOUT_DISCRETE;
+      // TODO need to also pass 'channels' into RendererWebAudioDeviceImpl for
+      // CHANNEL_LAYOUT_DISCRETE
+      NOTREACHED();
   }
 
   int session_id = 0;
   if (input_device_id.isNull() ||
       !base::StringToInt(base::UTF16ToUTF8(
           base::StringPiece16(input_device_id)), &session_id)) {
     if (input_channels > 0)
       DLOG(WARNING) << "createAudioDevice(): request for audio input ignored";
 
     input_channels = 0;
   }
 
-  // For CHANNEL_LAYOUT_DISCRETE, pass the explicit channel count along with
-  // the channel layout when creating an |AudioParameters| object.
-  media::AudioParameters params(media::AudioParameters::AUDIO_PCM_LOW_LATENCY,
-                                layout, static_cast<int>(sample_rate), 16,
-                                buffer_size);
-  params.set_channels_for_discrete(channels);
-
   return new RendererWebAudioDeviceImpl(
-      params, callback, session_id, static_cast<url::Origin>(security_origin));
+      layout, latency_hint, callback, session_id,
+      static_cast<url::Origin>(security_origin));
 }
 
 bool RendererBlinkPlatformImpl::loadAudioResource(
     blink::WebAudioBus* destination_bus,
     const char* audio_file_data,
     size_t data_size) {
   return DecodeAudioFileData(
       destination_bus, audio_file_data, data_size);
 }
 
@@ skipping 559 matching lines @@
   return &trial_token_validator_;
 }
 
 void RendererBlinkPlatformImpl::workerContextCreated(
     const v8::Local<v8::Context>& worker) {
   GetContentClient()->renderer()->DidInitializeWorkerContextOnWorkerThread(
       worker);
 }
 
 }  // namespace content