gecko-dev/content/media/VideoUtils.h
2012-07-30 17:20:58 +03:00

130 lines
4.1 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef VideoUtils_h
#define VideoUtils_h
#include "mozilla/ReentrantMonitor.h"
#include "mozilla/CheckedInt.h"
#include "nsRect.h"
#include "nsIThreadManager.h"
#include "nsThreadUtils.h"
using mozilla::CheckedInt64;
using mozilla::CheckedUint64;
using mozilla::CheckedInt32;
using mozilla::CheckedUint32;
// This file contains stuff we'd rather put elsewhere, but which is
// dependent on other changes which we don't want to wait for. We plan to
// remove this file in the near future.
// This belongs in xpcom/monitor/Monitor.h, once we've made
// mozilla::Monitor non-reentrant.
namespace mozilla {
/**
* ReentrantMonitorAutoExit
* Exit the ReentrantMonitor when it enters scope, and enters it when it leaves
* scope.
*
* MUCH PREFERRED to bare calls to ReentrantMonitor.Exit and Enter.
*/
class NS_STACK_CLASS ReentrantMonitorAutoExit
{
public:
/**
* Constructor
* The constructor releases the given lock. The destructor
* acquires the lock. The lock must be held before constructing
* this object!
*
* @param aReentrantMonitor A valid mozilla::ReentrantMonitor*. It
* must be already locked.
**/
ReentrantMonitorAutoExit(ReentrantMonitor& aReentrantMonitor) :
mReentrantMonitor(&aReentrantMonitor)
{
NS_ASSERTION(mReentrantMonitor, "null monitor");
mReentrantMonitor->AssertCurrentThreadIn();
mReentrantMonitor->Exit();
}
~ReentrantMonitorAutoExit(void)
{
mReentrantMonitor->Enter();
}
private:
ReentrantMonitorAutoExit();
ReentrantMonitorAutoExit(const ReentrantMonitorAutoExit&);
ReentrantMonitorAutoExit& operator =(const ReentrantMonitorAutoExit&);
static void* operator new(size_t) CPP_THROW_NEW;
static void operator delete(void*);
ReentrantMonitor* mReentrantMonitor;
};
// Shuts down a thread asynchronously.
class ShutdownThreadEvent : public nsRunnable
{
public:
ShutdownThreadEvent(nsIThread* aThread) : mThread(aThread) {}
~ShutdownThreadEvent() {}
NS_IMETHOD Run() {
mThread->Shutdown();
mThread = nullptr;
return NS_OK;
}
private:
nsCOMPtr<nsIThread> mThread;
};
} // namespace mozilla
// Converts from number of audio frames (aFrames) to microseconds, given
// the specified audio rate (aRate). Stores result in aOutUsecs. Returns true
// if the operation succeeded, or false if there was an integer overflow
// while calulating the conversion.
CheckedInt64 FramesToUsecs(PRInt64 aFrames, PRUint32 aRate);
// Converts from microseconds (aUsecs) to number of audio frames, given the
// specified audio rate (aRate). Stores the result in aOutFrames. Returns
// true if the operation succeeded, or false if there was an integer
// overflow while calulating the conversion.
CheckedInt64 UsecsToFrames(PRInt64 aUsecs, PRUint32 aRate);
// Number of microseconds per second. 1e6.
static const PRInt64 USECS_PER_S = 1000000;
// Number of microseconds per millisecond.
static const PRInt64 USECS_PER_MS = 1000;
// The maximum height and width of the video. Used for
// sanitizing the memory allocation of the RGB buffer.
// The maximum resolution we anticipate encountering in the
// wild is 2160p - 3840x2160 pixels.
static const PRInt32 MAX_VIDEO_WIDTH = 4000;
static const PRInt32 MAX_VIDEO_HEIGHT = 3000;
// Scales the display rect aDisplay by aspect ratio aAspectRatio.
// Note that aDisplay must be validated by nsVideoInfo::ValidateVideoRegion()
// before being used!
void ScaleDisplayByAspectRatio(nsIntSize& aDisplay, float aAspectRatio);
// The amount of virtual memory reserved for thread stacks.
#if (defined(XP_WIN) || defined(XP_MACOSX) || defined(LINUX)) && \
!defined(MOZ_ASAN)
#define MEDIA_THREAD_STACK_SIZE (128 * 1024)
#else
// All other platforms use their system defaults.
#define MEDIA_THREAD_STACK_SIZE nsIThreadManager::DEFAULT_STACK_SIZE
#endif
#endif