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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 "media/video/capture/fake_video_capture_device.h"
#include <string>
#include "base/bind.h"
#include "base/memory/scoped_ptr.h"
#include "base/stringprintf.h"
#include "media/audio/fake_audio_input_stream.h"
#include "third_party/skia/include/core/SkBitmap.h"
#include "third_party/skia/include/core/SkCanvas.h"
#include "third_party/skia/include/core/SkPaint.h"
namespace media {
static const int kFakeCaptureTimeoutMs = 50;
static const int kFakeCaptureBeepCycle = 20; // Visual beep every 1s.
enum { kNumberOfFakeDevices = 2 };
bool FakeVideoCaptureDevice::fail_next_create_ = false;
void FakeVideoCaptureDevice::GetDeviceNames(Names* const device_names) {
// Empty the name list.
device_names->erase(device_names->begin(), device_names->end());
for (int n = 0; n < kNumberOfFakeDevices; n++) {
Name name;
name.unique_id = StringPrintf("/dev/video%d", n);
name.device_name = StringPrintf("fake_device_%d", n);
device_names->push_back(name);
}
}
VideoCaptureDevice* FakeVideoCaptureDevice::Create(const Name& device_name) {
if (fail_next_create_) {
fail_next_create_ = false;
return NULL;
}
for (int n = 0; n < kNumberOfFakeDevices; ++n) {
std::string possible_id = StringPrintf("/dev/video%d", n);
if (device_name.unique_id.compare(possible_id) == 0) {
return new FakeVideoCaptureDevice(device_name);
}
}
return NULL;
}
void FakeVideoCaptureDevice::SetFailNextCreate() {
fail_next_create_ = true;
}
FakeVideoCaptureDevice::FakeVideoCaptureDevice(const Name& device_name)
: device_name_(device_name),
observer_(NULL),
state_(kIdle),
capture_thread_("CaptureThread"),
frame_size_(0),
frame_count_(0),
frame_width_(0),
frame_height_(0) {
}
FakeVideoCaptureDevice::~FakeVideoCaptureDevice() {
// Check if the thread is running.
// This means that the device have not been DeAllocated properly.
DCHECK(!capture_thread_.IsRunning());
}
void FakeVideoCaptureDevice::Allocate(int width,
int height,
int frame_rate,
EventHandler* observer) {
if (state_ != kIdle) {
return; // Wrong state.
}
observer_ = observer;
VideoCaptureCapability current_settings;
current_settings.color = VideoCaptureCapability::kI420;
current_settings.expected_capture_delay = 0;
current_settings.interlaced = false;
if (width > 320) { // VGA
current_settings.width = 640;
current_settings.height = 480;
current_settings.frame_rate = 30;
} else { // QVGA
current_settings.width = 320;
current_settings.height = 240;
current_settings.frame_rate = 30;
}
size_t fake_frame_size =
current_settings.width * current_settings.height * 3 / 2;
fake_frame_.reset(new uint8[fake_frame_size]);
memset(fake_frame_.get(), 0, fake_frame_size);
frame_size_ = fake_frame_size;
frame_width_ = current_settings.width;
frame_height_ = current_settings.height;
state_ = kAllocated;
observer_->OnFrameInfo(current_settings);
}
void FakeVideoCaptureDevice::Start() {
if (state_ != kAllocated) {
return; // Wrong state.
}
state_ = kCapturing;
capture_thread_.Start();
capture_thread_.message_loop()->PostTask(
FROM_HERE,
base::Bind(&FakeVideoCaptureDevice::OnCaptureTask,
base::Unretained(this)));
}
void FakeVideoCaptureDevice::Stop() {
if (state_ != kCapturing) {
return; // Wrong state.
}
capture_thread_.Stop();
state_ = kAllocated;
}
void FakeVideoCaptureDevice::DeAllocate() {
if (state_ != kAllocated && state_ != kCapturing) {
return; // Wrong state.
}
capture_thread_.Stop();
state_ = kIdle;
}
const VideoCaptureDevice::Name& FakeVideoCaptureDevice::device_name() {
return device_name_;
}
void FakeVideoCaptureDevice::OnCaptureTask() {
if (state_ != kCapturing) {
return;
}
memset(fake_frame_.get(), 0, frame_size_);
SkBitmap bitmap;
bitmap.setConfig(SkBitmap::kA8_Config, frame_width_, frame_height_,
frame_width_);
bitmap.setPixels(fake_frame_.get());
SkCanvas canvas(bitmap);
// Draw a sweeping circle to show an animation.
int radius = std::min(frame_width_, frame_height_) / 4;
SkRect rect = SkRect::MakeXYWH(
frame_width_ / 2 - radius, frame_height_ / 2 - radius,
2 * radius, 2 * radius);
SkPaint paint;
paint.setStyle(SkPaint::kFill_Style);
// Only Y plane is being drawn and this gives 50% grey on the Y
// plane. The result is a light green color in RGB space.
paint.setAlpha(128);
int end_angle = (frame_count_ % kFakeCaptureBeepCycle * 360) /
kFakeCaptureBeepCycle;
if (!end_angle)
end_angle = 360;
canvas.drawArc(rect, 0, end_angle, true, paint);
// Draw current time.
int elapsed_ms = kFakeCaptureTimeoutMs * frame_count_;
int milliseconds = elapsed_ms % 1000;
int seconds = (elapsed_ms / 1000) % 60;
int minutes = (elapsed_ms / 1000 / 60) % 60;
int hours = (elapsed_ms / 1000 / 60 / 60) % 60;
std::string time_string =
base::StringPrintf("%d:%02d:%02d:%03d %d", hours, minutes,
seconds, milliseconds, frame_count_);
canvas.scale(3, 3);
canvas.drawText(time_string.data(), time_string.length(), 30, 20,
paint);
if (frame_count_ % kFakeCaptureBeepCycle == 0) {
// Generate a synchronized beep sound if there is one audio input
// stream created.
FakeAudioInputStream::BeepOnce();
}
frame_count_++;
// Give the captured frame to the observer.
observer_->OnIncomingCapturedFrame(
fake_frame_.get(), frame_size_, base::Time::Now(), 0, false, false);
// Reschedule next CaptureTask.
capture_thread_.message_loop()->PostDelayedTask(
FROM_HERE,
base::Bind(&FakeVideoCaptureDevice::OnCaptureTask,
base::Unretained(this)),
base::TimeDelta::FromMilliseconds(kFakeCaptureTimeoutMs));
}
} // namespace media
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