gecko-dev/content/media/VideoUtils.h

142 lines
5.3 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: */
/* ***** BEGIN LICENSE BLOCK *****
* Version: ML 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla code.
*
* The Initial Developer of the Original Code is the Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2010
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Chris Pearce <chris@pearce.org.nz>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef VideoUtils_h
#define VideoUtils_h
#include "mozilla/Monitor.h"
// 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 prtypes.h
/************************************************************************
* MACROS: PR_INT64_MAX
* PR_INT64_MIN
* PR_UINT64_MAX
* DESCRIPTION:
* The maximum and minimum values of a PRInt64 or PRUint64.
************************************************************************/
#define PR_INT64_MAX (~((PRInt64)(1) << 63))
#define PR_INT64_MIN (-PR_INT64_MAX - 1)
#define PR_UINT64_MAX (~(PRUint64)(0))
// This belongs in xpcom/monitor/Monitor.h, once we've made
// mozilla::Monitor non-reentrant.
namespace mozilla {
/**
* MonitorAutoExit
* Exit the Monitor when it enters scope, and enters it when it leaves
* scope.
*
* MUCH PREFERRED to bare calls to Monitor.Exit and Enter.
*/
class NS_STACK_CLASS MonitorAutoExit
{
public:
/**
* Constructor
* The constructor releases the given lock. The destructor
* acquires the lock. The lock must be held before constructing
* this object!
*
* @param aMonitor A valid mozilla::Monitor* returned by
* mozilla::Monitor::NewMonitor. It must be
* already locked.
**/
MonitorAutoExit(mozilla::Monitor &aMonitor) :
mMonitor(&aMonitor)
{
NS_ASSERTION(mMonitor, "null monitor");
mMonitor->AssertCurrentThreadIn();
mMonitor->Exit();
}
~MonitorAutoExit(void)
{
mMonitor->Enter();
}
private:
MonitorAutoExit();
MonitorAutoExit(const MonitorAutoExit&);
MonitorAutoExit& operator =(const MonitorAutoExit&);
static void* operator new(size_t) CPP_THROW_NEW;
static void operator delete(void*);
mozilla::Monitor* mMonitor;
};
} // namespace mozilla
// Adds two 32bit unsigned numbers, retuns PR_TRUE if addition succeeded,
// or PR_FALSE the if addition would result in an overflow.
PRBool AddOverflow32(PRUint32 a, PRUint32 b, PRUint32& aResult);
// 32 bit integer multiplication with overflow checking. Returns PR_TRUE
// if the multiplication was successful, or PR_FALSE if the operation resulted
// in an integer overflow.
PRBool MulOverflow32(PRUint32 a, PRUint32 b, PRUint32& aResult);
// Adds two 64bit numbers, retuns PR_TRUE if addition succeeded, or PR_FALSE
// if addition would result in an overflow.
PRBool AddOverflow(PRInt64 a, PRInt64 b, PRInt64& aResult);
// 64 bit integer multiplication with overflow checking. Returns PR_TRUE
// if the multiplication was successful, or PR_FALSE if the operation resulted
// in an integer overflow.
PRBool MulOverflow(PRInt64 a, PRInt64 b, PRInt64& aResult);
// Converts from number of audio samples (aSamples) to milliseconds, given
// the specified audio rate (aRate). Stores result in aOutMs. Returns PR_TRUE
// if the operation succeeded, or PR_FALSE if there was an integer overflow
// while calulating the conversion.
PRBool SamplesToMs(PRInt64 aSamples, PRUint32 aRate, PRInt64& aOutMs);
// Converts from milliseconds (aMs) to number of audio samples, given the
// specified audio rate (aRate). Stores the result in aOutSamples. Returns
// PR_TRUE if the operation succeeded, or PR_FALSE if there was an integer
// overflow while calulating the conversion.
PRBool MsToSamples(PRInt64 aMs, PRUint32 aRate, PRInt64& aOutSamples);
#endif