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// 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 "ppapi/shared_impl/ppb_audio_config_shared.h"
#include "ppapi/thunk/enter.h"
#include "ppapi/thunk/ppb_instance_api.h"
namespace ppapi {
PPB_AudioConfig_Shared::PPB_AudioConfig_Shared(ResourceObjectType type,
PP_Instance instance)
: Resource(type, instance),
sample_rate_(PP_AUDIOSAMPLERATE_NONE),
sample_frame_count_(0) {
}
PPB_AudioConfig_Shared::~PPB_AudioConfig_Shared() {
}
PP_Resource PPB_AudioConfig_Shared::Create(
ResourceObjectType type,
PP_Instance instance,
PP_AudioSampleRate sample_rate,
uint32_t sample_frame_count) {
scoped_refptr<PPB_AudioConfig_Shared> object(
new PPB_AudioConfig_Shared(type, instance));
if (!object->Init(sample_rate, sample_frame_count))
return 0;
return object->GetReference();
}
// static
uint32_t PPB_AudioConfig_Shared::RecommendSampleFrameCount_1_0(
PP_AudioSampleRate sample_rate,
uint32_t requested_sample_frame_count) {
// Version 1.0: Don't actually query to get a value from the
// hardware; instead return the input for in-range values.
if (requested_sample_frame_count < PP_AUDIOMINSAMPLEFRAMECOUNT)
return PP_AUDIOMINSAMPLEFRAMECOUNT;
if (requested_sample_frame_count > PP_AUDIOMAXSAMPLEFRAMECOUNT)
return PP_AUDIOMAXSAMPLEFRAMECOUNT;
return requested_sample_frame_count;
}
// static
uint32_t PPB_AudioConfig_Shared::RecommendSampleFrameCount_1_1(
PP_Instance instance,
PP_AudioSampleRate sample_rate,
uint32_t sample_frame_count) {
// Version 1.1: Query the back-end hardware for sample rate and buffer size,
// and recommend a best fit based on request.
thunk::EnterInstance enter(instance);
if (enter.failed())
return 0;
// Get the hardware config.
PP_AudioSampleRate hardware_sample_rate = static_cast<PP_AudioSampleRate>(
enter.functions()->GetAudioHardwareOutputSampleRate(instance));
uint32_t hardware_sample_frame_count =
enter.functions()->GetAudioHardwareOutputBufferSize(instance);
if (sample_frame_count < PP_AUDIOMINSAMPLEFRAMECOUNT)
sample_frame_count = PP_AUDIOMINSAMPLEFRAMECOUNT;
// If client is using same sample rate as audio hardware, then recommend a
// multiple of the audio hardware's sample frame count.
if (hardware_sample_rate == sample_rate && hardware_sample_frame_count > 0) {
// Round up input sample_frame_count to nearest multiple.
uint32_t multiple = (sample_frame_count + hardware_sample_frame_count - 1) /
hardware_sample_frame_count;
uint32_t recommendation = hardware_sample_frame_count * multiple;
if (recommendation > PP_AUDIOMAXSAMPLEFRAMECOUNT)
recommendation = PP_AUDIOMAXSAMPLEFRAMECOUNT;
return recommendation;
}
// Otherwise, recommend a conservative 50ms buffer based on sample rate.
const uint32_t kDefault50msAt44100kHz = 2205;
const uint32_t kDefault50msAt48000kHz = 2400;
switch (sample_rate) {
case PP_AUDIOSAMPLERATE_44100:
return kDefault50msAt44100kHz;
case PP_AUDIOSAMPLERATE_48000:
return kDefault50msAt48000kHz;
case PP_AUDIOSAMPLERATE_NONE:
return 0;
}
// Unable to make a recommendation.
return 0;
}
// static
PP_AudioSampleRate PPB_AudioConfig_Shared::RecommendSampleRate(
PP_Instance instance) {
thunk::EnterInstance enter(instance);
if (enter.failed())
return PP_AUDIOSAMPLERATE_NONE;
PP_AudioSampleRate hardware_sample_rate = static_cast<PP_AudioSampleRate>(
enter.functions()->GetAudioHardwareOutputSampleRate(instance));
return hardware_sample_rate;
}
thunk::PPB_AudioConfig_API* PPB_AudioConfig_Shared::AsPPB_AudioConfig_API() {
return this;
}
PP_AudioSampleRate PPB_AudioConfig_Shared::GetSampleRate() {
return sample_rate_;
}
uint32_t PPB_AudioConfig_Shared::GetSampleFrameCount() {
return sample_frame_count_;
}
bool PPB_AudioConfig_Shared::Init(PP_AudioSampleRate sample_rate,
uint32_t sample_frame_count) {
// TODO(brettw): Currently we don't actually check what the hardware
// supports, so just allow sample rates of the "guaranteed working" ones.
if (sample_rate != PP_AUDIOSAMPLERATE_44100 &&
sample_rate != PP_AUDIOSAMPLERATE_48000)
return false;
// TODO(brettw): Currently we don't actually query to get a value from the
// hardware, so just validate the range.
if (sample_frame_count > PP_AUDIOMAXSAMPLEFRAMECOUNT ||
sample_frame_count < PP_AUDIOMINSAMPLEFRAMECOUNT)
return false;
sample_rate_ = sample_rate;
sample_frame_count_ = sample_frame_count;
return true;
}
} // namespace ppapi
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