buffer.cpp

GNU ccAudio2 is a stand-alone portable C++ class framework for manipulating audio data. It has exist

// Copyright (C) 2000-2005 Open Source Telecom Corporation.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
//
// This exception applies only to the code released under the name GNU
// ccAudio.  If you copy code from other releases into a copy of GNU
// ccAudio, as the General Public License permits, the exception does
// not apply to the code that you add in this way.  To avoid misleading
// anyone as to the status of such modified files, you must delete
// this exception notice from them.
//
// If you write modifications of your own for GNU ccAudio, it is your choice
// whether to permit this exception to apply to your modifications.
// If you do not wish that, delete this exception notice.
//

#include "private.h"
#include "audio2.h"

using namespace ost;

AudioBuffer::AudioBuffer(Info *i, size_t sz) : 
AudioBase(i)
{
	size = sz;
	buf = new char[size];
	start = len = 0;
	mutexObject = new ccAudio_Mutex_;
}

AudioBuffer::~AudioBuffer()
{
	ccAudio_Mutex_ *mutex = (ccAudio_Mutex_ *)mutexObject;

	if(mutexObject)
		delete mutex;

	if(buf)
		delete[] buf;
	buf = NULL;
	mutexObject = NULL;
}

void AudioBuffer::enter(void)
{
	ccAudio_Mutex_ *mutex = (ccAudio_Mutex_ *)mutexObject;

	mutex->enter();
}

void AudioBuffer::leave(void)
{
	ccAudio_Mutex_ *mutex = (ccAudio_Mutex_ *)mutexObject;
	
	mutex->leave();
}

ssize_t AudioBuffer::getBuffer(Encoded data, size_t amount)
{
	size_t left, copied;

	if(amount == 0)
		return 0;

	enter();
	if(len == 0)
	{
		memset(data, 0, amount);
		leave();
		return (ssize_t)amount;
	}

	if(amount > len)
		memset(data + len, 0, amount - len);

	left = ((amount) < (len) ? amount : len);
	if((start + left) > size)
	{
		copied = size - start;
		memcpy(data, buf + start, copied);
		data += copied;
		left -= copied;
		len -= copied;
		start = 0;
	}

	if(left > 0)
	{
		memcpy(data, buf + start, left);
		len -= left;
		start = (start + left) % size;
	}
	leave();
	return (ssize_t)amount;
}

ssize_t AudioBuffer::putBuffer(Encoded data, size_t amount)
{
	size_t nl, written, removed, offset;

	if(amount == 0)
		return 0;

	enter();
	nl = len + amount;
	if(len > size)
	{
		removed = nl - size;
		start = (start + removed) % size;
		len -= removed;
	}

	offset = (start + len) % size;
	if((offset + amount) > size)
	{
		written = size - offset;
		memcpy(buf + offset, data, written);
		offset = 0;
		data += written;
		amount -= written;
		len += written;
	}

	if(amount > 0)
	{
		memcpy(buf + offset, data, amount);
		len += amount;
	}
	leave();
	return (ssize_t)amount;
}