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// Copyright (c) 2013 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/browser/renderer_host/media/video_capture_buffer_pool.h"
#include "base/bind.h"
#include "base/callback.h"
#include "base/logging.h"
#include "media/base/video_util.h"
namespace content {
VideoCaptureBufferPool::VideoCaptureBufferPool(const gfx::Size& size, int count)
: size_(size),
count_(count) {
}
VideoCaptureBufferPool::~VideoCaptureBufferPool() {
}
bool VideoCaptureBufferPool::Allocate() {
base::AutoLock lock(lock_);
DCHECK(!IsAllocated());
buffers_.resize(count_ + 1);
buffers_[0] = NULL;
for (int buffer_id = 1; buffer_id <= count(); ++buffer_id) {
Buffer* buffer = new Buffer();
buffers_[buffer_id] = buffer;
if (!buffer->shared_memory.CreateAndMapAnonymous(GetMemorySize())) {
return false;
}
}
return true;
}
base::SharedMemoryHandle VideoCaptureBufferPool::ShareToProcess(
int buffer_id,
base::ProcessHandle process_handle) {
base::AutoLock lock(lock_);
DCHECK(IsAllocated());
DCHECK(buffer_id >= 1);
DCHECK(buffer_id <= count_);
Buffer* buffer = buffers_[buffer_id];
base::SharedMemoryHandle remote_handle;
buffer->shared_memory.ShareToProcess(process_handle, &remote_handle);
return remote_handle;
}
scoped_refptr<media::VideoFrame> VideoCaptureBufferPool::ReserveForProducer(
int rotation) {
base::AutoLock lock(lock_);
DCHECK(IsAllocated());
int buffer_id = 0;
for (int candidate_id = 1; candidate_id <= count(); ++candidate_id) {
Buffer* candidate = buffers_[candidate_id];
if (!candidate->consumer_hold_count && !candidate->held_by_producer) {
buffer_id = candidate_id;
break;
}
}
if (!buffer_id)
return NULL;
Buffer* buffer = buffers_[buffer_id];
CHECK_GE(buffer->shared_memory.requested_size(), GetMemorySize());
// Complete the reservation.
buffer->held_by_producer = true;
base::Closure disposal_handler = base::Bind(
&VideoCaptureBufferPool::OnVideoFrameDestroyed, this, buffer_id);
// Wrap the buffer in a VideoFrame container.
uint8* base_ptr = static_cast<uint8*>(buffer->shared_memory.memory());
size_t u_offset = size_.GetArea();
size_t v_offset = u_offset + u_offset / 4;
scoped_refptr<media::VideoFrame> frame =
media::VideoFrame::WrapExternalYuvData(
media::VideoFrame::YV12, // Actually it's I420, but equivalent here.
size_, gfx::Rect(size_), size_,
size_.width(), // y stride
size_.width() / 2, // u stride
size_.width() / 2, // v stride
base_ptr, // y address
base_ptr + u_offset, // u address
base_ptr + v_offset, // v address
base::TimeDelta(), // timestamp (unused).
disposal_handler);
if (buffer->rotation != rotation) {
// TODO(nick): Generalize the |rotation| mechanism.
media::FillYUV(frame, 0, 128, 128);
buffer->rotation = rotation;
}
return frame;
}
void VideoCaptureBufferPool::HoldForConsumers(
const scoped_refptr<media::VideoFrame>& producer_held_buffer,
int buffer_id,
int num_clients) {
base::AutoLock lock(lock_);
DCHECK(buffer_id >= 1);
DCHECK(buffer_id <= count());
DCHECK(IsAllocated());
Buffer* buffer = buffers_[buffer_id];
DCHECK(buffer->held_by_producer);
DCHECK(!buffer->consumer_hold_count);
DCHECK(producer_held_buffer->data(media::VideoFrame::kYPlane) ==
buffer->shared_memory.memory());
buffer->consumer_hold_count = num_clients;
// Note: |held_by_producer| should stay true until ~VideoFrame occurs.
}
void VideoCaptureBufferPool::RelinquishConsumerHold(int buffer_id,
int num_clients) {
base::AutoLock lock(lock_);
DCHECK(buffer_id >= 1);
DCHECK(buffer_id <= count());
DCHECK_GT(num_clients, 0);
DCHECK(IsAllocated());
Buffer* buffer = buffers_[buffer_id];
DCHECK_GE(buffer->consumer_hold_count, num_clients);
buffer->consumer_hold_count -= num_clients;
}
// State query functions.
size_t VideoCaptureBufferPool::GetMemorySize() const {
// No need to take |lock_| currently.
return size_.GetArea() * 3 / 2;
}
int VideoCaptureBufferPool::RecognizeReservedBuffer(
const scoped_refptr<media::VideoFrame>& maybe_belongs_to_pool) {
base::AutoLock lock(lock_);
uint8* base_ptr = maybe_belongs_to_pool->data(media::VideoFrame::kYPlane);
for (int buffer_id = 1; buffer_id <= count(); ++buffer_id) {
Buffer* buffer = buffers_[buffer_id];
if (buffer->shared_memory.memory() == base_ptr) {
DCHECK(buffer->held_by_producer);
return buffer_id;
}
}
return 0; // VideoFrame is not from our pool.
}
bool VideoCaptureBufferPool::IsAnyBufferHeldForConsumers() {
base::AutoLock lock(lock_);
for (int buffer_id = 1; buffer_id <= count(); ++buffer_id) {
Buffer* buffer = buffers_[buffer_id];
if (buffer->consumer_hold_count > 0)
return true;
}
return false;
}
VideoCaptureBufferPool::Buffer::Buffer()
: rotation(0),
held_by_producer(false),
consumer_hold_count(0) {}
void VideoCaptureBufferPool::OnVideoFrameDestroyed(int buffer_id) {
base::AutoLock lock(lock_);
DCHECK(buffer_id);
Buffer* buffer = buffers_[buffer_id];
DCHECK(buffer->held_by_producer);
buffer->held_by_producer = false;
}
bool VideoCaptureBufferPool::IsAllocated() const {
lock_.AssertAcquired();
return !buffers_.empty();
}
} // namespace content
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