// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <algorithm>
#include <limits>
#include <vector>
#include "ppapi/cpp/audio_buffer.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/media_stream_audio_track.h"
#include "ppapi/cpp/module.h"
#include "ppapi/cpp/rect.h"
#include "ppapi/cpp/size.h"
#include "ppapi/cpp/var_dictionary.h"
#include "ppapi/utility/completion_callback_factory.h"
// When compiling natively on Windows, PostMessage can be #define-d to
// something else.
#ifdef PostMessage
#undef PostMessage
#endif
// This example demonstrates receiving audio samples from an AndioMediaTrack
// and visualizing them.
namespace {
const uint32_t kColorRed = 0xFFFF0000;
const uint32_t kColorGreen = 0xFF00FF00;
const uint32_t kColorGrey1 = 0xFF202020;
const uint32_t kColorGrey2 = 0xFF404040;
const uint32_t kColorGrey3 = 0xFF606060;
class MediaStreamAudioInstance : public pp::Instance {
public:
explicit MediaStreamAudioInstance(PP_Instance instance)
: pp::Instance(instance),
callback_factory_(this),
first_buffer_(true),
sample_count_(0),
channel_count_(0),
timer_interval_(0),
pending_paint_(false),
waiting_for_flush_completion_(false) {
}
virtual ~MediaStreamAudioInstance() {
}
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& var_message) {
if (!var_message.is_dictionary())
return;
pp::VarDictionary var_dictionary_message(var_message);
pp::Var var_track = var_dictionary_message.Get("track");
if (!var_track.is_resource())
return;
pp::Resource resource_track = var_track.AsResource();
audio_track_ = pp::MediaStreamAudioTrack(resource_track);
audio_track_.GetBuffer(callback_factory_.NewCallbackWithOutput(
&MediaStreamAudioInstance::OnGetBuffer));
}
private:
void ScheduleNextTimer() {
PP_DCHECK(timer_interval_ > 0);
pp::Module::Get()->core()->CallOnMainThread(
timer_interval_,
callback_factory_.NewCallback(&MediaStreamAudioInstance::OnTimer),
0);
}
void OnTimer(int32_t) {
ScheduleNextTimer();
Paint();
}
void DidFlush(int32_t result) {
waiting_for_flush_completion_ = false;
if (pending_paint_)
Paint();
}
void Paint() {
if (waiting_for_flush_completion_) {
pending_paint_ = true;
return;
}
pending_paint_ = false;
if (size_.IsEmpty())
return; // Nothing to do.
pp::ImageData image = PaintImage(size_);
if (!image.is_null()) {
device_context_.ReplaceContents(&image);
waiting_for_flush_completion_ = true;
device_context_.Flush(
callback_factory_.NewCallback(&MediaStreamAudioInstance::DidFlush));
}
}
pp::ImageData PaintImage(const pp::Size& size) {
pp::ImageData image(this, PP_IMAGEDATAFORMAT_BGRA_PREMUL, size, false);
if (image.is_null())
return image;
// Clear to dark grey.
for (int y = 0; y < size.height(); y++) {
for (int x = 0; x < size.width(); x++)
*image.GetAddr32(pp::Point(x, y)) = kColorGrey1;
}
int mid_height = size.height() / 2;
int max_amplitude = size.height() * 4 / 10;
// Draw some lines.
for (int x = 0; x < size.width(); x++) {
*image.GetAddr32(pp::Point(x, mid_height)) = kColorGrey3;
*image.GetAddr32(pp::Point(x, mid_height + max_amplitude)) = kColorGrey2;
*image.GetAddr32(pp::Point(x, mid_height - max_amplitude)) = kColorGrey2;
}
// Draw our samples.
for (int x = 0, i = 0;
x < std::min(size.width(), static_cast<int>(sample_count_));
x++, i += channel_count_) {
for (uint32_t ch = 0; ch < std::min(channel_count_, 2U); ++ch) {
int y = samples_[i + ch] * max_amplitude /
(std::numeric_limits<int16_t>::max() + 1) + mid_height;
*image.GetAddr32(pp::Point(x, y)) = (ch == 0 ? kColorRed : kColorGreen);
}
}
return image;
}
// Callback that is invoked when new buffers are received.
void OnGetBuffer(int32_t result, pp::AudioBuffer buffer) {
if (result != PP_OK)
return;
PP_DCHECK(buffer.GetSampleSize() == PP_AUDIOBUFFER_SAMPLESIZE_16_BITS);
const char* data = static_cast<const char*>(buffer.GetDataBuffer());
uint32_t channels = buffer.GetNumberOfChannels();
uint32_t samples = buffer.GetNumberOfSamples() / channels;
if (channel_count_ != channels || sample_count_ != samples) {
channel_count_ = channels;
sample_count_ = samples;
samples_.resize(sample_count_ * channel_count_);
timer_interval_ = (sample_count_ * 1000) / buffer.GetSampleRate() + 5;
// Start the timer for the first buffer.
if (first_buffer_) {
first_buffer_ = false;
ScheduleNextTimer();
}
}
memcpy(samples_.data(), data,
sample_count_ * channel_count_ * sizeof(int16_t));
audio_track_.RecycleBuffer(buffer);
audio_track_.GetBuffer(callback_factory_.NewCallbackWithOutput(
&MediaStreamAudioInstance::OnGetBuffer));
}
pp::MediaStreamAudioTrack audio_track_;
pp::CompletionCallbackFactory<MediaStreamAudioInstance> callback_factory_;
bool first_buffer_;
uint32_t sample_count_;
uint32_t channel_count_;
std::vector<int16_t> samples_;
int32_t timer_interval_;
// Painting stuff.
pp::Size size_;
pp::Graphics2D device_context_;
bool pending_paint_;
bool waiting_for_flush_completion_;
};
class MediaStreamAudioModule : public pp::Module {
public:
virtual pp::Instance* CreateInstance(PP_Instance instance) {
return new MediaStreamAudioInstance(instance);
}
};
} // namespace
namespace pp {
// Factory function for your specialization of the Module object.
Module* CreateModule() {
return new MediaStreamAudioModule();
}
} // namespace pp
Codebase Browser
chromium