FLACHeaderTweaker.cpp

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//===========================================================================
//Copyright (C) 2004 Zentaro Kavanagh
//
//Redistribution and use in source and binary forms, with or without
//modification, are permitted provided that the following conditions
//are met:
//
//- Redistributions of source code must retain the above copyright
//  notice, this list of conditions and the following disclaimer.
//
//- Redistributions in binary form must reproduce the above copyright
//  notice, this list of conditions and the following disclaimer in the
//  documentation and/or other materials provided with the distribution.
//
//- Neither the name of Zentaro Kavanagh nor the names of contributors 
//  may be used to endorse or promote products derived from this software 
//  without specific prior written permission.
//
//THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
//``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
//LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
//PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE ORGANISATION OR
//CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
//EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
//PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
//PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
//LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
//NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
//SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//===========================================================================

#include "stdafx.h"
#include ".\flacheadertweaker.h"

FLACHeaderTweaker::FLACHeaderTweaker(void)
        :       mSeenAllHeaders(false)

{
        //debugLog.open("G:\\logs\\flactweaker.log", ios_base::out);

}

FLACHeaderTweaker::~FLACHeaderTweaker(void)
{
        
        //debugLog<<"Pre delete old..."<<endl;
        deleteOldHeaders();
        //debugLog<<"Pre delete new..."<<endl;
        deleteNewHeaders();
        //debugLog<<"Post delete..."<<endl;
        //debugLog.close();
}

FLACHeaderTweaker::eFLACAcceptHeaderResult FLACHeaderTweaker::acceptHeader(OggPacket* inHeader) {
        //debugLog<<endl<<"Accepting header.."<<endl;
        //debugLog<<inHeader->toPackDumpString()<<endl;
        const unsigned char MORE_HEADERS_MASK = 128;
        if (!mSeenAllHeaders) {
                //debugLog<<"Still tweaking... adding to old list..."<<endl;
                

                mOldHeaderList.push_back(inHeader);
                if ((inHeader->packetData()[0] & MORE_HEADERS_MASK)  != 0) {
                        //debugLog<<"This is the last header..."<<endl;
                        //Last header
                        mSeenAllHeaders = true;
                        if (createNewHeaderList()) {
                                //debugLog<<"Create new headers OK"<<endl;
                                return LAST_HEADER_ACCEPTED;
                        } else {
                                //debugLog<<"Create new headers FAILED"<<endl;
                                return HEADER_ERROR;
                        }
                } else {
                        //debugLog<<"Still need more ehaders..."<<endl;
                        //Still more headers to come...
                        return HEADER_ACCEPTED;
                }
        } else {
                //debugLog<<"All headers already seen"<<endl;
                return ALL_HEADERS_ALREADY_SEEN;
        }

}

bool FLACHeaderTweaker::createNewHeaderList() 
{
        //debugLog<<"Create new header list method"<<endl;
        //debugLog<<"Filling first pack"<<endl;
        
        
        unsigned char* locFirstPacketBuffur = new unsigned char[51];
        locFirstPacketBuffur[0] = '\177';
        locFirstPacketBuffur[1] = 'F';
        locFirstPacketBuffur[2] = 'L';
        locFirstPacketBuffur[3] = 'A';
        locFirstPacketBuffur[4] = 'C';
        locFirstPacketBuffur[5] = 1;
        locFirstPacketBuffur[6] = 0;
        locFirstPacketBuffur[7] = 0; //Num header HIGH BYTE

        //*** VERIFY ::: Is this even safe ie -2 ... are we sure this can't go negative ????
        locFirstPacketBuffur[8] = mOldHeaderList.size() - 2; //Num headers LOW BYTE
        locFirstPacketBuffur[9] = 'f';
        locFirstPacketBuffur[10] = 'L';
        locFirstPacketBuffur[11] = 'a';
        locFirstPacketBuffur[12] = 'C';

        //debugLog<<"Copying in packet data"<<endl;
        memcpy((void*)(locFirstPacketBuffur + 13), (const void*) mOldHeaderList[1]->packetData(), 38);

        mNewHeaderList.empty();
        mNewHeaderList.clear();
        //debugLog<<"Putting first header into new list"<<endl;
        mNewHeaderList.push_back(new OggPacket(locFirstPacketBuffur, 51, false, false));
        locFirstPacketBuffur = NULL;

        bool locFoundComment = false;
        int locCommentNo = -1;

        //Start at 2, 0 is just fLaC, 1 is the stream info
        for (size_t i = 2; i < mOldHeaderList.size(); i++) {
                //Loop through to find the comment packet...
                //debugLog<<"Scanning old header "<<i<<endl;
                if ( ((mOldHeaderList[i]->packetData()[0]) & 127) == 4) {
                        //It's the comment packet.
                        //debugLog<<"Found a comment packet..."<<endl;
                        locFoundComment = true;
                        locCommentNo = (int)i;
                        mNewHeaderList.push_back(mOldHeaderList[i]->clone());
                }
        }

        if (locFoundComment != true) {
                //debugLog<<"No comments present... FATALITY !"<<endl;
                //Maybe make one... for now bail out !
                throw 0;
        }

        for (size_t i = 2; i < mOldHeaderList.size(); i++) {
        
                //**** WARNING ::: Leave this unless you check it !
                if (i != locCommentNo) {
                        //debugLog<<"Adding another ehader..."<<endl;
                        //If it's not the comment packet we already added, put it in the list.
                        mNewHeaderList.push_back(mOldHeaderList[i]->clone());
                }
        }

        for (size_t i = 1; i < mNewHeaderList.size(); i++) {
                //Loop through the new headers and make sure the flags are set right.
                if (i != mNewHeaderList.size() -1) {
                        //Clear the first bit
                        //debugLog<<"Clearing header bit "<<i<<endl;
                        mNewHeaderList[i]->packetData()[0] = mNewHeaderList[i]->packetData()[0] & 127;
                } else {
                        //debugLog<<"Setting header bit "<<i<<endl;
                        //Set the first bit on the last header
                        mNewHeaderList[i]->packetData()[0] = mNewHeaderList[i]->packetData()[0] | 128;
                }
        }

        //debugLog<<"Deleting old headers..."<<endl;
        deleteOldHeaders();

        return true;


}

void FLACHeaderTweaker::deleteOldHeaders() {
        size_t locSize = mOldHeaderList.size();
        //debugLog<<"Num old headers... = "<<locSize<<endl;
        for (size_t i = 0; i < locSize; i++) {
                delete mOldHeaderList[i];               
        }
        //debugLog<<"Post old delete loop..."<<endl;
        mOldHeaderList.clear();
        
}

void FLACHeaderTweaker::deleteNewHeaders() {
        size_t locSize = mNewHeaderList.size();
        //debugLog<<"Num new headers... = "<<locSize<<endl;
        for (size_t i = 0; i < locSize; i++) {
                delete mNewHeaderList[i];               
        }
        //debugLog<<"Post new delete loop"<<endl;

        mNewHeaderList.clear();
}

unsigned long FLACHeaderTweaker::numNewHeaders() {
        return (unsigned long)mNewHeaderList.size();
}
OggPacket* FLACHeaderTweaker::getHeader(unsigned long inHeaderNo) {
        if (inHeaderNo < mNewHeaderList.size() ) {
                return mNewHeaderList[inHeaderNo]->clone();
        } else {
                return NULL;
        }
}

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